Pm-1440gt

[mksj]

Two things I'm a little uneasy about, sight unseen (but how much different can it be from every other Asian import of this size) and it being a first generation machine. Nothing like being a beta tester. Matt's got a good reputation and seems excited about this offering so I'll take my chances.

I believe this would not be an issue, from the sound of what it is described as. A lot of these have bolt on parts, so as mentioned the gearbox will be the same and probably many of the other major parts, seems (guessing) most likely the major change is to the headstock for the larger spindle bore. These manufactures have been making these types of machines for a long time and know what they are doing, so I would certainly go the route you are taking. It is refreshing to see newer models that have improved features, as opposed to the same old thing. My hat is off to QMT/Matt for actually have the ability to make these changes/improvements to these machines, while most other suppliers grind out the same old thing (warts and all). Now, if variable speed was a factory option for a few of these newer machines, that would be the icing on the cake.

 

[jbolt]

I took advantage of a recent Enco 30% off plus I had a 10% off with free shipping coupon from an order they screwed up and got a few things including an Aloris tool post. I had forgotten how much nicer these are than the Chinese imports.

 

[jbolt]

I got word from Matt today that the lathe will come with the 3HP 3PH motor. The coolant pump is 1PH so I will go the VFD route. I need to choose a VDF for the 3HP motor. The lathe is a 12-speed so speed control will be limited to optimizing speeds between the gear ranges. It also has a mechanical foot brake which I will probably leave as-is for now. I am not getting the optional light so the DRO and auxiliary lighting will be on a separate 110vac circuit.

I'm reading through the various VFD setups on the 1340GT but I would welcome any suggestions on what VFD and other parts I might need.

I would like to get as much ready as possible and have a general wiring plan before the lathe arrives. Without actually seeing the machine wiring I'm assuming most of the factory electronics will be removed?

I already have 60 amps/220vac near where the lathe will be placed so I can put in breakers/disconnect for the VFD and auxiliary wiring. I do have experience wiring the VFD and controls on my PM932 conversion and a couple of CNC routers so this is not totally foreign to me it just won't be CNC.

I would also like to add a tach so any recommendations on those would be appreciated.

 

[mksj]

Matt sells the Hitachi WJ200 at a reasonable price, they work well and have a lot of programming variables if one gets into it. The major negative, is the manual is quite poor, the positive is that the parameter files have already been worked out and are easily adaptable. I would avoid the Chinese eBay specials, as they may be hit or miss on working for any length of time, the manuals are bad, programming can be an issue and no warranty. Alternatives with be the higher end Teco's and Automation Direct sensorless vector VFD models.Yes, you would be removing most of the machines control electricals, and possibly the control switches. Keep the spindle, foot and safety shield switches.

Recently installed a 3Hp WJ200 on a 2 speed lathe and it worked very well, they are available for single and 3 phase input for this Hp. You have two options with the foot brake, one is to disconnect the manual brake and use the brake switch to activate the stop command (like and E-Stop), or to use the mechanical brake and use the brake switch an input to command the VFD free run to a stop (no electronic braking). You cannot use both mechanical and electronic braking at the same time. One note, installing a VFD with appropriate safety features is a bit more complicated on a lathe and can take some time to get it up and running. There are various schematics designs, my preference is to use a power relay, for/rev relay, and if needed a coolant contactor. It requires a separate 12 or 24VDC power supply, which can also be use for LED lights, tach, etc. as an option. The relays add safety interlocks, and the designs are similar to commercial units. The tach used was a $10 hall sensor unit from eBay with a $12 Hammond 1590 diecast enclosure. Works fine for RPM only. The MachTach is an alternative if you need SFM. I have the latter, but for the most part do not use the SFM.
http://www.ebay.com/itm/381179149186
http://www.ebay.com/itm/331534164211

 

[wrmiller]

I too have the Wj200 and MachTach setup on my 1340GT and am happy with the configuration. Mksj was a BIG help with the programming.

 

[Bamban]

I am with mksj on EV version.

Now in the months ahead if Matt offers a version with just hi/lo speed control and variable speed from factory, amd maybe lower spindle center line from the floor, I may be compelled to buy one (assuming she approves the cash outlay) I've never owned a new machine, holding out for the perfect-for-my-wants-in-a-lathe, made in Taiwan.

 

[jbolt]

Matt sells the Hitachi WJ200 at a reasonable price, they work well and have a lot of programming variables if one gets into it. The major negative, is the manual is quite poor, the positive is that the parameter files have already been worked out and are easily adaptable. I would avoid the Chinese eBay specials, as they may be hit or miss on working for any length of time, the manuals are bad, programming can be an issue and no warranty. Alternatives with be the higher end Teco's and Automation Direct sensorless vector VFD models.Yes, you would be removing most of the machines control electricals, and possibly the control switches. Keep the spindle, foot and safety shield switches.

Recently installed a 3Hp WJ200 on a 2 speed lathe and it worked very well, they are available for single and 3 phase input for this Hp. You have two options with the foot brake, one is to disconnect the manual brake and use the brake switch to activate the stop command (like and E-Stop), or to use the mechanical brake and use the brake switch an input to command the VFD free run to a stop (no electronic braking). You cannot use both mechanical and electronic braking at the same time. One note, installing a VFD with appropriate safety features is a bit more complicated on a lathe and can take some time to get it up and running. There are various schematics designs, my preference is to use a power relay, for/rev relay, and if needed a coolant contactor. It requires a separate 12 or 24VDC power supply, which can also be use for LED lights, tach, etc. as an option. The relays add safety interlocks, and the designs are similar to commercial units. The tach used was a $10 hall sensor unit from eBay with a $12 Hammond 1590 diecast enclosure. Works fine for RPM only. The MachTach is an alternative if you need SFM. I have the latter, but for the most part do not use the SFM.
http://www.ebay.com/itm/381179149186
http://www.ebay.com/itm/331534164211

Thanks mksj, I read through a lot of your posts on the 1340gt conversions last night. Lots of good stuff. Thanks for doing that.

Both my CNC mill and router use Chinese VFDs. While I was able to slog my through those and they both work fine I will not be going down that path for this machine. We have a Yaskawa drive on the CNC router we built for the high school which is a really nice unit but expensive. I have read some mixed reviews on the Hitachi drives but it sounds like they are being used successfully here. I will take a look at the drives you have suggested.

I had not thought about the integrating the various safety switches. I will have to give that some thought. I grew up on machines with foot brakes and learned to use them for more than emergency stops but that was in a production environment. I guess I'm old enough to still not fully trust what I can't see or feel.

 

[dlane]

Jbolt : I'm guessing your avatar will clear up when your new lathe is up and running.
Sounds like it's going to be a nice lathe.

 

[jbolt]

I'm trying to wrap my head around the setup if I keep the mechanical foot brake. If the foot brake is pressed and the switch commands the VFD to coast what happens if the apron handle is still in the forward or reverse selection? How is that reset?

If the forward or reverse handle is put in neutral does the VFD have to be set to coast like with he foot brake or can that be set to brake though the VFD?

How quick can the VFD stop an 8" chuck from high speed?

On another subject how are you switching the machine power on/off? On my mill I use a master contactor to switch the VFD and other contactors on/off using momentary NC/On and NC/off buttons.

 

[mksj]

It is very straight forward, I have both schematics with parts lists and programming parameter files that I can send you depending on what you want to happen. The switches for most of the safety systems are NC type limit switches, but can be configures as NC or NO at the switch. These limit switches are connected serially with the E-Stop to kill 24VDC power that maintains the power relay latch, once this occurs it deactivates the direction relays and the machine will normally brake to a stop. The braking in this mode is single stage and the chuck stops in about 1 second, even with a 60Lb chuck. Probably quicker than you could do mechanically. Many VFD machines do not use mechanical brakes, they just have a limit switch that operates the electronic brake. Normal braking, using the apron spindle direction switch can be set to different parameters, but electronic braking is the default mode. Most of the designs I use have a switch to select 1 stage braking ~ 1second or 2 stage braking ~ 3-4 seconds, current designs revert to 1 stage braking if any fault trips are encountered. If you wanted the foot brake to stop the machine and issue a freewheel command, then you would either need another NO switch that goes to NC when the brake is depressed and issues the freewheel command to a VFD input, or the NO side of the limit switch would close a single pole relay which would issue the freewheel command. I can draw the schematics for either. Until you have the machine there, it is a bit difficult to get your head around all it.

In any fault condition, the red E-Stop light comes on. The apron handle most be cycled to/through the stop position to reset the power relay latch. This also applies if there is a power glitch/outage or the the handle is in the forward/reverse position when turned on.

Convention to turn off the power is to use something like a 30-40A rotary power switch. Alternatively in some manufactured machines a latching power contactor is used, this requires the power to the lathe and the power supply/transformer be on all the time. You need a separate on/off momentary buttons to turn the machine on/off.

http://content.jettools.com/assets/manuals/1340_1440 EVS Lathes_Manual.pdf
Example of the JET 1440 EVS lathe, the VFD Grizzly machines with foot brakes do the braking via the VFD. I do not recommend killing power to the VFD as a form of the E-Stop or upon braking, for many reasons that could be detrimental to the VFD and it defeats many of its safety parameters. Also attached is a PM1236 system, that would be similar to what you are looking for, to use the mechanical brake would require an additional single pole relay or a dual pole limit switch.