Getting a 1440GT (Which VFD, and other small questions)

[LVLAaron]

Planning on ordering a 1440GT Lathe.

I will get the 3 phase version. Slow spindle speed will be important to me at some point (chambering barrels)

I've been through this thread and read the diagrams in the thread titled "The Pm-1440gt Has Landed" by @jbolt (new account, so I cant share the link)

I've also seen and fully understand Clough42's 7 part series on converting his lathe to run on a 3 phase motor with a VFD. (hnew account, so I cant share the link)

I'm comfortable with electronics, but everything that @mksj has in his wiring diagrams is a little overwhelming, especially without having the actual lathe to look at in person.

So, a couple questions.

* It seems like the Hitachi WJ200 is the VFD that is preferred. There are several sub-versions of it available... which one do I want?

* To get the lathe running, I don't need all of the extra things that mksj has done, correct? VFD with the basic lathe controls wired through it (direction, speed, stop) is all that would be required, correct?

 

[Cadillac]

For/rev switches stop button and a main power switch. Acouple fuses to be safe

 

[davidpbest]

Now that I've used my 1340 with Mark's controls system for 5 years, I would not be without the jog joystick or the proximity stop. Very useful additions. I'm also glad I upgraded to a vector-rated motor for more speed range and better torque. I use jog all the time to thread using smaller taps and dies, and the proximity stop takes the pucker factor out of boring to a blind hole bottom or threading to a shoulder (most of my work is metric). YMMV.

 

[Kiwi Canuck]

Welcome to HM Aaron.

You can order the Hitachi VFD from QMT (Precision Matthews) when ordering the lathe and they will supply the correct model, also saves on shipping, bought mine from them.

Probably the WJ200-022 for the PM1440GT
Here's a link to the unit, good for 3 HP and single phase input.

WJ200-022SF

www.driveswarehouse.com

I agree with David Best, the jog feature is very useful and I also love the soft start and two stage braking provided by the VFD combined with a large resistor.

David.

 

[mksj]

The circuit design I provided for JBOT is about 3 versions from my current design, unless one is well versed in VFD control systems, I would not recommend attempting it. There are also other components that are not listed in the control schematic and his system was built as an integrated single enclosure system. There are a number of variations and each persons build varies depending on the individuals requests.

The basic 1440GT install is listed at the end of this thread, it is very easy to follow the installation pictures and will get the lathe working with the VFD and has been done by numerous individuals. The information provided is based on the use of the WJ200-022SF VFD, which is the 3 Hp single phase input model. I have posted in different places recommendations for VFD enclosure parts, the 3 Hp VFD needs 10AWG input wire, 14AWG is fine for the motor and an external braking resistor is required, the specifications are listed in the document.

PM-1440GT Basic Wiring Changes for using the Contactors to switch the VFD inputs

Sure does

www.hobby-machinist.com

The complete replacement control systems with proximity sensor provide a range of VFD control features, the sensor gives very repeatable stopping for threading, shouldering or blind boring. It is an additional aid, but does not replace good machining practice. Some individuals choose to put the VFD in the headstock cabinet, some in a separate VFD cabinet either mounted behind the lathe or on the side. This is a system I recently made for an individual that will be using a separate VFD enclosure and also requested a custom micrometer stop.

 

[Rifleman1384]

Aaron,
Hi and welcome.
You are in the correct place, everyone here is very helpful. Especially Mark and Dave that have already posted here. Look in the thread Mark has a video using his proximity stop while threading. https://www.hobby-machinist.com/threads/erl1340-thread-cutting-with-a-proximity-stop-system.88124/

Man the photo above looks familiar and that is one sexy carriage stop, I wonder who's it is (wink,wink).

Yes you can get the VFD from PM and they will ship it with the machine, they do try and keep them in stock, from the research I have done 3ph is the only way to go. Flip side if you get the VFD on your own you can have it installed already if you are going with the external enclosure. Mine will come with the machine.

The install instructions for the system (above Picture) are very well put together, I get a few pages in and wondered if I was over my head ( I am not an electrician or electrical engineer) I read every page of the instructions and then went back over it again. It seems pretty straight forward and I am confident it looks a lot harder than it will really be.

I read everything I could find and spent way to much time thinking about if i really needed (wanted) the full conversion (upgrade) or just run the machine with the VFD only just as the machine comes out of the box. I will be doing some of the same work you are planning. I decided in my case it would be better to just do it all at once instead of a re-do later. Something to think about, please be patient there will be delays in getting your machine, not bashing PM at all with the new times we are in so many things are out of anyone's control. You accessorize will you are waiting on the machine I told the boss lady that I'm just getting the right purses and shoes while I'm waiting on the outfit and she has not questioned the arriving boxes.

Many here may suggest to try and upgrade the 3 jaw chuck that comes with the PEP package, I tried that several times with my order and the last response was that the better chuck would not be available for several months (summer likely). I will start with the 3 jaw and we will see how good it is and if I keep or replace it. Someone else has posted that they were told PM could get them a Bison or TMX if they wanted. Please make sure if you get a 4 jaw from PM that you understand the thru hole in the chuck is smaller than the spindle bore if you will be needing all of the spindle bore at some point.

Again Welcome and Good Luck, remember ask, ask, ask. The folks here are very helpful in sharing their knowledge and experience.

Steve

 

[LVLAaron]

Thanks everyone! - This has been very helpful. Almost everything makes sense.


The only thing I'm not fully understanding yet is what the factory contactors are being used for as described in "PM1440GT Basic Wiring Changes for using the Contactors to switch the VFD inputs 23 DEC 2018-1.pdf"

Looks like they're "between" the control panel switches/controls and the VFD - the controls cannot be directly wired to the VFD?

 

[mksj]

The VFD output is wired directly to the motor, the contactors are not used for this purpose. The VFD has low voltage/current inputs that can be programmed for many VFD functions, so you need a means to activate these inputs and maintain the machine safety interlocks. You remove the high voltage wiring to the motor run contactors and use one set of inputs to control the VFD forward and reverse input commands. If you want other features, you need to rewire the other switches so they operate the VFD inputs for those functions (like low speed jog). You will also need a speed pot. Contactors if new work acceptably to switch low voltage/current connections, but once used they build up contact resistance from arching and are less predictable. So this is a simple approach to using the VFD, but not an ideal dedicated control system. It is all a bit overwhelming when one cracks open the door to trying to understand how to use VFD's, once you have done one it gets more straight forward. VFD;s should be wired with all the safety interlocks, also with a manual foot brake, it requires shutting down the run commands to the VFD and activating the coast function to a stop on the VFD.

 

[LVLAaron]

Thanks again for the help. I've started ordering some of the core parts. (VFD, resistor, breakers, box, fuses, switches, etc)


Being new to the forum, what's the preference when I have new stupid questions? Keep this thread going, or start a new one?

 

[davidpbest]

You're a braver man than I and have a lot of work ahead of you. Good luck. I'm sure Mark will be standing by to assist.