How do i make a high strength lockbar

How do people make high strength lockbars, i bought some from robosource but i want to make some myself.

You need a quarter inch square broach, as well as a circular drill bit of the same or slightly larger size.

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We had issues with “lock-bars” stripping from the torque and redesigned to us gears or sprockets to carry the force. If the gear can be mounted to the arm and a gear driving that gear, the force on the gear tooth is less than the torque at the axel.

You don’t need a broach for this. You can just use a dremel and diamond file and get it done very quick. A broach needs some kind of press (maybe a vice if it’s big enough) and is very expensive. I would not recommend getting one unless this is a task you intend to do very frequently

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Just wanted to make a distinction between cost quality and time. The Robosource products are in that sweet spot of high quality, and lower money so it’s not worth the time to make them. If you are into making them, buy a broach and make good ones. Plus the broach allows you to put square holes in other things. So in the long run it may be cheaper to buy the broach and do things right all the time. Or buy their quality parts.

I worked in an environment that was driven by the three parameters “good fast cheap” or “quality time cost” You get to pick the two you want to control (I want good and get it fast it’s not going to be cheap)

Good luck on making your own, post pictures on how you made out!


i was going to make it for a c channel and not with flat metal, im probably gonna do it with a dremel

no idea how you would go about drilling a square hole with a dremel. I’d recommend buying some robosource lock bars, drilling our your c channel hole to be larger, then screwing some lock bars on either side of the c channel.


One other thing that I have seen done is to take a square file and slowly widen the square hole on the c channel. It isn’t very efficient, it’s hard, and it takes forever, but it gets the job done.

Something like this, but a little smaller should work.

Once again, this is not the best solution by a long shot, but if someone doesn’t have access to a broach, this is an alternative that I’ve seen work.


Here’s how they are made for High Strength Lockbars | Here's how VEX Team 3547: Virus makes high-strength lockbars. We'd like to thanks our corporate supporter Hassay Savage for donating the 1/4" square... | By VEX Team 3547: Virus | Facebook


Personally using a flat pattern file haS been the best solution for me. It takes longer but is much more precise. Make sure you do the measurements and mark how far you need to expand on each side and file till you reach that point.

Drill a 1/4” hole with a drill and use a a small Tungsten carbide burr bit in a dremel or a file to grind away the corners. Easy and precise

Wait are you guys the robosource suppliers for lockbars?

Yes, volunteers from our U-Team do it as a fundraiser.