What's the best 1/2" core box router bit?

[Roger Feeley]

I'm making 80 chinese checker games. Fortunately, these are two person games (sort of diamond shaped) so I'm only (sheesh!) drilling about 4,000 holes.

If I'm going to do that many holes, I would like the best darn bit I can find.

I have the jig from Rockler but I see a fair amount of tearout from the bit. I put a core box bit in my drill press and ran it at about 10K RPM. The results were better but not perfect.

Any suggestions would be appreciated.

[Mel Fulks]

The best core box router bits are high speed steel .They are now hard to find ,check with a pattern makers supply house .I have had to get them made . Used a custom tooling company . They are best used with an adjustable speed router ,using the slowest speed that will do the job.

[Ron Kellison]

I have several, in different sizes, from Lee Valley. They do a good job but I use them primarily for fluting columns, which means the wood is moving. HSS bits will probably be sharper and do a great job but I question whether they would last through 4,000 "dimples" unless you're using a soft wood like pine, poplar or alder.

Ron

[Mel Fulks]

Agree. I would get more than one. None if you don't have variable speed router .They cut fast ,don't burn,don't chip.

[Shaddy Dedmore]

Is there a way to attach a thin sheet of sacrificial wood to the bottom of the jig. Then cut through it to the piece, so it acts like a zero clearance, helping prevent tear out?

[Ryan Baker]

I did that very job right before Christmas. My choice is Whiteside. It's a lot of holes. A good template helps a lot.

Depending on the wood, you shouldn't get much tearout. But if you get some, you could cut through a sacrificial layer like Shaddy said. You can also do a better version of the same thing by leaving some extra thickness on the piece and taking a cleanup pass after the holes are cut.

[Mel Fulks]

Will the games be painted or stained ? If painted carbide might be ok,it's hard to get carbide down and back up without scorching .If its not painted I would definitely use steel.

[Morey St. Denis]

If you can accommodate a full 1/2" shank router bit, and your concern is primarily tear-out at the hole edges, then you may want to consider trying a full carbide spiral fluted ball-ended milling bit. These are usually employed in metal machining, not commonly for woodworking. May want to check if a down-spiral double fluted model might be readily available, sounds like these hemispherical "dimples" are not much beyond a radius deep and a down-spiral router bit is least likely to cause any edge tear-out on a shallow plunge cut.

[Ryan Baker]

A good carbide bit will not burn. Cheap carbide bits with uneven grinds burn everything they get near.

If you have a spiral ball-end mill available, or have time to order one, that likely would work even better.

[Jim Neeley]

Whiteside would be my first choice too.

[Mel Fulks]

As to the carbide burning,I blame it more on the peculiar geometry of core box bits. I don't think I have seen one pilaster fluted with a two flute carbide bit that did not burn. For that type of application I have had to order custom made bits for non painted work. The steel cuts much faster. I have not used the spiral types etc that have been mentioned ,but will try them.

[david brum]

Not sure if this would help, but it might be worth contacting the company to hear what they have to say about insert tooling: http://www.toolstoday.com/p-6016-in-tech-series-insert-core-box-router-bit.aspx

[Mel Fulks]

David,That is interesting and new to me. Looks like that would work better than the standard two flute by avoiding that 'not much happening ' awkward point at bottom center ,thanks.

[david brum]

Yeah Mel, I love the idea of insert tooling, especially for something that will probably get sharpened often. My understanding is that since the carbide doesn't get brazed, the manufacturer can use a different grade, presumably something harder. I have a Euro block cutter head for my shaper, which I love. It makes sense to apply the same technology to router bits.

[Andrew Joiner]

Yeah Mel, I love the idea of insert tooling, especially for something that will probably get sharpened often. My understanding is that since the carbide doesn't get brazed, the manufacturer can use a different grade, presumably something harder. I have a Euro block cutter head for my shaper, which I love. It makes sense to apply the same technology to router bits.

Thanks David for the link. I'm surprised at the low cost. It seems like a great idea.