sanding issue's

[POPS 64]

I've been using my shopbot for a year now. But I.ve been a woodworker for years. I'am having a issue with sanding some things with all the details removing the fuzzy's. Ive been using steelwool and it's been working but a new project i just finished it's not even touching. A sea shell box , I been thinking about trying the 3-M whisker wheels for hand carvers anyone ever try them or have better idea's.

[scottp55]

3M Radial Bristle Discs work great. Nicer if you've got variable speed. 3/4" are nice, but quickly wear down to not being usable for deep stuff. I like the white 1" 120G. One note-I found out the hard way that in softer woods(or wood with large growth rings) that it's better to use them ACROSS the grain or you'll get a sandblasted effect as it will cut the pith much faster.http://www.amazon.com/s?ie=UTF8&page=1&rh=i%3Aaps%2Ck%3A3m%20radial%20bristle%20disc

[cowboy1296]

I use a little bit of everything. After cutting a 3-d project i use a 180 grit sanding mop on a battery powered drill. I then use needle files. I then use a pen sander. I then use a 220 grit sanding mop. Some believe that if you put a coat of shellac on the project that it will make the fuzzies stiffen up and they break off easier. I would bet that i remove most of the fuzzies with the needle files.

[bbrozo]

This may sound a little crazy but I drop the stepover all the way down to 3-4% when I run 3d projects on the finish pass. I don't do alot of 3d work (mostly I use the SB for 2d work) but when I do, I've found I'd rather have the shopbot do the "sanding" by using a lower stepover than spend hours myself doing it.

I do a final pass with the white 3m radial bristle discs and the 3d work comes out looking polished.

My 2 cents...
Bill

[myxpykalix]

I use a sanding mop on my drill press. I found that my cordless drill doesn't have the power to dislodge some of those fuzzies:eek:

[POPS 64]

Thank you for the input , going to order a sanding mop and 3-M bristle this morning, and the stepover is interesting . I change that up when I do lithophane's from the numbers I was taught with , big difference.

[scottp55]

Jeff, quality of the cutter is important as well as species of wood and direction of the finish pass taking into account the grain direction. We tried a cheaper ballnose and got dramatic differences than when we used the Onsrud as far as "Fuzzies". If Quality is more important than your finishing time, then try running finish toolpath twice to see the difference.

[cowboy1296]

Since you are doing 2 passes in finishing what kind of step over are you using. Post some pictures of your projects if you dont mind.

[scottp55]

Kirk at second Desktop has been doing most of the 3D work so far. He started at 8% but think he's running about 5-6% with the 1/16" tapered BN from starter set now for small crib board(3.5X4"). He was using a dremel wire wheel on his Dad's(5'th generation Acadian wood carver), but now have him sold on 3M wheels as he was losing detail(the difference between CNC and chip carving chisels) using his Dad's methods. Only have some old cell phone pics from when he was learning and using wire wheel. He's learning so quick he's putting me to shame:) After coming down last weekend(we're 6 hours drive apart) for a finishing cram session his work will only get better. He used 1/8" Onsrud BN at 6% for the moose.

[bbrozo]

It's the "crazy step over guy" again. I forgot to mention that in addition to dropping the step over down to 3-4%, I also increase the feed rate. So, for example, if I would normally run a bit at 1.5 ips, I would boost it up to 3 ips so the combination of lower step over & higher ips yields a higher quality finish without taking much more time.

Bill

[scottp55]

Thanks for bring that up Bill. I forgot to mention that. Sometimes in VCarving we'll add a whole separate toolpath using the same exact bit but grab the tool from a separate category we made in the tool database we labelled"XXX FULLDEPTH SKINPASS" meant ONLY for a clean up pass with ridiculous settings like 1/8" 60vbit with a pass depth of .7" and a 3.5,1.5,16K so it's doing nothing but cutting "fuzz" and bit deflections. Especially on sugar maple.

[Brian Harnett]

This kit from harbor freight comes in handy for cleaning up fuzzy spots the grit is pretty fine.
http://www.harborfreight.com/50-piece-diamond-rotary-point-set-69665.html

[POPS 64]

Lot's of good information guys ,lots of things to try and think about . I hate to admit I never really considered wood grain direction . not being a computer person until this I guess I probably focus on things not as important . but iam getting more comfortable all the time. I guess thats why I finally decided to try the forum . here's a few picts.

[Roy Harding]

I often run the toolpath, shellac the piece in place on the machine, then run the toolpath again. It takes more machine time, but saves me labour time as the sanding required is close to nil.

[scottp55]

Especially like the bear Jeff. I'll let other people chime in but we've had best luck roughing against the grain, and finishing with(but we're newbies and just using some advice we got). Good info-nice people here.

[magic]

Here's another approach.
I use an oversize bit in a Hog Out scenario. The difference is .05 above the desired artwork.

Then I employ the old technique of wetting the wood and purposely wetting the grain (raising it) and when the smaller correct size bit makes the finishing pass, the fuzzies are not as prevalent.

Sometimes I'll mist the piece with water again before using all various sanders and hand swirling the sandpaper that's wrapped around different dowell rods.

I have also used a 3D spiral toolpath starting in the center THEN running the ssme file using the 3D spiral toolpath starting from the outside.

The direction of the grain and species needs to be respected and adjusted for. If the wood blank was cut near the outside of the tree and the grain is loose and fluffy you might not get the same results as harder interior woods where the grain stands straight up.

Finally, for small projects, I'll use two different bits with different geometry on the ball, rerunning the file and changing the stopover.

-------
Did I mention that I hardly ever turn a profit because of all the wasted time?

[Burkhardt]

For real tight spots I like the Proxxon Pen Sander and attach a fiberglass scrub stick with tape. I wish the Proxxon had a more elegant way of mounting it but it does work quite well. It removes fuzz easily without destroying the detail (not suited for volume removal of materials) The sticks are cheap (http://www.amazon.com/gp/product/B005ISQAFI) and last for a while. Unlike sand paper they don't clog . Minor disadvantage is the itch from the fiberglass fragments. There are brass wire brushes of the same size but I have not tried that.

https://lh3.googleusercontent.com/-CTK3B7biQPw/U5UxHV1y9VI/AAAAAAAAE1s/Dz8gTHB9V-o/w1347-h853-no/DSC02401.JPG

[cowboy1296]

I would not buy a pen sander to try the fiberglass brushes, but i own the pen sander already. I might just to try the brushes that you recommended G. Burkhardt. Thanks for the tip.

[bcondon]

You talked about reducing the stepover.. A second thought is what wood are you using? Poplar and Boxwood are good for carving because of the lack of grain but they fuzz up a lot.. You may want to look at other wood choices.... I like boxwood over poplar. I use the square sanding blocks and use the edges and corners of the block.... Enough block to hold onto but fine enough to get into the scallop shell grooves...

Thanks
Bob

[POPS 64]

I do a lot of carvings with hickory , bloodwood , and walnut , but i've been getting a lot of request's forcedar , pine , and different maples all fuzzy nightmares. I'll have to try popalaralot of that here but haven't seen any boxwood. thanks for input

[Burkhardt]

Since I posted a few days ago about the glass fiber brush I came up with a slightly more elegant holder on the pen sander. This is a thin wall brass tube that I glued to a chopped-off Proxxon sander extension. The length adjustment with the duct tape is still not that pretty but it works much better since the fibers are held together and don't fray as much (picture 1).

For practical test I machined intentionally a very fuzzy 4x4" relief from Birch plywood with an 1/8" ballnose and coarse 20% stepover (picture 2).

Removing the fuzz with the fiber brush took about 3-4 minutes (picture 3). Since the tip is only 3/16" diameter it can go really deep into the inner corners. It removes easily the lose fibers but the detail (here the bit traces) is still there. For further improvement maybe I will make a lightweight plastic collet to hold and adjust the fiber brush stick.

https://lh5.googleusercontent.com/-DhHCV3v8Ibc/U5-qYff0vcI/AAAAAAAAE38/lD_kpxYZmD0/w856-h853-no/DSC02419.JPG

https://lh3.googleusercontent.com/-lkxiyJi7zKg/U5-qVPTuA_I/AAAAAAAAE4M/7-2MdGD4LpQ/w884-h853-no/DSC02416.JPG

https://lh6.googleusercontent.com/-8k87MCrrXfI/U5-qW-rKobI/AAAAAAAAE4U/2GM6SOOk2tY/w1063-h853-no/DSC02417.JPG

[myxpykalix]

G,
That looks like it does an excellent job!!:D

[POPS 64]

G , looks like it works great think I'll have to give it a try. thanks

[Bob Eustace]

Reckon you are really onto something there Gert. Proxxson works a lot better if one doesnt use their short life abrasives. I cant wait to try your new technique.

[Burkhardt]

Maybe a video clip can show better how it works. I apologize for the video quality. It was not trivial shooting the clip with the left hand while sanding with the other hand :rolleyes: There is much better control of the sander when you can work with both hands.

This is the same relief as shown before but this time in softwood (unknown species, maybe yellow pine?) with same settings: 1/8" ball nose, 20% stepover, 150 ipm, full depth cut. This gets really fuzzy.

https://www.youtube.com/watch?v=YFhWqOjXZfM


Before
https://lh3.googleusercontent.com/-dCQmFC2iQdQ/U6JEmCzshaI/AAAAAAAAE4c/THpuBHVL0-w/w1170-h853-no/DSC02420.JPG


After
https://lh5.googleusercontent.com/-Yf_zI2XPN5k/U6JEoD31QRI/AAAAAAAAE4k/kfbbHbsYBGc/w1184-h853-no/DSC02421.JPG

[scottp55]

G. , You did use that wood and those settings to MAKE a fuzzy example--Right? :)

[Burkhardt]

G. , You did use that wood and those settings to MAKE a fuzzy example--Right? :)
Yes, that was the idea. That softwood is pretty bad but it still came out better than I thought. I have had worse examples in the past. Maybe that was with a dull bit or cutting across the grain.
Actually that 2x4 material was so soft the fiber brush could smooth out the bit traces, you can see some "bald" spots in the picture where I used the sander too long.