This a preview of a project that I am currently working on with a friend. I wanted to post this so that I could start to get some feedback while this design is still fairly easy to adjust. Right now this is just the wheel module. It currently is using custom 3 inch wheels inspired by some of the swerves posted by 2451. The wheels aren’t necessarily final, I’m waiting on some manufacturing quotes . I was also looking into using a Delrin washer instead of the silverthin bearing (silverthins are expensive and i wanted to test a cheaper alternative). Speeds aren’t fully determined yet but working on a reasonable speed. Any feedback, tips or questions would be greatly appreciated.
If you are interested in seeing some cad here is a preview file on grabcad.
https://workbench.grabcad.com/workbench/projects/gcJuFRZHAS3ehZbzrpnKxExVxQVFIkSP5gs4xwZ6jUWMld#/space/gcDWxQkLFjtUNdqfVXati6c4-z52IKp6kLYHE1_m1FmOgf
(Side note: personal project not necessarily for the team I currently mentor)
Looking good.
Where are you planning to source the large bearing from?
Additionally, how are the two vertical members of the module (the ones that support the axle) supported?
The Large Bearing is the amazon link. I am looking at a lot of different options but so far that is the cheapest I can find. I am also planning to test using some delrin instead of the bearing when I manufacture this and see if that would work because the bearings are a tad on the expensive side for me right now.
The vertical members are supported by some tabs (its a little lard to explain). its visible in the grabcad but here is a quick screen-grab.
https://goo.gl/photos/B9AngPXZfVwvvCRT9
If anyone has tried something similar to this and has some side plate mounting tips or advise I would greatly appreciate it.
192 posted about their plastic swerve for 2017. The lower bearing was delrin. The bearing you listed is not sealed and if dirt causes it to bind at all it will cause more problems for your controls. Dirt in bearings can cause them to jerk that makes things harder to control.
I wasn’t sure if the bearings needed to be sealed. I was kinda guessing since the bearing was higher up in the robot that there would be less chance for debris to end up in it. I do have a sealed varient priced out for the same bearing but it costs $20 more. I can also try to work out a way to keep debris out.
Sorry in advanced for all the follow up questions but I never got the chance to talk to your team in person about your swerve.
How did the delrin work for your team? Were there any special considerations you made? I’m also a little curious as to if your delrin bearing was just a disc or if there was more special geometry to it?
Once again sorry about all the questions just I have some experience with delrin but not in this application.
I wouldn’t be concerned about dirt getting inside the bearing.
I WOULD be concerned with the bearing being a radial ball bearing, and not a thrust bearing. The primary force it would be subjected to would be thrust.
Its a x contact bearing they can take thrust loads. I’m not at my computer right now so I can’t post exact specs but it should be able to take the thrust loads applied by the module. Thanks for the concern. (I designed around an x contact bearing and I’m pretty sure that’s the one I linked if not … I may have some redesigning to do real quick)
Dirt in the bearing should not be significant for a bearing that large with the loads and RPM it’s going at. Shielded and sealed are better, but open can work fine as long as you’re not offroading.
Delrin can work, but I don’t know if it will work on this style of swerve with the bearing on one side. Maybe somebody else has done it.
If you’re looking for a cheaper bearing, 6812 or 6814 bearings might work. The 6800 series bearings are fairly thin and work well for swerve drives.
Where are you sourcing the large turning gear from? How are you going to gear another gear to it?
Thanks for pointing out those bearings I’ll look into those further. The large gear is being custom machined and not all of the bolts around the large gear will be there in the final gearbox. Some bolts will be removed for a gear to mesh into the large gear. The gearbox is still being worked on so I don’t have a lot of details about that yet.