Variable speed conversions
col
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
Dr. Deb
Site? What site?
Deb
Bill Noble
"Dr. Deb" <debs...@mon-cre.net> wrote in message
news:ZPudnSMbnrA8tYzW...@neonova.net...
> col wrote:
>
>> 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
>
>
>
> Site? What site?
>
> 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 $300 (if you buy a new or refurb
unit). Most premium wood lathes use an AC approach to variable speed.
Good brands of controllers - I use Delta (not the lathe company) for AC on
my metal lathe, but there are many brands and for our purposes any will
work - be sure that the selected controller will accept single phase input
power. For smaller lathes, Minarik makes a controller that will take 120
AC in and make 220 3 phase variable freq.
For DC, I like the Minarik controllers that have a good feedback and slow
start circuit.
Motors - Baldor is what we all seem to gravitate towards, but again, any
good one will do - import motors like you get at sears or home depot are
typically rated optimistically - so look at the nameplate power draw, not HP
to get an idea of what the motor is.
col
> Site? What site?
> Good motor info on dimensions can be found at (http://www.lcautomation.com/pdf/marelli_motors/Marelli%20MAA%20Datasheet.pdf ). With my motor (on a old Turnstyler lathe) it was a 1hp motor but had dimensions corresponding to 90S mounting B3, 90S is hard to find as a 1HP motor so I had to go for 80 B3 mount it meant a drilling two holes for the mounting. Why not just put in a 1.5HP motor well the inverters here in UK rated at 1.5HP plus state in the tech info that a 19 amp min supply needed. Couldn't take the risk of the CB tripping every 5 mins, my supply is 13 amps.
As for the best supplier I found who is very helpfull based in Wales
is (http://www.motorcontrolwarehouse.co.uk) very good prices and
helpfull. As for the inverter driver just goto www.Invertec.com and
look at model E2, another Welch company.
You know over in the States your supply voltages are very different so
this really only applies to UK .
col
> look at model E2, another Welch company.
> You know over in the States your supply voltages are very different so
> this really only applies to UK .
SPELT that wrong its WWW.InverteK.co.uk for the inverters.
tom koehler
(in message <heu731$tls$1...@news.eternal-september.org>):
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
--
I will find a way or make one.
mac davis
>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
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
tom koehler
(in message <o0g9h5dtj078sc1vf...@4ax.com>):
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.
col
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
tom koehler
(in message <o0g9h5dtj078sc1vf...@4ax.com>):
> On Mon, 30 Nov 2009 23:31:50 -0600, tom koehler
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
(in message <o0g9h5dtj078sc1vf...@4ax.com>):
> On Mon, 30 Nov 2009 23:31:50 -0600, tom koehler
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
(in message <o0g9h5dtj078sc1vf...@4ax.com>):
>
> 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
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.
GDStutts
> 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
>
> --
> I will find a way or make one.
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
tom koehler
through. Well, the whole works showed up and I apologize for the extra
postings from the department of redundancy department.