Ok, it’s my first year doing anything with FRC, but I’m a bit of shock after looking up the price of shaft flanges on McMaster-Carr. The price of a single 1/4" shaft collar with a flange is about $45! I need a way to attach some shafts to some extrusion to make a simple rotating arm, and I need about 16 of them.
Is there anywhere I can go to buy inexpensive shaft flanges that clamp on and don’t just have set screws but that don’t cost more than the motors that drive them?
Also consider other options for the shaft–3/8" hex, for example.
Also an option, having done this on non-FRC stuff: Get a normal McMaster shaft collar, drill holes dead center on each half. Don’t do this for heavy-duty stuff but for 1/4" you may have a chance.
For non-load bearing wheels (like intakes) we just discovered that the Armabot F1 intake wheels also work as hubs for many FRC wheels. I am not sure how durable they are for drive wheels, but they do fit other things as well.
Are you using hex shaft? Hex shafts are a simple way to drive a robot implement without slipping. The Andymark hubs link above from @EricH is a great start if you are considering changing the shaft profile or size. If you are looking for a smaller shaft size you can go to FTC 5-6 mm D shaft or REV’s 5mm hex. Actibotics and GoBilda have a great selection including .25" round hubs. FindRobotParts is also a great place to start.
Also consider your approach to the mechanism. There may be a simpler design to achieve the same results. The Unofficial FRC Mechanism Encyclopedia – Project Bucephalus is a great source for inspiration. Spectrum Robotics 3847 also has a comprehensive list of robots in their FRC CAD Collection - Spectrum3847 - Google Sheets
Thank you. I am aware. Those are incredible resources that we spend a lot of time perusing. I was trying to answer the OP’s question. Each intake wheel is about 7 dollars and it comes in pieces (I think we even got one free in this year’s kit) The two outer pieces are each in effect 1/2 hex inch hubs.
However, they are plastic so I would not use them in a load bearing capacity for very long and expect them to survive. They were probably not meant to hold a lot of weight (unlike the versa hubs listed above).
Thanks to everyone, this is all great info.
Unfortunately, a hex shaft won’t work because the shaft needs to be in block bearings, but the idea of drilling through an aluminum shaft collar should work great, and those are only about $4 each.
($64 instead of $1024!)
It just boggles my mind there is no good cheap source for something as simple as a flange shaft collar, even if you did nothing more but then to make the $4 shaft collar in a slightly larger diameter drill three holes in it.
What are your machining capabilities?
Some options may include using thunder hex which has rounded corners to fit into round bearings
maybe depending on the application a 3d printed or machined spacer to let the hex fit in a round bearing. Also depending on the application you could machine the end of the shaft to fit in the block.
Instead of a flanged shaft collar we would have something (such as a wheel) mounted on the shaft with a hex bore and use normal shaft collars either side for temporary solutions and for more permanent solutions use Clips | McMaster-Carr. I like side mount clips because they don’t need special tools and can be put on in the middle of a shaft while everything is assembled.
Also what is your situation where you are using block bearings? Those are so rarely used in FIRST from what I have seen.
Thanks gobilda had just what I’m after! MOTION - Hubs - Shop by Hub Bore - 1/4" Round Bore Hubs - goBILDA They’re only $7 each. Thank you, thank you, thank you!
This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.
