Proofgrade Kerf Vs

Hello. This is my first post. I jumped into the deep end from the get go and hopefully will be able to share some of the cool fruits of my learning but I do have a question that I was not able to find an answer to on these forums (as I lurked along).

So I recently learned (far too late) that PG material settings have kerf settings built in. Are these settings automatically applied and can they be removed?

I have been doing mockups for a couple designs on 1/4 MDF from Home Depot. It works great under the “Thick Draftboard PG” settings but my tabs and slots are too loose no matter how much adjusting I do on the SVG file (Inkscape Noob here too).

I guess my question is really this: If I have little intention of using PG materials, should I just design, test cut and adjust using all custom settings? Just as another aside, does anyone have good settings for mockups using Home Depot 1/4 and 1/8 MDF as it is so inexpensive and easy for me to get.

Love this community and your awesome work. Digging the GF a lot. TIA.

I think you’re wrong here. Possibly existing catalog projects were kerf adjusted, but the settings by themselves don’t affect kerf adjustment on paths.

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Nope. They don’t account for kerf. It was discussed at one point, but they never did it. You can do your own kerf adjusting. The kerf on the laser is 0.2 mm or so for the 1/8" woods.

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Also this is precisely what search is for, look up mdf settings and you’ll find a lot of posts.

Also, controversial opinion: ignore all settings posts and just learn a good testing routine, you’ll never have to ask again.

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Thank you.

You might find these useful

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Also, if you are using Inkscape…the method for kerf adjusting your own files is here:

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I saw this and was using it. I think my main problem is having to test EACH design I create on EACH material. The tightness of the fit varies on more than just the unknown kerf. The SPEED and POWER are a big varible (too slow and too high power and you melt/burn a wider gap). I think I am going to use this template and play with some settings on a per project and per material basis.evans%20tests

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That’s the only way to be sure. Even different sheets from the same batch can vary to make a small difference.

While it’s significantly different for acrylics versus woods, and changes based on thickness of the material, you’ll eventually wind up with a set of about four to six kerf adjustments to apply to different materials while designing, so it’s not too bad.

To minimize kerf, you want to determine the fastest speed and highest power that it takes to just cut through the material cleanly, with a surface Focal Point. (It’s how the Proofgrade defaults are set up, so they are good starting points.) Once you have that determined, use it for that kind of material, and determine what the kerf is…then use that set of information going forward.

If you want to determine what a good kerf adjustment is for 1/8" acrylic for instance…just run a few tests using a simple shape that has a cutout tab and slot, see which one works best, then write that down with the settings used. The next time you need to kerf adjust for 1/8" acrylic, you can start with that number. Saves a lot of time.

One of the things you can also do, which I believe @evansd2 is a fan of…is reverse parts of the design so that the natural profile on the kerf works to your advantage. (He can tell you more about that technique.)

He has, many times. There are posts out there where I dig into it, but the heck if I can find them :wink:

Yeah, me either! :smile:

Here’s one:

The flipping trick works well with inlays and coplanar butt jointy things, but on corners, such as boxes? I tend to put all the “fronts” facing in, essentially the “backs” of all the sides face out. It helps get them aligned (the narrow top profile fits well into the narrow top profile of its mate), then I use a hammer to knock it all together, makes for a clean consistent exterior with a tight fit.

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Testing on each material and especially in acrylic each piece because of nominal sizes.

When with the Son of Man return? When will you get to the center of a tootsie roll pop? When will auto kerf adjustment materialize?

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Even different places on the same sheet can make a difference! I do a lot of press-fit acrylic signs, and when I am plugging a little piece into its receptacle, I usually cut out extra copies. They can all fit a little differently. Having multiple copies on hand costs a few cents more but it lets me find one that fits and move on.

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Good point. The hex design I did the other day had all kinds of variation in fit, although I was plugging them in to walnut so I put it down to variation in the natural material as opposed to the acrylic.

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