First pass much deeper than next pass

ive been using my xcarve for a while now, but for some reason whenever i start a new cut the first pass is much deeper than the next passes.

i have leveled the spoilboard, calibrated all 3 axis.

I use manual zero to set the top of the workpiece. a lot of times i use easel recommended cut settings. but setting will say something like .06in per pass, but 1st pass cuts .12in depth and i have to slow my ipm down until first pass finishes.

through cuts are spot on and barely touch spoilboard. wood is fairly consistant in thickness across the piece so it not any major difference in material.

bump.

Could it be that your carving material isn’t completely uniform, and that your origin points have been at the lowest point of the workpiece ? Especially with woods, you might discover the material is slightly bowed (even if the thickness is consistent throughout), so that the high point is in the middle of your piece. If so, find the the high point and begin your carve from that height.

No its not the material. the “over-depth” on the first pass is consistent across the whole piece (1000mm x carve). its like the first pass is setup for 2x pass height.

spoilboard has been leveled in current location, has not been removed from tabletop since last calibration.

I experience the same thing… Then when I try to compensate, I start carving air… but I’m with you, looking for a explanation too.

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What software is used, Easel?
Is Z-zero set using the probe or manually?
How is your workflow when setting up a carve?

More details = better chance to narrow things down :slight_smile:

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most of what you asked is in the original post.

load the material, zero to the top of the material (no longer use z probe). and use easel to run the cut.

like i said 1st pass is twice the depth of 2nd pass and so on.

bed has been leveled, xyz have all been calibrated and confirmed by manual movement. by digital caliper. the z axis screw is not loose or shifting (had that issue before). spoilboard rarely gets cut into unless i didnt confirm Exact thickness. (ex .75 when its actuall .73 or .77).

just cant figuire out why 1st pass is so different. lets say easel set up for 1/8in depth passes, but when it begins the cut it goes like 3/8.

Not by Mike who see similar discrepancy, but is your design made in Easel or is Easel used only as the gcode sender?

All work is done in easel and sent by easel. only outside software is inkscape/photoshop for image prep for eps curves.

Its a weird behaviour for sure, I have used Easel for several years and the only time my Z have been off its was due to operator error / misconfiguration of carve.

Its a long-shot but could you try the following:

  • Zero manually on the very top of your material, confirm that as your home position
  • What Work coordinates now showing in Easel Machine Inspector?

Did you run setup again after you stoped using the probe?

I have changed the computer i use to run the xcarve (old laptop died). But had previously stopped using z probe because i think the easel dimensions for the z probe did not match the actual dimensions of the probe and it kept cutting through to my spoilboard.

now when setting zero i move the bit to my zero position (by jogging manually) then i set my Z zero to top of material using a piece of reciept paper to tell if the bit is touching the material. then i “raise the bit” via easel confirm steps, and continue the “begin” steps.

it then begins the carve and proceeds to cut extra deep first pass than what is setup in cut settings. this applies to engraving and through cuts.

Can you share the Easel file? If the “double down” is in the code it will show there.
Also if there still is an z-offset lingering.

Puzzling issue.

I have this same issue also. The first pass is about 4mm deep and the rest of the passes are about 1mm (per my settings). At first I thought it was user error, or machine issues. I re leveled my spoil board. I joint and plane my wood so its perfect thickness. I even adjusted the thickness settings for my z probe. Then I opened easel, and discovered the first pass IN EASEL is set to be this deep and I can’t figure out how to change it.

See the screen shot showing how deep the first pass is.

Can you share the project?

Are you sure that thw z isnt topping out and loosing 3mm worth of steps in the Z?
This is more common than easel bug causing incorrect Z commands.

What is your $20 & $21 settings?

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It’s hard to tell if that pass is any deeper with the angle of the screenshot.

As Seth said, if your first retract is too high, you’ll crash the Z. It will “think” it’s higher than it is and plunge deeper on the first pass.

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Here is the shared file: Easel - walnut-profile-deep-initial-pass

I had to look up what $20 or $21 is (embarrassed!) Still not sure. I always home the machine to 0,0 with its limit switches. Then set workpiece height with z probe, the 0,0 on the lower left of the workpiece.

How can I check for the initial retract? Is that the same as Origin Safety Height? Mine is set to 2"

Hopefully, you can see in the path that the initial pass is in fact deeper than the others. I played with the depth of cut settings. It seems like after a cutting depth is set that’s as deep as half the width of the bit, it begins to do it. I wondered if it was an automatic setting in easel that the first pass is half the bit…but…that seems weird.

Looking at your gcode, the first pass is as it should be, at 0.09" deep. The gcode depth is not the issue.

Yes.

When your endmill is touching the surface of your stock (which is over an inch thick), do you have 2" of Z clearance before you max out the Z and crash?

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Yes it is, and 2" is likely way more than necessary, the default should be only 1/4"

You need only raise it if there is a clamp in the path and then only raise it enough so that the z doesnt top out and loose potion. It will think it is higher than it truely is and that will cause excess first plunge depth and the total depth will also be deeper than programmed (unless it also bottoms out the z movement)

I’ll set it to .25 and see. I changed it earlier today off a video I watched.

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I just changed the depth to 2mm. Can you check the file and see if the gcode is doing that on first pass?

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