VEX High Strength Pillow Bearing

Our VEX U team is in need of a pillow bearing (please see attached picture) that is used for the standard low strength shafts, but for high strength. As VEX doesn’t make them directly, it will require some modifications to the existing LS pillow bearing. Just curious rather or not someone has done some modification to the existing part in order to make this work. Let me know if you have a fix for this.
pillow bearing

I would not recommend this as there would be very little material left on the pillow bearing and the structure would become weak. I would recommend using a piece of half-C or C channel and drill out a hole to the correct size to fit a high strength Axel. At this point you can Mount it however you wish and it should replicate a pillow bearing fairly well.

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I can confirm from firsthand experience that this isn’t the best way to do this. What Zack suggested should lead to a much better build quality overall.

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You can 3d print in VexU, right? I wonder if anyone has a blueprint for that.

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I honestly can’t think of a material that would be strong enough and still have a low friction coefficient. PLA would break easily, as well as ABS and PETG. TPU isn’t rigid enough. Nylon might be strong enough, but you need either a higher end printer or an upgraded lower end one which many people don’t have access to. Maybe print something to insert a bearing into, but to print a bearing would most likely end poorly

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You can print nylon with a sub $200 printer if you’re smart about it. You just need to be ok with lower end after market products. If you want to see resourceful nylon printing, then look at hobbies like combat robotics.

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you could always take on the even more difficult, but perhaps better results, method of printing a ball bearing.

I know someone did a HS pillow bearing for the online cad challenge.

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Yeah, I’m currently working on a combat robot of my own. You can definitely get it cheap, but it still requires personal labor and time to upgrade the printer instead of getting the bot working with the resources you have at hand.
With my ender 3 pro it still took a couple upgrades to get it to print Nylon, and it takes practice to get actually solid pieces as Nylon is a tough thing to print with lower end printers. I think for this application it’s a decent amount of with for little benefit.

I’ve honestly thought about doing something similar. Would work really well for items such as fly wheels and anything with higher RPM. For this particular instance though it might be overkill to the point of wasting time.
It would be cool though.

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I’ve got five different 3-D printers, so I’m good with printing it. This is some thing that I wanted to do but wasn’t sure about how accurate my modification to an existing STL would be. That’s why I was asking whether or not anyone else I tried this, to avoid any issues.

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I’ve never actually used a 3d printer, so it was just a theoretical thought. :slight_smile:

Here’s a link to a challenge posted with HS pillow bearings like @Robo_Chicken mentioned above; I guess they did do a 3d print, and it looks pretty nice!
https://challenges.robotevents.com/challenge/112/entry/7586

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use onyx, it’s very strong (though i don’t know about friction.

Dude do you not know that one roll of onyx filament costs 230$, and the markforge printer costs 4500$. However, delrin can be a possibility since it has very low friction, while still being reasonably strong.

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Yes, onyx printing may be expensive, however, working with Delrin will most likely be more expensive. You see, the only method I see viable is injection molding or 3D printing. I’m not an expert in injection molding, but after a quick search, I’ve seen prices ranging from $1,000 to $5,000. Although this may seem a bit cheaper than printing with Onyx, in the long run, Onyx will still be a better choice. As for 3D printing Delrin, my friend here explains the complications of 3D printing with Delrin quite well.

TL;DR: Delrin and Onyx are both expensive, but Onyx will be cheaper in the long run.

Of course, you could just get a block of nylon, or maybe acetal, and machine the bearings from solid…like we used to do before 3d printers existed…

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At what point though does this become overkill for the given purpose? People achieve this very goal in VRC all the time with good results just by using a piece of c-Chanel with a high strength bearing on it.

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