Attaching Two Pieces of C-Channel Together By Their Flat Surface

What is the best way to attach two pieces of C-Channel together on their flat face? I’ve been working on a CAD model of our team’s robot and I can’t seem to find a way to attach them together as we are very close (about a half inch) await from the outside boundaries widthwise. I would prefer not to cut metal if at all possible.


Note: I am trying to attach the real life pieces together. I know how to do it in CAD but I would like real screws / metal to make it as easy as possible to show others my complete design.

there are pieces you can use … we use them all the time … link below …

they are called plus gussets …

simple cross them together and screw then together !

I know I’ve seen these laying around before. Thank you for the suggestion. Just wondering, how strong are they and do you use more than one?

I don’t really have a better way to do it because I am confused by your question but I have noticed that the + gussets are very weak.

I have a two pieces of C-Channel, one of them is horizontal for the drive train and the other is vertical for the arm. I would like to attach the horizontal piece of C-Channel to the vertical piece of C-Channel in such a way that it does not exit the bounds of the robot and also does not impede the movement of the robot.

So just to make sure, you want to attach a 5 hole wide C channel (the arm) to a normal width C channel (drive train).

Looking at your CAD, the easiest way would be to attach a flat plate on the outside, but problems might be out of size limits and not structurally sufficient.

To add on, you might want to try creating triangles out of C channels to increase stability.

Ideally, we like to put an L channel perpendicular across the 2 “wings” of our chassis (composed of 4 C channels) and use that as a strong mounting point for our towers. Also, instead of lining up the edge of our tower to the edge of our drive train, we like moving the towers inside the drive train so that we can attach them side by side instead of one above the other.

as long as you use a thew of them, they will be fine … but the only other thing i would do is bolt another piece of c channel to it …

The plus gussets are very weak. I have worked with them recently, and they got bent a lot :frowning:

I am still confused on what you are asking…

if you can can you zoom out a bit cause i think most of us are thinking if youre going to be out side the 18 what were mouting it to and if you mean the exact points of your arrows or just the face of metal that your arrows are pointing to

Do you have access to the Angle Coupler Gusset (8-pack)?

One side of the Angle will be on the Back of the Lower C Channel, the other Angle will be under the Edge of the Top C Channel…

One thing that has worked for me in the past has been creating a cross brace that spans the whole drivetrain. So basically, take a c channel or other metal and lay it across the top of the drivetrain metal (perpendicular, so it goes across the width of the robot. Then attach the arm tower to this, instead of the actual c channel on the drive. You can use standoffs to add clearance (such as for any gears or that 4" wheel visible in the CAD model.

Another option is to create a support with standoffs and collars. Attach a standoff pointing up from the c channel on the drive. Then, screw a collar onto the end of a standoff after removing the set screw, so the collar is attached with the set screw hole pointing towards the holes in the 5 wide c channel. Then using the smallest size vex screws, attach these two holes. This method requires lots of tweaking with spacers and washers to get the right spacing, and might be a bit of a tight fit (you might have to “force it” a little) but should be sturdy, especially if you use two of these standoff/collar supports rather than just one.

Both of these support systems are somewhat sturdy, but I would recommend adding a triangular support (if space permits) to really lock down the lift.

I hope this made sense. For the standoff/collar trick, look up some pictures of 24C’s recent robots that are on the forum, as they utilize this trick very masterfully and creatively. The support I described is not as extreme as the 24C application, but it should give you an idea of how to connect the standoffs and collars to be effective and get you thinking