Adding Y Linear rails to Lowrider CNC

I had issues with my CNC wandering a bit and I wanted to increase the rigidity of the machine. I made some brackets out of 2in angle iron to attach the bearings. I might see if I can come up 3d printable upgrade but figured the angle iron would be strongest for now.

After mounting the linear rails I used the belt tension file found on Thingiverse and made it so I could mount it directly to the linear rails. I was hoping this would be an easy way to take the CNC on/off.

I should be up and running this weekend! If anyone is interested in the files let me know and I can upload them to Thingiverse.


The belt tension box at the box looks great! How are you fastening it?

Can you post a BOM? Any binding on the Y axis? Looks great!

Pls upload to Thingiverse and post lik.
Thank you

The Tensioner sits at the very edge of the linear rail keeping it there. There are 2 bolts on the inside of the print as well to keep it there. Im only using one bolt as of right now.

These are just the linear rails you can find on Amazon for about $100. I spent like $12 on 2" angle iron from Home Depot and a few extra bolts that attached to the linear blocks. I haven’t ran it with the motors yet. There seems to be some minimal binding as of right now but I also haven’t tightened/squared everything up yet so that could be it.

Do the ends of the rails have holes in them for alignment pins to allow running longer rails by butting two end to end?

Unfortunately not. The ones I got from Amazon didn’t include that but I dont think I would be going any bigger at least not for a while. I am curious to see how hard it would be to actually line them up with another set though. These are 1500mm / about 5’ long.

Ok. My table is 10 foot in length, so that would be perfect if I could get alignment between the two rails. I have a machine shop source for stuff, so you’re giving me ideas.

How much rigidity did it add to your Y axis? Would you say it “glides on rails”? lol

Here are the files on Thingiverse. Let me know if you run into any issues with it.

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I have seen rails before that have the alignment pin in them but I can’t seem to find it right now. It feels quite sturdy and rigid now. I have a video fo it sliding before I added the belts and it was pretty nice but I can’t upload it on here because of the iPhone video format. If you find me on Instagram I can send you an example of what it looks like sliding. @TwoToolDesigns on IG

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I just picked up a set of the round rails and you can remove the bolts between the round rail and the mount and offset the round rail by one bolt hole. Then when you butt up the next length you do the same thing and the split in the rail is offset from the split in the mount. If you do this over a few holes it will really help alignment.


That is amazing… I never even thought to do that when I just picked up the extensions for mine to run the full table. Thanks!

No problem, post a picture of your install when you’re done. I’m just brainstorming my mount between the cars and lowrider. I’m thinking there is a benefit of tying the cars together but I have yet to figure out a clevee way of doing it since the z rollers protrude inboard of the wheel mounts you can just use a long piece of angle. It might not be worth it but would take some flex out of those 3d printer parts.

I used two short pieces of angle for mine so that the gantry could rest at its normal height. It definitely keeps the side plates square to the table, but if one stepper doesn’t home reliably (which I’m having intermittent issues with), then the printed parts flex like crazy.

Yeah my plan was to pair these rails with the aluminium xy square tube design that another member came up with. Then ideally I wouldn’t have to worry about squaring the machine anymore.

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That was my plan as well. I even have the aluminum stock for that purpose. But, my CNC plans have changed a bit… The wife has approved some… upgrades… I’ll update my build thread as I go… The upgraded machine will be able to finish making the aluminum X/Z corners easily, and then my LowRider will likely end up with a friend.

Awesome! Looking forward to seeing some of these upgrades!

this mod to replace the wheels improve quality ?

found these 8’ versions…

I’m also curious to hear what the performance upgrade was for adding these rails?

Thanks for the thingaverse link…