Table Level vs. Cut depths are opposite?

So I’m at a complete loss… I’ve tried to do searches prior to posting to try and figure this out myself. But all that did was confuse me even more. So I’m begging for help for my sanity. Here’s the issue…

By looking at the piece in the first picture, it would suggest that the table/gantry is off level and sitting high on the left side; as the carve is deep on the left and barely cuts on the right…
Here’s where I’m baffled. Taking a level to the table it is sitting on, the waste board, and gantry – they are all equally out of level (using a torpedo, I don’t have a digital level at the moment) and show as LOW on the LEFT, which is the exact opposite of what one would deduce by the way the machine is carving…

Now I get that everything needs to be level, however, if everything is equally out of level, then I would imagine the cut would still work correctly. I’m obviously going to address this issue, but naturally a dear friend has a wedding anniversary coming up and this is going to be a gift for her husband.

What I’ve come up with so far, is since the left side cuts are “okay”, I rotated the piece and artwork 90 degrees counter clockwise and it’s seemed to solve the problem temporarily. Which is better than my original idea of shimming up the right side and playing a guessing game.
But, why in the ever living F-Bomb is this happening?

Now the second issue is (which I’m assuming is related to the level problem), but holy crap do the cuts look like garbage. I’m using the following bit from Amana - V-Groove 60° x 1-1/16" Dia x 59/64" Cut Height x 1/4" Inch Shank Router Bit (RC-1148). I originally used the 60° bit selection on Easel, but after looking the Inventables bit, vs the Amana, they obviously didn’t look the same shape (I’m still new to this – so please forgive the ignorance). So I changed the v-bit width to 1.0625, and it’s running at Feed: 30 ipm, Plunge 9 ipm and Depth Per Pass .028 ipm. What I’ve noticed is that there are some circular divots when the bit goes in for what I’m assuming is finish work, but they don’t get cleaned up. I’m wondering if this has anything to do with it being off level?

Please for the love of god someone help me get this figured out and I will literally paypal you money to buy a steak and a beer.

The machine doesn’t care if it is level or not.
It will cut in any position.
What is VERY important is the the spindle is trammed in to the bed of the machine.
That is why you’re getting the difference in depth from one side to the other.
If you can post the file I will be glad to look at it for you.


So I don’t fully understand what you mean by trammed up, but here is the link.

The workpiece needs to be flat and parallel to the XY plane of the machine and perpendicular to the Z… The endmill needs to contact the work at a 90 degree angle. If everything on the machine is square, you can face your wasteboard or your workpiece (tough when it’s plywood and/or painted).

So, the work piece was planed out, so that was 100% true. And last time I checked using a speed square, the Z was 90 degrees to the piece. I’m going to recheck again tonight when I get off of work as I know things tend to shake loose over time. I’m looking at trying to find a good bit to face a new sacrificial board. Or I guess I can face the piece first, and then paint. But I feel like that’s just adding more time over and over again and not solving the issue at hand.

Please explain “planed out”, how was that done?

Facing a wasteboard and using a truly flat piece will work.
Running a board through a planer just makes it have a consistent thickness. It doesn’t mean it’s flat or square to the machine.

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You can get a 3/4" flat end mill (plunge bit) in most hardware stores for cheap, it will do fine.

What can cause height variations in Z?

  • Uneven surface board (solved by skim cutting it)
  • Surface board not level relative to the CNC (may still require a skim cut)
  • Surface board sag in the middle (support it better, then do a skim cut)
  • Z-assembly rotate around the gantry (twist in it, but not likely) as it travel, raising the Z every so slightly.

For height critical projects a skim cut surface board is required.

Planed the piece on a DeWalt 734 planer

So I’ve noticed that it wasn’t just on this piece though. So I’m assuming, that say I get a new waste board (WB) that’s 29"x29", and use a 3/4" flat end mill and surface that and use it on top of the factory Inventables WB… It should help. If it’s still causing a problem, THEN go back and skim cut the project board face as worst case scenario?

The whole assembly is on a giant bench that’s on 3/4" ply, so I would imagine it’s not sagging. But what do I know? I’m literally winging it as I go.

Ok,So once again I misunderstood.
I don’t use Easel.
But I still down loaded it and looked at it.
The number one problem that I see is the massive amount of nodes that you have.
Along with that, the font needs a lot of work.
The only way could get it to look halfway decent, was to reduce the number of nodes and carve it with a 20° V bit with a maximum depth of .060
I also do not have the divots that you are experiencing.

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Simply mount a 2nd WB over the Inventables WB and do a skim cut of that.
Doing so will atleast ensure that the height (Z) is uniform relative to the WB.

This is however just part of the picture.

V-carving with precision can be difficult because:

  • A V-bit with 60deg angle may infact be 59 or 61deg (numbers arbitrary)

  • Most V-bits do have a very small flat spot at the tip, not forming a true point. This make the bit go deeper than calculated and may create a dog bone effect on corners and such.

To dial all this in you need to do a couple of test runs, when doing so use letters in Easel to rule out any outside-Easel design issues.

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So I’m trying to research a “drawn in crayon” definition of the nodes. I’m assuming it’s the amount of “points in the path” (I’m trying my best to relate it to things I am familiar with - I.E. Photoshop/Illustrator). Unless you can explain it better, or relay a link to me. Per example, what is the line of “too many nodes” and how do I establish this number? Being said, without the option to go to a 20° bit, I would need to 1) reduce the depth to be even more shallow, and 2) possibly change the font to make it easier to carve? I do have a 30°, but I’m going to imagine it’s going to take a hell of a lot longer to carve, and I’ve yet to use it.

Best suggest for new WB? MDF that’s the same size, and skim cut it per project? Or literally make a whole new WB and start from scratch with a 29.5"x29.5" board…

Depending on program/configuration a cirlce may (in code) be represented by either one point and diameter value or a “million” points around the circumference. Which one do you think is heavier to process? :wink:
In some cases too heavy code will make the carve “stutter” as the machine need time to catch up.
It may or may not be the case with your design.

There are many ways to skin that cat, but since you do signs you´d want area so just get one that is almost as large as your reachable X/Y span.

Check your risers were they attach across the front and back below your waste board, Being they attach in the slots you may not have them all consistent there is a small bit of play there and I found with mine I had to adjust a little bit.

Check your base frame at all the points it connects to be sure it is assembled tight and correct at all the points and that nothing twisted or is out of line as you assembled.

Also be sure your waste board is tight to the frame

Use more clamps. I have found that when using some material over a sacrificial board i can actually pucker up the material this will cause you to cut to deep on one side. Make sure the clamp itself is level to the material and the riser it sits on.

Lastly mine was out a small bit on the right side. I shimmed my waste board up to the frame on the right side to bring it up a bit and to resolved my issue.

If all else fails shave your waste board. Mine is 15 months old and I have no marks in mine and I have NOT skimmed my waste board or my sacrificial board.

Just my two cents. Steve


I wouldn’t be so quick to start cutting on my waist board / machine bed.
The first thing to do is set up a dial indicator in your spindle and tram in the machine.
I’m willing to bet that you will get most if not all of the error out of the machine by adjusting the X and Y plates. (unless there is something else seriously wrong with the machine)

Played around with your file this morning.
Reduced the number of nodes, worked with the font, and adjusted the kerning.
This is a 60° V bit with a maximum depth of .06


Any videos that you can refer me to in this process? I get hesitant just blindly YouTubing things, being as I don’t know the process, it’s hard to decipher true scientific information from “expert opinions”. The more I think about it, I’m guessing that’s probably the issue, however I don’t know my head from a hole in the ground. So there’s that.

I have my CNC encased in a box to cut the sound down, and it looks like I’m going to have to deconstruct it to check a few things, so I will definitely look at the risers as well. I guess it will give me the chance to loctite everything as well. Yaaaaay.:roll_eyes:

In regard to the waste board, I think I’m going to try adjusting any of the mechanical parts that are out of spec first, then skimming an additional sacrificial board if needed. My factory WB looks like it was in a fight with Freddy Krueger already after only a few months. Guess that’s what happens when you’re too excited to play with your new CNC having absolutely Zero knowledge on it, ha ha.