Struggling with 30* on recent carve

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bushwacked32
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Struggling with 30* on recent carve

Post by bushwacked32 »

I have normally always used a 60* vbit since I do bigger photocarves, however since I tried out a smaller 8x11, I needed to switch to a higher angle bit to get the detail needed in the smaller area.

However, the 30* bit leaves walls so thin they break while using a wire brush to clean in between them ... not sure why or what is going on ...

I normally use:
60* bit - .06 DOC
30* bit - .1 DOC
2222.jpg
22223.jpg

Thoughts on why this is happening? Any way to correct this?

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Re: Struggling with 30* on recent carve

Post by jfederer »

I would decrease the DOC and raise the chip load. Some experimentation will be necessary. And of course the species of wood will make a big difference. That looks like Pine, with which will not be easy to get clean cuts. I use 30 degree bits all the time, but in Maple. Reducing the DOC helps me, it may help you. Disclaimer: I don't do photocarves, just v-carves with this bit.
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Re: Struggling with 30* on recent carve

Post by bushwacked32 »

jfederer wrote:
Thu Feb 03, 2022 3:57 am
I would decrease the DOC and raise the chip load. Some experimentation will be necessary. And of course the species of wood will make a big difference. That looks like Pine, with which will not be easy to get clean cuts. I use 30 degree bits all the time, but in Maple. Reducing the DOC helps me, it may help you. Disclaimer: I don't do photocarves, just v-carves with this bit.
its soft maple, so its a little more figured ... I tried doing .06 DOC with this and had the same issue, the "walls" basically disintegrated when I hit them with a wire brush.

I think this is something photocarve specific though, as it does regular vbit things just fine.

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Re: Struggling with 30* on recent carve

Post by jfederer »

An alternative would be to reduce the resolution - the line spacing. But that kind of defeats the purpose of using the 30 degree bit. I suspect that the wood just doesn't have enough strength in that narrow a cross section. I know that the Japanese planing competitions produce shavings of about 0.001", but that's along the grain. This is cross-grain where the wood has no strength. Maybe Corian or another synthetic would work better?
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Re: Struggling with 30* on recent carve

Post by scotttarnor »

Have you tried changing the "line angle" ?
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Re: Struggling with 30* on recent carve

Post by TReischl »

bushwacked32 wrote:
Thu Feb 03, 2022 4:08 am
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I think this is something photocarve specific though, as it does regular vbit things just fine.
Noooo. . . has nothing to do with the software and everything to do with the wood you are carving and the direction of the cut.
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Re: Struggling with 30* on recent carve

Post by bushwacked32 »

TReischl wrote:
Thu Feb 03, 2022 1:50 pm
bushwacked32 wrote:
Thu Feb 03, 2022 4:08 am
.
.
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I think this is something photocarve specific though, as it does regular vbit things just fine.
Noooo. . . has nothing to do with the software and everything to do with the wood you are carving and the direction of the cut.

ok, so I have never heard of 22.5* on maple ruining the cut like this ... do you have an article explaining wood types and angles I can read up on? I have made about 50 photocarves so far on maple and never had an issue with the 60* bit ...

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Re: Struggling with 30* on recent carve

Post by BDM »

The Fox Alien vbits seem to be either two or three flutes, so perhaps your chip load calculation is off? I would also use some wood sealer or diluted shellac first to stiffen up the wood fibers. Wouldn't hurt to try. I've also found that when using a 30 degree bit, you have to make sure your wood is perfectly flat and your machine is trammed.

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Re: Struggling with 30* on recent carve

Post by Wayne Locke »

Soft Maple is a completely different animal from Hard Maple. Just cut pieces from each and look at the grain structures.

I cut blocks for a Japanese wood print artist whose blocks have extremely small and delicate details and are sometimes 20" or more wide. After first using some very expensive 1" European plywood and some experimenting I now laminate 3/16" Hard Maple to both sides of 3/4" Baltic Birch and run them through the wide belt sander to assure all of the blocks (up to 11) are a pretty exact thickness with smooth faces. The Hard Maple cuts better and holds more details than other woods I experimented with. I use 45˚ Vee Bit from Drillman on eBay and cut 1/8" deep.

Try some Hard Maple.

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Re: Struggling with 30* on recent carve

Post by adze_cnc »

TReischl wrote:
Thu Feb 03, 2022 1:50 pm
...the wood you are carving and the direction of the cut.
As we used to say "Hello Mr. Short-Grain". Add to this the steeper angled bit and deeper potential depth of cut and Mr. Short-Grain is allowed to fully express his inherent crumbling tendencies.

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Re: Struggling with 30* on recent carve

Post by TReischl »

bushwacked32 wrote:
Thu Feb 03, 2022 3:39 pm
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ok, so I have never heard of 22.5* on maple ruining the cut like this ... do you have an article explaining wood types and angles I can read up on? I have made about 50 photocarves so far on maple and never had an issue with the 60* bit ...
Nope. No one I know of has run all sorts of tests/experiments for this sort of cutting.

You are not running 22.5 off the direction of the grain, you are running mostly across grain. Why ARE you doing that? Read somewhere that cutting in that manner will produce better results? I have seen that. Here is what I learned, sometimes it works, sometimes it does not. That is because wood varies greatly from one tree to another, where it was grown, how slow it grew, etc. Cutting Vermont/Maine hard maple is wonderful. But it will also chip out if you push the cross grain type of cuts.

My advice is to run your own test cuts. I would start cutting with the grain, see if that is good and then start varying the angle if I was not happy.

Just cause someone posts on the internet their latest greatest "trick" does not mean it actually works. I have seen a lot of internet "experts" spewing their nonsense.
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Re: Struggling with 30* on recent carve

Post by litzluth »

I don't think "soft maple" (which is actually a group of species, see https://www.wood-database.com/soft-maple/) in your picture is a good candidate for two reasons. First, it is pretty soft for a hardwood (about half the Janka hardness of hard maple, and only about double the hardness of big box pine). Second, this was a fast growing tree with lots of soft structures. Wood is mainly composed of fall cell growth structures and spring and summer cell growth structures. The fall growth (the darker annular rings) is quite a bit harder because of the higher lignin concentration. The spring and summer growth are celluloses that are relatively soft. The faster growing the tree, the wider the spacing of the annular rings, and the more cellulose. As I look at your picture, you have quite wide spacing between the growth rings, which means a fast growing tree with a lot of soft wood.

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Re: Struggling with 30* on recent carve

Post by bushwacked32 »

doing more tests ... I decreased the denseness setting ... instead off 100% (all the way to the left) I set it to 130%. Lost a little detail but not too bad. I think its good enough to call it good.

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