Cbeam z axis help please

Hi all! To those of you with a cbeam z axis, I’m having a slight problem with my build. The plate is secure to my router brackets, but Im getting toggle between the bearing/cbeam channel interface. I have made the tightening adjustments with the 6mm offset nuts, tightened and loosened bearing lock nuts, but still having problems :face_with_monocle:
Any suggestions?
c-beam z-axis toggle

It does look like the adjustment of the ‘off-centre screws’ that you tried already.
I was not successful in tightening the plate inside the c-beam with an allen-key. I had to take the plate out of the beam, turned the ‘off-centre screws’ with a wrench on the hex-part under the plate until the plate did not slide back in and went in tiny steps backwards until a little force was needed to get the rollers in the groves.
Not much help i guess, but if that does not work, it could be poor production tolerances.

Edit: I also tightened the self-locking nut with 3 tools, allen-key top, 1st wrench on the hex part (to be sure i don’t spoil the offset while tightening) and second wrench on the nut. Kind of 3 hands needed, but allen-key and middle wrench can be held with one hand.


@Gero thanks for your confirmation! I believe I received a unit with poor tolerances :smirk:
The only thing I can think of at this point is to have offset nuts on all 4 bolts/bearings. I think I will try moving the lower offset nut up to test if dual offset nuts will tighten it up. If so, I will just need to find a source to buy 2 more :crossed_fingers:
Edit: I will have to bore out approximately a 1.5mm deep, larger diameter hole on the front face of the plate to allow the bolt to offset. May need to rethink this.

Is the wheel just not in the right spot or slightly wrong size? It looks like the wheel itself has play in it, not even necessarily the offset nut. When my offset was wrong I had more twist play than in out play. I may just be seeing the video wrong.

Edit: Also, where did you get your C Beam from?

If this is from ‘Ali-Ex’ send the supplier a complaint, friendly asking if they want you to rate your purchase.
With a bit of luck and in 40 days :-/ you will have a second c-beam with a bunch of parts to replace.

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I agree, most places do not want a poor rating and in many cases they will send you a replacement or additional parts. I am also worried that if you try to have multiple of those nuts that your actual plate might start to be off level which would pitch your entire router. Potentially, not sure if it could or not but be careful.


@ChrisB and @Gero thanks for your help! I will send the supplier (aliexpress) a message. When I get home, I will check if there is play between the wheel and bearing(great point.)
Also, modifying the plate without precision machining is probably not the best idea. I have set the offset to the highest point and the bearings easily glide into the slots and is bot a tight fit whatsoever. I do think that the tolerances are off somewhere. Thanks for your help!!

The only other thing I could think of is maybe that gantry plate has been rotated 90 degrees? Sorry, Wish I could be more help.


Yeah, that’s not right, it shouldn’t do that.
You will have to take it apart to get the fit right, you cannot do it with the c beam assembled. It looks like your locknut is not tight, allowing the wheel to slide up and down the bolt. It needs to be tight, but not so tight that the wheel cannot turn.