Small bits

[genek]

I make small wooden jewelry from wood scraps with my scroll saw. Now I am looking at making them with the cnc using small bits and a 1/8 Collete. Here is a picture of one of the necklaces that I do. With the scroll saw I can not get the production runs that I could with the cnc. Has any of you had any experience with the smaller bits cutting wood.

[SomeSailor]

Looks like something a laser would be well-suited for. Fixturing something that small would be challenging but if you were doing many I'm sure you could work out a clever vacuum mount.

[genek]

laser leaves burnt sides that makes it less desirable. I have lasers and the necklaces do not move as good. I actually move more that I scroll saw. cutting with a small bit and onion skinning it will be no problem I do that every day. Fasting the wood down is easy.. would do a 4 inch wide board 48 to 96 inches long 1/4 inch thick held with screws.

[Max Girouard]

I've had a fair amount of experimenting and the use of smaller bits to cut out our stuff for our mandolins. I use a 0.023 bit to cut our inlay pockets, a 0.0625 bit to cut the peghead profiles and a 0.020 to cut the shell. All of them have a 1/8 shank and I buy them from precise bits. I think a 1/32 or even a 1/16th bit might work for your G cleff. Let me know if you need any more specific info. Here are some samples of work we've done with the smaller tools.

[scottp55]

Eugene, Have you ever inlayed? Max's stuff looks beautiful, and I always see walnut and maple in your pics. G cleff inside guitar pick shape?

[genek]

Girourad: That is supper nice.I think you have it down right for the bits. will order them Monday. I ordered the Collete yesterday. Your Mandolins must be top of the line from looking at the work you posted here. You make doing inlay look a breeze.

Scott: I do inlay from time to time. but the smallest inlay I have done is 1/8 and it was straight lines.. Nothing as good or as fancy as what Mr. Girourad showed us.

[cnc_works]

Color me impressed, Max. Could you go into a little more detail about hold down & release, feeds & speeds, tolerances and so forth?

[jerry_stanek]

Joe Crumley show a slick way to do this. He cuts small parts in thicker material then uses his band resaw to the correct thickness releasing the small parts.

[bobmoore]

Max don't be so humble. That is amazing work. I'm with Don, can you share any more detail of those inlays? I will watch for a new thread.
Bob

[chiloquinruss]

Also check out Wigetworks: Russ

http://www.widgetworksunlimited.com/CNC_Pressure_Foot_br_for_ShopBot_PRS_p/cnc-pressure-sb_prs.htm

[Bob Eustace]

Eugene, a clever person on this forum came up with a brilliant way of cutting out small letters without tabs. He simply did an outside profile using a 1/8th bit around 1/4 deep in 3/4 thick material. You then pop over to the bandsaw and cut a sliver off the front. Very clever method that we have since used often.

[Max Girouard]

Scot, that is a great idea with the inlay in a guitar shaped pick. I've got a ton of small ebony scrap and tiny bits of pearl that are building up. May have to expand on that idea and come up with some jewelry for the wife! Thanks for the idea!

Eugene, thanks for the kind words. We try our best and the bot has sure made things easier. Inlay may look easy but it took lots of experimenting and broken bits to get it right, but I'm happy to share what I know to help others from busting those expensive little bits!

Don, For fret slotting, I use a 0.023 sized cutter with my PC router full bore at 23,000 rpm. I take only 0.010 deep passes at 100 IPM. This seems to be a sweet spot for the ebony as I have not broken a bit in a while and just ran 20 fretboards on a single bit. For my inlay pockets using the same bit, the RPM and pass depth are the same, but I go only 7 IPM due to all the curves and direction changes. Most importantly, I change my ramp values in the control software from .4 to .2 I learned this little tid bit from Brady. He has a paper he wrote on ramp values, I'll see if I can find it and post it. I'm thinking I can go faster with my feed, but I need more time to experiment. My inlay pockets are 0.006 larger than the actual inlays. I have a vacuum fixture that I made for holding the headstock overlays for inlay pocket cutting and profile cuts. The shell is glued to a piece of wood with super glue and then I cut through the shell and a little bit into the wood. I then toss the hole thing into an acetone bath and within a few hours I can just pick the pieces out. I'm going to try doing the same thing with a piece of phenolic and some hide glue so that I don't have to mess around with the acetone. It gives me a headache. For profile cuts, I've been cutting at 23,000 rpm with a 1/16 bit at full pass depth running at 100 IPM.

Russ, I've thought about using the widget works pressure foot, but have not had a chance to purchase or experiment with one. I have however used the diamond drag to engrave our tail piece covers. They came out great!

[scottp55]

Max, a little off topic, but what adhesive are you using for ebony/shell. Made a opal/ebony necklace years ago but she moved to Tucson right after and I never saw how it held up. I think I remember using opticon after cleaning ebony oil off with acetone, but not sure. Want to use up some Macassar "scrap" and opal "waste" with the desktop. Thank in advance.

[Max Girouard]

We have been using medium viscosity cryanoacrylate (super glue generic name) for putting the inlay's in. I used to use epoxy with black pigment as a filler but with the bot there is no need for filler any more. I just switched over to an odorless cryanocrylate that I got from hobyinc.com Great stuff and it is gap filling too if needed.

[scottp55]

Thanks Max, think I need a longer work time to orient the opal chips and there is as much clear glue as there is opal to show some multi directionality. different uses. I use a 14,000 thru 50,000 to bring flush and polish exposed opal. Sure the other guys will try yours for their stuff. Thanks again. scott

[shoeshine]

www.precisebits.com (http://www.precisebits.com)

One of the things that has been a mainstay, though not a huge business, is making inlay pieces for a pool cue maker here in town.