Bronze is indeed malleable. Interesting that it smooshed so asymmetrically. Was this washer sandwiched between two beefy flat washers? or was it pressing against the ball screw?
Deforming the middle of the aluminum tube suggests a strong off-axis crunch. If the nyloc jam nut catches, you can run a file across each of the 6 faces to reduce it a few thou. It doesn't need to be a tight fit, just a fit that won't rotate or skip past the keyring retainer at the top.
There was only one beefy washer, I'll put two around it now. Thanks for the tip!
I did recently bend a draw stud pulling a tapped sleeve from a hole that wasn't quite perpendicular to the rock, wondering if that could've done enough bending damage to the tube to lock the jam nut.
There was only one beefy washer, I'll put two around it now. Thanks for the tip!
I did recently bend a draw stud pulling a tapped sleeve from a hole that wasn't quite perpendicular to the rock, wondering if that could've done enough bending damage to the tube to lock the jam nut.
I’ve struggled with the nut jamming even in new tube. The dimensions are so close, and the ball screw is able to shift out of alignment which can cause the the nut to jam. Filing the nut like Greg mentioned helps. I’ve also played with adding a full nylon nut below the locknut. The nylon is slippery and helps keep everything in alignment.
When the hole is not perpendicular, using a spacer on the low side to make the pull perpendicular really helps. A knife blade/LA piton, or an old hanger work well for this. It will help prevent bending the drawstud, and on those off angle bolts reduces the force needed to pull them. I’ve also found getting a straight pull reduces the chances of the sleeve breaking and coming out in pieces.
I’ve since started using the washer from the hanger that I just removed (or the hanger itself if the angle is big enough), as a spacer to keep the tube perpendicular. One fewer thing to carry.
On Aliexpress, RBD Bearing and Mechanical Parts now has the custom threaded ball screw as a standard item now. It even has your same diagram pictured. I guess enough climbers have bought them that it isn't custom anymore!
I designed and 3d printed a handle for the doodad. I've only used it a couple of times but it seems to work just fine. The small screws thread right into the handle arm so you don't need nuts on them. If anyone is interested I can throw the STL files online and try to figure out the measurements on the screws + bolt.