Binding router bits

[Pegasus Guitars]

I have used LMI router bits with bearings to cut my binding ledges for years. I have several extra spare parts to fit that expensive set of bearings and bits. I'm coming to the end of my last sharp router bits and wondering if anyone knows if the Stew-Mac bits are interchangeable with the LMI ones? Do the LMI bearings work on the Stew-Mac bits?I'm afraid that I can already guess the answer, and it probably is not a good one. No conjecture please. Just the real answer, if you know it. Much appreciated. Enjoy your building.-Bob

 

[Timbuck]

I've always assumed that all bearing come in international standards ..and the size and type is designated by a number I/d ..just look up a few bearing suppliers charts and you will find the bearings you require at a lot less cost than LMI or Stewmac prices.

 

[Timbuck]

Bob here is a typical chart ... https://iskbearing.com/news/knowled...rings-a-comprehensive-chart-for-ball-bearings

 

[JJohansen]

Hey Bob, a little off topic but I recently switched from the bearing style binding bits to the Luthier Tool self aligning binding cutter. It uses a regular 1\4" down cut spiral bit and is universally adjustable. Its pretty awesome.

 

[Pegasus Guitars]

Thanks for the replies. I'll check with Stew-Mac and see if they have a direct answer. Josh, I tried that Luthier Tool and ended up selling it. The concept is great, and it is a great take on the traditional style cutter that many builders use, but I was not able to get the hang of it. I did try it on several instruments and, unfortunately, just was not able to control it.

 

[Tom Snape]

I have the Stewmac cutters and the shaft that the bearings mount on measures 0.249" diameter. The bearings from Stewmac are 1/4" wide (except for some older ones I have that are 3/16" wide). The smallest bearing I have is 1/2" OD. The bearings look like standard ball bearings with metal shields on both sides. For some of the older ones I have, the bearings are pressed into machined rings to gain the additional diameters. I think many of the newer ones are also made that way to gain the large range of sizes, but the work is much better so it's difficult to tell. SM calls the 0.925" OD bearing the flush cut size, and I measured 0.929" from tip to tip on my cutter.

 

[Pegasus Guitars]

Thanks for the measurements. I guess no one has actually tried to interchange the cutters or bearings. Stew-Mac has not answered me, but maybe they will. They used to be very responsive to e-mails or calls. things change!

 

[Tom Snape]

I was trying to find some information on the LMII cutter set, and ran across this:

Binding Cutter & Bearing Set - Birkonium

This is the cutter and bearing set formerly available from LMII. One of the most useful binding cutter kits available for a number of reasons: Cutter has an outside diameter of exactly 1″ to make any math intuitive and easier. Cutter edge is slightly down cut to prevent tear out on your top...

birkonium.com

I think the key thing for you is whether or not the LMII bearings have a 1/4" bore. If so, they should mount fine on the SM cutters. Then you would have to calculate (or do a trial cut, always a good idea anyway) the cutting depth, as the SM cutter appears to be a little smaller OD than the LMII (the link above says 1" OD for the LMII cutter).

 

[Pegasus Guitars]

Stew-Mac has confirmed that the bits and bearings from the now defunct LMI are not compatible with theirs. That's unfortunate as it will cost us builders a bit of money. Oh well!