Quote:
Originally Posted by JesseK
22T Hex-bore Sprockets
We are using these in our drive train, geared for 12 ft/s. It's a typical 4WD WCD, with these sprockets transmitting power from front to rear in a 1:1 ratio. We've been hit hard twice, and both times had one of these sprockets eat itself a few seconds later while driving. It'd be nice if someone also offered a steel version that was hex broached. The first time we thought it was because the wheel block slid on the impact; the second time we verified that the block didn't move (so the chains were in proper tension the whole time).
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I'm pretty confident this is something caused by your design, not a defect or inadequate material. We have used 7075 22T sprockets for 7 years (of our own design, or from AM) with no failures whatsoever. 7075 is stronger than many steels, including some commonly used in sprockets.
Quote:
Originally Posted by JesseK
Hex Shafts
We got the hex shaft stock, then sized them for our WCD drive train. Found that the shaft isn't perfectly straight nor an exact consistent diameter even over short runs, meaning that it doesn't "just work" with the hex broached VEXPro items. Sanding down the corners helped. Could have been a shipping / temperature thing. We have had the same issues with every hex shaft stock we've purchased. Imperfections were on about 50% of the shaft length, so about half of our shafts still have their nice annodized corners.
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We have had the straightness problem with the majority of our hex shaft. We're almost 100% certain it is because it is shipped in a flat package that is extremely non rigid. A switch to round cardboard tube (like McMaster ships all shaft/rod/tube in) would likely eliminate this problem. We have not had issues with VEXPro gears sliding onto straight shaft though.