Variable Speed

[dhall]

How much of an asset is a lathe with VS vs belt changes? Is it just convenience, or increased function? How about durability? Is it worth the extra bucks?

[Lawrence Brown]

The variable speed is awefully convenient. The trouble is that most systems (I think) vary the speed by removing power from the motor, so the motor will run slower, but it will also stall easier. With belts you get the same amount of power, just at a slower speed. I think the power actually increases due to mechanical advantage, but that's another story.

So if you have a big motor, you might not notice the reduction in power from a VS system, but on the little ones, it can get quite critical. I have a small delta that has a DC VS conversion I was interested in, but after reading all the complaints about the power, I decided to just live with the belts.

[dhall]

Thanks. How often during a project would you need to change speeds. I'm talking common projects turned on small lathes.

[AlanZ]

Variable speeds is more than just a convenience

It allows you to "dial in" the proper speed for a cut. Start off slow and gradually increase the speed until you're comfortable.

This is especially useful for newer turners who don't have a good way to guess at the proper speed for an out of balance blank.

Also it makes it easy to choose the "right" speed for the particular cut or sanding task at the moment.

Changing belts is generally an easy process, but so is procrastinating doing the belt change and proceeding with a cut with less than optimal speed.

I have a Nova DVR XP lathe, no belts at all. My wife has a Delta 46-460 and has been delighted with the VS on her new lathe.

[dalboy]

I have just invested in a variable speed lathe for turning pens. Compared to my other lathe(Belt change) it is great to be able to just dial the speed needed. With pens because I prepare several at a time and also the time it takes to turn and then sand I would spend alot of that time changing from 1 belt position to another.

So the preference is really down to you and possibly the type of turning you intend to do

[billboard]

My first lathe was a cheap one from ebay that was belt change. I thought at the time that it was fine. After a few years the lathe broke and I picked up the new Delta Midi Lathe with variable speed at the first of the year. I can honestly say that it is definitely worth it. There were times on the old lathe that I couldn't get the speed just right. When I had a very rough bowl blank on the old lathe, the lowest belt setting would still be too fast.

[Lawrence Brown]

Yeah, you'll definitely change speeds more than once per project: roughing, turning, sanding, finishing, etc. So there are advantages to each. I was mostly just saying, if you get a variable speed, be sure it has enough power to do what you want at the slow speeds. My first one was the tiny Harbor Freight variable speed. It worked fine for pens because they were so small. If I tried to turn anything much bigger, say about 6 inches around, which was about the biggest that clear the bed, with the speed dialed all the way down I could stop it with my hand. That's when a full-power belt drive (or a bigger motor) comes in handy. On the other hand, like Bill says, when roughing something that's really unbalanced, it's nice to be able to turn the speed knob up just to the point where it starts to vibrate and then back it off a bit. Not so fun to do with a belt drive.

[dhall]

Lot of good points, thanks. I have been watching Craigslist for something locally, but you just don't see the name brand VS midi lathes come up for sell. I guess the folks that have them want to keep them.

Do you think Jet & Delta will have a sale around Christmas time? I have often made the mistake of getting in a hurry and settling for what I could afford rather than what I need/want. I don't want to repeat that mistake this time.

[PaulMarcel]

The Jet will come up for sale during Powermatic/Jet's long sales event they have going on right now. Every two weeks, a different set of their tools comes on sale. Usually there are more Jets than PMs on sale. This week is bandsaw week, IIRC, but you could keep an eye out for lathe week.

[AlanZ]

I know it's a little pricey, but in case you're interested, Woodcraft has the Nova DVR XP on sale now for $1,699... that's $550 off of the regular price.

I bought mine last year during a similar sale... seems to come around once a year.

[dhall]

Thanks Alan, but that's out of my reach. I see you have the Delta 46-460, how do you like it?

[AlanZ]

Darryl,

The 46-460 is a great little lathe. 1HP, great torque, very smooth and quiet, 12.5" swing, variable speed, reversing, 1x8" thread.

Can't ask for much more of a lathe this size. It's one of the great bargains in turning tools.

[Cacy]

Have turned on the new Delta. It has to be at the head of the class for this size lathe.

One huge advantage of the variable speed lathe is that you can always turn at a SAFE speed for the situation at hand. I have seen and am guilty of not changing speeds when it whould have been the prudent thing to do.

The power issue. The loss of power depends upon the type of drive and motor control. A DC controlled motor will loose considerable power, thus the complaints with some of the smaller lathes and replacement motors available. 3 phase motors controlled with a variable frequency drive (VFD), have little loss of power at lower RPM's. As an example, the little white plastic box on Powermatics is the VFD.

The older mechanical vari-speed drives should not loose much power with RPM changes.

I would not buy a lathe without the variable speed option if it is in your budget or buy an older lathe and retro fit it with a 3 phase motor and a VFD. It is not hard!

[Lawrence Brown]

Oh, maybe it was just the DC drives I was thinking about then.

So the VFD: is that what's in the "router speed control" boxes you can get at Rockler and so on? Since the motors aren't 3-phase (right?), Will that work the same, or is that different? I have one of these on my tiny watchmaker's lathe, but that thing is spinning so fast (relative to a wood lathe) that I don't think it's a problem.

I know those speed controls won't work on "soft start" motors, but that's a different issue. If I just put one of those speed controls on a straight AC motor, will that work reliably at slow speeds? The motors seem to just stall when you get them to real low settings, so I'm guessing the 3-phase works differently.

[PaulMarcel]

If you don't have three-phase available, what are some reasonable options? I know Laguna makes a 3-phase converter, but it's the cost of a tool. Mebe Harbor Freight makes one; likely only makes 2.5 phase, though.

[Cacy]

Router speed control boxes are NOT VFD's. A VFD will only power and control a 3 phase motor.

I bought 3 VFD's on EBay as I am converting an old cast iron bandsaw that I am restoring. Want the variable speed so that I can slow it down when cutting aluminum. Also repowering a smallish belt sander that resembles an edge sander, but with only 24" plattens. One side is fixed at 90 degrees and the other side has a tilting table.

Note that VFD's are rated by the HP rating of the motor they can control. Do a google search on VFD for more info.

[samhell]

I put one of those Harbor Freight router speed controls in front of my lathe just to see if it would work. It worked just fine. I don't know if it would fry anything over time but it worked well for the little while I tried it.

[dhall]

Thanks for all the input. I have decided on the Delta 46-460. It will be a bit before I can get it, but I would rather wait a bit than wish I would have waited. Man, I'm going to need to buy the lathe, slow speed grinder, tool jig, tools, and a shop vac. This is getting expensive. That's going to be a high dollar pen

[AlanZ]

Darryl,

Great decision on the lathe.

Don't forget that eye, ear and lung protection are among the basic tools.