pic: 159's innovative bearing block system

[Monochron]

That's an awesome idea. Have you found any issues with the blocks drifting slightly and loosing tension under rough play? My team years ago decided to mount our drive train on 80/20 and ended up dealing with the mountings sliding along the crevices and loosing tension.

[Chowmaster4695]

Not really necessary or worth it when you can buy this and a bearing block to do the job...

http://www.vexrobotics.com/217-3431.html

Save your resources and time. Its money. Chow out

[Jared Russell]

I am a big fan of this design. Very clever packaging within the structural member for an 8WD. Cam tensioners work well (see my team affiliation), but aren't always the best choice depending on the other constraints of your design.

[Exla357]

Originally Posted by Monochron

That's an awesome idea. Have you found any issues with the blocks drifting slightly and loosing tension under rough play? My team years ago decided to mount our drive train on 80/20 and ended up dealing with the mountings sliding along the crevices and loosing tension.

No issues with movement. Kind of hard to see, but the blocks are secured with pretty large bolts. (As an electrician I have no idea what kind/size they are)

[Monochron]

Originally Posted by Exla357

No issues with movement. Kind of hard to see, but the blocks are secured with pretty large bolts. (As an electrician I have no idea what kind/size they are)

Ah, I see. The change in tension is not dynamic for play on the field, it is used for loosening when you want to work on something. Nice.

[Jeffy]

Originally Posted by Monochron

That's an awesome idea. Have you found any issues with the blocks drifting slightly and loosing tension under rough play? My team years ago decided to mount our drive train on 80/20 and ended up dealing with the mountings sliding along the crevices and loosing tension.

Bolt tensioners like this are common in motorcycles. The chain tension provides a force which keeps the bolt from loosening.
80/20 is often a system that uses a clamping forces to hold the material in place which is different than how these blocks function.

[Michael Hill]

3138 went with a similar bolt tensioning system this year. We also opted to use helicoils (which I suggest). It's worked out pretty well for us so far (provided the drive base doesn't bend and the tension blocks haven't moved). It is rather touchy though. A little bit of rotation goes a long way.