Need Carving Help.

[Designer]

I was reading over some older posts and am getting the picture that my techniques are all wet. I am new to carving as I just purchased my BT32 in March.

BT 32 Standard
Aspire 8.0
2.2 HP Spindle

I have made a few carvings using the Aspire clip art. Some fair and some bad. None were great like those I saw in the older posts.

I am currently trying to carve a Bass (fish) out of Walnut. It came out fuzzy.

I am using an 1/8 inch ball nose tool for finishing and a 1/4 end mill for roughing. Both are Onsrud.

Roughing at 8,000 RPM 100 IPM with a cut depth of .125. I am leaving .020 to finish. I am using 10% step over. That seems a bit small.

Finishing at 7,000 RPM with equal feed and plunge of 80 IPM.
I am using a raster feed direction. I am using 7% step over.

I finished it across the grain. That appears to be a mistake.

I am getting a lot of fuzz.

Here are some of the tips I saw.
Use a round nose bit to rough. I have a 3/8 and 1/2 inch round nose bits.
Use a 1/16 finishing bit (I have one).
Use higher speed rates.
Finish in the direction of the grain.

I just don't know where to start.

I also wonder what the best woods are to carve.

All advise will be greatly appreciated.

Here is a picture.

25208

[Brady Watson]

Crank that RPM up. It's a router and not a milling machine. Slow your speeds down. Read my VR article in the web columns area on the main SB site for speed recommendations.

Run 12-15k for roughing with 2-flute upcut.
Run 15-18k for finishing with 2-flute ball.

The tool will never go 4"/sec on that little fish. It will be ramping while cutting and will kill your cut quality because the tool will not move as smoothly as it should. 3D finish machine that at 2,1 inches per sec at 15k to 18k and see how it turns out....

Rough @ 40% stepover. Set it in the tool DB and leave it for ALL 2D operations, unless doing very dense material like aluminum.
3D finish with 3D raster WITH/parallel to the grain @ 7 to 12%; 10% is fine.

Try it...report back with your findings.

-B

[Designer]

Will do and thanks. I knew that my set up was way off. I will try it this weekend and report back on the result. I am excited to see what happens.

[Designer]

Brady, I changed the settings. Much better.

Changed from 1/4 inch end mill to 3/8 round nose bit. Speed 13,500 feed 80 IPM.
Changed speed to 16,500 and 80 IPM for the 1/8 tapered ball nose finishing bit.

Still have a little fuzz. I am thinking more speed and slightly reduced speed. 17,500 with a feed rate of 70 IPM for finishing.

Your thoughts?

25273

[myxpykalix]

hit it with a mop sander to get rid of the fuzzies. Sometimes i've had to just take a knife and cut out some of the little "hangers-on" because of their position down in a carving.

[Designer]

I'll have to find out what a "mop sander" is. It sounds like something I would like. I just purchased a couple of attachments for my Dremmel, but they did not last long and cost way too much. Thanks.

[scottp55]

Philip,
3M radial bristle discs work great,but not cheap. 1" work better, as the 3/4" quickly get too short to get into deep stuff. 220G works well, but 400G(blues) will take most fuzzies off and leave even fine detail like scales and feathers alone.
Bamboo skewers for shish-kebabs, are great for getting into cracks and burnishing rough areas.
A stiff boar bristle brush (hair brushes at Rite-Aid:), also does a great job for the small ones that just need a little persuasion. (softer ones are great for buffing/spreading out a finish wax or oil finish).
Just for your own experience....Maybe try a smaller stepover just once so you can compare?
I've thought more than once about gluing some Nyalox 220G(Blue) bristles onto my dust foot bristles to sand it as it carved(but haven't tried yet), but that's just me trying to be lazier than I already am:)
Think you're getting in the ballpark!
Congrats.
scott

[Brady Watson]

Changed from 1/4 inch end mill to 3/8 round nose bit. Speed 13,500 feed 80 IPM.
Changed speed to 16,500 and 80 IPM for the 1/8 tapered ball nose finishing bit.



Use a square end mill or router bit for roughing. Avoid using a ball because it will take more time or miss places.

When you run ideal speeds and get fuzz in natural materials, it is a function of the wood grain. In some woods - and even on the same board, you might get perfect cuts in one area, and then tear out & fuzz city in another. This is all to do with the grain direction of the wood itself.

I run 18,000 when finishing with 1/8" and smaller tools. It lightens up the chipload and keeps the tool from getting 'grabby' and tearing out chunks. It also helps reduce fuzz. The model you show at that scale would probably benefit from using a 1/16" ball to really make it pop, providing that there is enough detail on the model to take advantage of the smaller tool. The toolpath simulation will let you see the difference between 1/8 and 1/16 tools.

Keep experimenting...It's the best teacher.

-B

[myxpykalix]

Sanding Mop:
http://www.amazon.com/s/?ie=UTF8&keywords=sanding+mop&tag=googhydr-20&index=aps&hvadid=29558965147&hvpos=1t1&hvexid=&hvnetw=g&hvrand=7812065960010147765&hvpone=&hvptwo=&hvqmt=e&hvdev=c&ref=pd_sl_8dqav4d5um_e

I use one similar to the "Sanding Flee"

As a wise man once told me...."Google is your friend"