Cutting small parts in very thin stock

[mmak2916]

I'd like to cut round pieces that are 0.370 and 0.245 in diameter on 0.066 thick maple stock. Has anyone have experience in cutting small parts on very thin stock, any do's and don'ts? I'm thinking about using the Onsurd 61-040 1/8" straight O flute bit that came with the Desktop starter bit kit.

Thanks!

[steve_g]

Margaret
Here’s how I cut very small parts
· Design and toolpath as normal.
· Cut into a board much thicker than the thickness of your part. Do not cut through the board! Cut only a little deeper than the desired thickness.
· Put tape over the face of the board
· Resaw on bandsaw to correct thickness
The parts are held in place by the tape while you’re cutting them to thickness.
The attached image shows some earrings that approach the size you’re proposing. They were cut from the blank on the left. After cutting them out, I taped them to the board they are on now for finishing.
SG

[mmak2916]

Thanks Steve, that's such an awesome idea, I will try your method!

I purchased the Desktop starter bit kit (#13698), is there any online documentation of what bits are good for what kind of cuts? I understand (I think) the straight bits and up/down cut bits but in which cases would you use a ballnose, "Upcut Super O" straight bit, or a tapered ballnose bit? Or should this question be asked in another post?

[steve_g]

Margaret...
Here’s a link to an article I edited a number of years ago with the help of many ShopBotters! I hope it’ll answer a number of your questions about router bits…
If not don’t be afraid to ask!
SG
https://drive.google.com/file/d/0B8GtiBWUjRyRY01lYmNrWW5CVUU/view?usp=sharing (https://drive.google.com/file/d/0B8GtiBWUjRyRY01lYmNrWW5CVUU/view?usp=sharing)

[scottp55]

Margaret, Onsrud 61-041 was one of my most used bits when I first started:)
After reading Steves excellent article, You'll see that the 61-040 doesn't tear out on top or bottom like an up or downcut, won't lift material like an upcut,but doesn't exert down pressure either. Decent chip clearance with a good dust collection system and with DC off-packs the chips in kerf to help hold small parts, very reasonable pocket finish and sidewall cut. In short a VERY versatile bit. Good settings for Hard Maple for 61-040(for me) seemed to be 1.1,.5,14K for the best finish. See pics for 61-040 cuts in Maple.
Good bit for Steve's method with bandsaw.
Another method if no bandsaw is to surface another board Flat ON YOUR MACHINE (not MDF if you can-tape doesn't stick enough if bare-unfinished),2 coats Lacquer or Zinser universal sanding/sealer(unwaxed shellac) (to prevent tape residue sticking) and then tape the surface board(medium tack 2" masking/packing/transfer tapes have been used). Then Tape the material you are cutting the same. Now, on backer board lay carpet tape(I use Ace Hardware heavy-duty 2" fiberglass reinforced, but other tapes that DO and DON'T work in this thread starting at #14http://www.talkshopbot.com/forum/showthread.php?t=18763)

If using this method for Small parts, see Brady's note to use the smallest available bit! If you can live with a steep 30degree angle on the piece, I'd cut out using a 1/8"30degree bit( I use these and they cut clean but you need an 1/8" collet which I would recommend buying no matter whathttp://www.ebay.com/itm/30-degree-bits-for-scoring-or-engraving-sharp-point-narrow-tip-Kyocera-Tycom-/151386398234?pt=LH_DefaultDomain_0&hash=item233f551e1a)

Rambling,
scott

[mmak2916]

Thanks Steve for the document, it's downloaded in my resources folder. :)

Scott, the cuts with the 61-040 looks very clean and crisp. Can't wait to try it out!

[Roy Harding]

Margaret
Here’s how I cut very small parts
· Design and toolpath as normal.
· Cut into a board much thicker than the thickness of your part. Do not cut through the board! Cut only a little deeper than the desired thickness.
· Put tape over the face of the board
· Resaw on bandsaw to correct thickness
The parts are held in place by the tape while you’re cutting them to thickness.
The attached image shows some earrings that approach the size you’re proposing. They were cut from the blank on the left. After cutting them out, I taped them to the board they are on now for finishing.
SG

I do something very similar - only instead of resawing on the bandsaw, I run the piece through the drum sander until the carvings are released.

Never thought of the resaw idea - I'll have to give it a whirl for smaller pieces.

[moell54]

Just a curiosity question. I wonder if a drag knife can cut something that thin?