mica under cutting tool

[rogerkb1936]

hi, duz anybody know a source of the little (5/16 dia) buzz-saw shaped cutting tools that some of the old time shop equip used? this equipment was used to undercut the mica on gen commutators. got a couple nice machines but need these little "saws" to use them. thnax, roger kb

 

[Russ/40]

Harbor Freight sells them, but the mandrel size is small. Dremel brand makes them also.

 

[criswellnk]

This is the company that I buy all of my undercutter blades from for my old Weidenhoff undercutter. http://www.martindaleco.com/
They have just about any size that you would need (arbor and thickness), hopefully this was helpful.

 

[Tom Wesenberg]

I use an ATLAS hobby saw to do all my undercutting. It works great and goes fairly quickly. The saw costs about $2 at the train store and most hobby shops.

 

[Jim Kellett]

I believe Tru-Cut is still in business. Suggest you contact them for blade replacements.
Tru-Cut Machining Co Inc

Address: 100 Industrial Dr
Fox Lake, WI,
53933-9624
Business Activity: Manufacturer

Phone: 920-928-3383
Fax: 920-928-3791

 

[Cool Hand Lurker]

I use a short length of hacksaw blade with a handmade wood handle. I trim the end of the blade down to the first tooth and then grind back so that half the tooth is left. This creates a sharp tooth that works like a metal shaper and cuts as you draw back across the commutator. When it wears round it can be touched up on the grinder.

 

[Kurt in NJ]

If you just need one try a rebuilder---electric motor shop, or automotive electric ---go in with a story about you are learning and want to play with your old car--this is how I got the first sharp one.

After that I got mine at a yard sale, probably will be a lifetime supply for me, I bought a Hillhorst undercutter that was well stocked.

 

[Cool Hand Lurker]

You guys that use a Dremel or similar tool, how do you keep it from cutting too deep? How do you get in close to the winding end of the commutator?

 

[H. L. Chauvin]

As mentionned above, hacksaw blades with a sharp forward point work extremely well, and also:

a. The blade's teeth have built-in "road"; i.e., longitudinal swerves to provide a cut a little wider than the thickness of the blade so the blade does not bind when cutting metal.

b. One can easily remove this "road" on a grinding wheel whereby the blade will cut a narrower precise grove the thickness of the blade.

c. Because of soft mica material, after "road" removal, the cut is easy to control & the blade's teeth are still sharp enough to re-use for hundreds of commutaters.

d. One can also get a small wood dowel, the length of the blade, cut a long groove in the length dowel with the modified blade to a certain depth, and epoxy glue the dowel to the top of the non-cutting edge of the blade to provide a precise mica cutting tool with an attached wood dowel depth gauge.

e. An extension of the wood dowel may be used as a handle.

 

[Tom Wesenberg]

I've always heard this refered to as "set". I'd never heard the term "road" for it before. The Atlas hobby saw I use cuts only the width of the blade, as it has no set. I was told it's used a lot for cutting the brass rails on HO train tracks.