Hi All
I’m using a 15 degree vee bit to engrave my headstock logo 1/8" deep. The wood left between the letters is very thin, like 1/32" wide. (The engraved logo is filled with epoxy later on so the thin wood is protected.) I’ve engraved the logo successfuly in about 50% of the guitar necks I’ve been making but the other 50% are getting chewed up in the engraving. Is there any settings changes for the tool I can re-configure that will give me a higher success rate?
Situations vary and can depend on a lot of factors, including the individual piece of wood.
But some things you might try:
- being less aggressive with feeds, speeds, and depth of cut (per pass)
- masking your material before cutting to add surface strength (same concept as using tape to prevent tearout with a saw or drill)
- cutting V paths before clearance paths, if applicable
- using a thicker piece of material and setting a start depth for your carve of greater than zero, then surfacing to remove the extra material after the epoxy has been applied
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It may help to show what you mean by getting chewed up, also what kind of wood?
But, adding to Matticustard’s list, here are a couple things I can think of:
- Change direction of the cut from “Climb” (usually default) to “Conventional”
- Try the same toolpaths in a different, harder, wood
- Check to see what the width of your V-Bit tip is. In other words Amana has two different 15 degree bits; the 45611 and 45628. The 45611 has a near nothing 0.005" tip and the 45628 has a 0.666" much wider tip. So perhaps try to see if you can get a smaller tip?
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Thanks for the replies.
I have the narrower 45611 tip.
The wood is Douglas Fir so ueag, that in itself is an issue with its early and late wood lines, but I don’t want to change to any other wood.
I don’t know what a V pass is or a clearance path.
So, what Matticustard means by a V pass is the assumption you used a “V-Carve” toolpath, with a separate clearing pass. But to me, it looks like you are using a regular Pocket toolpath.
As far as the fraying and “chewed-up-ness”, some of it may just be a matter of regular cleanup being needed, but the walls between the letters W and A, and between A and R could be a result of the V-Bit trying to carve too deep and the upper sides of the bit (since they are angled outwards) are starting to hit the walls of the material.
I would first suggest what Matticustard said about slowing down, feed rate, plunge rate, and depth per cut. Then try not to carve so deep. Since it looks like you are doing an epoxy pour, I would think it should not matter too much if the pocket was a little shallower. The only other thing I can think of right now, which is probably not an option, is to put more space between the letters.
P.S. To clarify, if you decide to use a V-Carve toolpath in conjunction with using a “Clearing” bit/toolpath, fine details like this can benefit from running the toolpath for the V-Bit first. Then come along with the end mill to clear out the bulk material second. Using the V-Bit first gives more support on either side of the bit to prevent walls from collapsing.
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What would be good for “masking” the surface?
I use a wax candle that I rub onto the top of the headstock, over a successfully routed logo, so that when I pour in the epoxy it doesn’t touch the top and cause epoxy bleed into the wood. That works well but I doubt wax would add much strength to the top.
For epoxy inlays, I have successfully used a heavy coat of either polyurethane or sanding sealer on the wood around the epoxy, which works well to prevent drips and overruns from staining these areas. This of course requires sanding or surfacing the material after the epoxy dries, but if I don’t use something like this, then any drips of epoxy will tend to leave a stain/discoloration, even after sanding.
For applying paint, or pouring epoxy on a piece that I cannot sand/surface afterwards, my go to product is Oramask 813 vinyl. This can be tricky getting to adhere and can pose a challenge when trying to get crisp cuts from your bit of choice. For adhesion, I found a smooth surface sanded to at least 180 but no more than 240-ish grit lets the Oramask grip as intended. I have even used a very minimal coat of the aforementioned polyurethane to get the masking to stick like it should. As far as fuzzy edges of the cut: use as sharp of a bit as possible, watch the direction of cut (conventional vs. climb) and using things like a downcut bit can make a big difference and less manual cleanup.
I have seen, but never tried, using hot glue to build up a wall or dam around the epoxy, but this can tend to gum up sandpaper and endmills when trying to remove it.
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So I just discovered why none of my tweaks are making a difference. None of my changes are sticking. For example, if I change the RPM’s from 10000 to 18000 and then save and upload the new nc file, when I run it the OneFinity screen shows 10000 for RPM’s. I also notice that plunge and feet rates always look the same and the time is always 19.11 minutes for the job. I am creating the nc file in Carbide Create. Anybody else ever see this issue?