Can someone help out... Round bottom holes with a drill bit

[Steve Juris]

I hope some one can point me in the right direction...

I'm a newbie to the Creek but have enjoyed the content and appreciate the work of the members...

I want to make some Mancala boards with my daughter.... the board is really simple but has round and oval "holes" that I cant figure out how to do.

I would prefer to use a drill press vs a plunge router and a round or cove shaped forstners style bit would be great.

I hope you can see the attachment.

Thanks

[Greg Hines, MD]

Welcome to the Creek.

What you need is a round bottom router bit. I doubt that you will find a drill bit that will do the job. What you are looking for is a core-box bit, in the appropriate size.

Doc

[Randall Scott Smith]

Unfortunately, the best way to do this is with a plunge router and a cove bit. Drill bits are not designed to make holes like that, as the rounded bottom means that you would be unable to accurately position the bit on the work piece - it would slide around too much.

Alternatively, you could carve these depressions by hand, but that's about the only other way I can see to do something like this.

Randy

[Terry Barr]

slowly cut with a rotary file in the drillpress. wood burn if done to fast

[Dewey Torres]

One option might be a rosette cutter with a profile that lends itself to the ergonomics of grabbing up the stones such as this one:

http://www.amazon.com/Magnate-8015B-Rosette-Cutters-Diameter/dp/B0002FHMN6/ref=sr_1_12?ie=UTF8&s=hi&qid=1228024931&sr=1-12


There are many profiles out here though.

Hope this helps.

[David Epperson]

slowly cut with a rotary file in the drillpress. wood burn if done to fast
I've done this with a round burr in a drill press, but there's no real reason you couldn't also use a router bit in the drill press as an alternative. Just take light cuts and don't try to hog it all out at once.

[Bill Huber]

One of these should do it.

http://eagleamerica.com/round-nose-bits/p/130-0202/


Now if you want to take the time and have a drill press here is what I did a long time ago for my Dad to put small watch parts in so he could get them out again.

I took a 1/2 rod and cut a slot in it to hold a washer, then use some small bolts and nuts to hold it all together. I then sharpened the washer on the bottom half and then slowly made the cut in the drill press. It worked.....

102345

[Dewey Torres]

One of these should do it.

http://eagleamerica.com/round-nose-bits/p/130-0202/


Now if you want to take the time and have a drill press here is what I did a long time ago for my Dad to put small watch parts in so he could get them out again.

I took a 1/2 rod and cut a slot in it to hold a washer, then use some small bolts and nuts to hold it all together. I then sharpened the washer on the bottom half and then slowly made the cut in the drill press. It worked.....

102345

Dog gone Bill! That is quite clever~!

[Rick Thom]

How about one of these http://www.leevalley.com:80/wood/page.aspx?c=1&p=30180&cat=1,46168,46173&ap=1? Nice round hole to the depth you want.

No clean-up required from removal of bearing from cove bit.

[Bill Huber]

Dog gone Bill! That is quite clever~!

Thanks....... and that was before I knew how to spell wodwrking

[kevin loftus]

Dog gone Bill! That is quite clever~!

I agree, that's a brilliant tip. :D

[Doug Shepard]

I can't tell how big the round ones are, but if they're not too big Rockler has a drill bit for game boards that might work.
http://www.rockler.com/product.cfm?page=5912&filter=marble%20bit

But I'd just buy the one router bit you'd need to do the slot and do the round ones with that too.
http://eagleamerica.com/round-nose-bits/p/130-0202/

[Richard Wolf]

Nice suggestion Bill. Don't over look making your own drill bit. Start with a spade bit and head to the grinder. I make custom drill bits all the time from spade bits.

Richard

[Bill White]

Nice suggestion Bill. Don't over look making your own drill bit. Start with a spade bit and head to the grinder. I make custom drill bits all the time from spade bits.

Richard

How do ya keep the bits from chattering? Slow speed? High speed?
Bill

[Richard Wolf]

I use custom made bits at slow speeds. Most of the bits I make are tapered or custom sizes for drilling holes for balusters on my railings.

Richard

[Dan Hahr]

http://www.amazon.com/Magnate-1515-Extra-Deep-Router/dp/B000WZ3FWI/ref=sr_1_2?ie=UTF8&s=hi&qid=1228103124&sr=1-2

You'd probably need a template and guide bushing in the router.

Dan

[Chip Lindley]

Since this project is with your daughter, she may be frightened by the BRN!!! ( Big Router Noise) Just use your router cove bit in the drill press. Slower cutting speed may mean a rougher cut with more finishing to do. My other suggestion is to use a round nose milling cutter designed for metal working. Either will work in a drill press but you must decide to freehand the cut or guide it beneath the cutter in a jig.

[Chip Lindley]

WayyyCool! Bill !! You receive my *NITMOI* Award for the month of December, and its only the 1st!!

*NITMOI* = Necessisity Is The Mother Of Invention.......*chuckles*

[lowell holmes]

A spoon bit in a brace might do the job..

[Rob Russell]

I would say that the core box bit in a plunge router with a guide collar is the way to go.

Make template in the pattern you want. Use guide bushings that are close to the bit size so the template holes aren't too much oversize. With some thought, you could route the flat of the oval part. Put in a straight cutting bit with a larger guide collar so the router is held away from the curved sides of the oval. Otherwise just route out everything with the core bit.