Frame Material

[PaulHalverson]

Originally Posted by Tristan Lall

It's going to come down to the corners, in terms of structural strength and stiffness. What methods of joining and securing the corners are available to you? (Components for joining corners include rivets, tubing inserts, bolts, welds, gussets, 80/20 hardware, etc.; tell us what you can use.)

Not sure what you mean by tubing inserts, but we have access to everything else you listed.

Originally Posted by Tristan Lall

Also, what's your budget for the frame (roughly), and do you have any of the specialized tools needed for any of the above joinery techniques? Some methods will have higher costs, obviously.

We have access to a shop with welding materials, spare brackets and gussets, as well as some 80/20-specific parts, and enough room in our budget to order more.

Originally Posted by Tristan Lall

What wall thicknesses of tubing did you have in mind? Conventionally, most teams that use it use either 0.050 in, 0.063 in or 0.125 in wall thicknesses. This decision will depend somewhat on what you want to do with the frame, and what needs to be mounted to it. This decision will also have a substantial impact on the robot weights.

We've used .125" in the past, so that's probably what we'd stick to.

Originally Posted by Tristan Lall

The kit frame is a solid option, if you're interested in making use of its predefined mounting positions. It's somewhat less good if you have complicated machining in mind, or need something other than Ø0.25 in holes. The corner gussets are quite strong as well (but heavy).

We certainly like the simplicity and how easy it would be to mount things, but our main concern is structural stability. In the past, we've used 80/20 and aluminum square tubing and have still had the occasional problem with warping/bending if we get hit hard enough. We've included supports in our frame designs in previous years and are worried that with a weaker material (the kit frame) our problems would be magnified.

If anyone's used the kit frame successfully in the past, we'd appreciate tips or any data if it's available. We'd love to test, but this far into the build season we really don't have a lot of extra time. Are there any major flaws in using any of the three materials?