Rough patches appearing during v-bit carving

I’m making a sign using some hard maple I just picked up from the local wood worker’s shop and having an odd thing happen with just the v-bit.

I used an .25 end mill to flatten the board and the surface was even and smooth. No problems.

Then switched to a 3/8" 90 deg v-bit for the actually carving. There were some 3D carvings of knots at the corners of the sign, so the v-bit ran a smoothing pass over the entire board between the knots.

In the middle of the board I noticed a rough patch was forming. If I ran my fingernail over it then it would scrape off pretty easy, so I let the x-carve finish and then ran a 1.5" chisel over the rough patches to clean it off.

I’m new to CNC woodcarving and this is my first v-bit sign, so I’m not really sure how else to describe what’s occurring. It was only happening in the middle of the board, the edges were fine. I was worried it might be sap oozing from the board, but it’s not sticky and I don’t see any signs of sap anywhere else.

Could this be an issue of the z-axis not being square, or is there some twisting occurring when the spindle is in the middle of the x-axis?

So this is probably just a normal thing that occurs?

Here’s a link to the bit I was using, it’s a Yonico 90-Degree V-bit.

If this can be solved by getting a better bit, that’ll be a relief.

You used a V bit to 3D carve? That’s not the best tool for that. You want to use a ball end mill. I use a tapered ball end mill.

Yeah, it was a simple “3D” carve. I’ve used engraving bits and had better results, but I figured maybe that wasn’t necessary in this case. This is only my second attempt at making these kinds of reliefs.

Here’s a couple of pics:

You can see there is a lot of rough edges and I’m not sure how to clean that out… maybe tracing over it with a dental pick or something? Any recommendations?

Best to use a 1/2" or 3/4" flat bit for surfacing.

I used a 1/4" initially since it was all I had on hand, and I’ve since learned there are planing bits available for just this sort of thing so I need to go and invest in one of those. I’m still learning the ins-and-outs of V-Carve Pro and I must have done something dumb to have it want to plane the entire surface. It took about 8 hours to do that, so I’ve learnt my lesson the hard way.

I’ve experienced this. Usually from a bad spot in the wood. Remember it’s organic. There’s no guarantee that it will be perfect.

This is really good to know. Are there any tricks of the trade to clean it up? I was thinking a razor blade might be better than risking the chisel diving into the wood.

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One other thing that hits beginners is the settings for the Vbit. if you have the wrong settings it will not carve correctly.
Measure the bit and make sure you put in the correct values.
I did this wrong on mine and had all sorts of artifacts as I had wrongly assumed the values.
Vbits are not like end mills when you enter in the values.
I did a post about it but cannot locate it now. :confused:

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Just tried doing this and unfortunately something must have come off with the alignment on my x-carve because it started carving into fresh wood. Everything felt secure (belts, bolts, waste board, etc.), so I’m not sure what happened… unless it jumped the belt somewhere.

Hopefully it’s something simple, like adjusting my feed / plunge rate.

Here’s a sign I just made. I ended up cleaning out the grooves with a pocket knife.

Some things still bothering me…

Notice the top of the R appears to have been pushed over, and there are little bumps around the cornering.

I’m using V-Carve Pro and set the feed rate to 50 ipm, and the plunge rate set to 20 ipm.

In the D (above) and the Z (below), you can see where I tried to clean it out with the pocket knife.

I’d say it looks good from far, but far from good. :wink:

Good advice… I didn’t even think of that. Considering that these bits are on the cheap side, I should have checked them with a caliper instead of trusting the packaging.

I’m also learning that there can be several terms to describe the same piece or part… I need a CNC thesaurus.

Check out your Vbits. This guy has a nifty way to do it.

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This is useful too.

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