variable speed

[robyn2839]

is it possible to convert the motor on my lathe to variable speed? or do i have to go and buy the complete unit. bob

[hughie]

Bob, Could you describe your current set up?

Variable speed can be electronic or mechanical. It can be done to anything that has a motor......for a price, its only a matter of money :U

[Jim Carroll]

In most cases the existing motor cannot be changed to variable speed.

You usually have to change the motor and switch gear to be able to use variable speed.

[RETIRED]

Seeing as Jim is too modest to say it, have a look here http://www.cws.au.com/cgi/index.cgi/shopfront/view_by_category?category_id=1107144886

[OGYT]

I think Jim's talkin' about you can't change the motor itself, if it's a single speed motor.....
But you can rig a series of pulleys on the motor and the lathe, to accomplish different speeds.

[Solutions Aust]

is it possible to convert the motor on my lathe to variable speed? or do i have to go and buy the complete unit. bob

Hi Robyn.

If you are looking for electronic infinite variable speed on your lathe you require a three phase motor and electronic speed unit including stop / start and speed knob.
The electronic speed unit converts the power back to your normal single phase for home workshop use.
Whole system is not cheap, adapting your existing motor pulley can present problems but if all is achieved, then you enter a new world of woodturning.

Cheers Woodfast Aust
www.woodfast.com.au (http://www.woodfast.com.au)

[robyn2839]

thanks for that ,it was to change my beaver with pulleys ,to a full electronic variable, will have to start saving.(nothing worse than changing belts and pulleys just to drill a hole then change back up). bob

[Caveman]

A little bit further afield but these (http://www.haydockconverters.co.uk/) guy's seem to have all that it needs to do the job in hand.
I'm sure someone in Oz does similar.

[Poloris]

These guys sell single phase to 3phase variable speed controllers.
If thats what you want.
They are a lot closer to you too.
http://www.automationdirect.com.au/

Poloris

[Frank&Earnest]

In most cases the existing motor cannot be changed to variable speed.

You usually have to change the motor and switch gear to be able to use variable speed.

I had a look at the motor indicated by . Can't tell from the photo and the specs are not listed. What is it that makes it regulable with a simple potentiometer? If Robin's motor just happens to be of the same type (we do not know this) just buying a potentiometer will suffice. (Last time I dabbled with this stuff it would have been a rheostat... no semiconductors yet!:D)

[Sebastiaan56]

I had a look at the motor indicated by . Can't tell from the photo and the specs are not listed. What is it that makes it regulable with a simple potentiometer? If Robin's motor just happens to be of the same type (we do not know this) just buying a potentiometer will suffice. (Last time I dabbled with this stuff it would have been a rheostat... no semiconductors yet!:D)

Usually in AC motors the speed is controlled by the hertz, not the volts, hence the electronics is a very different to DC which can easily be controlled by a pot. Ive been looking as well but there are no cheap solutions. For the $A500 it would cost you can almost get a new lathe.

[Jim Carroll]

The motor has indicated is a 3 phase motor with some fancy electronics built in. There is no other boxes or connections needed.

You use a standard single phase power point to plug into.
The motor is 1hp constant torque with a speed range of 550rpm -1700 rpm.

Now coupled with your existing pulley setup you can have quite a few speed options from very slow to very very fast.
You have to work out the driver against the driven to get the range on each pulley setup.

All this with constant torque which is what a woodturner requires. So you can turn a very out of round bowl at a slow speed and still have good torque and not stall the motor all the time.

Please note it will not fit onto the MC900-1100 asian variety of lathes as the mounting of the motor is not suitable, plus the motor is physically bigger so reducing the diameter of work you can do.
The main thing to get used to is that you turn the power on at the main switch and about a minute later all the electronics have warmed up and you are ready to go, you must only turn the lathe on and of at the pendant, if you turn on and of at the power point you confuse the electronics and it will just stop and not go anywhere. It is an easy thing to get used to.
The lead from the motor is 1.5m long so the switch can be placed in an easy to get to position.

If you have seen Neil {"U Beaut"} demo the rotary sander at the shows you will have seen the motor running as this is the motor he has on his lathe.

A lot of people with older lathes are upgrading to this motor as they have a shop full of accessories for their current lathe and do not want to go to the bother of changing chucks, faceplates and othe accessories they have, this is a cheaper option.

[Frank&Earnest]

Thanks, got the idea (I think). I gather that the "fancy electronics built in" is a rectifier and the motor runs on DC. While we are on the topic (sorry if it is a bit hijacking) I have seen 1.5 HP motors advertised as "allowing bigger work". I can't really see any substantial advantage over 1HP in practical terms, assuming constant torque, and the potential disadvantage of higher power in a bad dig in situation. Am I missing something important? In what situations the added power would really matter?

[hughie]

Thanks, got the idea (I think). I gather that the "fancy electronics built in" is a rectifier and the motor runs on DC.


Not really converts single phase to DC then to 3phase for the 3 phase motor. The DC set-up is usaully on the smaller variety.




I have seen 1.5 HP motors advertised as "allowing bigger work". I can't really see any substantial advantage over 1HP in practical terms, assuming constant torque, and the potential disadvantage of higher power in a bad dig in situation. Am I missing something important? In what situations the added power would really matter?
[/QUOTE]

I have stalled my 1hp several times at full speed. So personally I would prefer 1.5-2hp. My most recent lathe has 1.5kw motor which is just over 2hp. yeehaa :U

[Jim Carroll]

Hughie just gotta ask.

What were you turning that you stalled a lathe at full speed.

[hughie]

What were you turning that you stalled a lathe at full speed



:U, Lumps of green timber mainly soft, having roughed the lumps off, I tend speed the RPM's up.
It used occur on the variable speed drive of the MC1100. Changed belts a few times to get better drive still found it lacked a bit grunt.
However since I went over to a VSD and changed to stepped pulleys I can now fiddle around and get much better results.

I suspect my 1hp chiwanese motor probably was not up to scratch, still runs but never use it now, just spare for the bandsaw.

[woodcutta]

Good price on a Variable Frequency drive (USD). As has been previously said a 3ph motor is required.
http://www.midwestequipment.com/Product.aspx?ProductID=18061

Regards
woodcutta

[Frank&Earnest]

:U, Lumps of green timber mainly soft, having roughed the lumps off, I tend speed the RPM's up.
It used occur on the variable speed drive of the MC1100. Changed belts a few times to get better drive still found it lacked a bit grunt.
However since I went over to a VSD and changed to stepped pulleys I can now fiddle around and get much better results.

I suspect my 1hp chiwanese motor probably was not up to scratch, still runs but never use it now, just spare for the bandsaw.

That sounds more like the belts slipping. Did the rotor actually stop spinning?

Assuming that the motor did actually stop running, what was it that caused it to stop? The tool getting stuck in a lump? In that case, isn't more power just going to compound the bad possible outcomes of the dig-in? These are the questions I was alluding to.

[hughie]

That sounds more like the belts slipping. Did the rotor actually stop spinning?



In the beginning yes I shredded the chinese belts after a few hours of use. Cleaned up the ali pulleys and fitted a better belt and away I went.




Assuming that the motor did actually stop running, what was it that caused it to stop? The tool getting stuck in a lump? In that case, isn't more power just going to compound the bad possible outcomes of the dig-


No real dig ins, just an overload on the depth of cut [13mm gouge ]. Initially I thought it was belt slippage. Retightened the belt and tried again. It was not a common occurance with the old motor but it could be done. It also ran very hot, so hot I could not touch it. So I did some mods to the fan and cowling to try and get it to run cooler.
As I said in the end just dumped it and went over to a 3 phase and VSD with A 4 step pulley arrangement . So far so good :U

So now I err on the side of more power. Hence the 2hp on my latest lathe. The only real calamitous dig in I have had bent my 3/8 P&N gouge off at about 35' angle, now that was exciting........ :o :U Have not done again tho' :U

[rsser]

So now you can turn around corners Hughie? ;-}

Musta been something heavy duty you were trying.

[Frank&Earnest]

Woodturning: the extreme sport for the over 50!

That should make a good advertising campaign...:U

[rodent]

I think you should try my chisel hughie his nick name is Brutus :U he is a 1 inch bowl gouge . What do you think ern would brutus be big enough for him. lol He has a sister called bertha she is going to erns today . May be for some spindle turning :o

[hughie]

So now you can turn around corners Hughie?



cant everyone :? :U



Musta been something heavy duty you were trying


Yeah sorta like the way used to ride bikes, faster than my ability... :U




Woodturning: the extreme sport for the over 50!


:U Do you think it will catch on? :U



I think you should try my chisel hughie his nick name is Brutus :U he is a 1 inch bowl gouge


Yeehaa! the mother of all gouges. Imagine what sort of trouble I could get my self into with that one.......:o..:C...:U :U