Trucut lathe

[Nolatoolguy]

Got this the lastnight, as some saw in the other thread. I plugged it in an it runs. Its a litte dirt but looks like it should clean up good, I was wondering a few things.


1-main function. I know its a lathe but just sort of confused as to what its specialized for.
2-Whats undercutter? it sais lathe and undercutter, I have no idea what the undecutter part is.
3-is it all there, I can tell its missing at least a belt. I don't see a faceplate or chuck like a normal lathe.
4-how old is it. Its obviously not a antique but its still older then me.
5-is it a quality piece for its type? Is this just a cheap import or a highly thought after lathe for professionals?
6-availbilty- is this a common piece, and are replacement parts easy to find?
7-anything else you know please tell me, as ime interested in learning more about it.

If anyone would like a specific picture let me know, and ile take one.

[ron darner]

I'll start the guessing by suggesting that it's for reworking commutators on generators or motors.  May be called an "armature lathe".  The mica insulation between segments had to be cut down below the new surface ("undercut") after you cleaned up worn surfaces on a lathe.  Otherwise, the brushes would soon be destroyed, and no current generated.  Most repair tools I've seen used a simpler cutter that was simply slid parallel to the axis (when I was a teenager, we used a hacksaw blade with most of the wave set ground off to narrow it, and prevent cutting away commutator segment metal).
See http://www.caminnovation.com/dc-motor-equipment/multi-process-universal-machines/jht-large-universal-commutator-repair-machine for a large machine similar to yours.  There is a vimeo clip showing one in action at http://vimeo.com/79898022.  Between about 30 and 45 seconds, watch the horizontal arm, and the vertical spindle that come into it from the bottom; it cuts on the left-to-right pass, then the spindle carrying the cutter moves out of the slot while the machine traverses to the left for another pass.  The spindle feeds into the next slot, and action repeats.
You'll also want to see http://www.ebay.com/itm/TRUCUT-Armature-Lathe-and-Undercutter-Model-B15-Nice-/310560078990?pt=LH_DefaultDomain_0&hash=item484ed2bc8e.  I hope you got a better price . . .!

[oldgoaly]

TM 9-4940-462-14&P is a manual that help you operate it
You will need to download it from here www.liberatedmanuals.com or one of the other places on the net.

[Aunt Phil]

Back in ancient times before vehicle alternators and mechanics not "technicians" worked on cars, starters & generators were rebuilt in the shop rather than coming in a cardboard box from Autozone.  Most starter & generator problems were brush or commutator wear. 

The device was disassembled and the rotor was set up in the lathe you have for recutting after being verified on a growler to be sure it had no shorts or opens in the individual windings.  Your lathe is capable of cutting away both the copper and the mica between the copper elements. 
Depending on how deep the brushes chewed into the commutator, it is either recuttable or not worth trying.

The mica insulators between commutator bars are hell on the cutting bit.  Copper does not cut like steel, so you learn on some junkers before you try on one that you need.

Once the commutator is returned to round and smooth, the second part of the job is cutting the insulators.
The lathe has a device to lock rotation that keeps the small saw blade on the spindle properly indexed.

The saw is indexed above the insulator, spindle locked, and moved thelength of the insulator to insure proper tracking before cutting begins.  There are no second chances at this stage of the job.  After confirming saw position the saw is lowered a few thousanths for the first cut.  Repeat for each insulator on the commutator.

Each commutator will have depth of cut and you will follow the specification.

These lathes were common in many shops in the 50s and 60s.
Replacement saw blades are still available and commutators on machines are still serviced today.

There is a lengthy thread on this site about commutator servicing and mica cutting from a while back.

First thing you Need to do with the machine is cleanup.  I suggest molasses as the best process from what I see in the pictures.

[Nolatoolguy]

Thanks for all info guys. I appreciate all the responses.

Its nice to know what I actually have, and its purpose. I watched a few videos on youtube an read a few manuals an am more interested now. It will be some time before I get a chance to clean her up. When she is thoe I will be sure to post pictures of me attempting to use it.

Looks like ile be calling my scrap metal buddy(who I got it from) to get me some to turn.

[oldgoaly]

the cutters for the under cutter are hard to find, closest ones I have found are 1/2" diameter

[Aunt Phil]

the cutters for the under cutter are hard to find, closest ones I have found are 1/2" diameter

OG try here
http://www.martindaleco.com/MetalWorkingMicaSaws.htm

[oldgoaly]

Thanks Aunty!
that is what I need!

[Aunt Phil]

That's why Auntie exists.

Don't even think of asking for cookies though.