Maslow inscribing letters at different depths

I am trying to inscribe text onto a template and I am getting 2 or 3 clearly different cut depths within the letters. All the text was handled the same way in the cam software and exported together. Any thoughts? I am sure I will need to add more info, but not sure at this point what to add.

Quick thought is your z-axis slipping?

Are you using the stock Z axis. If you have not upgraded the Z axis, this is what I would highly recommend before chasing anything else. I had this same issue before I changed mine to a more robust (faster) solution.

If you have already upgraded your Z axis, then you might want to make sure everything is snug and functioning properly. Make sure it is not binding or loosing steps. Is the bit good and not slipping in the router?

Is your sled tilting? If it goes off the edge of the workpiece it will tilt and lift the router bit. The same thing happens if there is any debris or screw heads on the surface of the workpiece, or if the workpiece material is not flat.

To avoid the first problem you can attach some extra boards or strips of material the same thickness around the edge of the workpiece.

second all that they said and ask if you have the bungee on top of your router keeping it down pressure on it. You really need a meticulous setup, a c-channel, or an M2 (not yet available) to get this type of z axis accuracy. it is possible that this could help you.

I copy all that and like to add the 3D-printed z-axis option which works very well for me

Thanks to all of the great responses. I should have thought z-axis slip might be something here. It is interesting that the post-processor I use (Intellcam GCode *NC) tells the Maslow to cut the letters in a seemingly haphazardly pattern (I am sure it is following some algorithm). But at the end, within a word I could have such a difference in depth between adjacent letters. Anyway, back to the z-axis, I hacked the faster z-axis from the metal maslow (photo below). Should I still use the bungee to hold down the pressure? I do have supports 360 around the cut piece to help prevent tilting of the sled. I will check on the c-channel, and check bit (brand new) for slipping and other snugness, Thanks so much for all the suggestions. For a tad more background, I cut the letters once and noticed the variance, I moved the workpiece to another area, more central for the Maslow, and cut again and the exact same letters were showing up more shallow. Maybe I should have mentioned this first. Could it be a processing thing?

Would be easy to check the G-code. It is (almost) human-readable, and a good skill to acquire anyway. Look for Z values and see if there is much variance. Or, run the G-code through a simulator and view the simulated cuts to see if they are different depths. If they are then great! Your Maslow is faithfully reproducing what your code specifies, in which case the problem is with the software that generated it. If not, and the code is consistent in Z-depth, then it’s in the Maslow. Could be firmware, could be mechanical.

Thanks ame, good points, i did the simulations and thought I noticed some differences in depths, but wasn’t completely sure since the depth of cut I inputed was 0.065 in and I wasn’t sure if my mouse was sensitive enough to land on the deepest part. I will take on the challenge to actually look at the code to see if there are differences. If I happen to be able to detect differences, what is the next step? Can I change the code? or should I find a different post-processing software? or other? Thanks again.

Ok, well, as I said, Maslow should follow your instructions faithfully. If your software is generating different depths then you’ll have to look at software functions and settings to prevent that. If your software is generating consistent depths then you need to look at the Maslow. “Maslow” includes Ground Control (or Web Control), the firmware, and the physical machine.

Just out of interest, is it always the same characters that are deep or not deep? e.g. ‘a’, ‘b’, and ‘c’ are always deep and ‘p’, ‘q’, and ‘r’ are always light. Or is it the order in which the characters are cut (you said the machine moves around a lot in a seemingly unordered manner for this job)? Also, are you trying to use V-carving? V-carving will try and cut different depths to make a chiselled or carved shape, but it only works with a V-shaped bit. Different letters, or different parts of letters, will have different depths depending on whether they have thin or fat strokes.

Thanks ame, I think I need to look into the software for help. the depth issue is not letter specific, but might be related to the order of cut, the first cuts were the shallow ones and the last cuts were the deepest. In my software there is a setting for engraving and another setting for profile cutting, I tried both with the same result, early letters shallow, later letters deeper. I am using a very narrow, tapered bit. Thanks again to all and if I figure this out, I will share.

Ah! A clue!

It sounds like you’re onto something. So, the letters are distributed pseudo-randomly in location, which doesn’t affect the depth, but over time the depth is affected.

Since nothing has ever got in the way of me speculating wildly about things I’d suggest that your Z-axis is not retracting properly, i.e. the Z-axis should go down into the workpiece by a certain amount to cut, then back by the same amount to travel in free space. If it goes down by a certain amount then comes back by not-quite-the-same amount then you will accumulate an error over time which means that over time each cut is ever-so-slightly-deeper than the one before.

If you look at the letters over time, do they get progressively slightly deeper? Or is there a step-change such that the first letters are shallow (but all the same) and the later letters are deeper (but all the same)?

I feel like it is progressive, I will study the cut path closely with the piece that is cut and get back with you. I know the very last cuts were the deepest, I’ll have to see about the progression. Thanks for speculation. You might be on to something.

Is it an upcut bit? If so, maybe your bit is loose and working its way out? (not likely but an idea)

I did a poor job on my first belt-driven z axis. I hand drilled a pulley because the hole was too small and it was offset. Every once in a while, the belt would jump a tooth. Could it be something like that?

Also FYI: there should not be a bungee on a metal maslow setup, so disregard that idea

The v-cut tool setting as ame mentioned sounds like a plausible option, but not if the bit is systematically deepening. How fast is your router running and what is your feed rate?

On a different note, if you’re gonna make a lot of letters and if you’re using fusion, try using v-carve for letters. It’s a different result and it uses a lot more z-axis movement, and you’ll need a v-shaped bit, but it gives a nice result and lets you use more complex fonts with nice sharp corners.

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I will check the feed rate, I turned the speed of the router down to ~9000 rpm and the bit is an uncut bit, and I had only set the depth of cut to 0.065 in. I am not using Fusion right now, but I might try it for this project. Thanks again to all for the help. I am hoping to try more test cuts tomorrow with the advice. Thanks to all and I will report back if/when I figure things out.

If you like, you could post your G-code file. Or a similar one which exhibits the same problem if the original is private. Other can look at it and see if there are any obvious problems. If there are, it’s software, if there aren’t, it’s probably mechanical.

I am trying to inscribe text onto a template and I am getting 2 or 3 clearly different cut depths within the letters. All the text was handled the same way in the cam software and exported together. Any thoughts? I am sure I will need to add more info, but not sure at this point what to add.
same question.

Thanks Ame, how do I get to the actual code to save it? Sorry for the rookie question, but I would be glad to share the code if I knew how.

Um… well at some point you make a G-code file from your CAD/CAM software and then you transfer it to the Maslow. Then, you open it with Ground Control (or Web Control) and that drives the machine. So, the file you open on the Maslow is the file we need to see.