Weight Keeper Construction
After Completing the Steampunk Analytical Balance I found that I needed some accessories to go with it. First, I found a set of weights on eBay. Second, was a weight tray that could hold all of the weights in an organized fashion. Then I needed a tweezers for lifting the weights and placing them on the balance. This post contains the an overview of how I made these three pieces. Starting with the weight keeper tray. The Steampunk Analytical Balance blog was already quite long. Moving these accessories here was a way to break up the post in a logical way.
I purchased these scale weights on eBay around $20. The set contains one each of a 1g, 2g, 5g, 10g, 20g, 50g and 100g weights. When I checked them on my electronic analytical balance I found the following weight errors.
Weight Label Actual Weight
The weights were all off some of them significantly. As I am trying to make my scale accurate to 0.01g I obviously have to make some adjustments. The 10, 2 and 1 gram weights were all a bit high in value. These are a fairly easy to fix by just sanding the bottoms slowly and checking weights as you go until the values line up with what is on the label.
My approach to the weights that were too low in mass was to drill and tap each weight.
Then I inserted a brass screw into the tapped hole.
This puts the weight slightly above the labeled value. Again sanding the bottom while checking the weight was used to adjust each weight to the proper mass.
This worked well for all of the weight except the 5 g. The head on this weight was too small to drill and tap.
For this weight I drill a 1/16 hole into the head end as before, but do not tap it.
Instead I cut and drilled a small brass disk. This hole is not tapped.
As a support I inserted 1/16 rod into the hole in the weight. You can see the small brass disk made in the right hand picture.
I then slipped over then rod far enough to rest on the weight head.
Excess rod I cut flush with the surface and crimped the disk into placeplace. Finally I sanded to the correct weight as the other weights.
The aluminum slide weight on the top of the scale can add or subtract up to 0.1 grams. This leaves some gaps with the set of weights adjusted here. In order to fill those gaps I made some small 0.2g and 0.5g weights.
These small weights I made by cutting lengths from brass rod to the approximate weight based on the density of brass and the volume of each disk cut. I then sanded these to the correct weight as I did before with the larger weights.
A 0.5 label is stamped into the weight shown above.
I did this for all the weights I made. Three 0.5g and four 0.2g were produced.
When I completed the adjustments, the weights were all much closer as you can see in the table below.
Weight Label Actual Weight
All of the small 0.5g and 0.2g weights were sanded to within 0.0002g of the stamped value.
The Weight Keeper Tray
I have not been idle the last few weeks. First, I finished a “weight keeper” that holds the weights that were modified or fabricated previously. Second, I completed a brass tweezers in a matching style that is used to place the weights on and off of the scale.
I have also been learning how to edit the videos I’ve been shooting for my website with my Gopro. To do this I am using “OpenShot Video Editor” which is a free open source piece of software. For more on this software check here.
I used it to create the new Steampunk balance over view at the beginning of this blog. Right now it does not have sound, but I plan to add a voice over soon. I also edited videos showing the making of the “weight keeper” and tweezers, which I will add here when they are completed.
For this project I started with three main pieces I had in my stash of stuff.
I had a 3 inch diameter brass spur gear. I also had the 4x4x1.25 inch block of beautiful rosewood. Some brass rod stock as well as brass sheet. I also needed various brass screws and fasteners.
I first used the brass rod to make a shaft that could be inserted into the gear. I drilled and tapped the end of the shaft so the brass gear and finial could be held to it. The weight keeper is designed to match the individual weights, so a matching finial was turned on the lathe. The weight keeper video goes into pretty fine detail as to how this was done.
The rosewood was first turned on the lathed to 3 inches in diameter and then drilled to fit each of the weights from 1g to 100g.
The base was coated with 4 coats of polyurethane varnish. I also added a small brass button between the weight holes. This allows the tweezer ends to rest on the base without slipping. I also used this as a spot to sign the piece.
Adjacent to each a brass label was added indicating the weight the hole contains.
Next up will be the tweezer fabrication. This will also have a video that will show the process in detail.
I actually finished the tweezer fabrication a few weeks ago. I have been working on editing several videos and trying to change the layout of the Technology Imagined website. I’ve also been taking a WordPress class in an attempt to make my website a bit better.
The tweezers was made from these brass pieces. Some 1/4 inch strips for the tongs and a 1/4 inch square for the head of the tweezers.
I started by making the head. A section of the 1/4 inch square was turned round on the lathe. The end was cut to match the finials on the weights and weight tray. The end was tapped for a 4-40 brass screw. This screw head will make the head end match the other finials and is not meant to hold anything in place.
I added some 1/8 inch grooves to the along the shaft and cut the head flat on the end. The grooves allow for a better grip on the head as well as provide an additional decorative element.
On the flat end of the head I milled in a slight arch. Just cause I liked the way that would look when completed.
Two holes were drilled into the end of the head. They were tapped to accept 4-40 screws. These screws will hold the tong ends to the head.
This is another view of the completed head with screws threaded in.
This is the head with the 1/4 strips lying where they will be mounted once they are made into the correct shape.
In this image the tong pieces have been tapered and drilled for mounting. I also initialed the piece on what will be the inside of the tongs when mounted.
Here the tongs have been attached to the head just to see how it looks.
It’s hard to see here, but a slight warp was bent into the tong pieces in a longitudinal direction. This warp stiffens the tongs giving the rigidity needed to pick up the heavier weights.
Side view of the completed tweezers.
Here is another view of the completed Steampunk tweezers for use with the analytical balance.
And finally all put together with the weight tray. I will be completing another video that will show the whole tweezer fabrication from the beginning. I am just finishing the edit for that now.