Threaded rod issues


So I finally managed to set up my MPCNC (I ended up converting the basement into a usable space and building a large workbench), but I’m having a few issues with the Z-axis.

The threaded rod that came supplied in my pack from Ryan seems to have a few problems and there’s a few extremely tight bits that no amount of lubricant seems able to fix.

I’m looking online at options for replacing it, but I’m a bit confused. I’m assuming the threaded rod that Ryan sent was imperial, so if I buy a metric M8/1.25 threaded rod and coupling, what will I need to change in the software to account for this?

Is there any particular material I should be looking for when ordering a threaded rod? Or can anyone recommend a UK based supplier?

Many thanks!

Did it get damaged in shipping? I actually test the rods before I seal them up. I put them in a drill and run the coupler up holding it with my fingers, If I feel anything grabbing or bent too much it gets scrapped.

Let me know what new one costs you, I assume you are not in the US?

If you get a metric one you just need to change the z steps in the firmware.

Hi Ryan,

I saw no shipping damage!

I think I’ve found a solution to this - I’ve taken it apart and turned the rod upside down. The tough spot was at the bottom end, so putting it at the top should mean it’s mostly out of the way.

I’ll give it a test in the morning - maybe I can avoid having to buy a new rod.

Loving the machine so far! Next step for me is to look at how I’m going to mount this Kress.

I’ve noticed that the collets for the Kress are pretty expensive - about $25 each. Are there any sizes that you’d recommend a beginner getting?


Edit: I appreciate you testing everything. It could well be that I damaged the rod myself without realising - it’s been sat on the workbench for the past few weeks while I created the workshop.

I put them in a drill and run the coupler up holding it with my fingers
Great idea! I'm facing z-axis grabing right now. I will try your method. Thank you!