Thoughts about rotary carving and burrs

Re: Thoughts about rotary carving and burrs

Peter Hyde

Look for the "Bitman" on ebay. He sells a variety of solid bottom and side cut rotary rasps with 1/8" shanks. They are straight sided solid carbide and remove wood at an incredible rate with no burning.

If I can find him I'll post a link to the product.

Re: Thoughts about rotary carving and burrs *LINK*

Peter Hyde

Mmmmm he seems to have disappeared. However this one is selling similar look at the listing and you will get some idea of the bits I'm talking about, especially the 3 on the right.


Bits

Re: Thoughts about rotary carving and burrs *LINK*

Keith Newton

Here is my favorite. They are pretty expensive, but they really remove wood fast with little effort, or loading. I use my smaller bits with 1/8" shafts in a Dremel, and several others with 1/4" in long neck die grinders.

Not only can you climb cut, you can also drag sideways, as long as the sharpened part is all emerged in the wood.


http://http://www.rotarychisel.com/info.html

Re: Thoughts about rotary carving and burrs

Dave Belser

Keith, these look pretty good however I think the heads are a little too wide for what I'm trying to do.

The smallest square cut head could be used sideways to trench the outlines, but I'd be left with the quarter circular waste at the ends of each trench. I guess I don't see how I'd get tight corners with this cutter.

An approximate example of what I'm trying to cut: a 1/2" square hole with straight sides and a flat bottom. Obviously, the only way I'd get sharp inside corners would be with a knife or chisel. A 1/16" rounded (cylinder cutter) might be acceptable.

How grab-y are these cutters?

Re: Thoughts about rotary carving and burrs

Dave Belser

I'll look for CNC router bits. The smallest sizes would probably work well.

All I have available is a 1/4" spiral bit - I just tried it (very carefully) in my rotary tool and all I'll say is DON'T! Way to grabby, I had a test block in a vise. If I'd been holding it there was a very good chance of cutting myself seriously.

Re: Thoughts about rotary carving and burrs

John K Jordan

What about a ball end mill made for a milling machine? Most wood mills nicely with end mills. I think John Lucas has done a lot of this, building jigs and things to route turning - maybe he will chime in.

JKJ

Arbortech mini tungsten carbide blade *LINK*

Dick Coers

No faster way to remove wood with absolutely no fouling than with an Arbortech. Router bits need rpms to really cut cleanly and are hard to keep in a freehand straight cut.


http://www.arbortechusa.com/view/woodworking/mini-grinder/query/product/min-fg-012

woodcarverssupply  *LINK*


http://www.woodcarverssupply.com/Steel-Carbide-Burrs-_-Bits/products/57/

Re: Arbortech mini tungsten carbide blade

mikeee12345

The arbortech tool and cutters look like a nice tool to have in the wood shop.

Sometimes my electric chainsaw is too big and my high speed grinders are too small.

This might also work for trimming my toe nails. :-)

Re: Arbortech mini tungsten carbide blade

Dave Belser

While it may be a good tool, it looks entirely inappropriate for what I'm trying to do. An example would be a 1/2 inch sq void about a 1/4 inch deep with straight side walls and ever so slightly rounded corners.

I just don't see how you could come anywhere near that with the arbortech.

Re: Arbortech mini tungsten carbide blade

Dick Coers

I'd say it meets your original post description perfectly. "I would call trenching or routing turned surfaces to a depth of about a 1/4 inch"

Sorry it is entirely inappropriate now.

Re: Arbortech mini tungsten carbide blade

Dave Belser

My bad - I put the example in one of the sub-post/responses.

Thanks for the advice. After some experimenting I'm zeroing in on the kinds of cutters that seem to work.

why didn't you describe the need better first time

Keith Newton

Tiny router bits really never work very well because they can't self clear the chips.

If you are wanting perfect sharp edge squares, get a hollow mortise chisel, then give it a whack to mark the outlines. Then go back with a 1/4" or larger straight plunge bit to get the bulk of the middle out. Then go back with carving knives and chisel or whittle up to the line.

One little trick I've come up with to remove bungs over screws on a wooden boat, was to carpet tape a thin clear plastic sub base on a small trim router. Without tightening the collar, I use it like a plunge router. Just put the hole through the plastic over where you want it, then push the motor down. You could get a half inch round perfectly inside a half inch square with less risk than creeping up to the line with smaller bits.

To be a little more specific.....

Dave Belser

My original post was long winded and fishing for ideas - that's the point I'm at with this idea. Thanks for the responses.

What I'm trying to get to is vertical-wall, flat(ish) bottomed voids carved into the surface of a turned blank. These holes are going be freehand blobs (this is important) and about the size of a half inch square, circle, oval etc (freehand blobs).

Technically, the cleanest way to do this would be with a router on sled with a small bit with the piece in a chuck on a lathe. Using a 1/8 CNC bit I could get nice straight sides and flat bottoms. However this approach will not allow the freedom I'll need for freehand part - the setup is just too cumbersome for a freehand approach. (I also don't have a mini-router).

After some experimentation - I've decided to work with a drill bit with a collar on it to set the depth and drill holes to rough out a void and then use carbide bits to finish it. This accomplishes several things - the bottoms of the holes will clearly mark the depth regardless of the surface contour I started with and the drill is a relatively efficient way to remove the bulk of the waste.

I can use this approach freehand.

Re: To be a little more specific.....

dick hines

Check out this sight. www.woodcarvingsupply.com.

Maybe you should just get a YBSS....

Keith Newton

From your description, it sounds like the pattern Yellow Bellied Sapsuckers peck through the bark in some trees. If you are like me, in taking inspiration from Nature, you should do a search to see some of the wonderful patterns that they peck.

They are only in my state during the Winter months, and most of their wells are just lines of dots. But some trees like the Beech get worked on year after year, and the lines look somewhat like a morris code.

Good old plain gouges,

Jorge

chisels and knives work best for me, and it is a lot more quiet and enjoyable.

forgot

Jorge

the hatchet and the curved adze, everything surgically sharp.

Re: To be a little more specific.....

Justin Stephen

If I am not mistaken, J. Paul Fennell uses the depth-establishing drill bit trick you describe on some of his pieces.

Re: To be a little more specific.....

Dave Belser

I'm not surprised. Works very well for what I'm doing.

Yesterday I was able to rough out a small piece in a couple of hours. It is a bit of a challenge to keep the walls between voids even on the cleanup pass. Part of my problem now is finding the right size and shape carbide bits to use without going broke.

I need more variety in my set and at $10-30 each it's not fun buying ones that don't work out.

Re: To be a little more specific.....

john lucas

Dave to make small square openings like you are talking about is difficult. I did a basket weave patter once and cleaning up those gaps was tough. I could clean the sides up with carving tools cut the bottom was hard to clean. using a 1/8" up cut router bit cleaned up the bottom well but was hard to be really accurate on the sides so I used both. I would cut the square as close as I could to the sides and clean up all the bottom and middle. Then go back with the carving tools to clean up the walls. Worked great.

Re: Thoughts about rotary carving and burrs

Rum

The Proxxon "milling bits" do a remarkably good job of making very clean and crisp cuts. I really like the fluted cutters better than the burr style because they leave a much cleaner surface .

http://www.proxxon.com/us/micromot/tools-milling.php?list

I know they say "metal/plastic/plaster" but I've only used them on wood. Mostly on things like ebony miniatures. With really hard wood like that it didn't really need sanding (a bit of polishing but no real sanding).