Hello CD,
We are planning on manufacturing these gearboxes, and before we move into that stage I want a few more people to check them over. Let me know if you can find any problems with them. They are meant to be mounted using the vex pro WCD bearing blocks. The gear ratio on them gives us a 14.5-16 FPS adjusted speed depending on what combo of cims and mini cims we put in it. Here is a link so you can view and download the model: http://a360.co/2AH9G8T
That is all,
18sampson
The flange on the bearing of the output shaft needs to be on the outside of the gearbox, not the inside. That’s something I noticed on a quick once-over.
Why? It’s done that way it is so that the shaft is retained by turning a 1/2” hex down to a 3/8” round. I don’t see a problem with the bearing being on the inside, in fact, that’s how it’s done on all the WCP gearboxes…
If the flange is on the inside with the retaining ring where it is, then if your bearing block also has the bearing flange on the outside of the bearing block your shaft and bearings can just slide right out.
All in all, good looking gearbox design. While I am not a custom gearbox expert, I did notice one thing that gave me cause for concern. I would rotate the CIM mounting holes to give a larger clearance between the upper mounting hole and the first stage gear (picture below). The current alignment might be good enough to work as is, but for a gearbox I would prefer to have some extra safety factor in case that bolt were to ever come loose.
Good point. Will do. Maintenance and failure is important to think about.
Are you aware of brownout conditions with 6CIMs?
Will the plates be machined or waterjetted? If machined, check your fillets. You have some very tight or zero radius corners that cannot be machined with a reasonable size (1/4") endmill.
Machined, I went back and added all the necessary fillets.
You can also just not put on a retaining ring. If the shaft is lathed down, the gearbox plates sandwich the shaft together, and it won’t fall out. In fact, both the bearing and the shaft won’t fall out if the flange is facing toward the inside of the bearing. Like stated above, this is how wcp gearboxes are constructed, and it makes it much easier to both assemble and disassemble with fewer tools.