Variable speed conversions

Having searched this site on various options they all came up with custom made speed attachments at a high price. Modern drive converters are digital allowing many parameter to be put in from max speed to min speed, pre set speed, forward reverse etc. On choosing a drive inverter as they are called its confusing, these drive inverters are aimed at industry and trained electricians however talking the the dealer who sold it to me they are ok for diy "intelligent" woodturners such as me. Intelligent in that read the instructions 3 times and take no shortcuts and are not all us woodturners intelligent!!. So I bought one and a 240v 3 phase motor all for less than £200, my lathe a old Turnstyler is now magic, a 1HP motor that goes from 50 rpm to max that i set at 2000rpm. My turning is now a pleasure a turn of the dial to get a good rpm. Now technical details the motor (you need a 3 phase motor) they all come in different mountings foot called b3, flange mounting, and take foot they all have different dimensions, fortunately a lot of motor manufactures list all the dimensions and most motors have a code stamped on them ie 90ls or 80M plus more numbers, this is the mounting code. Most 80 codes are 1HP 90 are 1.5 HP. Next the inverter (I am in UK) they are 240v input and 3 phase 240v output. They dont like sawdust, because they operate high voltages sawdust and moisture is not good. So you build a dustproof box with a perspex panel and a vent from outside. You can get IP55 dust protected drives but they are £100 more. I sweated on buying this gear knowing that I was in the field of trained electricians but it was very easy, my electronic drive is a "Invertec" drive, they do a economy one called E2 and easy start, you can use it out of the box without entering any data, mine cost £88, then you just get a 3 phase motor and screened cable for motor to inverter drive. This is a cheap up to date option for variable speed drive and really if you can wire a plug and take your time with the instructions its a great conversion at a good price. I am in the UK I used a dealer who was very helpfull if you want his web site I will send it to any one considering this route or web sites of motor dimensions. As for drives search on Invertec and download the manual. After 4 weeks of research and looking for the best option I thought I would post my results. My turning is on a new dimension its magic. Col

Reply to
col
Loading thread data ...

Site? What site?

Deb

Reply to
Dr. Deb

you don't need a site - there are three common ways to get variable speed - reeves drive (variable diameter pullies), DC motor drive (with a DC controller) and AC motor with a variable frequency drive. These are in order of "goodness" for most of us, though the Reeves drive is better for some cases (or if your lathe already has one). For smaller lathes, DC is usually cheaper, and a fractional HP 3 phase motor is harder to find. In the 1,2,3 HP range, 4 phase motors in working condition sell for scrap value (I have one, Los Angeles area, about to go to the scrap dealer if anyone wants it for $15) or a small premium above scrap, and controllers cost from about $15 (if you are really lucky) to $300 (if you buy a new or refurb unit). Most premium wood lathes use an AC approach to variable speed.

Good brands of controllers - I use Delta (not the lathe company) for AC on my metal lathe, but there are many brands and for our purposes any will work - be sure that the selected controller will accept single phase input power. For smaller lathes, Minarik makes a controller that will take 120 AC in and make 220 3 phase variable freq. For DC, I like the Minarik controllers that have a good feedback and slow start circuit. Motors - Baldor is what we all seem to gravitate towards, but again, any good one will do - import motors like you get at sears or home depot are typically rated optimistically - so look at the nameplate power draw, not HP to get an idea of what the motor is.

Reply to
Bill Noble

SPELT that wrong its

formatting link
for the inverters.

Reply to
col

On Sun, 29 Nov 2009 10:21:56 -0600, Bill Noble wrote (in message ):

well, this is all very interesting. I use a Shopsmith, and it has the Reeves type system for variable speeds, but the slowest speed is still way too fast for most of my turning, and pretty noisy. I have a 4:1 reduction unit that Shopsmith sells, to add to the power head. Well, this works after a fashion, but is still clunky way to go, and still not as slow as I'd sometimes like. I have often thought of converting to a variable speed motor on my Shopsmith, if I could do it cheaply enough. I guess I got some homework to do. tom koehler

Reply to
tom koehler

On Mon, 30 Nov 2009 23:31:50 -0600, tom koehler

I really don't think it's worth it, Tom, and would probably screw up the Shopsmith..

Buy a real lathe and be happy with it.. New start at about $300 for a mini.. Nice used "full sized" ones out there fro $500 or so..

I use my Shopsmith all the time as a drill press and disk sander, wouldn't consider using that fast, shaky thing for turning any more..

mac

Please remove splinters before emailing

Reply to
mac davis

On Tue, 1 Dec 2009 1:07:40 -0600, mac davis wrote (in message ):

well, I agree. It fits in my very small shop, though, and is what I have, so I am accommodating its shortcomings. Its saving virtue is what it allows me. I use all of its functions and am willing to fiddle with it. I also recently rewired the motor so I can easily reverse it for on-lathe sanding. tom koehler

Reply to
tom koehler

On Tue, 1 Dec 2009 1:07:40 -0600, mac davis wrote (in message ):

I agree. However, my very small shop will only accommodate one machine, so I am willing to fiddle with the SS and put up with its shortcomings, as it allows me to do much more than I otherwise might. I have also rewired the motor so that I can easily reverse the motor with a flip of a switch (and restart). This is useful for me for on-lathe sanding. tom koehler

Reply to
tom koehler

On Tue, 1 Dec 2009 1:07:40 -0600, mac davis wrote (in message ):

I agree. However, my very small shop will only accommodate one machine, so I am willing to fiddle with the SS and put up with its shortcomings, as it allows me to do much more than I otherwise might. I have also rewired the motor so that I can easily reverse the motor with a flip of a switch (and restart). This is useful for me for on-lathe sanding. tom koehler

Reply to
tom koehler

On Tue, 1 Dec 2009 1:07:40 -0600, mac davis wrote (in message ):

I agree. However, my very small shop will only accommodate one machine, so I am willing to fiddle with the SS and put up with its shortcomings, as it allows me to do much more than I otherwise might. I have also rewired the motor so that I can easily reverse the motor with a flip of a switch (and restart). This is useful for me for on-lathe sanding. tom koehler

Reply to
tom koehler

Ok most of this sites readers are based in the States, my original thoughts and results were aimed at UK users just to show that a lathe can be conveted to variable speed at a good price with little electrical knowledge. Here in UK specialist lathe speed conversions are £300 plus a DIY conversion for 1HP is less than £200. Digital converters have so much to offer literally everything from economy energy saving when the lathe is not under stress to time to max speed, to time to stop, you cant beat the modern digital technology. A twist of the dial and i can get down to 10 revs a Minute, so if you are into painting wood its great. And Ilike painting with wood dyes or acrylic. OK could go back to the pole lathe and I would love one but modern technology is there to be used, changing belts on pulleys, a pain, a twist of the dial and you are doing what we enjoy, creating. For 12 years used belt changing now in the modern world and its great. Col

Reply to
col

Tom,

If you can rewire for reverse then you can handle a VFD for your SS.

I have just completed wiring one (Square D) I bought on ebay for $75 into a Powermatic 90 (reeves drive) and it has more options than I ever expected. I started this project to get from single phase to 3- phase and to slow the beast down just like you need to do. I programmed ramp-up/down for start and stop to control coasting, vary the speed between 0 and 200% of normal (1800 rpm @ 60 Hz), forward/ reverse and I also wired into the control circuit a slap switch in a magnetic box that I can place anywhere on the lathe. The control circuit voltage is only 15 VDC which make many options easy to take advantage of. Try one for your machine I don't see how it could hurt.

Gerald

PS thanks to the group for all the tips for us chronic lurkers

Reply to
GDStutts

oh nutz! I was having trouble posting, rewrote things, the finally got through. Well, the whole works showed up and I apologize for the extra postings from the department of redundancy department. tom koehler

Reply to
tom koehler

InspirePoint website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.