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Daniel Gigliotti@danielgigliotti99dg· 612 viewsin General Discussion

Question about J1 tapered roller bearings

Hi there, I'm new here.

I was just looking into AR4 and following some build log on youtube. I noticed that two tapered roller bearings are used for joint 1. Some time ago I researched this for a personal project and read that a certain type of preload must be applied to tapered roller bearings in back-to-back or face-to-face configurations (as well as to all other types of bearings). I just wanted to ask out of curiosity if the preload in this case is guaranteed by the tight tolerance of the machined pieces or if it is not always necessary. I just want to understand and to, hopefully, become a better engineer.

Thank you!

Comment 5

Chris Annin

Hello, In the build manual page 67 shows tightening the tension screws that apply bearing preload. Please let me know if you have any questions on that. -Chris

Daniel Gigliotti

So there is a small gap between the two components and tightening the screws brings them closer?

Chris Annin

no the screws place direct pressure on the bearing center housing and preload the bearings. Im attaching a section view.

preload.jpg (//anninrobotics.com/wp-content/uploads/wpforo/default_attachments/1757624302-preload.jpg)

Daniel Gigliotti

Ok got it, thanks. This is very nice. Just out of curiosity, if I were to do something like this with a different material, for example PLA + heat set inserts, it wouldn't work because the tension of the screws will deform the plastic rather than preload the bearing, right?

Chris Annin

I would use PETG but it should work fine - its not that much pressure to preload.

5 replies

Photos