# Its Ordered , Pm-1340 Gt



## oldhank60 (Apr 23, 2015)

I finally have officially ordered my PM-1340 gt today
with prefered package,
3 phase motor
plus 5C collet chuck
coolant system 
DRO with glass scale high resolution

I am not sure if i will use a VFD or build or purchase a RPC,  does using a vfd damage the motor quickly or over long period of time, or at all  
I am going on what i have read at
http://www.hobby-machinist.com/thre...3-phase-equipment-on-single-phase-power.1585/

I can save money purchasing a larger RPC so I can run more than 1 machine. I have 3ph bridgeport on home built RPC, I have a spare 5hp 3ph motor that I could use to build 2nd RPC that will allow 2 machines to run at same time.  plus I have hopes of purchasing a new Mill also in 3 ph.  
Just more mind numbing thought processing to come up with best working solution for whole shop.

I do like the variable speed  option with a VFD but damage to motor could be costly I just am not sure how long the motor will last using VFD.   I was all set to go that option till I read the above post. 
anyone have input/ experience  on this that may help me decide?

thanks for any replies 

Hank


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## Ken_Shea (Apr 23, 2015)

Am sure they are there can be but  never heard of any real  issues using a VFD other then getting them tuned. There is a lot to be said about both really. I use a RPC in a separated room, while it is not really loud at all it's whining could get annoying if in the same room and a separate trip to turn it on and off is always required for even momentary use. With a VFD, it is silent and local and one is needed for each piece of equipment. I suspect this could be circumnavigated with some innovative switching though. In retrospect, a VFD may have an edge in use is my thinking.


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## Doubleeboy (Apr 23, 2015)

The problem IMO with running a VFD is are you using it for straight phase conversion or are you using it for rapid braking and speed control.  If using for braking and speed control you really want an inverter rated motor.  That being said I have a 2 speed non inverter rated Taiwanese motor that I have used with inverter for 10 years with no problems..... but I baby it, the only time I really dial down the Hz is for power tapping and that is brief.  I rarely ever go above base speed of 60Hz.  No problems but if I ran it 2 shifts a day hard by people who did not own machine I would have an inverter rated motor on machine.  IMO opinion all converters no matter if they are VFD or RFC make motors whine.   I have a 10 hp motor for my RFC for lathe and I am thinking about moving out doors in its own shed so I don't have to listen to it, but then again I would like to hear it to know how its doing so that is a toss up.

Nice lathe choice btw, congrats!
michael


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## mksj (Apr 23, 2015)

QMT sells these lathes with the stock 3 phase motor and the WJ200 VFD. I have not had any problems, nor have I heard of any issues with this combination, and you will be hard pressed to find another inverter rated motor that will fit in the motor space (there was only one that I could find). The stock 3 phase motor (made in Taiwan) works well with the VFD and it is smooth running.  It does not indicate its ratings or insulation rating.  You do not specifically need an inverter rated motor (newer motors have better insulation), and you can program the acceleration and deceleration to anything you want. It is a lot less traumatic on the drive train using a VFD soft start, then turning it on from a dead stop without a VFD. There are different ways/braking curves to implement if you use the electronic braking, I currently use a switch to choose between 1 or 3 seconds. Just because you set the VFD to "stop" at a specific time, doesn't guarantee it can stop in that time frame. The motor is just applying electronic braking in accordance with the programmed setting, there is still the momentum in the system to deal with. So a larger chuck with high speeds will take longer to stop or you may get an over-voltage error because of regeneration. If you have concerns, talk to Matt at QMT. I find the VFD variable speed and programmed stopping,to be a really advantage, but either way it is a nice lathe. You can always add the VFD at a later point.


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## wrmiller (Apr 23, 2015)

Nice lathe choice. No bias on my part though...


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## GA Gyro (Apr 23, 2015)

Yes, nice lathe choice!  There are a growing number of 1340GT owners at this forum.

On the VFD... IMO as long as you do not run the motor excessively slow or fast (say stick between 45 and 75 htz most of the time)... you should not have any issues. 

As I understand it... RPC's waste some power... however this is 'forum knowledge', have not owned or used one.


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## oldhank60 (Apr 23, 2015)

thank you for the replies

Hank


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## mksj (Jun 8, 2015)

Hi Hank,

Noted some concerns on the VFD install in your PM-935-TV posting. Wish I had ordered that mill when I got mine, but that was years ago, great choice. At least I ended up with a PM-1340GT.

A RPC will work very well, and many forum members use one to power multiple 3 phase tools. But since you purchased the WJ200, a VFD offers a lot of programmable options if using it on a single machine. The strong points for the lathe is the ability to dynamically adjust the speed without stopping, faster braking and better overall motor control (using sensorless vector mode).  The VFD install is more daunting at the start before you have everything in font of you, once you get started it goes fairly smoothly, and there are a lot of forum members to help you out. Many who have done installs on this model, or similar machines. Once you have the parts, it is a good day project. I can send you (pm me) the program file and circuit options for the WJ200, which may need some fine tuning to get it dialed in to your specific build. You will essentially remove all the wiring, contactors, relay in the electrical control box, but keep the terminal strip (if you have a 24V light, then you can use the stock transformer to power that or add a separate 24VDC supply). You will keep the spindle operation control lever switches/wiring.  The front control panel will need to be rewired, must of us have replaced the switches and added a speed pot (this information and source is all provided). Bill did the most recent VFD build of a PM1340GT, and he is not very wire friendly. This is his Looong posting. http://www.hobby-machinist.com/threads/bill-ms-pm1340gt-setup.33578/


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## jds (Jun 9, 2015)

Hi Hank,
 I just finished my VFD build for a 1340 GT and a 935 T-S,  I am not an wire savvy.  I pretty much copied how Mike-Zmotorsports wired his 1340 GT no problems, no smoke.  I like the lathe, but have not done any real work with it yet, my day job keeps getting in the way.
Good choice of machine in my opinion.


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## mksj (Jun 9, 2015)

Information needed to convert your PM-1340GT to VFD operation using a Hitachi WJ200-015SF and using the stock 3 phase 2HP motor. The average price for this VFD is around $300, I would buy from a mainstream supplier. But most of us ordered it from QMT with the machine.
https://www.driveswarehouse.com/p-2526-wj200-015sf.aspx   $283
http://www.wolfautomation.com/products/33622/sensorless-vector-ac-drivebrhitachi-wj200   $306
Basic circuit diagrams and programing information. Optional proximity sensor if used. I would review the information and look/read what others have done for ideas, and where you want to place the VFD, fusing and if you need a main power disconnect. The VFD is mounted either in a separate ventilated electrical box, or it can be mounted in the left lathe cabinet. If you need stepwise directions, something more specific can be put together, but everybody does their build slightly different.


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