Lathe gears ID help

[Private Lugnutz]

I picked up this set of gears at the flea market last week. They are 3/4" wide and 7/8" bore with a single 5/16" keyway. Part number plates are pin welded on. The teeth count is stamped, with serifs. All black except the smallest. Does anyone recognize them?

PN, Tooth count, Diameter

61 010, 100T, 5-5/8”
61 012, 110T, 6-1/8”
61 013, 115T, 6-1/2”
61 014, 120T, 6-3/4”
1080 67, 125T, 7”
61 017, 127T, 7-1/8”
1080 88, 130T, 7-1/4”

 

[larry_g]

They may also be change gears for a milling machine; https://en.wikisource.org/wiki/Practical_Treatise_on_Milling_and_Milling_Machines/Chapter_4

lg
no neat sig line

 

[Private Lugnutz]

Good point, Larry. And thanks for the link. The "spoked" gears in the instruction illustrations are the closest I have seen yet. I have no use for them, but I would like to identify them before attempting to move them on. I am hoping Ed and other machinery guys can help.

 

[WAS Jr]

The presence of 100 and 127 tooth gears means that they were part of metric transposing gears for an imperial leadscrew lathe. The other gears escape me. As an intellectual exercise have you determined what the diametral pitch is? Might get an idea at least to the size of the lathe.
Bill S

 

[Private Lugnutz]

Those calculations are beyond my ken, WAS. I am familiar enough to know they were probably lathe gears, that the numbers stamped into the hubs were tooth counts, and to take pertinent measurements, but I am not a machinery guy. I have some old lathe maker catalogs and a Class 40 catalog from wartime that includes several OEM's that I plan to look through, but that's just a crapshoot.

Thanks for the lead.

 

[Oregon rock crusher]

I picked up this set of gears at the flea market last week. They are 3/4" wide and 7/8" bore with a single 5/16" keyway. Part number plates are pin welded on. The teeth count is stamped, with serifs. All black except the smallest. Does anyone recognize them?

PN, Tooth count, Diameter

61 010, 100T, 5-5/8”
61 012, 110T, 6-1/8”
61 013, 115T, 6-1/2”
61 014, 120T, 6-3/4”
1080 67, 125T, 7”
61 017, 127T, 7-1/8”
1080 88, 130T, 7-1/4”

Not sure I can help with the lathe they fit Lugz as it could be a long list. They appear to be 18 diametrical pitch though which is relevant. There are probably a lot of lathes that used 18dp change gears including South Bend. The change gears on my Reed lathe are 16dp. The gears on my B&S dividing head are 14dp but the highest tooth count on those is 100. I'm attaching a photo of my Reed change gear chart and you can see it uses many of those same even numbered high tooth counts for the screw gear so likely for a lathe. I'd agree the 127 tooth gear is likely for metric transposing. Ed.

 

[Private Lugnutz]

Thanks, Ed. That's helpful.

I was hoping the spoked flywheel look and/or the numbering scheme would be clues.

If you had to guess on the age range, what would you say? 1930's to 50's?

 

[DocsMachine]

I believe you'll find that "tag" on the arm was in fact pinned to the master used to form the mold, and is therefore molded into the iron.

Not that that really helps you any, just thought I'd point that out. Very common to see back in the day, even up through the eighties on domestic engine crankshafts, heads and the like.

Doc.

 

[Private Lugnutz]

Thanks, Doc.

 

[Oregon rock crusher]

Thanks, Ed. That's helpful.

I was hoping the spoked flywheel look and/or the numbering scheme would be clues.

If you had to guess on the age range, what would you say? 1930's to 50's?

A bit of speculation on my part but those look like 14.5* pressure angle gears as opposed to most "modern" 20* PA gears. Most my stuff running 14.5 PA is pretty old, likely turn of century up to the 30's. Your blue spoked gears do look distinctive though and I've got a book around here somewhere that may show that style....all I've got to do is find it.

 

[Private Lugnutz]

There's only one of those. I'll post photos of all of them, both sides, tomorrow.

 

[Provincial]

Those markings on the gears were made by embossing the raised letters on a metal strip, which was trimmed to length (with rounded ends) and holes punched for the nails or screws that hold the tag to the proper location in the Core Box.

The Core Box is the wooden form that was used to create the open space into which the molten metal is poured, along with an outer frame that matches the shape of a frame that will hold the parts (usually halves, with a parting line at the halfway point in the casting), in the proper orientation. It does this by occupying the space that represents the desired casting, which is then packed with wet sand. The sand is baked to dry it, and the halves of the sand mold are assembled into a frame that both holds them in alignment and supports the entire outside surface of the sand.

The metal is poured into the resulting opening, hardens, the outer support "box" removed and the sand stripped away, leaving the casting ready for further machining operations.

Probably more than anyone here wants to know, but it explains why the marking look the way they do.

 

[DocsMachine]

I said the same thing, just with fewer words.

Doc.

 

[Provincial]

I never should have got that college degree!

 

[Private Lugnutz]

As far as I can tell, they're not from a Hendey, Jones & Lansom, South Bend, Warner & Swasey, or Sheldon, which all had solid change gears - at least per the illustrations or artists' renderings in catalogs. Hunt and peck like this is not going to work I need a breakthrough.

 

[Private Lugnutz]

I said the same thing, just with fewer words.

I never should have got that college degree!

I appreciated the short and long versions. As you know, I can give you a run for your money on elaborative verbosity depending on the subject, Jock!

 

[Private Lugnutz]

For what it's worth...

 

[Private Lugnutz]

And for a closer look...

 

[Private Lugnutz]

And those fancy serif tooth count stampings...

 

[TailGunner3000]

I can't be sure, but I think I saw gears like that on a Prentice lathe I used many years ago.

 

[Private Lugnutz]

Thanks for the lead. I'll check it out.