Robot Weight Bracket

[Don52]

We needed to measure the stiffness of the waist axis of a robot. We have a bunch of 50 lb bar bell weights. I designed and fabricated a fixture that we can hang from the elbow of the robot to safely add the weights one by one while we measure the deflection of the joint using a LVDT type probe. We are only using one axis of the control so it reads " "error" on the axis we aren't using. I bored the hole for the 3/4" pipe because I didn't have a 1-1/16" drill and I didn't want the sloppy hole that my 1-1/8" drill would make.

Pictures:

1. LVDT probe
2. Facing eye bolt block
3. Center drilling eye bolt block
4. Tapping eye bolt block
5. Boring 1.050 Inch Hole

Don

[Don52]

I chamfered the upper weld on the 3/4' pipe so that the weld wouldn't interfere with the bar bells. In addition to the corner braces picture 9 also shows the weld symbols. I really like the swivel mast horizontal band saw to miter the ends of the tubing.

Pictures:
6. Using Ø1.5 drill to chamfer hole
7. Using swivel mast saw to cut tubing
8. Pieces Ready for Welding
9. Corner Braces and Drawing
10. Eye bolt block welded

[Don52]

I like to cap the end of the tubing because it looks cleaner.

Pictures:
11. Tube cap welded
12. Inside of corner welded
13 Outside of corner welded
14 Bracket all done

Don