Not cutting all the way through in entire workspace

I’m noticing than the machine isn’t cutting all the way through consistently through the workspace. I’ve attached the finished product that I extracted from the stock by sanding the back side and the waste board.

It’s missing in the middle front to back and more strongly on the left.

Is this most likely a sagging center of the waste board issue? I checked the height of the y axis bar and it’s within 0.005 inches at each end.

Any thoughts?


Surface your waste board to get rid of those pretty lines that mean nothing.

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Do What Mark Said! You need to have a parallel plane wasteboard in order to have even bottom of your workpiece and this accomplished perfectly in one way: Surfacing it.

It is also a common practice to ADD another MDF board atop the stock one so that it can be fully surfaced since the stock one cannot be entirely reached with the spindle… :+1:

While it is most likely that your wasteboard needs to be surfaced to ensure it is parallel to the machine as mentioned, it is also a good idea to surface your stock as well depending on the material being used.

{:0)

Brandon Parker

Thanks. That piece was brand new mdf, so I’m fairly sure it was in good shape.

I’ve only had the machine two weeks. I guess I need to get my permanent set up figured out and surface it.

Thanks.

So what was meant by

Is that Especially with a V Bit, the top surface of even planed flat. or even Sheet goods are used, the top is never perfectly parallel to the spindle movement.
To Get perfect V-Bit carves there are 3 realistic options:

  1. Surface the wasteboard and use Sheet Goods that are not cupped, twisted, or bowed AND Plane any real wood… AND HOPE FOR THE BEST.

  2. Repeat the Prior Option AND shim the board as best as you can while using the spindle with a bit in it to gauge the top being perfectly parallel… (this is a bit more time consuming but works better than option 1 but not as good as option 3)

  3. Surface every workpiece (and if plywood is used refer to option 2) If painting or Staining, then surface and paint/stain on the CNC without removing for best results
    (I have a video of doing this with for my Flags if your interested…)

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Here is an example showing a planed flat Board VS a surfaced on the CNC board. Notice the consistent depths and thickness on the CNC’d one vs the varying depths, and thicknesses in the Planed flat one.

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Yes I just posted about his issue with my x-carve. .Im guessing surfacing is my issue as well. I guess I should confirm with my system that everything is INDEED square… then see what the wasteboard is doing. I guess I just assumed my New wasteboard was flat… and parallel to the X gantry. What Surface bit is everyone recommending for this process? is there an Easel project that I can use as a go by?

I did a bunch of digging. What I read is that you cut very shallow with the biggest bit you have. With the starter bit set that is unfortunately 1/8". I also read about setting the overlap to something like only having it overlap by 10% per pass but I don’t know how to do that in Easel. I intend to try it with a sped up feed rate since its only cutting out 0.01" per pass. Even that is saying its going to take almost 3 hours per attempt. I expect to need maybe 0.03 to get mine levelled.

I’m going to surface with this for now.

Then I’m going to score some new gridlines so I can be 100% sure what my machine considers square. Easel - Grid

I’ve got the frame squared and I’m going to do the step calculations before I surface it.

I’m also intending to run this project and check measurements. https://www.inventables.com/projects/calibration-test-pattern

Great info thank you. Spoilboard bit
What about something like this?

Yes, I was looking at a 1” of the same style. I’m not going to buy it yet, but I’m dropping three walnut trees on my property this week and getting them milled. As the lumber from that is dried and out into use I’m sure I’ll need to surface, especially the stuff that I can’t get into my 12” planar.

After checking all three calibrations (x and y with 0.5 mm and a within 0.1 mm).

Ran the surface with 1/8 then grooves with 60 degree v.

Waiting on spray paint to dry on an mdf stock before a new test carve.

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Just keep in mind you’ll want seasonal resurfacing or more often, and doing that will remove more and more material from. That stock board. AND since you’ve created a pocket you can no longer use the tile function without adding a spacer In there to lift the workpiece up

It is a common practice to add another piece of mdf on top of the stock one, this new piece being smaller so that it can be fully surfaced without creating a pocket. Just something to keep in mind once the current setup reaches its limitations :+1::call_me_hand::call_me_hand:

Next time it needs resurfaced I will definitely be adding a new layer to the waste board.

That said, the results are worse :frowning:

I’m attaching some more pictures.

The full one was a previous carve with minimal missed areas on the left side.

The others are of this latest one. I scaled it up from 11.5” wide to about 15”. I removed some of the more detailed snow flakes. But it missed a lot more spots.

The mdf was bought two days ago. It’s clamped at all 4 corners and no noticeable sponge in the middle. Is it at all likely the mdf needs surfaced? I wouldn’t think this fresh on a manufactured material would.







With straight edge across I see the barest hints of light, but not aligned with areas that skipped.

Just update, tried carving 0.015 deeper and missed the alignment… so I’m just surfacing the carved area on this board then will try again.

Is paint likely to cause a problem if I’m doing stuff where I want the board painted then the carving to have the wood color show through? This was spray paint and wouldn’t have thought it would have added measurable thickness. If it does I can leave a portion un painted to use as my zero z.

A straight top is different than a top that is parallel to the spindle’s movement.

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Kinda, surface engravings will not be perfect UNLESS the top surface is parallel to the spindle movement.
Which option of the 3 options provided are you using?

  1. now trying 3.
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if your interested in at least the first part… here is how I do #3 with stain and the video features a flag of course… because there are not enough ppl making flags, right? lol

I’ll definitely watch it this evening. Thanks.

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