Official Luthiers Forum!

I 'm looking for bits for an upgraded saddle milling rig. Does anyone have strong feelings about what they like best? and a source? I would think a 1/4" shank, up cut, solid carbide would be the natural choice for a stopped slot but someone mentioned spiral bits tend to have chatter or a harmonic flutter when trimming one side of a slot.Anyone else have that experience? Maybe a straight bit w/a high pressure air nozzle to clear chips would run smoother. I figured with all the discussion of David Collins's trick saddle mill and run out of router motors and collets the bit is next in the discussion of precision.

Hi David: I'm going to wait for Dave Collins to come along and provide details of why we like bits from this company: http://www.precisebits.com

They are not cheap but in our experience they do a great job.

Forgot to add that the collets are part of the equation as well, Oh Dave, oh Dave?

David, something to consider: you can eliminate the chatter by using a under sizes cutter and driving around the perimeter of the saddle slot.
I have no idea of what you jig looks like, but you can do this using a collar in a slot. Hope that makes sense.
In addition to Precisebits I also like RobbJack.

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Jim Watts
http://jameswattsguitars.com

wow! looks like a great site. I'm not sure why I never made it there before. Maybe a little late night reading. I like to give business to folks who are so generous with information in addition to selling stuff. Thanks!

Thanks Jim, I'm using a long reference edge on a trapped sub-base. I never really considered using a guide collar with such a small application. visibility is such an issue to say nothing of collar centering. I guess if you used a really large collar you might start to gain visibility again. I'll have to think about that. I would think a clean up pass is the way to go. That way the forces acting on the bit should tend to deflect it parallel with the slot rather than perpendicular. I'm really going to experiment with what works best in the next couple of weeks. After watching how effortlessly David Collins can cut a clean slot with his rig I realized I need a method that will drop the stress level so I eliminate the temptation to avoid a fill and re-slot when it really should be done.


I realize now the cnc crowd has been dealing with this stuff forever but I wonder if an end mill that works in a supper rigid set up might not necessarily be the most forgiving of a more rickety Luthier rig.

I use a solid carbide 1/4" shank down cut bit in a 310 trimmer . I do it in one pass. In Ebony. It works perfectly. Every time.

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Pat

http://www.bqtool.com/
they also carry .031 and .020 bits but you must ask.

as a machinist I never use a down cut bit in an uncleared cut. The chips are forced down and you build up heat, you need to clear chips. Still it is more important to be sharp.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I use this bit in ebony with no problems, nice and clean and straight ever time. I use multiple passes.

http://www.amazon.com/Freud-03-120-8-In ... reud+1%2F8

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"I've been had again"
Tim Benware
Creedmoor, NC

We get most of our production bits from these folks

http://www.bamcarbide.com/

Superior quality, quick courteous service.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Sorry - almost forgot about the forum this weekend.

I would give the folks at precise bits a call. Aside from providing great products, they really know the ins and outs with exhaustive experience, and can help guide best choices for the right tools and components for each job. I can't speak much to chatter and what not, because with our setup using straight, spiral, shallow cuts or deep, we just don't see any of these issues.

I recall having problems long ago, but was never able to find the perfect reliable solution with bits and procedures alone. Every time I solved one issue, there was another shortcoming or inconvenience that became apparent. My solution obviously was to design a whole new system from scratch, no expenses spared where it may leave the slightest room for inconsistencies or inefficiencies. If there were a simpler way, I would never have gone as far as I did with our saddle mill.

That said, if you're not going to be using it several times a month, with care in design, procedures, and a bit of extra time you can do quite well with a more simple jig. Call the folks at Precise Bits, tell them what you are trying to do, what tools you have at your disposal, and what issues you are experiencing that you would like to improve. Their expertise and customer service is perhaps the most valuable product they offer, and they don't even charge for it.

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Eschew obfuscation, espouse elucidation.