Mesh Bed Leveling

No the rigidity of the machine is more important than the waste board.
I can use anything I want for a waste board.
The system I have the waste board came warped.
It does not help at all keeping the machine square.
This is the reason some of the folks here did do the upgrade to a more rigid system.
Inventables even makes a new maker slide that is loads better due to someone’s mod and how much it improved the system.
I for one do not mind paying a bit extra for more stability. MDF is cheap and Home depot and other places sell it as well as other material for waste boards.

Here’s what I did (I wish I had taken pictures).

  1. Make a nice and flat (and rigid) torsion box for the x-carve to sit on. Can’t recommend this enough.
  2. Place your x-carve on the torsion box and square it up (before putting your waste board on) and fasten it down to the torsion box however you like - I made some simple clamps that in hindsight I could have done better.
  3. Between the three cross member extrusions for the 1000 mm x-carve base (which are about 3/4" thick if I remember), I placed a 1" thick (or two 1/2") piece of mdf, each roughly about 12" x 22" if I remember correctly (it just needs to all be within your cutting envelope of your router) and fastened those directly to the torsion box with some countersunk screws. This will act as a base for the wasteboard.
  4. Skim off about 1/16" across these two bases. That should make your base square to your gantry, but still keep it above the cross members so the waste board sits on the base and not the cross members. Mine ended up being within 1/64" from the front right corner to the back left corner.
  5. Attach your wasteboard to the base. MDF is pretty flat as it is, so for what I use the x-carve for, its flat and level enough.

What I like about this method versus milling out a large square pocket on the wasteboard is that it allows me to sit long pieces flat on the waste board with an overhang if needed.

Sorry for not having pictures…

Pictures would be helpful as I can’t quite follow you on the description.
I have never built a torsion box so it makes it hard to picture.
Sorry I am a picture kinda of guy. :stuck_out_tongue:

One thing that no one’s brought up is that the Z probe doesn’t directly measure the distance to the wooden wasteboard anyway, so getting a good measurement of the entire board is going to be extremely tedious.

The z probe relies on completing a circuit between something metal sitting on the wasteboard and something attached to the cutting bit. Just lower the bit slowly until the circuit is complete, and then you know the bit is exactly at the height of the metal piece (carefully machined, and has a known size) sitting on the wasteboard.

The induction sensors that 3d printers use also detect distance to metal objects, so they’re going to have the same issue.

Anyone know of an inexpensive way to detect distance to a wooden object, with the kind of accuracy we need? Most of the distance sensors I know about for Arduino-style projects are an order of magnitude off in their precision (they’re trying for ± a few centimeters, not sub-millimeter).

go down to Harbor freight and ask for a digital dial indicator.

Then have this part made for you. it will allow you to connect it to the X-carve

I have a 3d printer if you do not and can easily print one.

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Found this article about how to get data off a HF digital indicator. Yuck.

The article is actually about exactly this topic, so definitely useful.

I actually think this isn’t useful for the original idea, but it would be useful for something very closely related: reporting whether or not (and where) your wasteboard needs reskimming. Just push a button, walk away, and N hours later get a report about the state of the wasteboard. Maybe you only need to reskim a section, but most of it is ok; that’d let you get more work done before another reskimming operation.

I think its worth mentioning that prior to skimming the surface that you ensure that your system is square.

James I have seen that article and not everyone has the skill for that.
I do but I do not want to try to rely on that.
Its much easier to square the system then do as Robert says to flatten the surface.
if your doing PCB’s then you should look at other options and not use the Xcarve as it is a different setup. Chillipeppr will do them but you have to do a setup each time you do a run.
If your going to do irigular surfaces then you need a different machine unless you want to spend hours modifying the X-carve to do what 20k or higher machines can do.

On the topic of the Z probe.
its meant to ensure you start at the right place.
when you run the g-code it resets the home to the right location for the work piece.
It will not work for you if your surface is uneven.

I agree

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Very nice! The picture tells a lot. Are you willing to share your plans and sources for things like the slots?

Thanks!

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I agree there needs to be some sort of mesh bed leveling because I’m trying to cut thin gaskets out of 1/16” flimsy material while also having tabs to hold it in place until the cut is finished to trim out later. The center of the waste board is a full 1/8” just about further from the bit than the 0,0 point is so the wedge method would do nothing for this material and by the time it tries to cut the gaskets located at the middle of the wasteboard it won’t even cut material. I’d like to do this without facing my entire wasteboard but easle seems to have a few features still needed to make it truly user friendly. It wasn’t until recent that they even added a home button so i guess we just need to wait for further improvement updates.

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@KaapFabrication until they get around to adding this feature here is a solution that may work for you.

I regularly use OpenCNCPilot to generate a height map of my work piece and then I use that program to modify my exported gCode from easel to match my workpiece.

Example:

Now, heads up on this. You can’t use the software as is right now b/c it did not modify rapid movement heights, and with the recent easel update that allows for rapid out of material, this caused a few issues. Here is my fork of the software that fixes that issue: GitHub - firetunes/OpenCNCPilot: autolevelling gcode-sender for grbl

If you need any assistance, let me know.