Large Forstner bits?

[ian maybury]

As above. I'm wondering if the economical alternative mightn't be a cheaper set that's had some fettling/tender loving care - in the way that more economical hand planes can be made to work very well too.

To be more specific. I'd need to sit down and go through the required grinding and honing operations to even work out the requirement properly - but I wonder if it wouldn't be possible to organise some sort of jig to accurately guide a die grinder to get the angles right. That Colt chip breaker set up might be possible to duplicate. All before some sort of final hand honing with say a diamond slip.

I wonder too if there is a definitive statement of the correct angles somewhere about? It looks very much like one aspect of the design of the Colt is to make it easy to machine grind.....

Ian

[Van Huskey]

As above. I'm wondering if the economical alternative mightn't be a cheaper set that's had some fettling/tender loving care - in the way that more economical hand planes can be made to work very well too.

To be more specific. I'd need to sit down and go through the required grinding and honing operations to even work out the requirement properly - but I wonder if it wouldn't be possible to organise some sort of jig to accurately guide a die grinder to get the angles right. That Colt chip breaker set up might be possible to duplicate. All before some sort of final hand honing with say a diamond slip.

I wonder too if there is a definitive statement of the correct angles somewhere about? It looks very much like one aspect of the design of the Colt is to make it easy to machine grind.....

Ian

If you are a fan of hand sharpening there may be some truth to that, I would look to an older set that didn't have metal the consistency of pot metal though.

[Greg Portland]

I realize thet 600 rpm is too fast, but that is as slow as my drill press will go.

If you are drilling through-holes then get a hole saw and cut from one side, flip, and cut from the other side; those bits should work at the high RPM you're using. 600rpm is way too fast for a traditional Forstner of that size.

Its rare that I'll suggest a trip to the borg, but I've been buying freud Diablo's from the HD, they work quit well both freehand and in a drill press

+1. I have a large Freud for drilling out door knob holes and have been pleased with its performance. However, they are not cheap ($45 or so IIRC). Freud sells a cheaper non-carbide version that I have not tried. Here's an example of the "good" Freud bits: http://www.amazon.com/Freud-FC-015-2...sr=1-2-catcorr