Slower Speeds on Shopfox and Grizzly 16x42 lathes

[bitshird]

A friend stopped by the shop last week and was telling me I could get a direct plug in device/component the would in effect give more speed range adjustment than the conventional Reeves drive assembly's, I know there are speed controllers available for things like routers, but whats available for a 2 hp, 110 AC motor?? 500 or 600 RPM is just a tad fast when you have a BIG chunk of off balance wood on the lathe, and we get tired of cutting every thing round or buying it that way.
So does such a device exist and could be found for under a couple hundred bucks??

 

[Russianwolf]

be careful Ken, my understanding (limited as it is) is that supplying a motor with less than the intended power can shorten its life. This is why many power tools warn against using overly long extension cords since there is a power loss in them.

 

[bitshird]

be careful Ken, my understanding (limited as it is) is that supplying a motor with less than the intended power can shorten its life. This is why many power tools warn against using overly long extension cords since there is a power loss in them.

Thats always what I thought, the guy is a half baked engineer, I know some electronic motors can be messed with, but I didn't think one like these could, that's why Jet and everyone else get about 850.00 to 1000.00 more for a lathe with a variable frequency control.

 

[EBorraga]

Half Baked??? Isn't that a movie Ken:biggrin:.

 

[bitshird]

Half Baked??? Isn't that a movie Ken:biggrin:.

And if you met this guy, you would understand, I think he was in the bear scene.

 

[Wildman]

People used to modify Nova 3000 lathes so they went from 0 to max RPM by adding additional electrical gear. Think they were first poor folks EVS lathe around.

You would have to remove your reeves drive set up. Add a pulley wheel to your headstock spindle if that is possible. Your headstock cover may hinder that modification. Not sure if you can completely remove that cover or not.

People more knowledgeable than I would have to give you technical data on electrical set-up. Connect/mount an electrical inverter, switch, and speed dial to your motor. Cost not that bad if you know where to buy components and do work yourself.

Of course might look into buying a Jet headstock, motor, and inverter now that might prove expensive.

 

[bitshird]

Thanks, the guy said something about an inverter but I thought he was thinking I was running 220 V. I can get the back and side off the headstock easily enough, the electronic genius may be the hard part, I've worked on CNC machines and built circuit boards but had easy to follow instructions.

 

[Wildman]

If not mistaken need DC motor too, would require 220V. Went looking for NOVA 3000 conversions at Google groups and could not find much info. The old woodturning forum at Google had complete instructions and where to buy components. Info may still exist, just didn't find it.

Considering Nova 1644 converted to variable speed?
http://www.woodworkersinstitute.com/forum/forum_posts.asp?TID=6462&PN=2
http://www.haydockconverters.co.uk/variablespeeddrives.htm

This guy talks about doing conversion here and provides sources.

http://www.sawmillcreek.org/showthread.php?134952-Nova-1624-adding-variable-speed

Because NOVA 3000/1624/44 do not have reeves drive much easier to convert. Converting a Grizzly would require lot more work.

 

[randyrls]

To join the thread; There are two ways to electronically convert a lathe from fixed speed with pulleys to variable speed.

#1 VDC - Change out the motor with a DC motor and drive controller. This is the technique used on Jet 1014 and 1014 VS drives. I did this on my Grizzly G4000 metal lathe (see video link below).

#2 VFD - Change out the motor with a three phase motor and use a Variable frequency drive. the VFD takes 110 V AC single phase and converts it to three phase with a variable frequency. Since the frequency of the AC signal control the motor speed, varying the AC frequency changes the motor speed. Usable ranges are about 10 HZ to 120 or 200Hz.

In both cases, I would keep the pulleys in place. Motors can be sized by the frame number on the motor. The shaft isn't as tightly specified and you may have to do some work on it to make it work.

Figure on about $200 to $300 for the conversion. This short video shows the low speed capability of my metal lathe with a VDC drive on it.

http://www.coleman-family.org/gallery2/v/metalworking/Slow+Speed_001.flv.html

 

[KenV]

Ken ---

If you are at 2 HP, AND at 110 volts the inverter is not your friend -- If you are lower HP, you can afford the losses in efficiency but you are already pusing the max amps on a 110 volt circuit.

At 220 volt input, you lose amps and gain capacity -- The 2 HP setups want 220 volts for the inverters and motors.