Print in place hex shaft collar

my team was thinking on what things we need to buy for 2021’s robot and we saw that we spend a lot of money on shaft collars. so we decided to have a competition on who can design the best shaft collar for a 1/2in hex shaft.

this is my design for the competition, it is a 3D printed shaft collar that prints as one part and it has a few cool features.

  • it needs no tools for it to lock or release
  • it can be hinged apart so you can put it onto a shaft without disassembling everything that is on it
  • it is very small, only 25mm(1in~) in diameter
  • and it is much cheaper then the ones you can buy

video on how you use it

link to the thingiverse page for you to download the file: https://www.thingiverse.com/thing:4584540

i hope some of you will find it useful and use it on your robots!

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Have you done any testing to see what kind of loads it can handle compared to COTS shaft collars?

I have connected it to a shaft and spinned it at 3000 RPM and it did not open or move at all.
I can barely move it when it is locked even when i put all my strength into it.

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Were any axial loads applied to it? Would be cool to see something like a vertical shaft with a weight attached above it, spinning at relatively high speed.

It’s a really neat concept, using leverage to lock into the shaft and the snap fit quick release. Seems worth playing around with.

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This is a very cool design! Looks to be useful.

Any advice on printer settings?

Thanks!
I would suggest printing it in materials other then PLA as it will deform over time and might lose its holding power. Also this model does not use any supports.
The only other setting i will change is putting a lot of walls in the print as it will give it strength.

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Aviv, that is really nice! Good work and thank you for sharing!!

I can barely move when i put axial load on it with my hands, i have not tested it enough to have a numerical value on how strong it holds axialy.

This looks really useful for prototyping! Re:saving: We’ve actually saved a lot of money on shaft collars by using bolt+washer retention on shafts and tapping the end, which has also proven to be more reliable for us, but ymmv

We had the same realization and have used them for 2 years now. They close with an M3 Nut and bolt. Work Nice. Only problem is at the end of the season we got to mark them or throw them out so we don’t violate the rules in unsing them again the following years. I guess its the FIRST way of “recycling” them into a landfill

Why not use them for prototypes? I’m sure plenty of teams would be willing to take old ones for prototyping, if you have extras

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We used some for prototyping - Prototypyng is limited though especially now - Have not had any interest for sending anything 3DP to another team. A collar printed in HIPS or PETG is a little less than 1c a piece So it hardly pays sending them in the mail. We have printed some for competition for local teams like we printed HTD pulleys and other stuff but they discard it too as its deemed illegal to use in the next season. It happens with a lot of things that way - there is only so much you can use for prototyping. Like for example the rack and pinion. It worked so there is no more prototyping exept maybe going to the next iteration right now its on display in a case in a closed school. But there is only so much we can stick in the case. Even if we give something to another team they can use it this season (maybe this season is a bad example) and then never again except for something non FRC related. We had a prototype robot with reuseable frame pieces and some where used in 2020 about 25kg worth. We have a small room, only electronics for 1 robot thereabouts and so the plastic goes away and we have to print anew for the next season. Granted a lot becomes itteration N+1. So currently we can use the 2020 stuff for 21 as this is the endless build season it seems even if its 99% remotely. But then what do we do with all we printed that could be reused? Its the same with other teams that have machined parts. FIRST is not really interested in or even wants you to build something yourself cause if you do VEX, Andymark etc don’t make money.

In my experience working at a (really small) competition robotics startup, FIRST doesn’t particularly care about suppliers’ bottom line – the reuse rules as of right now seem similar to the bag, in that they’re antiquated rules designed to prevent teams from using robots or mechanisms (i.e. elevators) from prior seasons, but don’t actually help anyone

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IMO they should be done away with. This has been discussed plenty and FIRST will do what FIRST does. Lets hope we have a season this year and all teams survive

So cool. Great job! I want to integrate this design into gear and sprocket hubs.

What material is the example in your video made from?

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Also, what print settings were used?

I printed a few @ 100% infill with default Cura settings with PLA and all the shaft collar latches broke off when I tried to open them.

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What? You do realize that VEX and AndyMark are SPONSORS. FIRST does not frown upon teams designing and creating their own solutions to the game and robot mechanisms - in fact, it has been quite the opposite!

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My exact reaction. This is completely unsubstantiated. But I’m sure we could split this off to another thread if needed.

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Let’s just let is pass - I don’t think we need another controversial thread on CD!

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It is printed in PETG

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