pic: Linear bearing rails: the Cheesy RAWC way

[thefro526]

I've always looked at the 254 and 968 elevators and wondered how'd they do that. IMO it looks like the best way to do an elevator if you can machine the bearing blocks and if you can weld the aluminum. We used 80/20 the is year an it worked great for use but I noticed that the pads had a tendency to sag at full extension towards the end of the season. Also 80/20 is some heavy stuff (and that's putting it nicely ). Did you notice that the teflon pads wore down on your old elevators after a lot of use? I'd really like to experiment with an elevator like this and it seems like the teflon pads are a more feasible option for us.

Thanks a lot for discussing your designs here as well, I know 254 and 968 and even 60? when they were with 254 back in the day have inspired more robots then you'll ever be able to count.

[=Martin=Taylor=]

Originally Posted by JesseK

I think it's actually alot easier than most people think to keep things square and precise while welding. The biggest success we had this year was the fact that we had a perfectly square and flat frame on the first try. Our student build team captain took a bit of time to consider everything that was needed before welding and came up with a plan for manufacturing the frame. We didn't start welding until I and (more importantly) the professional welder at our sponsor approved the plan.

When we welded our drive train frame together, we also brought in threaded rods that matched the axle holes and a bunch of nuts to fit the rod. We then spaced out the frame on the rods and welded the outer rails to the rear cross support. Then we used precisely-cut wooden blocks as spacers, and clamped the inner rail to the outer rail with the spacers in between. We measured diagonals as well as across the gaps before we welded, then after we spot-welded, then again after the final welds. Since the rods and spacers were firmly in place, the frame could not bend/warp.

I think the key word here is "professional welder," I could best be described as a "professional n00b" seeing how all I weld are the team robots...

Thanks for the tips though. We'll keep that in mind if we ever do it again.

[sdcantrell56]

Were the bearings attached with simple bolts or shoulder bolt? If you just used plain bolts then it would be much cheaper.

[Travis Covington]

Regular screws with nylon washers so the outer races could spin freely.

[sdcantrell56]

I was hoping regular bolts was the answer. That will make things much simpler.