pic: 3 CIM WCD Ball Shifter Second Edition

[R.C.]

Originally Posted by asid61

We tried assembling WCP gearboxes. It took us around five hours to assemble two gearboxes due to some unforseen issues. It's a great gearbox design for teams with little manufacturing resources. But some parts, like the sping washers, are really annoying to work with if you have enough machining resources to make it fit properly.
Also, R.C, if you are reading this, there was a slight error in the instuction manual. A 1/32" spacer is explicitly stated to be a 1/16" spacer in the instuctions. Not sure if that's our problem or something wrong with the manual.

Assembly should take around 20-30 minutes a gearbox, we used 4 3 CIM WCD gearboxes this year.

I'm not a fan of the spring wave either, it'll be replaced out to a solid washer in the future here soon...

I'll take a look and your more than welcome to email me here. Please email me what gearbox you were using and which manual etc.. That way we can take care of the typo.

Thanks

[asid61]

Originally Posted by R.C.

Assembly should take around 20-30 minutes a gearbox, we used 4 3 CIM WCD gearboxes this year.

I'm not a fan of the spring wave either, it'll be replaced out to a solid washer in the future here soon...

I'll take a look and your more than welcome to email me here. Please email me what gearbox you were using and which manual etc.. That way we can take care of the typo.

Thanks

In the future I'm sure we could do it faster. First time is the hardest, I think.
I will shoot you an email just as soon as my team has its next meeting.

[Chris is me]

As others have mentioned, bearing bore gears and shoulder bolts will save you some weight and bearings. You can even bore out a smaller gear to accept smaller OD bearings.

It is non-trivial to ensure that the idler gears mesh with both pinions and the large cluster gear at the same time. While the outer CIMs can freely rotate, the middle CIM meshing with both idler gears will lock their orientation relative to each other, and if this combined orientation does not line up with the large cluster gear, the gearbox will not work. It is a lot less elegant to do it this way, but two motors on one idler and one motor on the other idler would be a bit safer and more tolerant of misalignment.

about the above - sorry, misunderstood gearbox initially. I see the gears on the right idler gear now, for some reason I thought another shaft was buried in there. In this case, I would just like to comment on the use of a 12T CIM pinion as an idler - this may not work well particularly if the pinion is aluminum. A lot of force going through a tiny gear. That's not to say it's impossible or not doable, just be careful.

Personally I like this design a lot better than the previous revision. The extra gear is a thing, yes, but the design is more symmetrical, compact, and in many ways simpler. Just seems more elegant to me.