bodger
|
| posted on 10/12/12 at 09:17 PM |
|
|
Lathe motor sizing
I've just got a Colchester Bantam. It's the Hawk version without the screwcutting gearbox & max 800 rpm. I want to fit it with a 3
phase motor + inverter to get it up to 1600 rpm. The original spec for this lathe was a 1hp motor. If I double the speed with the inverter do I need
to double the hp rating of the motor (i.e. 2hp) to handle the increased power being fed to it & provide the same torque or will the 1hp motor cope
ok?
|
|
|
|
|
dave r
|
| posted on 10/12/12 at 09:29 PM |
|
|
assuming the motor is mounted internally in a bantam, i would fit the largest i could easily fit in the frame size
I'd love to give my imaginary friend a great big hug,
but this jacket makes it impossible.
|
|
|
v8kid
|
| posted on 10/12/12 at 09:38 PM |
|
|
Strangely enough I had the opposite advice, probably for a different reason.
If you are damn good at lathe work fit a stonking great big motor. If an amateur like me fit a wee one 'cos you will do less damage when (not
if) you foul up.
Only you will know the answer!
You'd be surprised how quickly the sales people at B&Q try and assist you after ignoring you for the past 15 minutes when you try and start a
chainsaw
|
|
|
v8kid
|
| posted on 10/12/12 at 09:41 PM |
|
|
Before anyone asks all a bigger motor will do is let you finish faster, which is important to a professional, but quite irrelevant to most amateurs
who are just enjoying learning the process.
Cheers!
You'd be surprised how quickly the sales people at B&Q try and assist you after ignoring you for the past 15 minutes when you try and start a
chainsaw
|
|
|
owelly
|
| posted on 10/12/12 at 09:57 PM |
|
|
Would it be a better idea to fit a single phase motor and gear it up? I'd say fit the biggest motor you can but that's the sort of guy I
am. And I'm also the sort of guy who found himself wrapped around a lathe a few years ago desperately wishing the lathe would stop trying to
pull me out of my skin.....
Small motor=small cuts=slow
Big motor=big cuts=faster...
http://www.ppcmag.co.uk
|
|
|
trextr7monkey
|
| posted on 10/12/12 at 10:53 PM |
|
|
Bodger did your lathe come with a 1Hp motor whichh you aren't gonna be using?
I could may be do a deal with the 3 ph motor on the Denford viceroy we are selling as if single phase it would be more useful to more people 
atb
Mike
http://www.flickr.com/photos/14016102@N00/ (cut and paste this dodgey link)
Our most recent pics are here:
http://s129.photobucket.com/albums/p211/trextr7monkey/
|
|
|
Phil.J
|
| posted on 11/12/12 at 08:41 AM |
|
|
I fitted my Colchester Master with a new 3 HP single phase motor. It is still easy to stall the lathe when working on larger diameter work ie greater
than 3" diameter.
My advice would be to go for the biggest motor you can accommodate.
|
|
|
designer
|
| posted on 11/12/12 at 09:09 AM |
|
|
As said, fit a single phase motor, not a 3.
|
|
|
bodger
|
| posted on 11/12/12 at 01:00 PM |
|
|
quote:
Originally posted by trextr7monkey
Bodger did your lathe come with a 1Hp motor whichh you aren't gonna be using?
I could may be do a deal with the 3 ph motor on the Denford viceroy we are selling as if single phase it would be more useful to more people
atb
Mike
No, did a deal to tale it without the motor 'cos it wasn't looking too great after it got smashed up whilst moving the lathe. Thought
I'd go 3 phase so I can have nice speed control & there was a good deal going on a 1hp inverter drive. Start's getting quite a bit
more expensive as you head up to 3hp though so maybe I'll look again at 1 phase.....although then I could get a mill....STOP!! 
|
|
|
paulf
|
| posted on 11/12/12 at 01:34 PM |
|
|
I have a 1 HP 3 ph motor on my lathe and it is sometimes a bit underpowered compared to using an industrial machine when in direct drive but has
plenty of torque in the back geared speed range .The high speed range when using an inverter is not so much of a problem as usually when needing the
higher speeds then you will only be taking light finishing cuts or turning small diameter work .
Paul
|
|
|
coyoteboy
|
| posted on 11/12/12 at 09:04 PM |
|
|
Personally i'd fit the biggest you could find/fit, and rely on common sense and care while learning so that you don't have to upgrade
later. I learned on a monster machine with enough power to wrap you round the chuck, the motor power made no difference to my learning? You
don't want to go with a piffling little thing and end up with too low a chip load and start demolishing tools.
[Edited on 11/12/12 by coyoteboy]
|
|
|
philfingers
|
| posted on 14/12/12 at 07:58 PM |
|
|
a 0.75kw/1hp 3ph on mine with an inverter. basically think of it as the difference between carbs and 3 row, self mapping fuel injection. for those
that don't know you run a 1ph to 3ph inverter, you can run from 1-2rpm upto the double the motor speed I think. have programmable overload,
soft start and soft stop, emergency stop, reverse. Bit complex to set up but once running you'd never go back to single phase
The true home of cars born under the Sylva name - http://jpsc.org.uk/forum
STM Phoenix R1
Sold-Sylva Striker 1300xf, 40s etc
Sold-Sylva Phoenix, 1300xf, BVH, 234cam, 2xDCOE 40s, live axle - 'old school', rally car and a few bikes
|
|
|
.jpg)
