Thread: SpeedMaster VSD

Do you mind if I ask how much they cost?

And also the 1.5hp if you know.

Thanks, Greg

I don't think you can use the reverse switch.

Jim Carroll will enlighten you.

CMG have tried to develop the motor with a reversing switch and keep coming up against glitches in the sysytem and the main one beign the human factor.

The motor is like a tv , you turn it on at the main power point and all the electronics warm up then you only turn it on and of at the switch on the pendant, under no circumstances do you turn it on and of at the power point as the electronics do not like this.

You only turn it of at the end of the day.

Like all electronics you do need surge protection.

For woodturning there is no need to go any bigger than the 1hp as you have your pulleys to give you more torque. The standard motor has a B56 frame and a 5/8" shaft to go bigger means going metric and a bigger shaft so incurring more expense.

I remember reading somewhere that you need to make sure the 3 phase motor is designed to be run at slow speed. Some motors rely on the speed of the motor to supply the correct airflow to keep the motor cool. Even though the VFD will run the motor slowly, it is still drawing current and hence heating up. Without the correct airflow, you would soon burn out a motor which is not designed to run at slow speed.

Originally Posted by Jim Carroll

CMG have tried to develop the motor with a reversing switch and keep coming up against glitches in the sysytem and the main one beign the human factor.

Jim, I have received the wiring diagram for the factory fitted reversing switch from the NSW distributor and it looks easy enough to fit an external switch.

The motor is like a tv , you turn it on at the main power point and all the electronics warm up then you only turn it on and of at the switch on the pendant, under no circumstances do you turn it on and of at the power point as the electronics do not like this. You only turn it of at the end of the day.

I understand that the electronic components stay "live" for about ten minutes after the drive is switched off.

Like all electronics you do need surge protection.

Thanks for the tip

For woodturning there is no need to go any bigger than the 1hp as you have your pulleys to give you more torque. The standard motor has a B56 frame and a 5/8" shaft to go bigger means going metric and a bigger shaft so incurring more expense.

Nalmo, fair comment, but I think with the limited amount of turning I do (ie hobbyist ) this should not be a problem. I will check with the distributor how long the drive can run at minimum speed, just in case..
Cheers

Originally Posted by Greolt

Do you mind if I ask how much they cost?

And also the 1.5hp if you know.

Thanks, Greg

Hi greolt,
About $850.

I do not know the price of the 1.5hp as I was not interested, because it would not be a straight swap-over as the motor frame size and shaft diameter are larger, resulting in extra costs and difficulty.

Cheers

GoGuppy, what lathe are you putting this on?

Hi Fred

It's going onto a Leady lathe.
Cheers

Originally Posted by GoGuppy

Hi greolt,
About $850.

Thanks GoGuppy

Greg

Originally Posted by GoGuppy

Hi Fred

It's going onto a Leady lathe.
Cheers

Thanks, that's a nice lathe

Assuming the CMG VSD and motor are similar to the those on a Jet 1642, some ref. info. follows. The motors (1.5 and 2 hp.) on the Jet and PM 3520B are TEFC (totally enclosed fan cooled) and do get warm at low motor speeds, as mentioned above. The factory programs the minimum spindle speed at 50 rpm (on lower of two belt positions) to maintain sufficient motor rpm and fan speed to prevent motor overheating. After about 30 minutes at 50 rpm the outside of the motor feels like about 125-130F. Note that there is a <st1>LOT</st1> of variation in how the VSD can be programmed, and the actual spindle and motor rpm also depends upon your pulley sizes.<o></o><o></o>
<o></o>
Some people unplug their VSD lathes or turn off the circuit breaker (in wall panel) at the end of every day. Others (self included) leave power to the lathe full time, except when bad weather with lightning is expected. The switch on the control panel is always turned off, of course, when finished turning, and is a good idea to turn the speed knob to zero or low speed. Probably y’all already know all this, but maybe helpful to someone.

Good info Texian and Jim.

I spent some time looking at the changeover to VSD for my TL1200. The information I obtained from various sources aligns with that given here.

There is no really cheap or easy way to do this. You have to get the right gear. If my memory serves me correctly Jim has the motor plus VSD control for well under 1K.

A separate VSD can cost more than $500. Why would you bother with separate components at that rate>

Originally Posted by artme

Good info Texian and Jim.

I spent some time looking at the changeover to VSD for my TL1200. The information I obtained from various sources aligns with that given here.

There is no really cheap or easy way to do this. You have to get the right gear. If my memory serves me correctly Jim has the motor plus VSD control for well under 1K.

A separate VSD can cost more than $500. Why would you bother with separate components at that rate>

Hi artme, you are right, there is no cheap way of doing this. I got the following quotation back in June before I decided to go with the CMG:

1 x AC motor D80 0.75kW 4pole B3 foot mounted 3 phase WEG @ $206 + GST.

ADD:
EITHER: 1 x AC Variable speed drive Eurotherm model 650 240V 1phase 240V input 3 phase output @ $523 + GST, (note this model is variable speed only and will not give torque at bottom end of speed range),

OR: 1 x AC Variable speed drive Eurotherm model 650V 240V 1phase 240V input 3 phase output @ $631 + GST (this model is a sensorless vector unit and will give full torque through most of the speed range).

Above prices are net and exclude GST.

If you are willing to fiddle around with the electrics and slightly different motor (frame)
size, the second option may be suitable as well.
Cheers

The speed of the CMG motor ranges between 500rpm and 1700 rpm.

This was done so the external fan could still keep the motor at the proper working temperature , if you find you are working at the lower end of the speed for a long period then it is better to go a step lower in your pulley set up and let the fan work a bit harder and keep the motor running more efficiently.

There is no loss of torque at the slow speed unlike the others which can be stalled at the lower end.