Thread: Spindle speeds

I been trying to find the spindle speeds for both my 9 inch (1947) and heavy 10 (1976) Both are 6 speed flat belt. I have seen some where in the past South Bend brass plates with posted speeds. I would like to see a picture of these for both lathes. Or try to find one of each.
Thanks Chet

Given the motor speed, and pulley dia's...from there it is simple math.

from HTRAL- 50,78,130 in backgear and 235,392,680 in direct belt drive. assuming a 1725 rpm motor. hope this helps

I think I should of said twelve speed 6 standard speeds 3 high, 3 low, Back gear 3 high 3 low. Still want to find a picture of the brass tags or get the brass tags. I want to find the South Bend Lathe advertised Speeds Like I said they have made brass tags and the speeds where not the same. Just wish I had save a picture of them. But am hoping someone as done so and can help me.
Thanks Chet

for a 12 speed- 50,81,134 and 244,410,692 on first motor pulley step and 86,145,250 and 446,750,1270 on 2nd motor pulley step. it is recommended not to use the 250 rpm in backgear.

The 86-145-250 RPM back gear high speeds should not be used.They are basicly duplication anyway and the book says not to use them.Also they are noisy.

My heavy 10 has a brass spindle speed chart attached to the headstock. I can make reproductions of this plate as well as most of the other plates found on lathes and other machinery.

I have two 9" lathes and neither have a brass plate showing the spindle speeds. I don't recollect seeing a picture of such a plate on a 9" lathe but it doesn't mean they don't exist.

Tom

This is a photo of the spindle speed plate on my heavy 10 SB lathe. The original motor was a Westinghouse 3/4 hp, 3 phase, 208-220/440 volts, 1425/1725 rpm.

Originally Posted by jkull

This is a photo of the spindle speed plate on my heavy 10 SB lathe. The original motor was a Westinghouse 3/4 hp, 3 phase, 208-220/440 volts, 1425/1725 rpm.

Thanks jKull,Yes that is the heavy ten brass tag I was talking about. So at 1725 RPM the SBL Heavy 10 speeds are 1400,898,585 740,470,304 250,160,105 130,85,55, or that is what South bend thought when they made the tag. I will PM you about making me a Tag like what you have.
I hope some can or will post a picture of the 9 inch one. I am sure I had a picture of a brass tag on a 9 inch and it was laid out a little different.

Originally Posted by iwananew10K

for a 12 speed- 50,81,134 and 244,410,692 on first motor pulley step and 86,145,250 and 446,750,1270 on 2nd motor pulley step. it is recommended not to use the 250 rpm in backgear.

Thanks for the post this is why I am looking for the brass tags. Because most of the info I can find list these speeds but I can not find them listed by South Bend any place. And I hope some one can help with the 9 inch Tag.

Thanks Chet

Originally Posted by coyotechet

Thanks for the post this is why I am looking for the brass tags. Because most of the info I can find list these speeds but I can not find them listed by South Bend any place. And I hope some one can help with the 9 inch Tag.

Thanks Chet

South Bend lists the speed for the 9" machine right in the back of the How to run a Lathe book.

Originally Posted by mcruff

South Bend lists the speed for the 9" machine right in the back of the How to run a Lathe book.

Thanks mcruff I new that I think I going back to bed . I guess I just liked the idea of wanting the brass tags and was looking for them to long on the computer. I just stated the wording wrong. Still want to find and get the brass tags. I just think they are neat.

Thanks Chet

You can probably have one made at a good photo/print shop if you supply the brass tag.

I am a little confused about the "SPINDLE SPEEDS OF LATHES" chart on page 23 of "How to run a lathe".

But let me set this up.

I bought this Heavy 10 lathe a few months ago and the previous owner had a single phase, 110v motor on it. He threw in the original 3 phase, 220v motor and later on, he found the original pulley and was nice enough to send it to me. I assume it's the original pulley, anyway.
So after I removed that other motor and pulley I installed the original set up and played with it and ran the lathe at both steps of the motor pulley on all three steps of the cone pulley. I began to wonder.
This pulley has two steps or 2 V-belt grooves on it. Both are different sizes and I didn't bother to measure it. But does that mean that this is a two-speed pulley and once I put it on that original 3 phase, 220v motor, it's a two-speed motor?

And if it's a two-speed pulley, does that mean my lathe has 24 speeds?

I know that it's not recommended to run the lahte at 160 and 250 RPM in back gear.
So would that mean that I have a choice of 22 speeds?

And what is meant by High and Low in the speed range collum as seen on the chart.
Ed

Ed

the small groove of the motor pulley is the low speed range, the bigger groove is the high speed range.

Hi again,
I still don't understand why there's 2 different sets of speeds.
Is there 2 different sizes of two speed pullies?
How do I know which one I have? Do I need to measure?
I'm sure at least a few of you can explain this to me.
I just want to have an idea what speeds I'm capable of turning on my heavy 10.
It seems I'm having trouble adding the pics of the chart for some reason ...
I'll give a try.
Ed

This sounds like a perfect excuse to buy one of those antique Starrett RPM counter gadgets that you use in conjunction with a stopwatch.

For those of you who want to know how fast to rotate your workpiece. The formula to determine the cutting speed produced by different pulley and back gear settings.

DESIRED RPM = 4 X CUTTING SPEED IN FEET PER MINUTE DIVIDED BY DIAMETER OF WORKPIECE BEING TURNED.

The recommended cutting speed in feet per minute for turning low to medium carbon steel with a HSS toolbit is 100 feet per minute.

If machining 12L14 increase that by 50 percent.

If machining high carbon steel decrease that by 50 percent.

Lord Byron

Sorry guys,
I could not upload my pictures of the chart onto my reply.
But if anyone was interested in looking at what I'm talking about, the Spindle Speeds chart is on page 23, 10L collum, in the "How to Run a Lathe" book.
But I guess it wold be a good excuse to buy some kind of RPM sensing device.
Ed