I purchased this antique analytical balance. An analytical balance is designed to weigh very accurately, usually to 0.0001 grams. It is glass enclosed to prevent air movement from causing errors in measurement. In the old mechanical types,weight can be determined remotely through the use of outside levers and slides. This prevents air movement from effecting the measurement.
This unit appears to be fairly old, I suspect sometime in the 1920’s or 1930’s. It has a beautiful dark wood frame and internal components made of brass.
It was fairly dirty and missing some pieces.
I was able to find a similar scale at Beckort Auctions that was missing fewer parts. It was not the same scale but does have a similar construction and is made by the same manufacturer. The auction piece does show the missing balance piece shown below.
The scale along the top would have a weight resting on it that could be slid back and forth with a remote brass rod that slides in and out above it.
The plan is to restore the pieces I have and then fabricate a balance section from both new and vintage pieces. I plan to make the balance section in a steampunk style.
The first part of the process is to remove the black obsidian base and mechanical’s from the wood frame. The glass was also removed.
Someone had previously stripped the varnish from the wood, but when I took the sections apart there was still some varnish left on the joined surfaces. This I stripped, then sanded all of the wood surfaces.
Some of the wood screws that held the frame together broke off inside the wood when I tried to remove them.
I used a brass tube mounted to my drill to extract the broken screw pieces.
Wood dowels were then placed into the resulting 1/4 inch holes and glued in place.
I then machined the surfaces flush on the milling machine.
The balance is now completely disassembled and the wood sections repaired, stripped and sanded.
In the top of the balance is this slide mechanism. It’s purpose is to allow the movement of a weight across the scale on top of the balance. The slide allows this to be done without opening the front door, eliminating errors caused by air movement.
Above is a closeup of the slide. Below, the brass pieces after stripping, sanding and polishing.
The frame is then reassembled. Some parts of the brass slide are integral to the frame and can be seen in the reconstruction below. The frame for the front door glass piece is not seen, but is designed to slide up and down in the groove on the front of the piece. The top frame has not been replaced in this picture. The top frame was missing the glass pane. Presumably this had broken at some point. I will need to get a new piece cut before my balance can be completed.
All wood surfaces are then re-varnished. The wood is most likely mahogany. It has a very rich dark color after varnishing. No stain was used.
Below are pictures of the bottom of the balance.
This is a lift mechanism. When the knob on the front of the unit (seen in the picture at top right) is turned it lifts the balance and weighing trays. In practice this essentially turns off the balance. This allows the weights and item to be weighed to be placed on the scales trays. Then after the door is closed, the lift can be released to allow the scale to balance free of air movement.
This is a closeup of the cam rod and front rod removed. This is turned to lower the lifts and tray supports when weighing. Note some of the screws that held the frame together. You can see one broken one in this picture.
During the cleanup and painting of the cast iron piece that holds the release mechanism, I dropped the part, braking off a small piece. Since this is required to both hold the cam shaft in place and allow it to be limited to a 180 degree rotation it needed to be repaired.
The first thing I did was to machine a relief for a permanent clamp that would be installed. This clamp will hold the broken piece in place.
A clamp was then machined from 1/4 inch brass square rod.
Finally, I used the clamp to glue the broken piece in place with a military grade epoxy.
In the restored unit I placed the clamp onto the repair permanently. This probably wasn’t necessary as the glue joint is bonded with a 4500psi adhesive, but better safe than sorry.
The obsidian base was then cleaned and prepped for reassembly.
The bottom of the unit has three legs. This one is the back peg leg.
It was wire wheeled, polished and reinstalled.
The two front legs are made from these brackets, with knurled screws. These allow for the leveling of the scale.
The brass nuts and brackets are shown here after cleaning and polishing.
The base and legs are reassembled and attached back to the wood frame.
The cam shaft and lift mechanism is then reattached. You can see the brass clamp I fabricated holding the repaired cast iron in place in the center of thebase.
The front door slides up and down. This small brass handle is used to facilitate this. At right it has been cleaned and polished. Below it is attached to the door frame.
With the outside frame and base completed, it is now time to move on to the mast and lifts that will ultimately support the balance section.
The mast and lifts are made from brass that has been painted black. The small brass point on the base of the mast (left) is a pointer that is used to level the scale. A plumb bob dangled from the top of the mast is lined up with the pointer by adjusting the front leg heights.
After cleaning you can see that the paint is chipping from the brass.
Paint stripper was used to remove the paint from the lifts and mast.
This is a side by side view of the two lifts. The one on the left is just stripped, the one on the right is also cleaned and polished.
This is both lifts ready for assembly. These will lift the missing balance piece when the lift is engaged by rotating the knob at the front of the unit.
Pictured here is the mast after stripping, cleaning and polishing. The center section was re-painted black.
The mast and lifts are then put back together.
Then mounted back into the base and frame.
These wood strips hold the glass panes into the frames. These were sanded and varnished.
The panes are then cleaned and re-installed. I used brass round head screws to hold the mounting strips in place. The top glass pane has not yet been replaced.
Here counter weights have been put back into the unit. The strings are threaded though the pulleys. They will be attached to the bottom of the front slide door.
This is a close up of the metal plate that covers the right side counter weight. It has been re-painted after stripping and sanding. The left looks the same.
The restored unit with the front door closed. The two brass holes on each side are for small posts that will rise up when the lift mechanism is engaged by rotating the knob on the front. This lifts the weighing trays removing tension from the balance.
With the front door open.
Before moving on to the fabrication part I cleaned up the hangers and weighing pans. One hanger was pretty bent and needed to be straightened. These weighing pans are supported, when the lift mechanism is engaged, with brass posts that lift up. These will need to be fabricated.
That’s all for now. The next step will be fabricating the balance and steam-punking it up a bit. Making the lift rods for the pans as well as the plumb bob for leveling are also on the agenda. The glass pane for the top frame needs to be purchased and installed as well.
When the weighing pans are in the balance they are located over the two brass wholes in the base.
There are supposed to be lift rods with pans attached that lift the weighing pans when disengaged.
I decided to fabricate the rods from brass stock.
These insert into the holes and lift up and down when the knob on the front of the balance is turned. For the lifting pads I used antique brass clock gears.
The gears were each drilled in three locations for the contact points under the weighing pans.
Brass nails were soldered into each hole.
The nails were trimmed and the brass pads were attached to the lift rods using 6-32 brass screws.
With that completed it is on to the leveling device. This brass point on the base of the mast is for leveling the balance.
A plumb bob/pendulum is suspended from the top of the mast. The adjustable front feet are used to get the pendulum to line up with this point. When they are aligned the scale is level and will weigh accurately. The pendulum was missing when I purchased this balance. I fabricated one from brass rod.
The top of the pendulum was turned down and drilled.
A metal spring round was inserted into the hole to provide a tie off point for some black thread.
The thread was inserted into a hole in a suspending rod at the top of the mast. The thread is inserted through a hole and notched into a slot in the rod. A brass screw acts as a weight to help keep the thread from slipping.
At the bottom the thread is tied through the spring round and the pendulum is suspended above the leveling point. By adjusting the front feet the pendulum can be made to line up with the leveling point at the base of the mast. The balance is now level.
Here is a picture of the balance so far, with the weighing pan lift pads and leveling pendulum in place.
Next will be working on a fabrication project; the balance piece itself.
I will use this picture as a rough guide for the balance piece. I hope to find some vintage and antique pieces to use in the design. My plan is to make it a bit more steampunk than the balance piece pictured above.
I have been working on the balance piece over the last weeks. I started by making the scale that runs along the top of the balance. For this I used a 1 inch by 0.09 inch brass strip cut to length.
Using the mill I was able to accurately mark 20 locations along the bar.
There are ten marks each away from the center. The two outside marks will be directly over the pans when they are hung on the balance. A 0.1 gram weight resting on the top of the beam will add 0.01 grams per marker when it is slid along the balance. If slid to the right it will subtract 0.01 grams per mark.
A 1/4 inch by 1/4 inch brass rod was cut to length and will serve as a support for the bottom of the scale.
The base was milled to fit the scale section.
The base was mounted to the scale with screws.
A quarter inch steel piece was used to make a jig that will allow accurate indexing for labeling the marks on the scale from 0 to 10 from the center each way.
A small slot was milled into the piece that fit the number stamp.
This slot will just fit the number stamping tool shown here.
The jig is clamped into place and the stamp is inserted into the slot.
A hammer is impacted onto the stamp allowing the numbers to be imprinted into the brass.
The numbers are changed after each stamping. This picture shows the scale with all of the numbers imprinted.
This picture shows the eventual location for this part.
A fulcrum for the center of the scale/balance was cut from one inch round 303 stainless.
The fulcrum will be milled from this disk.
A 1/4 inch slot was cut into one side of the disk so that it can slide over the 1/4 inch brass base of the scale. A small hole was drilled and tapped that will allow for a set screw to hold the fulcrum in place.
This is the partially completed fulcrum held in place on the scale with a brass set screw.
The fulcrum piece was milled to provide a 1/4 in section in the center.
This 1/4 inch section was then milled to a point.
The balance requires a mount for the pointer which extends down from the balance piece to this small indicator.
In the original scale above you can see the V-shaped piece underneath the fulcrum with a black rod extending vertically below it that is this pointer.
For my balance I will use a section cut from this copper ring to support the pointer which will extend downwards below the fulcrum.
A paper pattern was used to mark the copper ring for holes that will line up with the scale base mounting screws as well as a hole that will be directly below the fulcrum.
This is the copper ring with the two holes drilled mounting it to the scale base.
In this picture the copper ring has been cut to the proper length and a hole drilled below the fulcrum that will ultimately support the pointer shaft.
Here the balance is set with the fulcrum resting in the proper location. The pointer support is underneath ready for the pointer, which will be the next piece fabricated.
It has been a few weeks since I last posted, but I have not been idle. I’ve been working on and have completed both the pointer shaft and the hooks for the weighing trays. I still plan to add some Steampunk elements to these when the scale is mechanically complete.
The brass rod in the picture next to the balance shown here was used to make the support for the pointer shaft.
The brass rod was faced and cut into a disk.
The disk was drilled and tapped so it can be attached to the copper arch of the balance piece.
The disk was then drilled and tapped perpendicular to the center.
In this way the pointer shaft can be threaded into this disk.
A 7/32 diameter inch brass rod is used for the shaft. One end is threaded to the 6-32 thread size of the disk fabricated above.
The shaft when mounted not only act as a pointer, but also stabilizes the balance when it rests on its fulcrum.
This black pointer was salvaged from my box of antique clock parts. It is one of the hands from a clock face. I used it as the pointer end of the shaft.
Again a piece of brass rod is cut and tapped. In this case the perpendicular hole isn’t tapped but rather drilled to the 7/32 inch diameter of the shaft. The other threaded hole is used to both add a set screw for holding the disk to the shaft as well as a screw to mount the clock hand pointer.
Here the pointer has been mounted to the pointer shaft.
This picture shows the pointer after the balance has been set on its fulcrum in the scale.
The picture above shows the brass mounting piece for the number scale I made earlier. The scale has been removed so I can drill holes in the ends of this mount. These holes will are used for attaching mounting clips.
The mounting clips are made from small 1/4 inch brass pieces machined to the correct size.
Each side will be L shaped.
Here one of the pieces is held in place while it is soldered together. The bottom two brass pieces are the clip. The other two pieces of brass are just spacers fro clamping.
After soldering each piece is drilled and tapped so it can be screwed to the balance.
The clips are shown here mounted to the balance in there final location. The open space is for the rests that the lifts make contact with when the scale lifts are raised.
The hanger hooks for the trays are made by cutting and bending some 1/4 inch brass strips.
A notch is cut into each hook where the tray hangers can be slipped into.
The clips are drilled and tapped a second time so the hooks can be attached to the balance beam.
These are closeups of the left and right hooks and clips after placing the whole assembly back in the scale.
In this view trays are seen hanging from the hooks and everything is mounted in there final locations.
This is a top view of the balance resting on its fulcrum in the final location. The fulcrum floats so here it is not aligned. When the lift rests are in place they help straighten this out before the balance is released.
A closeup of the progress so far.
This is another view.
The last mechanical pieces that need to be constructed are the rests that the lifts connect with when they are raised. These pieces also have counter weight nuts that are used to center the balance when no weights or test pieces are on the scale.
I’ve been doing quite a bit of work over the last few weeks. I started by making the cross pieces that are mounted perpendicular to the beam. The lifts impinge on screws in the cross pieces that allow the whole balance piece to be lifted off the fulcrum when turned off.
The cross pieces were cut from quarter inch brass rod. The ends were drilled and tapped to allow screws to be inserted into them. These will hold decorative pieces later on.
The cross piece is drilled for mounting to the beam. The center of each piece was milled with a one quarter inch notch for aligning with the beam when mounted.
Each cross piece was drilled and tapped in two locations for inserting the ajustment screws that are set so the lifts impinge on each screw at the same time when lifting.
Each cross piece was mounted to the beam by screwing it to the brackets that hang under the beam. These were made and soldered together earlier in this blog. Counter sunk allen screws were used for mounting.
This picture shows both cross pieces mounted to the beam.
This is a top view where the four temporary adjustment screws can be seen.
In this picture you can see the adjustment screws impinged on the lift when mounted in the scale.
These points were machined on the lathe.
The non pointy ends were machined smooth and then tapped so they can be mounted to the adjustment screw ends.
One point is made for each adjustment screw. The lifts impinge on these points centering the balance when lifted.
Instead of using hex nuts I machined disks type nuts that match those used throughout the scale originally.
Small holes are drilled into each disk perpendicular to the threaded portion. These allow the nut to be tightened with a small metal rod. I used a 1/16 inch drill bit.
Finally each disk is threaded for use. I think I made about 6 or 8 of these total.
This shows the disk nuts used to mount the adjustment screws. I used 3/4 inch 6-32 allen screws in place of the brass for a cleaner look. The threaded brass rod seen extending from the balance is for mounting counter weights for centering the balance.
This is another view of the balance with the cross pieces and adjustment screws mounted. You can also see the threaded rods extending out from the balance for the counter weights.
This is the whole piece mounted in the scale.
Here the hangers are mounted and the weighing pans are hanging from them on the left.
Here the counter weights are machined from brass rod.
These are screwed on to the brass threaded rods that extend from each end of the balance. By adjusting these in and out the balance can be centered/set to zero when no weight is in either pan.
These large clock gears are drilled for mounting to the back of each cross piece as a decorative element.
Here they are attached to the back of the balance.
The beam is mounted in the scale with the large gears seen in the back.
Two smaller gears are added to the front of each cross piece for that Steampunk look.
So this is the whole scale so far. It is almost complete. A small weight (0.1 grams) still needs to be fabricated. This weight will slide back and forth across the beam. This adds or subtracts weight to the scale at 0.01 gram increments as it slides from number to number on the scale. I still plan on making some decorative pieces for the vertical pointer shaft. The last thing will be getting and installing the top glass window. This was missing from the scale when I got it. I’ve left this until last as the top being open allows for an easier time working with the scale.
I am finishing this project. There are just a few things that were left to do.
On top of the balance bar a small weight is added that can be slid between the numbers on the top of the scale. I made a 0.1 gram weight for this purpose from aluminum.
An aluminum piece is milled to a small size and then a notch cut into it to allow it to slide along the scale.
This piece is much too large at this point, but you can see the idea. The weight can be slid from number to number by the brass rod assembly from outside the scale when the glass door is closed. This prevents air movement in the room from from upsetting the balance.
At 1.4583 grams I need to remove a whole bunch of material to get to 0.1 grams.
This is a lot better but still 3 times the weight I need.
Finally success. I am within two ten thousandths of 0.1 grams. This scale just happened to be calibrated the day I made the final adjustments.
Sliding this weight to the left adds 0.01 gram for each number up to 0.1 grams when it is slid to 10. When sliding to the right it will subtract 0.01 grams for each number.
This is the complete balance assembly I created so far. The central shaft is a 11/32 inch diameter brass rod. To jazz it up a bit I decided to add a decorative wood element to this shaft.
I have these small wood scraps that I will use for the shaft cover. The two larger are ironwood. The small one is mahogany. The brass tube is 3/8 inch outside diameter, which just slides over the 11/32 shaft rod.
Each wood block is center drilled with a 3/8 inch drill so they can be slid onto the brass tube.
The longer ironwood pieces are used for the outside with the mahogany in the center.
The pieces are then glued, clamped and allowed to dry.
Brass end pieces are turned on the lathe. These will mount on each end of the piece.
One end part is soldered to the brass tube.
Both end pieces are then drilled and tapped for a set screw that will eventually hold the whole thing to the shaft.
The wood piece is then bonded to the brass rod with epoxy.
This 11/32 brass rod is used for making a jig to mount the wood to the lathe for turning.
One end is turned and threaded so it will accept a nut that will hold everything in place.
Star washers and the nuts on the right end along with the live center hold everything in place.
This is the piece ready for turning on the lathe.
The piece is turned down to the same 1/2 inch diameter as the brass end caps.
As a splash of color, grooves are machined in the piece and painted red.
Three coats of varnish later and the shaft decoration is complete.
I decided to change up the front decorative gears on the balance piece. These are spread out and used gears with spokes to make it all a bit more transparent.
This is the whole balance assembly that I fabricated in its final form.
A complete front view with the balance piece in place.
From slightly above.
And a side view.
The top window is still missing the glass piece, which has been ordered and should be ready for install Monday. Other than that I will be making a set of weights for the balance, unless I can find some antique ones on line. Very close to being done now.
Well this is the top glass plate that I had cut by a local glass store. It’s 1/8 double strength.
This is the glass just laid in place.
And mounted in place with the varnished wood strips screwed into the frame with #2 brass wood screws.
This is a back view, where you can see my reflection. The plumb bob is suspended from a thread and is used to level the balance.
Here we can see the completed balance from the front.
This is a closeup of the internal parts that were made. Here the front glass door has been removed so you can get a better view.
So the project has been completed. Check out the video I added at the top of this blog that shows how the Steampunk Balance is used. I have ordered some brass weights from eBay that I will be using with the balance. I also need to fabricate some 0.1 gram weights to complete the set and make a weight holder of some kind. I will add these to this bog when that is all completed.