TBDCNC Belt and Z axis upgrade issues

I will start this by saying this is 98% my fault!! lol

I got my CNC (750x750) in mid 2019 and I got these upgrades from tbdcnc at the end of 2019. Due to personal issues I was not able to mess with it till now.

The upgrades I got from tbdcnc was their 2" risers, Y stiffeners, motors, 9mm belts and Supergrade DirectDrive Z Axis.

I have completed the risers and the stiffeners, and that went well

Now I am working on the belts and motors and where I have come into an issue. On the 2 Y axis’s the idler rollers everything went fine - no rubbing or anything. When I put the rollers inside the X axis carriage the idler rollers rub and rest on the X rail (you can see this in the pic)

I looked at the install instruction found here and I see some discrepancies in what I have. This could just be time and improvements made while I had parts in the cabinet. But, my new idlers do not have a “detent” side but 2 “flat” sides. Mine also came with 1 washer and not 2.

I have tried swapping the idlers and get the same result.

I reached out to Luke via facebook last week trying to get the instructions that were removed from his site, but have not heard back yet. What are your thoughts on what’s going on here?

I also have no instructions for the Z axis upgrade so if any of you have the instructions or a good youtube please let me know. The youtubes I have watched are not real informative or they are not the same piece that reuses the inventable router holder thing.

Thank you in advance and thank you for reading,


Can’t you stick a washer in between the pulley and the spacer? You just want the pulleys to line up to the belt IIRC. I had an assortment of bolts, precision washers, wheels, and nuts that I bought in case I needed them…just to be on the safe side since parts can sometimes be screwed up.

Thank you for the response Martin. I did try moving the washer to the inside then back to the outside of the idler but it still rubs on the frame. If you look at the second pic, you can see its rubbing on the rail itself… Almost like the idler is to big? I am fixing to reach out to inventables and see if they would be willing to sell me a set of idlers for the 9mm belt and just forget about the ones provided by tbd…
I started this project on Thursday and im tired of messing with it :frowning:

Thank you, Drew

Is the outer diameter of the pulley larger than the others? I wonder if you could chuck it up in a drill and sand some of the outer rims down?

Martin, thank you for your responses. I ordered the new rollers from inventables and we will see if that works. I will keep you updated. Thanks again, Drew

Martin, thank you for all the help. I got the new rollers in from inventables and they did have a smaller diameter. I have finished putting it together and have been able to set up the new machine. Looking forward to getting it back in the shop and running a program or two. Come on warm weather!!!

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