Orrery Two – Making a Working Solar System Model

Page Index

• About the Solar System
• Orrery Design Concept
• Counting Gears and Teeth
• Gear Selection
• Orrery Gear Ratio Calculator
• How to make a Gear
• Making a More Difficult Gear
• Gear Calculator for Rotary Table
• Gear Making Vide0
• Making the Motor Powered Orrery Base
• Let’s Put Some Hubs on These Gears
• Plates for Supporting Gear Levels
• Venus Level is Completed
• Video of Venus Level Completion 6/26/21
• Earth Level Gearbox is Completed
• Video-Part-Three-Earth-Level
• Mars Level Takes Shape
• By Jove I Finally Finished Jupiter Level
• Saturn Gears are Completed
• Cleaning Up and Surface Finishes
• The Motor Cover and Wiring
• The Sun Shines
• Planet Orbital Rods
• Planets and Supports
• Orrery Completion

Initial Thoughts 4/1/21

It’s been a couple of years since I created the Orrery Solar System Model found on this Technology Imagined website. I found it to be a lot of fun to make and have been thinking about building another one for some time. This time around I wanted to make something a bit smaller. I’m thinking of an Orrery that would fit on a desktop or shelf. The new Orrery will be made using more available gears scavenged from old broken wind up clocks.

But first a review of some solar system facts that will be relevant as I move forward with the construction of the new Orrery.

The table 1 above shows the planet diameters and orbital lengths (radii) for each of the planets out to Saturn in kilometers. Two things are evident. First, the Sun is incredibly huge. It is about 100 times larger than the earth. So if I were going to make planets all the correct size relative to the Sun, I would either need to make the Sun very large in order to see each planet as more than a dot, or make the planets very small and have a reasonably sized Sun say one inch (2.54cm) in diameter. At one inch diameter the Earth would need to be about 0.009 inches (0.23mm) in diameter. Very Tiny.

Second, the solar system is very spread out. Which brings us to the next problem. The orbital radii are absolutely huge compared to the size of the planets or even the Sun. So if these radii were kept to the correct ratio with respect to the planet sizes, again the planets would have to be dots, or the Orrery would be gymnasium size. If the sun were made to be one inch in diameter (2.54cm), the radius of Saturn’s orbit would be over 1000 inches or something like 85 feet (26 meters).

Just a side note on these orbital distances. The planets do not move in circles around the Sun. They move in elliptical orbits so are traveling in more oval paths. For my Orrery I am taking the averages of the nearest distance to the Sun (perihelion) and it’s farthest (aphelion). While it would be possible to make an Orrery with elliptical planetary orbits it would be pretty difficult. Maybe someday, but not this day.

Clearly something has to give beyond changing the shape of the orbits. I want to be able to place the Solar System on my desktop. So stay tuned and we’ll travel down a path to a completed Orrery that will be as accurate as needed, but still aesthetically pleasing. I envision an Orrery where the planet sizes are of the proper ratio to one another. The orbital radii and speeds of movement will also be in proportion to one another, but not to the planet sizes. That leaves the sun diameter, which will not be in proportion to any of these. I will probably make the Sun in the 1/10th size range with respect to the scale of the plants. I want the orbit of Mercury to come pretty close to the surface of the Sun. The picture below is taken through a telescope as Mercury transit between the Earth and the Sun. You get the idea as to how small and how close Mercury is to the Sun.

Some Gears and Calculations 4/2/21

We have not talked much about the planetary movement beyond there elliptical orbits. The crux of building an Orrery is the difference in the times it takes each planet to complete one trip around the Sun. The closer the planet is to the sun the faster it moves and the less distance it has to travel. This means all the planets need to move at the proper speed with respect to the others in order to better represent reality.

This table (2) shows ratios of orbit times for each planet with respect to each other planet. For example, the first column shows how long it takes each planet to complete one orbit compared to Mercury. So obviously Mercury’s orbit will take one Mercury orbit, but Venus will not complete one orbit until Mercury has gone 2.55 times around the sun. Incredibly Mercury will complete 122 orbits in the time it takes Saturn to complete one. Each column shows this ratio compared to all the other planets. So for for Earth, when it has gone 0.24 (24%) of its way around the Sun, Mercury will have already completed a full orbit. It will take 1.88 orbits of the Earth for Mars to complete one. This is where gears and gear ratios come in. This is how we will mechanically try to replicate the relative movements for all of the planets.

The ratios in the table above are not only the ratios of the orbital periods, but also the ratios needed for gears that will produce the orbits in my Orrery.

This image (figure 2) shows the basic design concept I used for the last Orrery and will use again. The image is simplified showing only the first two planets, Mercury and Venus. Each additional planet adds an another layer that will stack on top of one another. The concept for each of the layers is the same. In this design, the shaft that turns Mercury’s orbit is powered directly so all the other planets are ultimately tied the rotation of this axle. This axle is made from a tube with a shaft going through the center that will be used to support the Sun. This “Mercury” tube/shaft/axle will have an arm attached at the top. At the end of this arm will be the sphere the represents Mercury. As the tube turns the planet Mercury will orbit the Sun. The rest of the planets will have similar tubes and arms and work in generally the same way. The difference will be that the rest of the planetary tubes will be turned by a set of four gears. I will probably be using the terms “tubes”, ‘shafts” and “axles” interchangeably. I when I use these terms I am talking about the things the gears are attached to.

So let’s take a closer look at how we will power the rotation of Venus by using the rotation of the Mercury tube. The small gear B on the Mercury tube rotates against Gear A which is larger. Gear A is mounted to a shaft that has another small gear C also attached. Gears A and C will rotate in unison. Then gear C rotates against a larger gear D. Gear D is mounted to a tube that slides over the tube that powers Mercury and is attached to the arm holding Venus. So when the Mercury shaft is rotating the Venus shaft will rotate at a slower rate based on the ratios of gears A, B, C and D. How much slower.? Well the rotation ratio of gear A to B will depend on the number of teeth each has. So if gear A has 48 teeth and gear B has 24 teeth, then the ratio of rotation will be 48/24=2 or 2:1 . Now gear A is turning gear C at the exact same rate. If gear C has say 10 teeth and gear D has 30 teeth the ratio of D:C will be 30/10=3 or 3:1. So in this example gear B will turn two times for every time Gears A and C turn once. Gear D will turn three times for every time gear C turns once. So the overall ratio will be 2×3:1 or 6:1. In this example gear B will turn six times for every time gear D turn once. This is not the ratio we need between Mercury and Venus. We need gear combinations that will result in 2.55:1 ratio not 6:1 per table 2, but you get the idea.

The rotation speed ratio equals (A-teeth/B-teeth) x (D-teeth/C-teeth)

The selection gears A, B, C, and D need to give the ratio value using this equation matching those found in the “Ratio of Planet Orbits Around the Sun” table 2 above. We will have four sets (A,B,C and D) of gears for each planet. If we are using the Mercury tube to power gear A, B, C and D for Venus we then need the ratio found in the first column labeled “Mercury” in the table corresponding to Venus. In this case 2.55 to one.

The nice thing is that each planet can be powered by any tube that is below it. So while Venus can only be powered by the Mercury tube, Earth can be powered by either Mercury or Venus. Mars by Earth, Venus or Mercury. Jupiter by Mars, Earth, Venus or Mercury. You get the idea. This opens up many ratio possibilities and that means many more possible gear combinations. This is good as we shall see it can be difficult to get all of the correct gears for all of the planets.

Some More About Gears 4/3/21

When the four gears for each planet are mounted on their tubes/axles, the shafts must be parallel in order to function. That is, when all the gears mesh properly, the axle holding gears A and C must be parallel to the tube holding gears B and D. In my first Orrery I used gears from one manufacturer, Boston Gear. If I used gears with the same diametral pitch (DP) number this parallel alignment would occur as long as the total number of teeth in gears A+B was equal to the total of C+D. The DP number is the number of teeth on an individual gear divided by the gear diameter. This number tells us about the size and spacing of the teeth on the gear. This worked great in gears from one manufacturer of quality gears like Boston Gear.

The image (figure3) above shows the collection of gears I will be working with for this Orrery. These are antique and vintage clock gears removed from old broken wind up clocks. I have a lot of these as I pick them up whenever I see them at a flea market or on eBay in larger lots. The main problem is that the DP numbers do not always match up for these gears as they have been made by different manufacturers over many decades. For example I have three different gears that all have teeth that mesh and all with 72 teeth. However, all three have different diameters. This would cause problems for getting the parallel placement of shafts for AC and BD if different ones were used in an ABCD set. This is only one example. So for this new Orrery I cannot use the A+B = C+D rule for selecting gears as I did last time. This is both a blessing and a curse. It is a curse because it limits the number of possible gear combinations I can use. It is a blessing because the gear calculations become much easier to process.

For gears of similar enough tooth size so they will mesh properly I only now can be assured of parallel shaft placement if gear A is an identical gear to D and gear B is identical to gear C. That is matching sets of identical gears. This makes gear calculations easier as the equation above simplifies to:

The rotation speed ratio now equals (A-teeth/B-teeth) x (A-teeth/B-teeth) or (A/B)(A/B) which is (A/B) Squared

This is because the number of teeth on A equals the number of teeth on D and B equals C. So how does this equation make gear calculation easier? If I take the square root of the ratios found in the “Ratio of Planet Orbits Around the Sun” table 2 above, I get the ratio required for only two gears. A/B which will be identical to D/C for each orbital/speed ratio.

So this makes things much easier to calculate. I just need to find two of the same gears for A and D with the same number of teeth, and two of the same gears for B and C with the same number of teeth. The other stipulations are that all the gears mesh properly, that is have the same number of teeth per inch, and the ratio A/B matches those found in the Square Roots in table 3 above for each planet of interest. For example, if I find two identical gears with 48 teeth for gears A and D, I will need two identical gears for B and C of the same tooth size with 30 teeth for Venus to be powered on the Mercury shaft. This gives me a ratio of 48/30=1.6, which is the ratio found in the square root table 3 above. Next will be the hunt for the gears. Stay tuned.

The Search for Gears 4/4/21

My first step was to sort each gear in my collection by the number of Teeth Per Inch (TPI) and then into identical gear types. In order to find the TPI for each gear I used a thread pitch gage found in figure 4 below.

Normally this device is used to measure the teeth per inch on a screw or bolt. If you are interested, I got this one at Little Machine Shop.com, a great place to get all kinds of metal working tools for a small shop.

You can see in figure 5 that it works pretty good for measuring the TPI for gears as well. In this example the gear has about 14 teeth per inch. Using this gage measured the TPI for each gear type in my collection.

Next I separated the gears into identical gears and then counted the teeth on each. This can be tedious. The best method I found was to photograph each gear close up and then count the teeth on the photo.

I set up this temporary photo booth (figure 6) with a piece of paper to provide a white back ground.

Then I took a closeup photo of each gear like this one. Using an editing program (MS Paint) I circled a gear roughly at the 12 o’clock position on each gear and used it at the starting point for the count. The paper in this example is labeled with a gear identifier D6. Each gear type was given a unique identifier based on the TPI and number of teeth. Don’t confuse these A,B,C and D with the gears required for the Orrery, these are just catalog numbers for my inventory. The letters group them by TPI. The numbers are arbitrary, but generally follow the pattern that lower number have more teeth than higher ones. This didn’t happen all the time as I would discover new gears that had to be added to the list later messing up my numbering system a bit.

After sorting and counting all the gears, what I came up with is (table 4) inventory of gears I have available. I have 31 types of identical gears in 4 different TPI groups. For each group I labelled the gears with an A, B, C or D and then a number. Again, these are just for cataloging the gears and to not indicate gear types found in the design concept of figure 2.

Figure 8. All the gears sorted and placed into individual bags.

Figure 9. And here they are back in the “Small Gears” storage drawer.

Selecting the Right Gears

Above in table 5 is a copy of an Excel spread sheet I used as a gear calculator. I have also added a download button below so you can use it to do calculations with any gears that you may be using. It’s not real complicated, but does require some explanation. I’ll go into some detail on how to use it for gear selection next.

Columns Labels in table 5:

• Gear – Just my catalog number for each gear in my collection.
• TPI – The number of teeth per Inch for each gear.
• Dia (in) – The diameter in inches of each gear
• V/Me- The V stands for Venus and Me for Mercury. V/Me lists the gear required for Venus to be powered off the Mercury shaft/tube using it in combination with the gear in first column .
• E/Me – E is Earth so E/Me is the gear required for Earth powered off the Mercury shaft/tube with the first gear in this row.
• E/V – This is the gear required for Earth powered off the Venus shaft/tube.
• M/E- The M stands for Mars and E for Earth. M/E lists the gear required Mars to be powered off the Earth shaft/tube.
• M/V- The M stands for Mars and V for Venus. M/V lists the gear required Mars to be powered off the Venus shaft/tube.
• M/Me- Gear for Mars powered by Mercury shaft/tube.
• J/M- Gear for Jupiter powered by Mars shaft/tube.
• S/J- Gear for Saturn powered by Jupiter shaft/tube.

If you enter all the gear tooth numbers of the gears you have to work with into the TPI column the calculator will calculate a gear tooth number required for each column for powering the planets. All you have to do then is see if you have a gear of the right size in column one. The yellow highlights in my table are gear matches or near matches that I found in my collection. These will be the gears I intend to use.

So in table 6 is the final selection of gears to be used. I have kept several options open for Mars as I have yet to decide which combination to use. I would like to use Earth to drive Mars, but I don’t have a gear combination in table 5 that will get the exact ratio. Since Jupiter and Saturn will be powered off of the Mars shaft this error will be compounded. You will notice I already have some errors entering into the Saturn and Jupiter ratios. Jupiter is giving me a 6.25:1 ratio when I would like a 6.31:1. Saturn at 2.42 versus the desired 2.48. These outer planets move very slowly so I’m not too worried about their errors. I also have not decided whether I will even include Jupiter and Saturn in my finished design. In this design I want to keep the Orrery fairly small. Adding in the orbits for Jupiter and Saturn will make this more difficult unless I make some kind of size compromise.

The other thing you will notice in tables 5 and 6 is a new 30 tooth gear inventory number C9. This is a gear not currently in my inventory. I wasn’t able to find a good combination of gears for driving Venus. I decided to make two 30 tooth gears that will mesh well with the two 48 tooth gears C4. Making these gears will be the subject of the next section.

How I Made a Gear 4/9/21

I was able to select gears A,B, C and D from my stock for all of the planets except Venus. Unable to find a set that would be in an acceptable gear ratio range to the 2.55:1 required, I decided to make gears that could be used with an existing pair. Having a bunch of 48 tooth gears you can see in table 5 that 30 tooth gears would get a ratio A:B of 1.6:1 (48/30=1.6). Doing the same for D:A I get 1.6:1 x 1.6:1 = 2.56:1 for the final ratio. This would be close enough to the target value of 2.55:1 for our Orrery.

Now we need to calculate the dimension of our new gears B and C. We know we need them to be 30 tooth with about 14 teeth per inch. This will allow them to mesh and have the proper ratio to gears A and D.

Figure 12 above is the scratch paper I used to help me calculate the new gear dimensions. The results of these calculations are as follows:

Specifications Gears B and C (new gears)

Teeth = 30

This means 360 degrees/30 teeth or 12 degrees between each tooth.

Need to have 15.56 T/in on the new gear inside or in the tooth valleys to mesh with the teeth per inch of the the 48 tooth gear tips of gear C4.

We need to have 30 teeth, with the outside meshing with the inside of A and D.

Circumference = 30T / 15.56 T/in = 1.928 inches

Diameter = 1.928/3.14159 (pi) = 0.6137 inches

Radius = 0.3069 inches at the inside or valleys of the teeth on the new gears.

Now we are ready to actually fabricate two new gears from the brass stock piece you can see at the bottom of figure 12. It is a six inch brass piece that is one inch wide and 0.09 inches thick. This is a standard size that can be purchased at most hardware stores. I bought mine at ACE.

So how are we going to make a gear? Part of the answer is in figures 14 and 15 above. The milling machine on the left has an X Y table mounted below a drill chuck. The X Y table allows you to center a work piece under the drill chuck and the move it an exact amount to the left or right (X direction) or back and forth (Y direction). The next piece of the puzzle is the rotary table seen on the right (figure 15). This device allows us to rotate a work piece a specific number of degrees and seconds with respect to the drill chuck.

Now we are ready to start making our gear. I plan to make a You Tube video of this complete process and add it to my You Tube channel, but more details are available here.

Cutting Teeth

The plan for making the gear is to cut a ring of small holes around a center. The inside edge of these holes will be the inside or bottoms of the teeth. I actually cut a second set of holes just outside but in line with the first set. This made it easier to finish the tooth shape with small files. Excess brass is then machined off using a lathe and the final fit and finish was done with small hand files.

Here the rotary table has been centered beneath the drill chuck. This was done using an edge finder and was centered both in the X and Y directions. You can see here how the brass will be held in place for drilling. The metal is too long in this picture to allow for a full rotation of the table so before starting it was trimmed a bit shorter. Underneath the brass is a scrap piece of aluminum. This is so we can drill all the way through the brass without drilling into the rotary table.

A center drill is marking a second set of holes centered 0.04 inches out from the first set.

The band saw was used to trim the drilled brass to a roughly round shape. The aluminum rod in this picture has one end bored and tapped to accept an 8-32 screw. This will serve as a mounting fixture for the gear.

The future gear all chucked up and ready for turning to the correct diameter.

In these pictures the gear has been turned to the correct diameter and removed from the lathe and mount.

And here in these last two images are the gears completed ready for the next step in our Orrery. That would be choosing the brass tubes and rods for the shafts and then mounting the gears to them in the proper order.

I Digress- Making a 35 Tooth Gear 4/25/21

So I was looking at the gears that I had chosen and didn’t like the Mars to Venus gear combinations available. If I could get a gear set to turn Mars off of the Earth shaft it will simplify the rest of my design. When I looked at the gear combinations in table 5, I saw that I could use two 48 tooth gears in combination with two 35 tooth gears for gears A,B,C and D for turning Mars off of the Earth tube/shaft.

48teeth/35teeth = 1.37 and 1.37×1.37 = 1.88 the desired ratio for Mars to Earth.

This gear is a bit more complicated. A 30 tooth gear is pretty simple. 360 degrees divided by 30 teeth equals 12degrees/tooth. Now my rotary table moves through 4 degrees of rotation for each one complete turn of the hand wheel. 12 divided by 4 equals 3. So to drill for 30 teeth I needed to turn the hand wheel 3 rotations between each drilling. I would always land back at zero after each hole. 35 teeth is different. 360 divided by 35 equals 10.2857 degrees per tooth. This means if I get 4 degrees for each rotation of the hand wheel I will turn it 10.2857/4 or 2.5714 rotations per hole drilled. 2.5714 works out to 2 turns plus 2 degrees 17.1 seconds for each set of rotations between holes. So you wind up with these odd ball stopping points after each hole. What I decided to do is make a calculator in excel that would set up tables for me to follow while making each gear.

You can down load the excel spread sheet here:

Let me explain how this works. In the first column under “Teeth” you enter the number of teeth you want the gear to have in the highlighted box. In the D/turn (degrees per turn) box in the third column you enter the number of degrees for each rotation of the hand wheel on your rotary table. You then enter the number of teeth per inch in the “T/in” box and the diameter of the drill you will be using in the “Drill dia” box. In between these to is the amount you want to offset the X-Y table in the X direction for drilling your ring of holes.

The red box surrounds the turns, degrees and seconds required on the rotary table for each drill location. So starting at the top the first hole is drilled without any rotations. Then, in a clockwise direction, on my mill I do two full rotations plus 2 degrees 17.1seconds and drill the second hole. Then before the next adjustment I rotate the hand wheel clockwise back to Zero.

So why do I do this? First of all it is a lot easier to count turns from zero then some random location on the hand wheel dial. Second, it helps prevent errors from accumulating as I advance the gear through 360 degrees. If I mess up by a couple of seconds of arc this won’t be added to the next hole. The excel spread sheet automatically subtracts off this extra rotation from the 2 turns 2 degrees 17.1 seconds back to zero off the next turn.

You will notice that there are 5 sets of 7 turns that bring us back to the starting hole. What ever tooth number you select will start repeating a sequence at some point and you only need enough to complete your total gear tooth count.

The columns marked Check 1, Check 2, Check 3 and Check 4 are for marking each drilling. I do four sets of drillings for each tooth. A center drill marking each hole. Then a #61 drill hole. Then I offset in the X direction 40/1000ths of an inch (drill bit diameter) and do another set of center marks and drills. This means four drillings for each tooth. The way I found that works best is to drill then advance clockwise to zero, unless I am already at zero, and then check the box for that drilling. I then advance to the next hole and repeat. I continue this process until all 35 holes have been marked. Then repeat with the #61 drill bit. After that I increase the offset in the X direction another 40/1000ths and repeat the center drills and #61 through drills again.

Once all 70 holes are drilled the rest is the same as that for the 30 tooth gear described above.

In this picture you can see my 35 tooth gear prototype. I’ve started using cheaper aluminum to experiment with as I’ve been going through quite a bit of brass. That gets expensive.

Finally in table 8 is the current gear selection table with the new 48 and 35 tooth gears for driving Mars from the Earth shaft. Now I just have to make two 35 tooth gears from brass. Then I will get into selecting tubes and shafts for each gear combination. All of the gears will also need hubs attached for mounting to the shafts/tubes.

35 Tooth Gears Compete 4/27/21

5/9/21

It’s a couple days later and the 35 tooth gears are done as you can see above. Next up the power base.

Making a Motor Powered Orrery Base 5-31-21

Once the gears were all selected and completed I decided to make the base for the Orrery. This will not only support all the tubes/shafts for each planet and the Sun, but also contain a small DC motor that will power the planetary movement.

In my box of electric motors I found this gear reduced motor that used to power my robot. At some point I’ll blog the Robot project I did 10-15 years ago. The robot was switched to stepper motors at some point which left me with two of these motors. For more power the Orrery will be turned using the worm gear shown here. This impinges on the spur gear on the bottom left. The brass rods will serve as drive shafts.

The original drive shaft was drilled so a cotter pin could be put through the worm gear to hold it in place. I wound up changing the drive shaft later, but the cotter pin was also used in the modified drive.

I made this connecting shaft with set screws to connect the 1/8 inch diameter motor shaft to the 3/16 inch drive shaft.

• 

• 

• 

The main drive spur gear did not have a set screw, so here I am drilling and tapping the gear hub so a set screw can be inserted. The picture on the right has the elements that will go into the base sitting in there approximate final locations. The bottom of the base will be made from an oak board. The motor, gears and shaft we have already discussed. Finally I will be using brass plates taken from my bin of antique clock parts for the top and bottom of the main gear box.

A one inch by 0.064 in brass plate will be used to mount the motor. In order to do this holes were drilled into the base plate that will match holes to be drilled into the motor mount.

The two ears on the base plate needed to be bent to right angles before the motor mount could be screwed in place. I used 1/4 inch steel plates that I clamped in line with the bend lines indicated in the picture to facilitate a clean bend.

Here I have completed the right angle bend and the motor mount is temporarily screwed in place.

• 

• 

• 

• 

In these images you can see the progress of drilling the motor mount and how it all fits together.

In these pictures I cut the oak bottom to the final dimensions. The edge was routered to provide a rounded edge.

In these images I am drilling holes into the wood bottom. The four small holes hold the brass base plate in place. The large one inch diameter hole is where the Sun shaft will be mounted on a stationary bracket.

In this picture I have pre-drilled the top plate and have set it in place where it will be mounted. This is also an antique brass clock gear box piece.

I used a 5/16ths in brass rod to create the mounts for the top plate. They were drilled and tapped at each end so they both hold the top plate to the base and the base plate to the oak bottom.

Two, three and four mounting posts are completed here.

I realized that the Orrey drive would be more stable if the drive shaft was supported on both ends. I made a longer drive shaft as well as an L-bracket to support the distal end.

The L-bracket was also cut from old brass clock parts. This is a closeup before drilling holes to mount it to the brass base.

The Sun is mounted to a stationary shaft the runs through the tube shafts for all the planets. I made this brass mounting bracket to hold it in place. You can also see the screws and nuts that hold the L-bracket from the previous pictures in place. The bottom right is a picture of milling a groove into the bracket. The top right is the Sun bracket after soldering to the Sun tube. In the bottom of the left picture you can see holes drilled into the oak bottom to fit the nuts from the L-bracket. The Sun shaft is hollow so I can run a wire through it later for power to light up the Sun.

I have slid the Mercury tube over the the Sun shaft and through the base here. It is hard to see, but the Mercury tube slides into a brass housing that I turned on the lathe. The housing is 1/4 inch in diameter along its length. Each end is turned down to 3/16 inch to fit into the holes in the top and bottom plate. It was then bored out all the way through to 1/8 inch, which is the diameter of the Mercury tube/shaft. One thing I learned from my first Orrery was that the gear set screws that impinge on the planetary tubes can easily press the tube in far enough to prevent the tubes from turning if over tightened. On this Orrery each tube will be soldered into a brass support bushing/housing that will support the tube so this won’t happen.

Here you can see the construction of the Mercury housing as I solder it to the Mercury tube shaft. The central one inch section is 1/4 inch with 3/16 in diemeter ends to insert into the top and bottom brass plates.

After soldering, the Mercury drive tube with housing and gear is slid into place..

This gallery shows the completed Orrery base. The Sun and Mercury shafts are both in place. The shafts have not been cut to there final length at this point. This will be done once the final design for the rest of the planets is completed. Finally a short video showing the drive mechanism in action.

Let’s Put Some Hubs on These Gears 6/13/21

Well I’ve got my gears sizes ready, but now I need to be able to attach them to the correct diameter tubes and shafts. They need to fasten in place and be stable once mounted. To accomplish this each gear will need a hub with a set screw attached to it.

In the picture on the left you see the 4 gears that will be used to turn Venus. On the right is the Venus B gear with the 5/16ths in brass rod that will be used to make the Hub.

The first step was to face off the surface of the rod and then bore a hole down the center. These were done on the lathe. The hole was drilled with a #18 drilled bit which gives a tight fit for an 8-32 screw. The hole in the gear is the same size.

Next a hole was cut into the side of the hub and then tapped to take a 4-40 set screw. Finally the hub was cut off to length.

The surfaces of the gear and hub are cleaned with steel wool, then treated with solder flux. The hub is held to the gear for soldering with a 8-32 zinc coated steel machine screw. Solder will not stick to the steel so it can be removed after soldering.

After removing the zinc clamping screw the hub and gear are drilled out to the correct diameter to fit over the shaft extending up from the Mercury level that will power Venus. In this case that is 3/16ths of an inch.

After I finished the gear I realized that the hub size was too narrow to provide the strength needed. There is only about 1/16ths of an inch of threads and this gear ultimately powers the rest of the planets.

Instead of starting over a added a second set screw to the hub and then soldered on place two 4-40 brass nuts that provide extensions to the number of threads. Here Venus gear B has been slid over the 3/16ths inch shaft it will be mounted too. It is upside down so you can see the additional set screw and nuts that have been added.

Gear A was treated similarly using a 1/2 inch brass rod. Here a 6-40 set screw was used instead of the two 4-40’s used for the gear B.

Finally both gears are set in place right side up on the Orrery base.

Plates for Supporting Gear Levels 6/14/21

Before I went much further I wanted to get a better handle on how all the gears will line up in the completed Orrery. I have the design in my head but needed to get it a little more finalized.

The picture above is a rough sketch of the gear box design for the Orrery. It is a side view looking at the plates and gears edge on. There are five levels, with brass plates separating the levels. The main tube shafts run up the center of the plates. Each level contains the A, B, C and D gears for each planet. The solid side shafts for the A and C gears alternate from side to side as you go up each level. This keeps the side shafts from intersecting the plates too close together or even in the same spot.

In this image I used SketchUp to draw the Layout for the first two levels Venus and Earth. Here again we’re viewing from the side. The plates are white and the gears, shafts and level supports are pink.

I purchases these half inch brass strips at Ace Hardware. They are 0.064 inches thick which is just wide enough to accommodate the largest of the tube shafts which is for Saturn (9/32 in).

The plates were rough cut on the band saw and then the ends were trimmed on the milling machine resulting in five 4.5 inch by half inch plates.

The strips were then stacked and drilled simultaneously for the off center tube shafts and two holes on each end for the level supports. This will ensure that when mounted the holes for the tube shafts will line up between levels. There are two holes on each end because the supports will be staggered from one level to the next.

The picture on the left shows four of the brass plates cut to length and drilled with the tube shaft and support holes. The picture on the right shows one of the plates laying in the approximate orientation it will have in the finished Orrery.

I then decided it would be a nice design element to cut a radius on the ends of each plate. The milling machine and rotary table were used for this.

On the left are the plates are stacked and screwed together after cutting the radii. On the right are the five completed plates. The set up to cut these radii took about two and a half hours. Once the mill and rotary table were set up the cutting took a couple of minutes.

Here again one of the plates is shown in the approximate final location. Each plate will have the central hole widened to the proper diameter for its planet tube. Each will have additional holes added for the side gear (A and C) shafts. I also cut a blank plate on the rotary table just in case I screw one up or need an additional plate.

Venus Gear Level is Completed 6/21/21

After completing the plates for the various planetary levels I started on the workings for Venus.

I used the mounting shaft to support Gear B (small gear) and the top plate for Venus. At this point the central hole of the Venus plate is still 3/16 inches in diameter, the same size as the Mercury shaft extending above the base. This means the plate fits snuggly over the mounting tube. I then impinged gear A onto gear B and used a 1/4 inch center punch through the hub of fear A (large gear) to scribe a mark onto the Venus plate. This is where the center of the shaft for side gears A and C will be.

A 1/8 inch hole for the side shaft was this drilled into the Venus plate. This plate was then used to mark the location of the matching hole in the base plate. This was then drilled with a 1/8th inch hole as well. When the plate is mounted these holes will align vertically so they can support the side shaft for gears A and C for Venus.

Two 5/16ths inch brass rod sections are used to support the Venus plate above the base. These were trimmed to 3/4 inch length on the lathe and then drilled and tapped for 6-32 threads.

The plate supports are held in place with brass 6-32 by 3/8ths screws. The plate is resting in place in the picture at right with the supports screwed to the base.

Next, this 1/4 inch brass rod is used for the side shaft that gears A and C are mounted on. It is turned to have a 1/8 inch narrow section on each end with a 1/4 by 3/4 inch length in the center. These 1/8th inch sections slide into the 1/8 inch holes drilled in the Venus plate and base.

In the picture at the top right the shaft is set into the 1/8 inch hole in the base. The top 1/8 inch section hasn’t been turned onto the shaft yet. In the lower left is a close up of the completed shaft with A and B gears mounted. The left is another view with all the pieces in place.

The 5/32ths inch brass tube for turning Venus was cut to length so it will be the right height when slid over the Mercury tube. So in the picture above you see the tubes for the Sun, Mercury and Venus.

The central hole is being widened from 3/16ths to 1/4 inch in this picture. The Venus tube has a 1/4 brass bushing soldered to the end that will slide into this hole.

The 1/4 inch brass bushing for the Venus tube is being cut to length and then soldered to the end of the Venus tube in these pictures.

Here the excess solder is removed from the Venus tube on the lathe and the brass polished up a bit. The busing acts to strengthen the tube so that tightening set screws on the gears won’t compress the tube. This would cause the Orrery to bind.

In this image the Venus tube with brass busing is resting in the final location.

Hubs with set screws are made for gears C and D similar to the ones made above for gears A and B. On the left gears A and C have been mounted to the side shaft. Gear D has been mounted to the bushing of the Venus tube and then slide over the Mercury tube. Gear B mounts to the 3/16ths inch tube from Mercury. The Venus level is driven off of the Mercury tube/shaft.

On the left in these images the Venus plate has been mounted. Gears A, B, C and D for Venus are in place and functional. On the right the Orrery has the Venus level completed and is powered up. The blue tape pieces act as stand ins for the Mercury and Venus orbital rods. You can see here I have put some green painters tape on the wood bottom of the Orrery. This is to protect it from grease and dirt while I continue work. I plan on adding a short video on how I make the gear hubs and showing the Orrery working when the motor is powered up.

Video of Venus Level Completion 6/26/21

Earth Level Gearbox is Completed 7/4/21

I have been busy completing the gears and plate for the Earth level of the Orrery.

The design of Orrery planet levels follows pretty much the same pattern. I’ve added the Earth level to my SketchUp drawing as you can see above.

Two of the gears for Earth, the small ones B and C had small gears inserted in the center that I did not need. I used a punch to remove them. The four gears for Earth are seen in the bottom picture. These are ready for hubs.

Hubs were created for the A and B Earth gears first. I followed the same process as I used for the Venus gears shown in more detail above.

The A and B gears were used to mark and drill the hole for the side shaft that supports A and C gears.

As with the Venus level a 1/4 inch brass rod was used to create the side shaft for A and C gears.

In these images the 5/16ths rod use to support the Earth plate have been cut, drilled, tapped and mounted.

The hubs for C and D gears have been made in this picture. C gear is mounted on the side shaft above A gear on the right of the main picture. D gear is sitting on top of the Earth plate ready for the Earth tube. The images on the right show some of the gear hub making process. The hubs were made the same way as those for Venus so I didn’t do as much detail here.

The Earth tube is measured and cut to length here.

The bushing that will be soldered to the Earth tube is seen being made in the pictures in this gallery. It is a 1/4 inch rod bored out with a 3/16ths in hole. This allows the Earth tube to be slid inside the bushing, which acts to support the tube wall.

The completed Earth tube with the bushing soldered in place. These bushings on the planet tubes strengthen them so they won’t get crushed when tightening the set screws that hold the gears to the tube.

The D Earth gear is fastened to the bushing of the Earth tube. Then the Earth level is put together with all the pieces in place.

The Orrery Earth level complete.

A closeup of the all the gears so far. These drive Mercury, Venus and Earth.

Another view. This one shows the blue tape attached as stand ins for the planets. These are taped to each tube for running the test seen in the video below.

Finally, for Earth, a top view. Below is the latest You Tube video.

Mars Level Takes Shape 7/11/21

The Mars gears have been mounted into place. I won’t go into as much detail here as the process and design are similar to what was done for Venus and Mars.

The four gears for Mars are seen on the right. The two smaller 35 tooth gears are the second set created above. On the right a the A and B gears are set in the larger A gear still needs a hub.

In these images you can see more of the progress for the Mars level. In the top right a hub has been added to the larger A gear. It is set in place upside down so the hole for the A/C shaft can be drilled. The bottom right shows A and C gears with hubs mounted to there shaft.

Finally all the pieces are completed and assembled adding the new Mars layer to the Orrery.

In this picture I’ve added some test wires as stand ins for the planets so I can run a test. The test can be seen in the video below.

By Jove I Finally Finished Jupiter Level 8/12/21

I’ve been on vacation so I haven’t had time to update in the last few weeks, but I have been able to do some work on the Orrery. In fact I have finished the Jupiter gear level.

• 

• 

• 

• 

First up is making the B drive gear for Jupiter. The ratio here is very high as the Jupiter orbit is so much slower than Mars which is used to drive it. This means B-gear is a very small diameter creating challenges not seen in other levels.

In the image above the hub has been attached to the small B-gear and the hole bored to the 1/4 inch diameter Mars drive tube. This gear being so small did not allow me to place a support around the Mars tube as I have been doing for the rest of the gears mounted to tubes. The hub walls would have been too thin.

• 

• 

Here the A-gear for Jupiter is hubbed and can be seen sitting meshed with the B-gear in the right picture.

• 

• 

• 

• 

The side shaft for Jupiter was made of two sections. One passes through the A gear seen here.

• 

• 

The C-gear location is seen in these images. It, again, is a match to B-gear which is pretty small.

• 

• 

• 

• 

• 

In these images a narrow section is created for the side shaft that will fit through the small C-gear. The whole thing is then soldered into one piece. The C-gear is actually soldered directly to the side shaft and no set screw is used.

• 

• 

On the left A-gear is attached to the side shaft. C-gear is already soldered to the shaft. On the right it is installed and the Jupiter top plate drilled and mounted. Gears A, B, and C are now in place.

• 

• 

• 

• 

Here the 9/32 inch Jupiter tube is cut to length and constructed in these pictures. A 5/16 inch support tube was soldered in place for this tube so I can go back to having some strength where the gear set screws are mounted.

• 

• 

• 

• 

D-gear for Jupiter has its hub attached and then the gear is mounted in place.

• 

• 

The top plate is screwed into place and the Jupiter level is done.

Of course I did test the Orrery with the completed Jupiter level. The purple wire is a stand in for the Jupiter orbital rod. When I get time I will be adding a video for this level and its test.

As promised:

A Saturnalia of Gears 9/5/21

So the Saturn Orrery gear level is completed much the same as the other levels.

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

Above gears A, B and C have hubs added to them. A side shaft is created for gears A and C. The support rods for the Saturn plate are also fabricated.

• 

• 

In these pictures the Orrery Saturn level is ready for gear D and the Saturn tube to be added.

• 

• 

• 

• 

• 

• 

The Saturn tube for the Orrery is made here. It is cut to length and a reinforcing bushing is soldered to place.

• 

• 

• 

• 

• 

• 

• 

The hub is added to Saturn gear D and it is ready for mounting.

• 

• 

As with the other levels, the Saturn gear level is tested using colored wires as stand ins for the planet rods.

When I cut the plates for the Orrery, I made a spare in case I screwed one up while making the various levels. That did not happen so I’m using the spare plate to make a cover plate for the final level. This will hide the extra holes that were drilled into the Saturn plate.

I do need to drill some holes into the cover plate. Two for the screws and one for the central tubes that need to run through it in the center.

• 

• 

• 

The holes are lined up using the Saturn plate as a guide. After drilling the plate is set into place.

I like the way copper looks on brass. I made a small copper label for my initials and date. This covers a mistake I made on the cover plate drilling a notch too deep and creating a hole over the A/C shaft location.

The copper label is then soldered to the brass cover plate. The cover plate is then sanded and polished as well.

• 

• 

These are some images of the completed gear box. I have taken the protective green tape off of the wood base. This is because the Orrery is about to be disassembled so I can stain and varnish the base. I have also decided to shorten the planet tubes by 7/8ths of an inch each. This will shorten the Orrery overall and make it look more compact. Brass rods and plates will be sanded and polished as well.

Cleaning Up and Finishing Some Surfaces 9/11/21

• 

• 

We’re getting near completion on the Orrery. Before I move on to the Sun and planets I did some finishing work on the gear box and base. In order to do that I disassembled the Orrery. In these pictures you can see the oak base in the foreground. The set of gears, tubes and shafts for each planet have been placed in individual zip lock bags in the background.

• 

• 

After completion of the gear box, I felt that the height of the Orrery was too high. So I decided to shorten each planet tube by 7/8ths of an inch. Here I am cutting the tube for Saturn, but all the tubes were shortened in this way, using the lathe and a pointed cutting tool.

• 

• 

On the left are images of the shortened tubes after temporarily re-assembling the Orrery. The Sun tube was left the original length. A closeup is on the right.

Each of the plates separating the gear levels of the Orrery are sanded and polished using a Dremel with a buffing wheel and buffing compound.

• 

• 

• 

• 

The oak Orrery base is sanded, stained and varnished.

• 

• 

• 

• 

The brass base is wired to provide power for lighting the Orrery Sun when we get that far. The brass base will be wired as ground, or negative. The red wire is run up the Sun tube and will provide the positive pole for the light. An opening can be seen in the side of the Sun tube so the wire can be pulled through it after the bottom hemisphere of the Sun is in place. The top right picture shows one of two acrylic hemispheres that will be used for making the Sun, They are two inches in diameter.

• 

• 

• 

• 

While I had the Orrery apart I added a bushing or stop to the main drive shaft. This will prevent the drive shaft from shifting to the right if a set screw comes loose where the shaft is connected to the motor. This happened during one of the tests and I wanted to prevent that in the future.

• 

• 

• 

• 

Finally the Orrery is re-assembled and is ready for testing. I’ll add a video of the test and all the work done from the Saturn layer to this point. You can look for that in the near future.

The Video as Promised 9/12/21

The Motor Cover and Wiring 9/22/21

Today I will agian update you on my progress. I have completed making a cover for the motor and wiring the Orrery with a switch and a power plug.

I decided to make the motor cover box from the 1/4 poplar pieces seen here. The copper plate is used to make a bracket that holds the box in place. Also seen in the picture are the electrical pieces I used. The switch is a vintage toggle type with a unique, more Steampunk, design. A couple of male/female plug assemblies are also shown. I decided to go with the red one.

• 

• 

• 

• 

The copper piece is seen here being cut and shaped into the bracket that holds the wood cover to the Orrery.

• 

• 

• 

• 

I wound up making a second bracket seen in the upper left picture. The first one had some 45 degree cuts on the bottom I didn’t need. In the other pictures the bracket is attached to the final location temporarily.

• 

• 

• 

• 

• 

One quarter inch brass strips are cut and soldered to the seams of the bracket. The bracket is then buffed and polished. These clean up the piece and give it more strength.

• 

• 

Here the bracket is in its final mounting location after polishing. The unused bracket can be seen in the background in the picture on the right.

• 

• 

• 

• 

• 

• 

• 

The motor cover is cut from the poplar pieces into three sides and a top. The top is pre-drilled for the switch and the back side for the power outlet.

• 

• 

• 

• 

The motor cover pieces are then glued and clamped together. The bottom picture shows the rough box after gluing sitting in the final location

• 

• 

After sanding the cover, it receives coatings of a red oak stain and a clear gloss polyurethane varnish.

• 

• 

• 

• 

• 

The male connector is soldered to the power line of a 5VDC power box from an old Sony PSP game system. The female outlet has wires soldered to it as well.

• 

• 

• 

• 

• 

Using more of the copper sheet material a support plate is made for the power outlet that will be screwed to the motor cover back side.

• 

• 

Using a terminal block to provide wire attachment points the internal wiring is completed.

• 

• 

I received this metal plate in a box of clock parts. I thought it would make a nice decorative element for the Orrery. On the right both it and the copper outlet plate have been screwed into place.

• 

• 

• 

I needed to make a spacer from a brass washer to get the switch to mount properly into the cover. The brass washer is being machined in the picture on the left. On the right both the switch and power outlet have been attached to the cover.

• 

• 

• 

In these pictures you can see the motor cover completed and mounted to the Orrery. The power plug has been inserted into the outlet and the Orrery is ready to be switched on.

This image is the Orrery as it is today. Below is a video of of the motor cover fabrication.

The Sun Shines 9/25/21

• 

• 

I purchased these 2 inch acrylic hemispheres on Amazon. I need to drill and bore them so I wrapped them in painters tape to avoid scratching them. They will be used to make the Sun for the Orrery

• 

• 

• 

• 

The hemispheres are drilled with a 3/32 inch drill bit on the lathe so the could be slid onto the Sun tube of the Orrery and be centered.

• 

• 

The hemispheres slide on to the Orrery. Here I am testing the fit, you can see they look pretty nice.

• 

• 

• 

• 

Next I made a brass bushing with a set screw to act as a stop to prevent the Sun from resting on the Mercury tube of the Orrery.

• 

• 

In these pictures you can see the brass stop has been mounted to the Sun tube and the Sun is resting on it in the image on the right.

• 

• 

• 

• 

I made a 1/2 inch bore into each hemisphere. This is the space that will hold the bulbs for illuminating the Orrery Sun.

• 

• 

• 

So the rough inside surface of the bore won’t block light, I sanded them with progressively finer sandpaper. Starting with 220 grit wet/dry they are sanded using grades down to 1500 grit.

• 

• 

• 

You can see the polished bores here.

• 

• 

• 

Using an epoxy tube made from a toughened version provided by Epic Resins, I made a small epoxy ring on the lathe that will support the bulbs. The brass tube is 1/8 inch diameter and can slide onto the 3/32 inch Sun tube. This will act as the ground contact for the bulbs.

• 

• 

• 

I used 3 2-cell bulbs that are replacements for a Maglite flashlight. I use them because they are very small and very bright. In the center image two small holes have been drilled into the surface of the ring. They are the right distance apart for the bulb leads to slide into as seen on the right.

• 

• 

On the left I completed holes for all three bulbs. The image on the right shows the grounding tube with a copper lead soldered to it.

• 

• 

• 

I wired the bulb ring by first inserting the ground tube into the center of the ring. The ground lead is put through one of the bulb socket holes. It’s hard to see but the image on the left has the ground lead through one of the holes. The holes are drilled large enough so that a bulb lead and 22 gage wire will both fit snuggly into each hole. In the center you can see I slid wires into opposite holes so that when when the bulbs are inserted they will be wired in series. On the right a positive lead wire goes into the last hole.

• 

• 

• 

After inserting all of the bulbs I slid the ring onto the Sun tube of the Orrery. The positive lead was temporarily placed into contact with the positive 5VDC supply line for a lamp test. It works!!!!

• 

• 

• 

Now these pictures are a bit blurry, but I am trying to show you how an electrical pin connector was used as the plugin for the supply voltage. I used heat shrink tubing to provide insulation around the pin to prevent shorting.

• 

• 

If you will allow me a bit of a digression, I wasn’t happy with the length of the Sun tube. The Sun tube only extended halfway into the upper hemisphere and the power line slotted hole through it was very short. To remedy this a took the hole Orrery apart and made a longer Sun tube that will extend 1/4 inch out of the top of the Sun. I also made the power slot about twice as long. You can see on the right the Orrery has been put back together and the bulb mounting ring is in place. You can also see the small black pin connector sticking up through the bore hole. It’s to the left of the brass Sun tube.

While I had the Orrery apart I made one last modification. Before I did this, the hole into the base under the planet tubes was only three quarters of the way through the wood. I thought that would be nice and keep everything protected…. However, this made it difficult to do repairs or work on the Orrery. So I drilled the hole all the way through the base. Now I have access to the power line that runs up the center of the Sun tube. I can easily replace it or slide the wire up and down to feed it out of the side slot of the Sun tube.

• 

• 

• 

• 

A test!!! I have completed the wiring and you can see the Sun with the longer tube lit up and working. The Sun tube now extends 1/4 inch out of the top of the sun. You can’t hear it but the motor is running as well.

• 

• 

• 

• 

As an added decorative element and to hold the Sun together I machined a brass finial for the top of the Sun. You can see it here with the set screw that holds it in place in closeup.

• 

• 

Two more pictures with the Sun completed. You can see two close ups here one dark and one illuminated.

A view of the whole Orrery…. so far.

Another with the Orrery turned on.

And one with the room darkened.

The Orrery is almost finished. I have to make the planet rods and clamps to mount them to the tubes. Then, I will need to make the planets.

The Sun Video

And here is a video of the process of making the Sun:

Planet Orbital Rods 10/17/21

With the Sun completed it’s on to getting ready to mount the planets. To do this I first needed to make clamps, orbital rods and elbows.

• 

• 

• 

The clamps hold the orbital rods to the rotating planet tubes in the center of the Orrery. I decided to make them from some quarter inch rod, screws and a quarter inch plate.

After cutting the rods to a 1 1/2 inch length each of the six were notched to the same size as the planet tube it will be mounted too. You can see in this picture how each clamp will mount to the Orrey.

• 

• 

• 

To cut down on the time for notching all of the clamp rods, I first drilled the notch into two clamps at once at the diameter of the lower size planet tube.

• 

• 

• 

• 

• 

After drilling I enlarged the notches, using end mills, the same diameter at the central planet tube for each notch. They were also cut deeper into each clamp.

On the narrow end of each rod I drilled and tapped a hole for a 6-32 screw.

I made clip pieces for each clamp from quarter inch brass plate. You can see I cut them to a half inch in length and then drilled one end for the 6-32 screw to pass through.

In these images you can see how the completed clamp is held to the planet tube.

In order to support the orientation of the clip piece while mounting the clamp to the Orrery, I added a small L shaped angle piece that is soldered in place.

Commercially available nuts were too wide to fit on the Orrery, so I custom made these small quarter inch diameter knurled nuts.

Here you can see a test mount of all of the clamps. These clamp ends still need a hole bored into each so an orbital rod can be inserted.

Using a for jawed chuck you can see how I was able to drill a 1/8th inch hole into the center of each piece.

I drilled and tapped a hole in the end of each clamp for a 4-40 set screw that will hold the orbital rods in place.

To give the Orrery a cleaner look, I turned the end of each clamp to a quarter inch in diameter.

These made for smaller less bulky looking clamps.

Here all the clamps are mounted. You can see how the clamps look less cluttered with the new design.

I used an excel spread sheet to calculate orbital rod lengths and planet diameters, keeping the ratios of each consistent with reality. A link to the spread sheet is provided below.

In these pictures you can see that each orbital rod has been cut to the correct length for each planet.

Elbows were made by soldering 3/16 inch rod to the end of each 1/8 inch orbital rods.

The top of each elbow was drilled with a 3/32 inch hole. The planet support rods will be inserted into these holes.

We are getting close now.

The Orrery is now ready for the planets.

The planet Orbital rods are all now in place. I need to make each planet and the 3/32 in support rod that support them.

Above is the full video of the orbital rod completion.

Planets and Supports 10/27/21

We now come to making the Planets and the support columns that plug into the elbows made above.

The inner planets, Mercury, Venus, Earth and Mars, I made from Fimo Clay. Fimo clay is a polymer clay that can be molded into shape and then hardened in the oven for 30 minutes at 230F. It comes in a variety of colors that can be blended and the final hardened material can also be painted with model paints. I use Testors.

The support columns I made from small brass tubing and steel wire. The elbows were drilled with 3/32nd holes and the bottom section of each column was made from a 3/32nd inch brass tube. For the inner planets I soldered a 1/16th inch tube into the bottom section. The planets rest on this tube and each has a short section of the wire inserted into it.

The diameters I used for each planet are in the column at the right in the table above. The inner planets Mercury, Venus, Earth and Mars are all made double the size with respect to Jupiter and Saturn. I did this to keep them large enough to be seen while keeping Jupiter and Saturn smaller than my Sun. You will notice that in order to have the size of Jupiter at 1.25 inches in diameter I would actually need a Sun that would be over a foot in diameter. So with some artistic license I am making my Sun 2 inches and Jupiter and Saturn 1.25 and 1.05 inches in diameter. The ratio between these two is accurate as are the ratios between the four inner planets.

In this picture are the hemispheres for Jupiter as well as the newly formed and baked Fimo clay inner planets. The wires that will be glued into each planet have been cut extra long so that I can paint and handle the planets more easily.

Here I made the support column for Mercury. The 1/16th inch tube is soldered into the 3/32nd. The column is cut to length so that the planet Mercury will rest at the equator of the Sun.

Similarly, I made support columns for the other inner planets. For Jupiter and Saturn I rough cut 3/32nd inch pieces. You can see the Orrery with all these columns inserted in the Elbows in the picture on the left above.

For Jupiter I drilled the center of one hemisphere with a 3/32nd inch drill and the other with a 1/16th. The Jupiter column will have a small 1/16 tube inserted and soldered into the top.

Here you can see the Jupiter column being made and the top hemisphere resting in place though the 1/16th inch hole.

I glued the Jupiter hemispheres together with plastic cement. You can see Jupiter in its final location with the 3/32nd inch tube passing through the bottom and resting inside the top hemisphere.

I added some paint to the inner planets. Mercury got a coat of gray, Venus a few swirls of white, Earth some white clouds and finally Mars a small white polar cap. Holes were drilled into each planet and a length of steel wire was glued into each one. Finally I cut the wire short enough for inserting into the brass support columns. Each inner planet was also top coated with a clear satin varnish to help blend the colors together.

I found a black hard ball of about 1.05 inch diameter for Saturn. I drilled a 3/32nd inch hole in one end so the support column could be inserted.

In this picture you can see all the columns have been cut to the correct length and all the planets have been inserted into them.

Both Jupiter and Saturn were given a coat of white paint to serve as a base. Each will be painted with stripes, swirls and the all important Jupiter red spot. I’ve heard that after 400 years scientists expect the red spot to disappear completely over the next 10 years. It’s so iconic though that I just have to add it.

As a finishing touch I replaced the brass flathead set screws with #4-40 1/8th inch allen screws for a less cluttered look.

Earth had to have a moon so I glued a small proper diameter Fimo clay Moon to Earth. This is a glow in the dark piece of Fimo so it should glow at night.

We’re getting close now. I need to finish painting Jupiter and Saturn. Of course Saturn will need it’s rings. When those two things are done the Orrery will be complete. Stay Tuned……

Orrery Completion 11/67/21

I finished painting Jupiter and Saturn giving Jupiter the iconic red spot. On the left you can see that I glued mounting posts for Saturn’s rings into the planet. They are tilted off the orbital plane of Saturn at 27 degrees.

I used the press you can see in these pictures to cut a clear plastic piece for Saturn’s rings.

You can see here that I masked the plastic ring and painted on some black and gray rings.

Here the small steel pins are cut to length and inserted into Saturn for the ring supports.

In order to hold the rings to Saturn I first trimmed the support rods and then used dabs of glue to set the rings into place.

As a finishing touch I added some adhesive felt pads to the base of the Orrery.

The Orrery is now complete. Here are the inner planets in closeup.

And the whole Orrery.

Another view.

This project has been a lot of fun. I started back in the beginning of April, so a little over seven months to complete. I wouldn’t want to guess the total hours, but I am sure it is over 200. I hope you have had as much fun following along, or if you’ve arrived after completion, I hope you find this helpful for your own projects. To see a complete video go back to the top of this blog and click on the You Tube link.

Back to top