DIY motorized camera slider

I built a motorized camera slider which I use for building dynamic timelapse. It's about 12 pound excluding my dslr camera. When you fly to different places(within U.S.) and you have a camera slider too, do you check it in or hand carry? Do you think they will question what it is?

Unless the slider can fit into a smallish backpack, I would find a hardcase for it and check it. You can check it at the ticket counter or, if you already have your boarding pass, you can check it at the gate. If you check it at the gate, you will have to carry it through TSA. If you check it at the ticket counter, you won't have to worry about it.

I have a traveling job. I fly a lot. I've seen some interesting equipment make it through TSA, so I don't think you'll have a problem. The stuff that hangs people up at TSA are things crammed into backpacks found by the XRAY machine, things like bottles of liquids and electronic devices. As long as everything is open for the staff to inspect, I doubt anyone will even ask you about it.

Checking larger items makes things less stressful as overhead bin space in airplanes is limited and competitive. If you carry a bunch of crap onboard, you don't want to get on the plane last.

I would find a hardcase for it, pack it with foam, and check it. But some people are more competitive than me and don't mind shoving other people's bags around to squeeze their crap into the overhead bin space. I only carry a small backpack on the plane with me, one I can squeeze under the seat in front of me. My other bags are checked. Either way, you'll get the slider through.

I'm back in the U.S.  I didn't have issue with the camera slider in the airport. I checked it in. I noticed though that during my vacation, my camera slider was a hassle to carry with me since it was heavy. I need to change the stepper motor and find something smaller. I also need to change the part of the slider that holds the rods. It's heavy. Thank you!