Seneca Lathe

Oh yes that motor pulley is way too big, no wonder it's running so fast- there's your first project
Mark
 
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I indicated the chuck this morning. At the back of the chuck, nearest the spindle, runout is about .003"

With a piece of round stock chucked up and measured as close to the jaws as practical, it's more like .030" Obviously, that's a problem. Not sure where to start looking for the fix.

Also, motor is a 1725 RPM 3/4 hp. 5" on the motor, 10" on the belt pulley shaft so upper pulley set (countershaft?) is running at 860-ish RPM.

Perusing the catalogs at Vintage Machinery, I'm seeing max spindle speeds of 340 RPM for the 9" lathe and countershaft speeds of 175 RPM. Am I reading that right? If so, I need a 10:1 reduction on the motor.
 
Probably you need more like a 5:1 ratio- spindle max speed about 700-800. I'd go with about a 2" motor pulley, countershaft speed 345
The chuck may very well be shot- used chucks often are. Sometimes you can grind the jaws to get some improvement.
 
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I indicated the chuck this morning. At the back of the chuck, nearest the spindle, runout is about .003"

With a piece of round stock chucked up and measured as close to the jaws as practical, it's more like .030" Obviously, that's a problem. Not sure where to start looking for the fix.

Also, motor is a 1725 RPM 3/4 hp. 5" on the motor, 10" on the belt pulley shaft so upper pulley set (countershaft?) is running at 860-ish RPM.

Perusing the catalogs at Vintage Machinery, I'm seeing max spindle speeds of 340 RPM for the 9" lathe and countershaft speeds of 175 RPM. Am I reading that right? If so, I need a 10:1 reduction on the motor.

Are you using a somewhat precision piece of round stock? To be sure the runout is in the chuck rather than the stock itself I would use a dowel pin. I have several 1"x4" and 3/4" x 4" dowel pins especially for this purpose. The pins are hardened and ground to be within .0001" to .0003". Most chucks give a runout specification at 1" and 3" from the face.

I would also check the face of each of the jaws to be sure there isn't a burr or piece of swarf causing the runout. As a side note I have several 4", 5", 6", and 8" chucks for my Star #20. None has more than .003 runout 1" from the face of the chuck. A couple came with the machine and I bought several of them used.
 
Good point on the dowel pins. I have some too, just didn't think of it.

Went to the smallest pulley I had on hand that would fit the motor shaft. Didn't think to measure it, but about 1.5 or 2 inches.

With the belt set on the slowest setting, I'm getting 225 RPM at the spindle in direct and about 26 with the back gear engaged. I'll go with that for now.

Any idea where I might find an exploded view of the compound? I need to figure out what's missing for the feed screw and how to lock the angle on the compound.
 
Nice score. What's the most recent patent date on the front of the bed and any other markings?

I've been pretty happy with mine.
 
Nice score. What's the most recent patent date on the front of the bed and any other markings?

I've been pretty happy with mine.

Jan. 11, 1910 is the last date. It's a Star #30
 
I used a 9 and a 10" pulley on the countershaft, and a 2 and 3" on the motor. The 10" and the 2" gave a top speed of 697 rpm. With the 3" and the 9", top speed is 1188.
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These...spacers, for lack of a better term...came with the lathe. Are they part of the change gear system for threading?

There are 2 sizes of square keyways, one set of a sort of half-round keyway, and some with no keyway at all in various thicknesses. Haven't measured but shaft size appears to be the same in all of them.
 
They're spacers for a horizontal milling machine arbor. I just made about 100 different diameters and widths for my US Machine tools horizontal mill. You can buy them from .001" to well over 3". I would guess yours fit a 1" arbor. I made adaptors for my machine to be able to accept 1 1/4", 1 1/2", and 2" cutters. I've found over the years the larger diameters are more readily available and cheaper. Mainly because they fit machines much larger than most hobbyists are able to get into their home shops.

Here's a link to some currently available on eBay:
https://www.ebay.com/i/283225162495?chn=ps
 
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