[Waynekofuco]

I currently have a Jainken JGL-80/2.2R24-20 and a WJ200-022SFat 220single phase on a DIY steel fixed gantry mill. For a year this spindle/vfd combo has worked great for milling plastics and aluminum. This issue is I don't think I need the 24000rpm and want to change from the ISO20 holders to BT30. Lastly Im moving from the steel router frame to a cast iron VMC frame. I really like the Jainken and looking at the Jainken JGL-100/3.2R24-30 the spec sheet;
-S1 Power (KW); 3.2
-Max Speed; 24000rpm
-Rated Voltage; 220/380
-Current; 8.8/5.2
-Max Freq; 800Hz
-Torque; 1.27Nm
-Pole #; 4

After reading other threads on driving 4 pole/800Hz spindles with 400Hz VFDs Im still confused. I understand running a 4 pole spindle up to 400Hz max will result in 12000rpm max, but...
1st Q; What I don't understand, does halving the freq/RPM affect the usable machining power of the spindle? Again will milling AL with the correct tooling at 400Hz/12000rpm be better same or worse? Currently milling AL using single flute cutters @ 18000rpm. I would assume running the spindle much slower would require multi flute cutters...

2nd Q; Assuming the 800Hz spindle performance was ok at 400Hz for aluminum, is the WJ200-022SF VFD adequate to drive the above spindle? Per the VFD sheet;
-Rated input current (A) w single-phase 200V VT/CT; 24/22A
-Rated output current (A) w 3-phase: 200 to 240V; VT/CT; 12/11A

The above spindle current of 8.8@220 I assume is at 800Hz. Does running the spindle only to 400Hz increase this current demand at load and make the WJ200-022SF insufficient?

Thanks Wayne

[joeavaerage]

Hi,
running an asynchronous spindle at only half speed is if not an outright mistake certainly poor practice.

If you run the spindle at half speed, the torque is about the same, but the speed if half, so you only get half the power, so instead of 3.2kW you'd get 1.6kW at best, and even that is likely
to overheat your spindle. In short you have paid a lot of money to get extra power but by not getting a matching VFD half of it is thrown away. Worse I think you'd destroy your spindle
in short order.

The above spindle current of 8.8@220 I assume is at 800Hz. Does running the spindle only to 400Hz increase this current demand at load and make the WJ200-022SF insufficient?

I would read it the same way, namely at rated speed ie 800Hz input 8.8A at 220VAC. Were you to run the spindle at 400Hz, the spindle would still take 8.8A but the voltage would be half, about 110VAC
If you tried to apply 220VAC at 400Hz to sort of 'get back all that power' the current would increase to 16A, and it would last for a few second before a puff of smoke stops everything.

The WJ200-022SF is good for 2.2kW. At only 400Hz you could only run your spindle to half speed, ie half power ie 1.6kW. So your VFD would get half power at best without undue risk to the spindle.

If anything goes wrong you have given JianKen the perfect opportunity to wash their hands of it, and to be honest I don't blame them . You are inviting trouble and disappointment. Get the matching VFD,
and I would not trust a cheap one.I personally like Delta VFDs but Hitachi also have a pretty good name.
Craig

[mactec54]

Hi,
running an asynchronous spindle at only half speed is if not an outright mistake certainly poor practice.

If you run the spindle at half speed, the torque is about the same, but the speed if half, so you only get half the power, so instead of 3.2kW you'd get 1.6kW at best, and even that is likely
to overheat your spindle. In short you have paid a lot of money to get extra power but by not getting a matching VFD half of it is thrown away. Worse I think you'd destroy your spindle
in short order.



I would read it the same way, namely at rated speed ie 800Hz input 8.8A at 220VAC. Were you to run the spindle at 400Hz, the spindle would still take 8.8A but the voltage would be half, about 110VAC
If you tried to apply 220VAC at 400Hz to sort of 'get back all that power' the current would increase to 16A, and it would last for a few second before a puff of smoke stops everything.

The WJ200-022SF is good for 2.2kW. At only 400Hz you could only run your spindle to half speed, ie half power ie 1.6kW. So your VFD would get half power at best without undue risk to the spindle.

If anything goes wrong you have given JianKen the perfect opportunity to wash their hands of it, and to be honest I don't blame them . You are inviting trouble and disappointment. Get the matching VFD,
and I would not trust a cheap one.I personally like Delta VFDs but Hitachi also have a pretty good name.
Craig

He is using a Hitachi VFD Drive so is a good quality VFD Drive so just as good if not better than the Delta VFD Drive

Most of the 4Pole spindle are rated at 12,000RPM with a max of 24,000RPM so would be fine to run at 12,000RPM, have to see the spindle specs to know for sure.

[joeavaerage]

Hi,

He is using a Hitachi VFD Drive so is a good quality VFD Drive so just as good if not better than the Delta VFD Drive

Thats as maybe but it's still not the right one for his spindle. Either way I would avoid the cheap VFDs and get something better. I've had great results with Delta,
but to each his own.

How many posts have you responded to in the last six months alone where cheap Chinese spindles and/or VFDs have blown up?

I've already priced one of these spindles, it's so much more affordable than my preferred German brand, and they are around $1500USD, so I sure as hell do not want some
cheap VFD risk my spindle!

Craig

[Waynekofuco]

Thats as maybe but it's still not the right one for his spindle. Either way I would avoid the cheap VFDs and get something better. I've had great results with Delta,
but to each his own.

@joeavaerage I think you're conflating all Asian made equipment you're not familiar with as 'cheap'. Jainken is a quality Taiwanese spindle manufacturer and by no means cheap. I use Delta ac servos for kinematics and Hitachi VFD for the spindle driver as it was these both were the best fit for my original set up. If you can spec a single phase VFD that would work better than the one I already own please show me. I am happy to purchase the 'correct' VFD.

Biases aside...

Most of the 4Pole spindle are rated at 12,000RPM with a max of 24,000RPM

@mactec54
This is why I am so confused about the practical use of 4 pole spindles at 400Hz. I cant find it now, but I saw another spindle manufacturer w a posted graph of the power curve of their 800Hz 24000rpm spindle and the power/torque peaks at 12000rpm and falls off sharply after 18000rpm. It made no mention if the spindle was running at 800Hz or 400Hz...

[joeavaerage]

Hi,

I think you're conflating all Asian made equipment you're not familiar with as 'cheap'. Jainken is a quality Taiwanese spindle manufacturer and by no means cheap.

I quite agree. I use Delta products myself and am very likely to buy a Jianken spindle in the future. I do not consider either brand sub-standard. I do have reservations about many
of the cheapest made Chinese made VFDs. I have not named any but can promise you I will not be buying any such thing. If someone else does that is their concern, it will not be mine.

I have attached the power/torque curve for the 380V 2.5kW 100mm Jianken spindle, the closest I can find to the exact one he wants.

I clearly shows that the torque peaks at 1.27Nm around 8000 to 9000 rpm and remains constant up to rated speed of 24000rpm.

At 24000rpm the power is:
Power = 1.27 x (24000/60) x 2 x PI
=3191W....so close to the 3.2kW advertised.

At 12000 rpm the power is:
Power = 1.27 x (12000/60) x 2 x PI
=1595W....so about 1.6kW

It seems to me a shame that OP should pay good money for what I regard as a good spindle, one that I would like to have myself, but only get half the power out of it
than it is capable of.

When I priced the spindle, about 18 months ago, it was $1500USD. I just bought a 3.7kW Delta VFD capable of 800Hz for $475USD delivered here in New Zealand. I can well imagine that OP
would like to re-use is Hitachi VFD, but I just don't think its going to do justice to the new spindle, no matter how good Hitachi is.

Craig

[mactec54]

Hi,



Thats as maybe but it's still not the right one for his spindle. Either way I would avoid the cheap VFDs and get something better. I've had great results with Delta,
but to each his own.

How many posts have you responded to in the last six months alone where cheap Chinese spindles and/or VFDs have blown up?

Craig

Just (1) that has failed, and that was after 10 years of use, I would not call that bad at all. Any VFD Drive or spindle can be damaged if incorrectly Programed

[fpbfpb]

Hi,

G-Penny on aliexpress is selling two (different ?) 2.2kw 4 poles spindle for metal.
one is 4p, 400hz, 6000-12000rpm, 1.75Nm other is 4p, 800hz, 9000-24000rpm, 0.88Nm.
same size same power same weight.

is there real mechanical / electrical differences or just the way to drive them ?

fuling (folinn) H1 vfd seems to be vector control up to 1000hz with custom V/f curve even in vector control mode.
witch G-Penny spindle do you think is the best one to be normally drive up to 400hz and then in constant power mode up to 800hz ?
why not full power from 0hz to get maximum torque all over the frequency range ?
is the over heat a problem on a water cooled spindle ?

thanks a lot

[joeavaerage]

Hi,

is there real mechanical / electrical differences or just the way to drive them ?

Like almost all electrical motors the torque output is dependent on current.

In the case of 4P motor, with lets say 1A in each of the coils and it produces 4Nm. The same motor but with 8P (the same number of turns etc) and the same 1A in each coil
the you'd get 8Nm. That's great, more torque, so why not add more coils....but to add extra coils means that you have to use thinner wire to make the coils smaller and thereby fit more in. The smaller coils
can take less current without overheating, lets say or 8P motor from above can only take 0.5A per coil, then it would produce 4Nm torque.

Each coil will generate a voltage as the motor spins. It opposes the current supplied by the VFD. The faster the motor spins the more the BackEMF. Eventually the BackEMF is the same as the voltage
output of the VFD and the motor can go no faster. If you joined your 8P windings in series the it will have really good torque for a small amount of current, very desirable, but the BackEMF will be higher
so for a given voltage VFD it will go slower. Alternately if your wired your 8P windings in two groups of four in series with the two groups in parallel then for the same current you get half the torque,
but the BEMF is now half and so you can go twice as fast for the same VFD.

Really there is little difference between the two motors, just how the coils are wound and arranged. Some CNCers want best possible torque for a given size motor, while others want max rpm.
Some CNCers want max torque and max speed, and I suggest they write to the Tooth Fairy to get one. Last I heard he was flatting with the Easter Bunny, smoking a lot of weed and bonking
all the girls.

Craig

[fpbfpb]

Hi,

Thank you for the explanation.

I very would like to experiment if a G-Penny spindle is able to match The Mechatron HFPM-8022-24-ER20.
You said there is little differences on SAME SIZE / SPECS spindle so I doubted Chinese manufacturers are not able to match the Mechatron, maybe "made in china" it self.
The G-Penny is a bit longer (more space for coils), same diameter, same weight, same nb of poles, same voltage, same power.
Because of these similarities and my wish to match it, not to beat it, no need to ask the Tooth Fairy here is the place to ask :)

Which G-Penny spindle, 400hz 12K or 800hz 24K, would you choose to drive it (full power 2.2kw from 400hz to 800hz) like the Mechatron and try to match it ?

I did notice that the Mechatron torque up to 400hz is the same as the G-Penny 400hz 12K and the Mechatron torque at 800hz is the same as the G-Penny 800hz 24K.
Curves of the two G-Penny and the Mechatron in attachments.

Regards

PS: I very would like to know if it can be done, but not to the point to buy both.

[joeavaerage]

Hi,
that's why I mentioned the 3.7kW Delta VFD that I bought recently, its not cheap but reasonably priced and includes free freight to New Zealand. I had it in five days....not sure
where it came from, I bought from Element14 and they have warehouses all over the planet.

This VFD is used in a three phase installation, but could quite happily be used in a single phase installation with a modest amount of derating.3.7kW derated to 3.2kW sounds about right.
Any decent VFD should work fine.

Craig

[mactec54]

Hi,
that's why I mentioned the 3.7kW Delta VFD that I bought recently, its not cheap but reasonably priced and includes free freight to New Zealand. I had it in five days....not sure
where it came from, I bought from Element14 and they have warehouses all over the planet.

This VFD is used in a three phase installation, but could quite happily be used in a single phase installation with a modest amount of derating.3.7kW derated to 3.2kW sounds about right.
Any decent VFD should work fine.

Craig

As I have said before there is no derating if the VFD Drive is correctly sized

You seem fixated with Delta when they are only a mid-range product. The GT HY VFD is better and is half the price.

[joeavaerage]

Hi,

The GT HY VFD is better and is half the price.

Then you buy them, I think they're s***t.

Craig

[mactec54]

Hi,



Then you buy them, I think they're s***t.

Craig

You have only installed one Delta VFD Drive and have no other experience than a single installation.

[joeavaerage]

Hi,
I have installed possibly any many as two dozen, most in single phase installations and about 5 or 6 in 3 phase installations.
So, rather more than one.

Craig

[crjohnson]

For whats its worth I bought this Fuling 3.7kW VFD, supposed to have vector control but I believe its only up to a certain amount of Hz. I'm in Australia running it on single phase 230-240v power.

It's run perfect so far with my jianken JGH105/2.2kw, 800Hz, 4 pole spindle. Something tells me the extra torque from being '4 pole' isnt really there OR I have the VFD set up funny. It seems to bog doe easier than some 2 pole spindles I have seen when taking the same cuts etc. Even still it's done the job very well for a while now, I just set it to 550-600Hz and that does 99% of my cutting.

https://www.aliexpress.com/item/1005...21ef1802exZHWp

[mactec54]

For whats its worth I bought this Fuling 3.7kW VFD, supposed to have vector control but I believe its only up to a certain amount of Hz. I'm in Australia running it on single phase 230-240v power.

It's run perfect so far with my jianken JGH105/2.2kw, 800Hz, 4 pole spindle. Something tells me the extra torque from being '4 pole' isnt really there OR I have the VFD set up funny. It seems to bog doe easier than some 2 pole spindles I have seen when taking the same cuts etc. Even still it's done the job very well for a while now, I just set it to 550-600Hz and that does 99% of my cutting.

https://www.aliexpress.com/item/1005...21ef1802exZHWp

It sounds like you don't have your VFD Drive setup correctly, and yes there are very few VFD Drive that the Vector control works with the High-Speed spindles they do work at the lower frequencies though.

Do you have a PDF manual of the VFD Drive you are using if you have I will take a look

[joeavaerage]

Hi,
power= torque x rotational speed.

If a spindle generates 2.2kW at 24000 rpm the torque is 2200/(24000/60) x 2 x pi=0.87Nm.

Does not matter whether its two pole or four poll the torque is the same.

If however you had a 2 pole motor of 2.2kW at 24000 and the company offered a 4 pole version still 2.2kW but at 12000, then the torque would be double.

Craig

[crjohnson]

Here is a link to it:

https://cononmotor.com.au/wp-content...600-Manual.pdf

I have done some test cuts where it hit 5 or more amps (on the VFD display) but just started bogging down. This happened at 14500RPM and 19500RPM. Not that I want to run it that hard full time, would be good to know that it is more capable than the standard 2-pole, 400Hz units around. Piotr Fox uses a 2 pole jianken spindle that I tried to compare mine to (whilst being mindful of the million other factors, machine rigidity, tooling etc).

[mactec54]

Here is a link to it:

https://cononmotor.com.au/wp-content...600-Manual.pdf

I have done some test cuts where it hit 5 or more amps (on the VFD display) but just started bogging down. This happened at 14500RPM and 19500RPM. Not that I want to run it that hard full time, would be good to know that it is more capable than the standard 2-pole, 400Hz units around. Piotr Fox uses a 2 pole jianken spindle that I tried to compare mine to (whilst being mindful of the million other factors, machine rigidity, tooling etc).

5Amps on the display =15Amps that is 5 amps per Phase so yes, I would expect it to bog down as that is above it's max operating amps