Engraving and Surface showing tool path

Hi!

I’m brand new to the x-carve community. I recently got the 750mm version and I’ve been doing a few test cuts on 0.2" mdf sheets.This is my third test cut. In terms of squaring, this seems to be pretty good on the x and y axis. However in this engraving, you can see the tool path. Is this an issue with the Z-axis? Or is the bit slipping? I am having trouble finding a similar thread on the forum. I used a 1/16 fishtail bit on the dewalt 611 with the precision 1/8" collet.

-Max

Hey Max, if it were me I’d check the Z axis… check for squareness… check the set screws on the pulley if you have them… check the belt tension if you don’t… and then check your V wheels. If that’s not it then you may have to go deeper and check your potentiometers. Best of luck!

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Thank you, I’ll go through those steps and see where that gets me. Could you just clarify what you mean by “if you have them… if you dont?”

If i’m not mistaken the newer pulleys are pressed onto the motor shafts so would not have set screws to tighten up

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To me it looks like you have repeatability issues with Z. What I mean is that it may move ever so slightly up/down during the carve due to slack. Is the Z-screw bolted tight? Any slop in the screw block?

To test how true the spindle (Z-axis) is to the surface try the biggest bit you have (say 1/2", 3/4" or whatever) set stepover = 90% and do a very shallow pocket. If the bit is not true to the surface you will see edges.

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I couldn’t see the picture earlier, but I would agree with losing steps, or something being loose on the Z axis. The cuts look too uniform to me to be from your spindle not being square either right/left or front/back

My guess is z zero. What method did you use to zero your bits to material?

Blue Loctite and free beer!!

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That’s what I love about my screws. :joy::joy::joy: No more pulleys.

Z-probe

Hmmm either a steps/mm issue or loose pulley or loose material.

Thanks everyone for the responses, I finally got around to another test cut, I’ve been building a table for the x-carve in the meantime. I tightened the set screw on the pulley on the leadscrew and I used shims to tension the pulley belt for the Z axis and I ran a test carve. Those small adjustments made tremendous improvement.

aaaaaaand the z-axis belt snapped… it was working fine, then it started making slipping noises and looked looser, i re-tightened it and then tested its motion and it snapped, should there be a level of give to the z-axis belt?

Just a guess, but I wonder if you motor and threaded rod pulleys were not quite lined up? With the standard setup I can’t see why your belt would start making a noise, unless it was rubbing on a pulley.

Or if you somehow had it unbelievably tight I guess

I’m thinking maybe the lead screw and the z-motor shaft are not perfectly parallel or I over tightened. The way I tightened was by inserting thin wooden wedge shims between the z-motor and the x-carriage body from the left and right sides and using a C-clamp to force them in, thus “pulling” the z-axis belt tight, then tightening the nuts and screws holding the motor in place. Maybe that was too much force?