The perfect pattern router bit?

[Tom Rick]

Can I get a up spiral dual bearing bit somewhere?
One of those with the bearing top and bottom?

I would like a a set perhaps in a few diameters/lengths.

Thanks all

[Tom Rick]

Ok- google is my friend.

So far I found this bit & it looks good:

http://www.amanatool.com/routerbits/images/47094-profile.jpg

http://www.amanatool.com/routerbits/down-shear-trimmer-47094.html

I think what I want is up shear though so it pulls the workpiece onto table...



I am also looking at this bit in a old thread:

http://www.sawmillcreek.org/attachment.php?attachmentid=135548&thumb=1&d=1261138038

http://www.sawmillcreek.org/showthread.php?t=127290&highlight=pattern+router

[glenn bradley]

I have not found them. I imagine the engineering challenge is decent; bit diameter, bearing I.D. and strength combination could be interesting. I have had success with shear cut versions but do prefer spirals. I wish someone would make a selection of sizes with top and bottom bearings and a spiral profile . . .

I have put my own bearings and collars on larger diameter bits (http://www.justfreud.com/freud_down_shear_trim.htm). For tighter curves it would be nice to have 1/2" and below. And you're title says it all, the perfect pattern bit would have upper and lower bearing and a spiral cutting area.

[John Coloccia]

Here's another source. I think this is a Whiteside bit.
http://www.lmii.com/CartTwo/thirdproducts.asp?CategoryName=Rout%2FShape%2FDril l&NameProdHeader=Flush+Trim+Router+Bit+with+Bearings

Just as an FYI, if you're ever looking for out of the ordinary tools, luthier suppliers are usually an excellent source to check. You if you've never browsed through the StewMac or LMII websites, you'll be pretty surprised when you see the collection of clamps and tools that are available and applicable to a lot more than guitars and violins.

[John Coloccia]

I have not found them.

I also can't figure out why no one makes a spiral with a bearing on top. I think they're just out to annoy us.

[Tom Rick]

I also can't figure out why no one makes a spiral with a bearing on top. I think they're just out to annoy us.

The whole world has 'my number' at times and are all out to get me.....
:)

Thanks for the heads up about the bits.

U a luthier?

I spent 5 years doing bench work on classical string repairs years and years ago. Was just about my first job. I ended up living on the bow bench but did the whole gamete of string repairs..
never built though.
:(

[John Coloccia]

The whole world has 'my number' at times and are all out to get me.....
:)

Thanks for the heads up.

U a luthier?

I spent 5 years doing bench work on classical string repairs years and years ago. Was just about my first job. I ended up living on the bow bench but did the whole gamete of string repairs..
never built though.
:(

I build, but I wouldn't consider myself a luthier. I don't generally do repairs, although I have a couple in my shop right now that I'm doing for friends. They're both on nylons. One has a neck that was coming apart. CHEAP thing. Getting the neck off was an experience. It was glued in with dowels, so I had to basically very slowly chop through them with a thin palette knife of all things. Took FOREVER. The other has a collapsing body, so the neck angle is seriously off (it's aiming at the base of the bridge!), but it has a Spanish foot. For that one, I'm going to pop off the fingerboard and either shim it to the correct angle or just simply build a new fingerboard tapered to the correct angle. Neither one of these guitars is valuable enough to do the rebuilding necessary to make them "right". My goal is to just get them playable again for my friends.

Anyhow, all I do is build, and rather primitively compared to some folks like our own George Wilson.

[Gene Howe]

I'd want a 1/2" shank, so the spiral would have to be some what wider. In solid carbide, that would be one $$expensive$$ bit.
Might as well go with that $130 end mill style bit.
Buy two:eek: One with a top bearing and one with a bottom bearing.
Personally, I use an over arm pin router. Almost as cheap as a couple of those end mills!

[Brian Gumpper]

You will not find a spiral bit with a beearing on the shank for one simple reason, cost.

The way the spirals are made is they start from a solid rod of carbide that matches the shank diameter. So in order for a 1/2" shank bit to be made, you would have to start with a 3/4" diameter rod and machine the shank down to 1/2". You can then put a bearing and collar on the shank to match the 3/4" cutting diameter.

Research 3/4" solid carbide spiral bits and you'll find they are typically over $100 just for the bit. Then add the maching for the shank and the bearing/collar and the bit gets even more expensive.

[glenn bradley]

Thanks Brian. That pretty much solidifies what I felt in my gut.

[Van Huskey]

You will not find a spiral bit with a beearing on the shank for one simple reason, cost.

The way the spirals are made is they start from a solid rod of carbide that matches the shank diameter. So in order for a 1/2" shank bit to be made, you would have to start with a 3/4" diameter rod and machine the shank down to 1/2". You can then put a bearing and collar on the shank to match the 3/4" cutting diameter.

Research 3/4" solid carbide spiral bits and you'll find they are typically over $100 just for the bit. Then add the maching for the shank and the bearing/collar and the bit gets even more expensive.


Add on top of this when it is sharpened the first time it doesn't match the coller anymore, so useless as a pattern bit after you spent over $100 on it.

[Peter Quinn]

http://www.infinitytools.com/Double-Bearing-Pattern-Router-Bits/products/1336/

Not a spiral, but not bad.

[Tom Rick]

I build, but I wouldn't consider myself a luthier. I don't generally do repairs, although I have a couple in my shop right now that I'm doing for friends. They're both on nylons. One has a neck that was coming apart. CHEAP thing. Getting the neck off was an experience. It was glued in with dowels, so I had to basically very slowly chop through them with a thin palette knife of all things. Took FOREVER. The other has a collapsing body, so the neck angle is seriously off (it's aiming at the base of the bridge!), but it has a Spanish foot. For that one, I'm going to pop off the fingerboard and either shim it to the correct angle or just simply build a new fingerboard tapered to the correct angle. Neither one of these guitars is valuable enough to do the rebuilding necessary to make them "right". My goal is to just get them playable again for my friends.

Anyhow, all I do is build, and rather primitively compared to some folks like our own George Wilson.

Hey John-

Brings back memories.
One thing you might try on the guitar necks: we used to rig a heavy hypodermic needle to a steam pot via some 1/4" hose. The long needle is thread into a 1/16" hole drilled into the neck so as to get the tip well into the joint. We could usually find some spot to drill the could be covered after the repair such as under the heel plate. Give it some steam and time and the necks can be pulled loose by hand in many instances. I remember some real messes on the cheap ones... 1/4" gaps in joints etc.. We would clean up the dovetails and add wood to the cheeks to tighten up the joint before putting it all back together.

[John Coloccia]

Hey John-

Brings back memories.
One thing you might try on the guitar necks: we used to rig a heavy hypodermic needle to a steam pot via some 1/4" hose. The long needle is thread into a 1/16" hole drilled into the neck so as to get the tip well into the joint. We could usually find some spot to drill the could be covered after the repair such as under the heel plate. Give it some steam and time and the necks can be pulled loose by hand in many instances. I remember some real messes on the cheap ones... 1/4" gaps in joints etc.. We would clean up the dovetails and add wood to the cheeks to tighten up the joint before putting it all back together.

The way this one was assembled from the looks of it (and this is a guess as I haven't removed the fretboard) was they clamped the neck where they wanted it with a couple of shims for the angle and a stop so it wouldn't move. Then they drilled through the neck from the top, and through the neck block, and inserted dowels. They they took it apart, slathered glue on it, and glued it all together with the dowels in place, and then glued on the fingerboard. It's not a dovetail or anything like that. It's a deep tenon like you'd find on a Les Paul, but they pinned it to the neck block! LOL.

I'm so happy I don't do repairs for a living. I would very rapidly come to DESPISE my time spent in the shop.