Speed, mechanical or variable

[James Boster]

Looking to repower my lathe. Just wandering what most of you turners prefer, electronically variable speed or step pulleys. Thanks.

[Andy Hoyt]

All other issues notwithstanding - EVS.

[Gary Max]

I go with Andy on this one---EVS
Heck I run my Mini lathe on a DC system that is great.

[Cecil Arnold]

EVS, as I don't see a way to get pullies slow enough for an unbalanced 50 lb blank.

[Jim Becker]

EVS....specifically a VFD controlled 3-phase motor. (uses single phase from the wall to the VFD) Greater speed range with good torque. You still need 2 or three steps on the pulleys to give you appropriate ranges in most cases, but I know I rarely change off the selection I have mine set up on.

[James Boster]

Thanks guys for the quick responses. I am currently running a 4 step setup but I'm planning on changing to a 3phase with VFD. Just wasn't sure if it was worth it or not, but looks like you all agree. Do you have plenty of torque at real low speeds with this setup. You mention turning an unbalanced blank, how slow do you start at?
/ Thanks again.

[Gary Max]

I always leave my big lathe on the low range pully setting---I only get about 1000 rpms out of this setting----which is fast enough for something big.

[Cecil Arnold]

James, on an unbalanced blank I start as slow as I can, then move up until I start to feel the lathe want to move. At that point I back off a little and go to work. I think most of us couldn't tell you an actual RPM unless we have a readout and bother to look at it. My PM 3520 is on the low range (0-1200 RPM) and since I don't do any (or much) spindle work it stays there.

[Jim Becker]

Cecil has it...there is no specific "number". It's a "feel" thing. You start as slow as it will go and turn the knob to make the out-of-balance blank spin with enough RPM to start cutting without walking the 800 lb lathe (in my case) across the room. That can be anywhere between 50 and 300 rpm, depending on the specific piece of wood. Like Cecil, I turn it up until the vibration is uncomfortable and back it off a few RPM to stabilize. As I cut, I increase the speed a little at a time.

[Ernie Nyvall]

EVS and yes, at the slow speed with a 2hp motor, it has enough power. I just roughed ot a piece weighing about 60 lbs and started it at 200 rpms... that's just under where it started vibrating.

Ernie

[Jim Bell]

How big is the lathe you want to repower?
Jim

[James Boster]

My lathe is a homebuilt lathe with 16" swing and 4' centers with a 4' extension if I need it. It is built out of HEAVEY structural steel and weighs approx 500#. I put a 3/4 hp motor on it at first because thats what I had, but now I want to up the power to 2 hp. I have posted pics of the lathe on here before on the general forum under shop built tools I think. Thanks for all the replies.

[James Boster]

http://www.sawmillcreek.org/attachment.php?attachmentid=30025&stc=1&thumb=1&d=1137727787 (http://www.sawmillcreek.org/attachment.php?attachmentid=30025&d=1137727787)
Heres a picture of the lathe without the 4' extension.

[John Hart]

I've put some pretty big gnarly off-center things on my lathe that I had to ride like a buckin' bronco at first...even at 200 RPMs. My stand is inadequate for this type of thing..even though it's sturdy for the most part. I'll build a new one for the new shop though.