pic: REV Robotics building system

[Greg Needel]

Originally Posted by BJC

It seems to me that the x shape and the very thin material that allow for the nut pockets on all four sides make this extrusion very susceptible to twisting loads. I noticed above you advocated using this for an elevator. Currently, many teams prefer 2x1 rectangular tubing for an FRC-type elevator because (among other reasons) its resistance to twisting is highly desirable to prevent binding. While it is probably serviceable in shorter/low loading situations, in a game such as 2011 Logomotion where elevators where the full 60" tall I don't think this extrusion would function very well in place of 2x1.

I do think that this is a really cool addition to teams' resources though. With the sliding nuts on each side it could especially have FRC applications in rapid prototyping.

Cheers, Bryan

The profile is actually much stiffer in torsion than what you would expect, but yes a 2x1 would be be stronger. You nailed it, as the implementation of the system is game specific, as some time a bit of twisting is acceptable (light game objects such as 2011). If people wanted to use this with heavier or more stout assemblies you can do a braced 2 post lift style (which I think is actually more common) and where the twisting on the individual member is less of a factor.

I agree about the prototyping, there have been many years when even if our extrusions don't end up on the robot the flexibility to prototype with them is huge.

Originally Posted by sanddrag

How would this be accomplished with normal hexagonal nuts? Would you pre-load the profile with any and all hex nuts you ever intend on using, and let them float free until you do? Or would you need to disassemble bracketry on one end to add something more to the middle?

Generally speaking you would load the rails from either side with nuts, but another method I have tested is to cut a clearance hole (just over 3/8) in the channel where you just remove just the retaining flange and then you can drop them in. This almost has no strength loss (bending) and is easy to do with a cordless drill.

Originally Posted by JB987

Or perhaps an actual drop in t-nut would also work on this extrusion?

I have tested a bunch of t-nuts with the system and some work and some don't. Most 1" profiles use 1/4-20 hardware, where this system uses 10-32 (or 24) so the nuts are bigger than the channel due to the corner holes in the profile. There are some smaller t-nuts designed for smaller profiles that do work with the system. We are not planning on selling t-nuts but if teams find ones that work we will be sure to link them from our product pages so a team can use them if they want that feature. In the future if people really want a drop in t-nut we can investigate making one specifically for this profile.


I love all of these questions! Right now REV is just a small start-up who wants to bring value products to the community. We will always be open to feedback from you all to help make our products better.