How hard is putting a VFD on a 3phase 1440 GT ?

S

Spotshooter

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Kind of last minute stuff, I should be ordering my lathe from Matt in the next month or so... Matt sells the VFD’s but doesn’t install them at last check so I going to have to do it.

I have electrical background but haven’t done stuff like this for years, so I have to ask ... how much fun an I in for ?

Mike
 
Pretty easy, Mike. That’s exactly the design center for a VFD. The main issues arise if you are not willing to use only the controls that are part of the VFD, but want to use the existing lathe buttons. Not hard exactly, but more thinking and planning is necessary. You will also need to read a manual to configure the VFD for your motor. If you can, say, set up a router and WiFi, your brain is big enough.
 
My electrical knowledge consists of basic household wiring, but I successfully converted my 1440gt. I just did a basic conversion, using the stock contactors. I don’t have a proximity stop, but all original function is there, plus infinite speed control, resistor braking, etc.
MKSJ has outlined the basic process, somewhere on this forum.
It wasn’t terribly difficult, took me between 10-20 hours, and I was moving SLOW. Has worked fine since, a bit over 2 years.
Do it!
 
Yep, it's pretty straightforward. Effectively the VFD replaces the contactor.

Getting the controls exactly the way you want is more complex, but basically you just hook the switches to the VFD and set up the VFD registers to recognize them.



Sent from my Pixel XL using Tapatalk
 
Thanks guys- That’s good - From reading threads, the new nomenclature (terminology) is going to be a bit of an issue, but hopefully not to bad.
I was somewhat concerned on reading / finding the right terminations on the lathe for the rewire, especially if the control boards inside the lathe change from time to time.

I have seen the MKSJ posts .. WOW.. he knows his stuff, those and will a huge asset.
I’ll see if I can get the model number of the Hitatchi VFD Matt recommends / sell so I can do some research on the setting / connections and terminology. I think it’s the WJ200 ?

After waiting a couple years before getting the lathe, then waiting to order it... having to do some custom wiring before using it... I’m just a tad anxious.
 
There are cheaper VFDs, but most PM users appear to use the Hitachi WJ200. Besides the group knowledge, it has an excellent and thorough manual. I've seen complaints on other forums about users struggling to comprehend how to set up Chinese VFDs, because the manuals were so poor, so the WJ200 is a good one to go with.
 
The posted basic 1440GT VFD install is pretty straight forward, I have made a few updates so send me your email and I can send the revised files. They are guidance documents as far as suggested wiring changes and programming parameters for the 1440GT with the WJ200 VFD, but you assume all risk/liability for any mods you make to the machine.

The lathe will operate the same as if it was on an RPC, but with the added features of controlled acceleration/ deceleration, braking, speed control, etc. The design is built around the WJ200-022SF sold by QMT, cheaper VFDs do not work well for the lathe nor support the input controls of the WJ200. I primarily use the Hitachi WJ200 and Yaskawa V1000 VFDs which are mid-price, support a wide range of programming features and have very good reliability. They also come with tech support (minimal) and a warranty. You can get an inexpensive (under $20) tachometer on eBay but will need a small 12VDC power supply to run it.

The basic 1440GT install strips out the motor high voltage wiring to the forward/reverse contactors and just uses a set of their contacts T1 to switch the VFD input for the particular forward/reverse command. Contactors are not ideal for low voltage (24VDC at around 10mA) used for the VFD signalling, but seem to be OK if the contactors are new. Using used contactors/rotary switches does not work. You do need an external braking resistor and you will need to replace the brake switch to a dual pole type, one side uses the existing wiring (NC) which goes open when the brake is applied and the other side (NO) sends a free run command to the VFD. Although there are variants on the internal wiring, those to the Forward/Reverse contactors does not change. I have seen them come with both single phase and 3 phase coolant pumps, last I saw they are single phase 220V so that needs to be checked if you plan on using it.

You will need to build a VFD enclosure, I have a guidance document as far as parts needed and some basic wiring schematics as to suggested connections. The VFD cabinet can be mounted behind the lathe on a wall or some people mount it to the outer side of the headstock cabinet. You need to meet all applicable electrical code requirements, so if you are unsure have an electrician check out you final wiring.

The 1440GT is a very nice lathe, so enjoy.
Mark
 
Thanks Mark... I did see the thread you mention - seeing a completely uninstalled clontroller board (completely de wired) kind of scares me a bit...
I’m hoping that’s not I have to do — (BTW- I would never attempt to tackle this without references like you are putting out there - so thank you !)
The fact that screwing with the boards / motor to any extent very probably voids the warranty... of course puts one off.

Ok.. now for my terminology stupid questions...

RPC ? - is that what a 3 phase lathe comes with in terms of control boards ?
Contractors - are these the reed switches / toggle and other physical switches on the machine ?

things I do get...
Mounting the VFD, I do get the cabinet requirement - like you have in your picture I plan to mount the VFD on a L bracket in the cabinet.
220 single phase in - 3phase out to the motor
VFD inputs (forward reverse, brake, Jog).. Not sure what other ones are there -I need to read the manual.

Things I’m still learning about but at least conceptionally get -
Brake resistors... I know I want them to stop it faster - where the heck do they go?
TAC / RPM meter - I assume there are output on the VFD ?
Speed control- I assume that’s a potentiometer that is an input for the VFD
 
Regarding the warranty, I talked with Matt about this, prior to making my purchase. He wasn’t concerned about it, and would honor the warranty regardless. I have had to get one part under warranty, and there was no issue. I don’t speak for QMT, I’m just relating my own experience.
 
I agree - Matt’s a great guy, but if I smoke a board because I did something stupid, I wouldn’t expect him to send replacement parts... it’s a tricky business area. Most of the piece parts are not at risk, but still.
 
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