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chip updates: step-by-step fixing the gearbox [updates]

So yes, we're actually going to post this because I think it'll help us understand what the problem is and where it actually comes from. And then, how to properly prevent it from happening. I actually do think there might be too much space in all of the gearboxes on chip but we aren't going to fix all of them today just the one that desperately needs it. The one that's so bad it's doing this:



Initial guess is we cracked a spacer and now the motor is no-longer biding to the planetary sun gear very properly, so the whole box is slipping and making a lovely and very dumb noise. This whole problem essentially started when we tried to use a NEO with the Versa-Planetary boxes, the issue here is that the NEO's shaft is just slightly too long for the versa boxes by about 1/8th in, and instead of cutting it we tried to put in a shim that wasn't exactly the right thickness, so we made it a little too thick. We're going to fix that today by finding something that IS 1/8th inch and using the smaller screws to put the box together instead of the bigger ones. I think we're only going to need to touch the motor not the rest of the box. For sake of consistency, we're going to likely dis-assemble everything anyways (part of that box).



So the first thing I noticed when taking apart this gearbox is when we unscrewed the motor a little it started moving around even before both screws were out which suggested that the gearbox wasn't put together properly (the motor wasn't connected to the gear). And we were right when we opened up the box the gear was on the side not connected. Oops.



But I also sense that the insides of the box are loose/coming apart so what we did was disassemble the whole box and clean it because of how oily the box is.



More images of the box disassembled on the cart. Ready for cleaning and re-assembly.



But we noticed something else. When the box went back together there was still a small gap where the CIM adapter connects to the box, and we realized that's because we've been missing a part on these boxes for some time now. Notice the extra black screws in this box as opposed to the original. Tightening these keep the box very compact.



Turns out the key fell off the motor shaft as well - Murphy's law everything that could've gone wrong with this box, did go wrong. So we replaced that with a few taps of the hammer.



Here's the gearbox fully re-assembled. These things are a real pain to get together. Mostly because of the screws holding the motor on.



As you can see from the above two photos we replaced the two laser cut spacers with a single one and the 3/4" motor bolts with 1/2" ones. This got rid of any extra spacing that was causing the gearbox to slip. We're not doing this for all the boxes right now, but we'll do it for all of them as needed.



Here's a picture of the final, fully-assembled leg and with the covering on. We tried rotating the leg by hand and everything felt good. The real test will come tomorrow when we take the puppy off the stand and make him stand up.


#updates #omgrobots #yay #chip #mechanical_fixes #get_greasy

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