This gear lapping tub is to help in lapping gears on a T-Jet chassis. When lapping gears things can get messy... so this little tool is to help reduce the mess and hold the chassis stable while lapping the gears.
I started with an Auto World case top.
Then cut from styrene the mounting posts and mounting post feet.
For T-Jets, the back mounting post is 1/2 inches long and the front mounting post is 5/8 inches long
I drilled holes in the mounting feet and glued the posts to the feet... trying to make sure the posts were perpendicular to the feet.
I then mount the chassis to the post before gluing into the top. This will ensure the posts are properly located.
Now I glue everything to the top.
The feet provide for more gluing surface and a stronger bond.
The chassis is mounted upside down to minimize the mess and also to make it easier to attach the alligator clips to the pick-up shoes when providing power.
Addendum: do not mount the chassis upside down. Attach the chassis right side up when actually lapping the gears.
Addendum 11/28/16: I picked up a train transformer to supply the power instead of the 9 volt battery. The transformer has forward and reverse as well as variable speed.
With the power supply upgrade I decided to up grade the tub to make it more convenient to use. I modified a pair of pick up shoes so that I could more easily attach the alligator clips on the outside of the tub. I also added two posts so that when the chassis is mounted in the tub there would be an electrical contact.
Below is the whole contraption hook up.
If you would like more information about lapping gears, you can go here.