Thread: 3-Phase Converter Help - Jaguar Cub CDS

Here is the operators manual: http://www.drivesdirect.co.uk/Downlo...B%20Manual.pdf

Much more here: https://www.google.com/search?client...utf-8&oe=utf-8


If you have the stepped pulleys still on the lathe, it is better to shift to the small motor step to big spindle step for running slow. I assume this was done.

If the motor is run very slowly the fan in the motor does not run fast enough to cool the motor and the magic smoke may come out, causing the motor to become disinterested in further toil.

There are two kinds of AC variable speed drives, the more expensive constant torque drives are used on lathes so they will give close to full twist at slow speeds. I am presuming this is what you have.

The other is used for fans etc. with constant load.

How big was the piece? What size HP motor. It is possible with a large piece, small HP, and big gouge to completely stall the motor.

If the lathe can't be bolted down, bolting the lathe to two pieces of 4 X 4 or 6 X 6 timber run at right angles to the length of the lathe will stabilize it. Make them twice as long as the width of the bottom of the lathe, and center the lathe on the timbers.

As to movement, an inch or so of gentle swaying back and forth I can stand. Four inches scares me.

My tuppence of advice, belt on small motor pulley - big spindle pulley, run as fast as possible without lathe flopping around, small sharp bowl gouge.

A low cost inverter will indeed only allow the motor to generate low power at low speed. To get more torque, the inverter has to be what is called a "Vector Drive" inverter, or use a completely different motor such as a DC motor and controller.

It should be possible to install an external potentiometer on most inverters to control the speed.
Can you post a close up photo of the left hand side of the inverter so the model number shows clearly.
Without that it is hard to comment much further as the models are often quite different.

Firstly, thank you Paul & Bob for your help with this. Your tips and insight is greatly appreciated.

Secondly, I apologise for the slow reply time. It seemed I didn't have enough information on the motor / converter when I posted first time around, and haven't really been over there much to go and investigate further.

I fear the inverted may be the wrong / lesser sort, which is resulting in low torque at low speed?

I've taken a bunch of photos of the details, and was wondering if either of you could share your opinion on what this might be, or what the best route may be?

I did take a long look through the PDF you shared when you first posted Paul, but unfortunately it doesn't seem to be quite the right model, nor could I find the exact model whilst searching. Also, the technical understanding of what it does and how to control it is quite a bit beyond my understanding to be honest.

I wonder if it may be simpler to, at some point, buy a regular single phase DC motor with a high torque, and replace the whole lot?

Your thoughts would be appreciated, anyway

He is getting on well with it in general, and getting A LOT of enjoyment out of it. But I think if we had better speed control / torque control it would make him happier.

Just to add: I forgot the side photo! It reads: Model Type CDS 75UK.

And just under the front, I'm not sure if it's readable, it says 'Motor Power 0.75kw - Overload 150% for 1 minute

IMG-20170518-WA0010.jpgIMG-20170518-WA0012.jpgIMG-20170518-WA0014.jpgIMG-20170518-WA0016.jpgIMG-20170518-WA0018.jpgIMG-20170518-WA0021.jpgIMG-20170518-WA0023.jpg

Just putting aside the issue of torque and the converter/motor combo for a moment... if I were to try and get him a more practical way of tweaking the speed, would this thing work without issues (or danger) ? It seems around the right size to fit in.

New AC 220V High Power Control Speed Electric Motor Replacement Module TH285 | eBay

I wonder if it may be simpler to, at some point, buy a regular single phase DC motor with a high torque, and replace the whole lot?

With the advent many years ago of greater control and controllers of AC motor DC became less and less in industry. So today DC motors and controllers are expensive, especially in the power range we talking about here.
If there is no way mechanically ie stepped pulleys to offset the loss of power I would go with Bobs suggestion look at changing to some sort of vector drive.

The good news is the motor appears suitable for a single phase 240V to 3 Phase 240V VFD/inverter.

The symbols encircled in red on the RHS (∆/Y) indicate the motor can be converted to ∆ so it can run on the VFD.
My guess is this has already been done to run with the Cub.

The other red encircled test probably dhows the dual 3 phase Voltage capability (220/380V), The 220 is with the motor configured as ∆ and the 380 as Y
The 220 is close enough to run on 240V


Motor.jpg

Setting up a Vector drive VFD is not that easy and requires setting about a dozen parameters on a VFD and running an auto tune program.
VFDs are all different and their several hundred page manuals can be relatively daunting to decipher.
This makes it really difficult and also unsafe to provide help for these form something like this forum
You really should seek the help of a local technically minded person to help with this.

On this page of the Instruction Manual which appears when I put in all the information on your converter, it shows that the converter can be set for constant torque or variable torque.

You may need to find someone to program the converter and write a simple cheat sheet for your father.

If you have the ability to download and put the manual on a CD, you could take it to a copy/print place and have a printed manual for yourself or a person to help.

The manual is located at: http://www.drivesdirect.co.uk/Downlo...B%20Manual.pdf

BAH! The page 70 would not upload. I will try again.

Got it. Applies to above post.

Originally Posted by Paul39

Got it. Applies to above post.

Thank you Paul! I was knee deep in this yesterday after posting, and did arrive at that page as well. It seems there are a couple of things I can easily change to see if it helps with torque. Seems I need to check the output voltage and the optimal torque boost in F09.

But, this may seem like a daft question, would he want constant torque or variable torque?

I would have thought that variable would be more useful for wood turning, so if you are a touch more aggressive with the cut, you'll get more torque to power through? Or doesn't it work like that?

Originally Posted by BobL

The good news is the motor appears suitable for a single phase 240V to 3 Phase 240V VFD/inverter.

The symbols encircled in red on the RHS (∆/Y) indicate the motor can be converted to ∆ so it can run on the VFD.
My guess is this has already been done to run with the Cub.

The other red encircled test probably dhows the dual 3 phase Voltage capability (220/380V), The 220 is with the motor configured as ∆ and the 380 as Y
The 220 is close enough to run on 240V


Motor.jpg

Setting up a Vector drive VFD is not that easy and requires setting about a dozen parameters on a VFD and running an auto tune program.
VFDs are all different and their several hundred page manuals can be relatively daunting to decipher.
This makes it really difficult and also unsafe to provide help for these form something like this forum
You really should seek the help of a local technically minded person to help with this.

I appreciate you taking a look Bob. And I also appreciate some things just won't be feasible via a forum. He does know a few people, such as the local electrician he's friendly with, and a hobbyist engineer at work, so I'm sure someone could help.

I would wonder though... a VFD seems to run in a similar price range to a new motor. If we can't get the current setup working better, might it not be easier to simple change the motor to a single phase AC motor of 3 or so HP?

Right, so I just went to do a quick test looking through the manual with the lathe in front of me.

Maybe I'm being stupid, but this manual just seems like the wrong one. None of the options in the menu are the same. In fact, the menu on the converter seems tiny in comparison to that of the manual.

Also, just to check something basic, he was using the max / min frequency as indicated on the front controller as P0 and P1 to control the speed. Is this the correct way? When I turn the max frequency down very low, to reduce the speed, I did also feel what my dad was describing, almost no torque at all. I pushed a piece of wood against the spindle (running low), and it almost stopped just under my gentle pressure.

IMG-20170518-WA0016.jpg

Originally Posted by davidjames

I appreciate you taking a look Bob. And I also appreciate some things just won't be feasible via a forum. He does know a few people, such as the local electrician he's friendly with, and a hobbyist engineer at work, so I'm sure someone could help.

I would wonder though... a VFD seems to run in a similar price range to a new motor. If we can't get the current setup working better, might it not be easier to simple change the motor to a single phase AC motor of 3 or so HP?

Sure but then you will be back to change belts - if you are OK with that then thats fine too.

Originally Posted by BobL

Sure but then you will be back to change belts - if you are OK with that then thats fine too.

Thanks Bob.

Can I ask why you'd need to change the belts? As the pull part on the motor just slips off the end. It seems that you could just replace the motor by unbolting it, and slipping it out of the belt. And then obviously making sure the alignment and new pulley arrangement is as it needs to be?

Is it not that simple...?

Originally Posted by davidjames

Thank you Paul! I was knee deep in this yesterday after posting, and did arrive at that page as well. It seems there are a couple of things I can easily change to see if it helps with torque. Seems I need to check the output voltage and the optimal torque boost in F09.

But, this may seem like a daft question, would he want constant torque or variable torque?

I would have thought that variable would be more useful for wood turning, so if you are a touch more aggressive with the cut, you'll get more torque to power through? Or doesn't it work like that?

On this side of the pond the system is called a variable frequency drive. Speed is changed by varying the frequency, the voltage stays close to the stated output of the drive. You want a constant torque for machine tools. As the resistance to turning increases by applying a cutting tool the VFD senses a slowing and applies more energy to the motor to keep roughly the same rotation per minute, (RPM).

If you jam a stick into a constant torque system, it will keep turning, burn the stick, throw the stick out, or the magic smoke will come out of the motor and/or the converter. I have a 1HP motor and constant torque VFD. With the speed turned way down, barely turning, I can grab the motor pulley with gloved hands as hard as I can hold it and I can not stop the motor.

Your controller is either a variable torque, or set on variable torque. Some of the slowing down while turning can be overcome by putting the belt on the smallest step on the motor and the largest step on the lathe. This will slow down the lathe but give a mechanical advantage, higher speed is made by running the frequency above 50 Hz, (cycles). It would be best to have the controller set on constant torque.

See: https://www.google.com/search?client...utf-8&oe=utf-8

I can make out a .75 after an unclear red legend. If that is the horsepower of the motor that may be a little underpowered for that size lathe. I think I recall it is a good size Wadkin, for which I would kill to possess but can't afford. The constant torque would overcome much of the smaller motor.

For a inexperienced hobby turner, slightly underpowered is an advantage, as a bad catch would slow or stall the motor rather than breaking the gouge and / or flinging the turning into ones face.

Assuming what you have is in good working order, I would not change to another system until you have explored getting the system you have correctly set up. From what I can see from this distance, it is a good system, but will take some time and effort to set up.

I have a 5 speed by pulley Hegner with the slowest at 700 RPM, and a 20 inch swing Woodfast with a 6 speed pulley and variable speed. This is most helpful as I make 95% bowls and my blanks are hacked out with a chain saw. I can slow the Woodfast using the pulley and variable speed to round off uneven blanks and with an interrupted cut, kerchunk, kerchunk, kerchunk. Even with that I had a catch on a dry locust stump that tore out 2 #10 screws, broke off 2 others, and flung the blank 20 feet out into the yard.

Originally Posted by Paul39

On this side of the pond the system is called a variable frequency drive. Speed is changed by varying the frequency, the voltage stays close to the stated output of the drive. You want a constant torque for machine tools. As the resistance to turning increases by applying a cutting tool the VFD senses a slowing and applies more energy to the motor to keep roughly the same rotation per minute, (RPM).

If you jam a stick into a constant torque system, it will keep turning, burn the stick, throw the stick out, or the magic smoke will come out of the motor and/or the converter. I have a 1HP motor and constant torque VFD. With the speed turned way down, barely turning, I can grab the motor pulley with gloved hands as hard as I can hold it and I can not stop the motor.

Your controller is either a variable torque, or set on variable torque. Some of the slowing down while turning can be overcome by putting the belt on the smallest step on the motor and the largest step on the lathe. This will slow down the lathe but give a mechanical advantage, higher speed is made by running the frequency above 50 Hz, (cycles). It would be best to have the controller set on constant torque.

See: https://www.google.com/search?client...utf-8&oe=utf-8

I can make out a .75 after an unclear red legend. If that is the horsepower of the motor that may be a little underpowered for that size lathe. I think I recall it is a good size Wadkin, for which I would kill to possess but can't afford. The constant torque would overcome much of the smaller motor.

For a inexperienced hobby turner, slightly underpowered is an advantage, as a bad catch would slow or stall the motor rather than breaking the gouge and / or flinging the turning into ones face.

Assuming what you have is in good working order, I would not change to another system until you have explored getting the system you have correctly set up. From what I can see from this distance, it is a good system, but will take some time and effort to set up.

I have a 5 speed by pulley Hegner with the slowest at 700 RPM, and a 20 inch swing Woodfast with a 6 speed pulley and variable speed. This is most helpful as I make 95% bowls and my blanks are hacked out with a chain saw. I can slow the Woodfast using the pulley and variable speed to round off uneven blanks and with an interrupted cut, kerchunk, kerchunk, kerchunk. Even with that I had a catch on a dry locust stump that tore out 2 #10 screws, broke off 2 others, and flung the blank 20 feet out into the yard.

Thanks for your insight Paul, much appreciated.

You're right as well. The system does work really well for almost everything, other than very heavy / off balanced items on the outbound end, where the torque is an issue. So it would be best to try and work out how to get the most out of this, before doing anything drastic.

I emailed the IMO Jaguar people to see if they have some information, or a more accurate/useful manual for this exact model and age. Will see if they get back to me...

In the meantime, yesterday, I went and did some testing after speaking to my dad. He mentioned that it was just cutting out at times and he needed to restart it, due to the torque being so low. So I went through and toggled with the settings and did my very primitive "jam a wooden stick at it to see if this slows/stops it", and indeed, at a low speed, it was stopping quite easily. I came to setting B3, which had either 1 or 0 as an option - I am thinking this could be variable or constant torque. As when I changed this, I can no longer may it slow down and certainly not stop with my "jam a stick in it" scientific test . So I'm going to leave it as that for now, let him use it, and see if I did actually change the right setting by trial and error.