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Offline Hood

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Re: Servo Motor question
« Reply #30 on: March 18, 2011, 07:43:11 PM »
Think you better double check the input voltage reuirements, to me it would suggest its 3 phase 220v.
Hood

Offline DMBGO

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Re: Servo Motor question
« Reply #31 on: March 18, 2011, 07:46:41 PM »
No, it's Ok, I asked about that too, the top line is single phase, and the second line is 3 phase, so they will take either.
Thanks
Dave
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David

Offline DMBGO

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Re: Servo Motor question
« Reply #32 on: March 18, 2011, 07:49:32 PM »
Actually I'm thinking of buying what they call a variator from them as well anyway. Apparently it's a phase converter and it would come in handy from time to time.
I wasn't planning too do this, but I am keen to use the 10,000rpm spindle motor and drive that comes with the mill and that's 3 phase only

Cheers
Dave
Cheers

David

Offline Hood

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Re: Servo Motor question
« Reply #33 on: March 18, 2011, 07:52:34 PM »
Ok, thats good, I was thinking the top line was in Chinese and the one under was the Engrish version.
Reason I thought that was if you look at theChinese writing in the Main Power its different from that in the Control power, well the first part of the Chinese writing is.

Hood

Offline Hood

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Re: Servo Motor question
« Reply #34 on: March 18, 2011, 07:53:20 PM »
Never heard of a variator, got any links?
Hood

Offline Hood

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Re: Servo Motor question
« Reply #35 on: March 18, 2011, 09:06:24 PM »
I have just done a translation of the Chinese 三相 which appears in the Main Power section and it means 3 Phase like I was thinking, I would check again with the suppliers to make sure, but maybe I am being overly cautious ::)
Hood

Offline DMBGO

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Re: Servo Motor question
« Reply #36 on: March 18, 2011, 09:35:52 PM »
Ok, I'll check now thanks for going to the trouble Hood
Cheers

David

Offline DMBGO

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Re: Servo Motor question
« Reply #37 on: March 19, 2011, 04:17:43 AM »
here's what they said in the quote:
"2. DA98B-10/110SJT-MZ040D(A2Y2) AC SERVO UNIT (1.0KW、4Nm、2500rpm、5000pps incremental
encoder, 3-phase or single phase AC220V input, short shaft, with brake) for Z axis: 1 SET "

However the DA98B user manual says 240v single phase up to 0.8Kw and 3 phase 1 Kw and over.

I will have to re-clarify this with them, but it does look like the drive will accept either single or 3 phase, there are just some output power limits on single phase.

Thanks for bringing this to my attention

Cheers
Dave


Cheers

David

Offline DMBGO

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Re: Servo Motor question
« Reply #38 on: March 26, 2011, 07:44:41 PM »
Well a bit of time has gone by and I have made a decision about the VMC-760 machining centre. I decided not to go ahead at the last minute. The supplier was adamant that I use their 3 phase spindle, which would have necessitated buying what they called a variator. Unfortunately, despite numerous e-mails they were unable to give me any clear information as to what a variator was. I assume that it is a phase converter, but whether it's  mechanical or electronic I don't know. To this day I am perplexed. I think they just didn't understand my questions; I would say "I believe a variator is a type of phase converter, could you please tell me if it is a mechanical or solid state device" and they would say something like "The spindle need 3 phase power you need variator to operate it with single phase". We just kept going in circles until I gave up. Once I had given up they sent me this link in an attempt to resurrect the sale but they couldn't tell me what model the one they were quoting was.

http://www.shinhsing.com.tw/index.php?option=com_content&task=view&id=46&Itemid=45

In the end I lost confidence and decided it was too much money to spend, when I didn't really know what I was going to end up with and how expensive and time consuming it was going to be to sort out the inevitable problems. I probably should have just bought the basic machine frame and then sourced the remaining electrical components after it arrived, but by this stage I was worn down and was getting impatient.

One day I will go to Taiwan and China and have a look at the factories over there it should be fascinating.

Having put the import business to bed I turned around and ordered a convention knee mill from a local Melbourne supplier, since I had just sold my existing mill being sure that I was going ahead with the VMC-760.

The mill I have bought is a King Rich KR-V3000, which is set up already for CNC conversion with ground C5 ballscrews on the X and Y and precast brackets for the servos. I just need to supply and fit the motors, put a ballscrew on the quill and do the wiring.
There are a couple of conversion threads on CNCZone for this mill:
http://www.cnczone.com/forums/knee_vertical_mills/117112-conversion_king_rich_3000_a.html
http://www.cnczone.com/forums/knee_vertical_mills/105668-king_rich_krv-2000_knee_mill.html

I had already ordered the 1 kw servos from GSK, after they confirmed that their 1kw servo is fine on 240v single phase, GSK was a bit concerned that I may be under powering the mill, but the guys on CncZone who have converted these mills have used 400watt and 750watt motors in their conversions, so hopefully I will be Ok.

Since I had saved some money by not buying the machining centre I went ahead and ordered some more servos for the lathe as well. I found a single phase 2.5kw one with 2500rpm and a 5000line encoder and drive from Adtech that runs on single phase. I intend to put this on the spindle, and two 500watt servos for the X and Z drives, which should put the lost steps from my steppers to bed.

The mill should arrive in the next week or so so I think I might document the conversion on CncZone, since it seems to be the in thing.

Cheers
Dave

Cheers

David

Offline Hood

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Re: Servo Motor question
« Reply #39 on: March 27, 2011, 03:20:36 AM »
Sad to hear that Dave, a bed mill would have been my choice but suppose it depends what kind of work you will be doing and whether the Z axis travel will be important. Add to that a toolchanger is much easier to add to a bedmill than a knee mill then ....... but as said all depends on whet you will be using it for.

1Kw servos should be fine as long as they are what they say they are, worst case you would have to gear which would impact on the rapids but would still allow reasonable rapids I think (depends RPM of motor and pitch of screws).

What kind of money are they asking for the 2.5Kw motors/drives, if you dont mind me asking. I have found a place in the UK thats selling Chinese drives/motors but dont know the prices for the bigger stuff, they have .75Kw motor/drive/cables for £650 which sounds reasonable, but I imagine that price would ramp up quickly with the Kw.

Please document here as well in the Show and Tell section, even if its just a copy and paste of what you put on the zone.
Hood