Not carving right

CNC Machines Shapeoko
7

no funny noises, sounds normal. It does not touch board when running the cut path

Z axis?

I have a shapeoko XXL

1 Like
8

Is is the steel Z axis with the rubber belt driving it up and down, the Z-Plus with the leadscrew or the aluminium HDZ with the ballscrew drive?

9

ah, ok. It is the one with the belt, not the upgraded really nice one :frowning:

1 Like
10

OK, great.

The belt driven Z can lose steps going up and down for a few reasons.

After the error, if you return to X, Y, Z zero does the bit sit above the board by the same sort of height difference you see during the cutting?

If so then you may well be losing steps, the main causes of this on the belt driven Z are

  1. Aggressive plunges losing steps as the Z can’t apply enough force to the cutter to push down fast enough
  2. Insufficient belt tension allowing the stepper pulley to hop over teeth and lose position on the belt
  3. Stepper pulley grub-screws not tight and the pulley itself rotating on the motor shaft.
11
  1. I have not ever changed the plunge rate since I got the machine, so I don’t think that’s it
  2. possible
  3. the z axis has NO play in it at all. Tightened everything a bit ago.

How do I check the belt tension?

12

@Julien - is there a guide to setting Z tension you know of anywhere?

There’s some good info on general tensioning and pulley set screw slippage

https://docs.carbide3d.com/shapeoko-faq/shapeoko-3-how-to-check-the-pulley-set-screws/

The Z belt is tensioned by the tension screw pushing down on the tensioner bearing, there’s some good pics in the assembly guide here

https://docs.carbide3d.com/assembly/shapeoko/s3/#xz-assembly

Getting a screwdriver to the top of this screw is a bit of a pain, I recall being able to reach down between the Z fixed and moving plate when it was fully down with a long driver.

The video in this post has a good view of the hardware too

The belt should have a reasonable twang to it.

2 Likes
13

Not that I know of (beyond the install instructions).
It’s basically “adjust the tension screw until the belt twangs when pinched”

2 Likes
14

ok, I will try that. Fingers crossed :crossed_fingers:

Thank you

1 Like
15

If it happens again, re-check the Z zero after the event, that will tell us whether it’s the machine losing steps or something else going on.

Good luck

16

will do.

I use the bit setter, so I am not sure why it is miscalculating the z depth. Very frustrating.

17

I read your first post as “the job first proceeds correctly, initially carves to the correct depth, but then later it starts to be off along Z”. Is this correct, or do you have a wrong Z from the start of the job ?

18

both are correct lol I hadn’t used the router for weeks. Then I started it up, it began to carve just fine, then it goes offline on the z axis. when I ran the file through again, it no longer touched the wood on the initial pass. So, now…it does not even touch the wood on the first pass at all.

19

Can you try and upload your c2d file ? and/or the .nc file ?
I know you tried earlier, but using the upload button you should be able too, it does accept .c2d and .nc extensions so worth trying again ?

20

my file is saved as a gcode file…it won’t upload. I am not sure how to save it as the files you mentioned :woman_shrugging:

21

You can zip it, .zip is an allowed format I believe.

22

see if this works
22craft 5x7 craft 90 vcarve.zip (178.3 KB)

23

I am not sure if the the Z-axis belts are the same but the reason I disappeared earlier is because my X-Axis just had a belt slip which caused the bit to go off the expected path and through my piece. In my case it slipped enough that the tension screw was not enough. The belt had actually moved a little in the L bracket that holds it. I had to feed a little bit more through again and then re-tension with the screw. If it does not feel like it is taught with just tightening the screw you may need to feed the belt through a little more. I took a little time to re-tension all the bolts and belts and make sure noting was loose. Also cleaned the v-Wheels.

I took a quick look at the file in CAMotics and it looks like the depths stays consistent throughout the cut so I expect you have some belt slippage as mentioned above.

1 Like
24

It looks like the smaller text is a less deep carve, is that where the transisition is? If so it could be the original Z zero is not being set properly.

25

if I ran it through as separate files you think it would work?

26

I will check out the video posted above…hopefully that will work

Thank you.