So a few suggestions, as I had many of the same questions when I was looking into this "before I received the lathe". So lots of conjecture, and most of the motors I had been looking at would not fit or were overkill. I can only give suggestions, but one needs to review all the specs (motor dimensions) and see what actually will work.
1. It would be doubtful that one would get much for the stock motor whether new or "slightly used". But worth a try. I doubt anyone would have an issue, if it was lightly used for a month. These are not very impressive motors next to the likes of a Baldor or Marathon. They are made in Taiwan, but beyond that I could not find any information on the OEM motor company or ratings beyond the nameplate.
2. Constant torque rating is the range that constant torque is maintained below the base frequency, so a 10:1 suggests that the range is 6-60Hz, a 1000:1 essentially 0-60Hz, above the base frequency (60Hz) torque drops off with speed for all AC motors. Vector motors can provide very high start up torque, locked rotor torque. Horse power is linearly decreased below the base frequency down to 0 RPM, so at 30Hz one has ~50% of rated horse power. Above 60 Hz, horsepower is maintained up to a rated motor speed, and 1800 RPM motor can easily be run at something like 80 or 90 Hz without problems, Vector motors are easily rated to 2-4X base frequency with no HP loss. There is a lot of information available on-line that goes into greater detail. If you look at VFD lathes and mills, many in the smaller 1.5-3 HP range have 2-3 manual speeds, the rest is taken up by the VFD. In my 1340GT I am currently using a 20-80Hz as a usable range with the vectorless VFD settings, which provides better power delivery with greater torque. Inverter rated fan air cooled motors (TEFC) should not be run continuously below ~15-20Hz due to the potential for overheating.
http://www.marathonelectric.com/motors/docs/manuals/SB371.pdf
3. I did not pull out my stock 3 phase motor to measure it up. You should be able to do this and get the exact measurements to determine the exact frame size. The stock motor dimensions are smaller than most of the replacement motors I was looking at, both overall length and diameter of the housing. Also location of the control box needs to be the correct orientation when mounted. The Leeson IEC metric allows the base to be mounted in multiple 90 degree position, the marathon also have the correct outlet box orientation. The Marathon Vector motors have impressive specs, but I think it is just too long and the diameter too large (these are TENV, no cooling fan is used so larger fins) to get it into the space, let alone have some adjustment room for the belt. But one needs to measure it up, and unless you need a very wide speed range I do not see the benefit in this application. In a 2 speed mill, I think it is more warranted because of the wide speed ranges needed (and high RPM).
4. Hitachi software is available at no cost from their site.
http://www.hitachi-america.us/ice/inverters/products/ac_variable_speed_drives/wj200/
Software:You must first install the PDN driver first before connecting your VFD
http://www.hitachi-america.us/ice/i...e_sales/software_dloads/?WT.ac=pro_smm_sss_sd
Then install the ProDriveNext 2.1.1 English
http://www.hitachi-america.us/ice/i...software_dloads/prodrive_next_software_dload/
At least for me the software was difficult to use and quite primitive, but I couldn't see manually programing from the VFD keypad. Out of the box the WJ200 will not respond to any commands, until you reassign the inputs. Some functions like the Jog need to have both a jog command and a direction command to function. I am still trying to get mine to behave correctly, along with safety interlocks that I am implementing.
I did toss the whole lathe control board, I have a new phenolic board with a DIN rail for a DC power supply and relay controls for all functions. A bit over the top, but allows some interlock and configuration controls over standard hard contacts. Also all the switches on the front lathe panel have been changed and reconfigured.
If you get into it, I would be happy to provide further information, but I am no wizard on these things. Just need to do a bit of reading and figure what you need/layout.
Mark
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