Just got these parts back from Boston Scientific. Amazing job done by them.
These are for that drivetrain project our team said we were doing back mid-summer. After a lot of things delaying this project we finally have some progress. For most of the people involved (including myself) this is the first experience with CAD, and machining. It was very cool.
Parts themselves are for a 6 wheel 6 cim tank drive designed to test different gear ratios and spreads, for the most optimum field traverse time.
looks like your using the West Coast gearboxes, I milled myself the same pieces. Unfortunate, the chain we ordered hasn’t come in yet, a mentor ordered it awhile ago. However, On Thursday we ran it and I had SOOO much fun using only the two wheels that are direct drives to the CIM/ Gearbox. It is quick as heck!
Nope, there are enough blocks for 4 axles, the bearing blocks are the ones with the bigger holes.
As previously mentioned those are actually for a 1/2 20 bolt to be held for a tensioner.
It is a tapped hole for 1/4 20 thread. This coupled with the bolt and bolt holder create linear motion with the bearing blocks, allowing for tensioning.
Having only really looked into COTS options for WCD, I would appreciate if you posted pictures of the final product, or even in progress product, so that I could see where and how all those parts are being used.
Looks crazy schnazy, but also confusing to the uninitiated
Also, one thing that I might worry about here is galling on the aluminum threads in the blocks. It’s rare with aluminum, but it sucks to say the least.
Galling is cold-welding between your screw and your nut material (in this case the aluminum) because the oxide layer of the aluminum wears away (this is why stainless steel fasteners can be a bad idea, the oxide layer wears away and they gall even worse than aluminum) .
I’ve only had it happen to me once before, but it makes the screw pretty much impossible to remove save with a drill.
Some ways that you can prevent this:
drill and tap your hole for a larger size and use key-locking inserts to put in a nice steel thread. This solves all problems and is my preferred solution.
Apply a PFTE-based compound onto the threads (or powdercoat / alodize/ anodize the material). Also solves most of your problems
use coarse threads with a loose fit (not really practical here)
Failing making any changes to the part:
Don’t over tighten! Use a torquewrench and tighten to a low torque.
Tighten the bolt really really slowly. This keeps heat from building up too much.
