Lathe RPM speed question

[LatakiaLover]

If all I'm going to do is make stems and (maybe) a few small tool-thingies now and again, which is the better setting of my lathe motor's RPM?

It's a Dayton split-phase that has a removable plate to configure rotational direction and rpm. But it is NOT switchable without considerable hassle because of the plate's accessibility, which is why I'd rather do it once and forget it, if possible.

The two available MOTOR speeds are 1750 and 1100 rpm.

The resulting SPINDLE speeds for each are:

-------------------------------

1750

High range

3500
2200
1400
875

Low range

1160
725
465
290

-------------------------------

1100

High range

2200
1375
880
550

Low Range

740
460
300
185

-------------------------------

Thanks


EDIT --- I just realized after typing it out chart-style, that the net difference is only one click of spindle speed either way. Add one to the high end, or add one to the low end. I can't imagine using 3500 for anything, and 185 would be a good option to have for some some lucite situations, so that would seem to settle it. Unless I'm missing something. (The power of my vertical brain when it delves into the horizontal realm is sketchy at best.)

[Alden]

I would guess you're good either way. Maybe err on the side of too fast. I can't imagine needing to go slower than 290.
Then again I can't imagine going over 2200 either.
I do everything at either 300 or 1000, mainly because thats an easy to remember belt change on my lathe.
Not saying that's the be all end all of lathe turning speeds, but it seems to work for me on high and low ends.

[PremalChheda]

The low speed is preferable to me.

[oklahoma red]

Generally speaking, with good cutter geometry, higher speeds with low chip loads (light cuts) will yield a better finish (at least it does for me).
Usually if you are drilling, the larger the bit the slower the rpm.
If you want to really study the subject, start here: https://en.wikipedia.org/wiki/Speeds_and_feeds
Then to thoroughly confuse the issue, some materials like low rpm with an aggressive feed rate and vice versa. Experimentation is always a good idea.
Lastly, get a copy of South Bend's "How to Run a Lathe". Old book but one of the best. Lots of good stuff in it.

[wdteipen]

IAWP, I see more use for the slower speed than the higher speed. I have worked a lot of Nate's PM lathe with variable speed and can't remember ever having the need to take it above 1500 rpm for any part of pipe making or tool making.

[caskwith]

Since you are not turning bowls then low speed will probably not be used much and higher speeds do work better with most stem materials. That being said, even on the low speed motor you still have 2200 at your disposal and that is more than fast enough for anything you will be doing (I don't think I have ever used the full 2100 on my lathe) so I would go with that setting if it were me.

[sethile]

....Lastly, get a copy of South Bend's "How to Run a Lathe". Old book but one of the best. Lots of good stuff in it.

Here is a link to a PDF of this. I think I've seen better scans of it someplace too: http://vintagemachinery.org/pubs/1617/3789.pdf

It may also be available at your local library. I checked it out from ours at Murray State for a while. Well worth buying a copy for the library. They can be had on Amazon for $6 or so...
http://www.amazon.com/How-Run-Lathe-Beg ... un+a+lathe

[Sasquatch]

George, I've got variable speed, digital readout on my new lathe, and 6 belt positions on my old lathe.

For stems, working right around 1000 rpm seems fine for ebonite, delrin, and acrylic. The speed I use the most on the old lathe was 1250.

For stummels, that's usually not accessible because the thing will wobble, so speeds between 500-800 rpm on the spindle are more usual.

So if you can hit 1100 as a top speed on your lower end of the high range (or... whatever), I'd say run with that.