Wood Lathe motor question

Beats the heck out of me where this question should go...so I'll just post here.

There are quite a few people on cpf with alot of electronics/electrical experience. Here's my question...

I have a wood lathe and the speeds are changed by moving the v-belt up or down the pulley system. I found a Router Speed Control device and here are the specs for it:

THE 43584 IS MORE EFFECTIVE WITH ROUTERS OF 2 HP, OR LESS.
ALUMINUM BASE, PVC PLASTIC HOUSING
POWER SOURCE: 110VAC/60HZ
POWER AMPS: 15(MAX)
POWER CORD: 16 GAUGE, 5 FT, CSA AND UL LISTED
POWER PLUG: 3 PRONG W/GROUND, UL LISTED
CONTROL FUSE: 15 AMP GLASS
UNIT GIVE STEPLESS SPEED CONTROL FROM ZERO TO MAXIMUM R.P.M.
ACTUAL SPEED AT ANY SETTING WILL DEPEND UPON THE MAXIMUM SPEED OF THE ROUTER.

It says it doesn't work with slow start motors. My lathe motor is Fan-cooled motor power is 3/4 HP/1725 RPM/8.5A. Not sure about the slow start thing... My lathe is almost instantly up to speed when I turn it on. Would this work with my lathe to make it variable speed without opening the case to change pulleys if I leave it on the highest speed? I'd have to get a Tachometer to mark the speeds though.

Won't work, may smoke..

Speed controllers work with "Universal (series wound) Motors" like hand drills and routers by using an SCR to chop up the AC sine wave. Motors on standard lathes and other bench tools are split-phase induction motors (induction start/run or capacitor start/induction run) that dont like chopped inputs.

The motor on your lathe was selected for its starting torque and smooth, quiet and constant speed running. It is close to optimum.

I have operated lathes for more than sixty years and can't recall ever needing "continuous variable speed control", thirty seconds to move the belt around solved any speed change needs. Most of my work involved spindles between 1/2in and 2in so I just left it at one setting that I was comfortable with.

Slow start routers use an SCR to ramp up the speed to reduce the jerk and twist you get when you switch on the machine. Using a speed controler on a slow start machine causes both SCRs to try to take control and results in irratic operation.

Takes me longer than 30 seconds... I have to take the bolt off that holds the hinged door shut... It is cold and I don't have an enclosed shop... so my hands get numb... and since i can't wear gloves while working on the lathe the metal makes my fingers and hands hurt worse.. /ubbthreads/images/graemlins/frown.gif Even Raffan prefers the convenience of a variable speed lathe that is controlled by a dial or a lever. When you make your living turning wood every minute counts.

Thanks for the reply... /ubbthreads/images/graemlins/smile.gif Glad I didn't try it... Some other people told me it would probably work. I didn't want to take a chance. I should have asked here first to begin with. I will probably be upgrading to a lathe that has the speed controlled by a lever and use this one for smaller jobs. I'm getting addicted to woodturning... Outside at all hours of the night turning boxes out of apple, cherry and even vine maple. Turned some Myrtle bowls...that was alot of fun.

whiskypappa3 is on the mark! BTW my new lathe in the garage is AC Variable Frequency Drive. 5HP from 100-500rpm (gear reducted,) and 5HP from 500-3000rpm direct. Digi readout for rpm and a pot on the panel to set the speed. The fans cooling the control enclosure make more noise than the motor! /ubbthreads/images/graemlins/grin.gif (Engaging the feed screw(s) gearbox is another story, noise-wise. /ubbthreads/images/graemlins/frown.gif )

Larry

Nice. More than I need, but can't deny that I want one..hehe. My lathe has a 12" swing over the bed. I can turn larger on the outside spindle. I just have to make a tool rest for it. My Myrtle bowls were warping terribly until I found the technique of using denatured alcohol. You rough turn your bowl to a thickness of about 1/2" for 6" bowls and under. Then you soak it in the alcohol for about 2hrs...take it out and let the outside dry enough so it's not wet to touch and then wrap it tightly on the outside with brown paper grocery bags. Let that sit for 2 weeks or so and then finish turning your bowl. I've turned quite a few bowls from green wood with this technique and every one of them so far has not cracked or warped... As far as I can tell. Eh, a bit off topic I guess.

You can get variable speed but it will cost a good bit. There are small variable speed drives for induction/capacitor motors. They cost several hundred $$ though.