T8 leadscrew issues

Mostly Printed CNC - MPCNC Troubleshooting
1

Hi

I’ve just added the new T8 leadscrew and coupling and have the latest MPCNC813_GLCD_T8 firmware.

My issue is when I set a depth of cut to say 1.5mm, the Z axis usually starts off

Ok. Then after a little while the Z axis gets deeper then 1.5mm and begins to cut through the job, not lifting above the work.

I have tightened the coupling and grub screws.

My previous threaded rod worked great.

Any help would be appreciated.

Simon S

2

Make sure you have a look through the basic page again and set the max rapid speed no more than 8.4mm/s, if that is good make sure the whole thing moves up and down by hand very smooth and easy, did you lube it?

 

 

3

Hi Ryan

Thanks for the reply. I’ll check the rapid speed and I haven’t lube the screw yet,

 

Thanks

4

Start with lube or the steel will chew right through the brass.

5

T8 leadscrews can have different pitches, I think (not sure) common is 2mm. I just got a 1mm pitch leadscrew from china by accident. Please check.

Unfortunatly even the vicious1 online shop doesn’t tell what size is sold, or what is configured in the MPCNC-marlin-firmware. I guess it’s 2mm. Maybe you have something else.

6

I sell 4 start 2mm pitch, 8mm/rev.