Waltham Gear Cutters

Good Afternoon All,

Hopefully someone out there can help me out.

I am looking at a number of Waltham gear cutters. They do not include any information found on a typical gear cutter (Pressure Angle, Diametral Pitch, Tooth Range). They have seemingly unrelated numbers and letters on them (P-9, 820, P-18, 1968, S-22, 1933).

Does anyone know how there labeling compares to the industry standard? If not, can you point me towards any reference or information that may help me in interpreting the information on the cutter? I've been in contact with Tony at store.lathes.uk, and he had little information, and suggested a posting here.

Thanks,

Greg

Are they very small cutters, like for watches? Pretty much every cutter from every maker I've seen for watch type gears have had an arbitrary numbering system. Most watch and clock gearing is cycloidal, and may adhere to one of several norms covering that type of gearing. I have many hundreds, and spent a lot of time tracing their profiles on a profile projector at 100x. When I need a cutter for a repair or prototype I compare the profile that I need to my drawings and usually quite quickly find something useful.

Like as not, Screwmachine above has nailed down almost all you can actually 'know'.

Likely made inside the Company, for internal use, so no need to have any markings but perhaps their own more or less standardized cutter number on them.

Working in Aircraft, it was not uncommon to need to have a copy of he manufacturers own Catalog, to translate their assigned part numbers, to commonly available fasteners, and hardware. Boeing, IIRC, was bad for this. But as long as the guys pulled the right Boeing part number from stores, it did not matter what the rest of the world knew the part as, eh?

Small is relative. I do not believe they are small enough for watch work. 1-inch diameter.

Are you sure they are gear cutters?

In this post on a watch forum the poster bought a machine that included many accessories including what he thought were gear cutters but turned out to be thread cutters.

Waltham original gear cutter, thread cutter, lathe... | NAWCC Forums

bug_hunter said:

Small is relative. I do not believe they are small enough for watch work. 1-inch diameter.

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I tried to read the maker name and think it says Wal. Mach. Wks. Waltham Mass. Waltham Machine Works has a long entry in Tony's website. Waltham Machine Works ? Company History That was a company that was separate from the watch factory.

The famous watch factory was founded in the 1850's and had several names before closing. It is best known by the name Waltham, which name is still put on the dials of cheap Chinese watches. The watch factory originally had their own group of talented machine designers and makers, who eventually left to work in other watch factories or start their own machine building companies. So the town of Waltham had a number of smaller independent machine builders that supported the watch factory and any other of the Boston area watch and clock makers (Howard, Chelsea and others over the years). The lathe maker F. W. Derbyshire is still hanging on over 100 years after the founder left American Watch Tool Co. in Waltham, which itself had been founded by watch factory tool designers.

So the cutters could be anything, but are probably not B&S-type standard involute gear cutters.

Larry

Thanks to all for the insight.

I think I will move on and keep my eyes open for an easily identified set of gear cutters. No rush.

Evening,

Greg

Haha yeah I picked up a bunch of these cutters at a local estate sale and they look like small gear cutters, but I can’t figure out what they are?? Anyone have any idea? Thank you

The 60 degree cutter is probably just a V-groove cutter, though I suppose it could be a thread miller. The bottom two pictures look like they would cut tiny gears of some sort.

Larry

Thank you Larry