The 1236T comes with a 2 hp motor in the 3 phase version instead of 1.5 hp with single phase.
A vector drive VFD is able to operate the motor at full torque at very low speeds, but I’m not sure the motor that comes with the lathe is up to running as low as a true inverter rated motor could do. The motor is custom and no information is readily available on it. I have been using mine for a year and a half without any issues, so I don’t feel there is a need to change the motor unless you are pushing it beyond normal operation. I haven’t oversped my motor yet like Mark recommends, and I don’t even have a speed pot installed. I set my vfd up differently than most and use it more as a soft starter than to vary the speed, so changing gears is necessary. I also used the coolant switch to change to a fast braking for threading, as well as reducing the speed to 50%, this way I get the low speed and high speed ranges at the flip of a switch. I do mostly metric threading, so I need to stop the spindle and reverse for each pass. I will probably add a speed pot at some point so I can fine tune the speeds to better match the machining conditions, and also try the expanded operating range of the motor that Mark suggested above, but so far it has not been a priority. I want a tachometer installed before I do that so I know what speed I am running at. I did not add a braking resistor and my Teco CV7300 vfd can stop the 4 jaw chuck from 500 rpm in a half second, so for my uses, a braking resistor is not needed. If you wanted to brake quickly from full speed, then a braking resistor would likely be needed.
You will want a VFD with single phase input and 230v for your rated motor power. You can use a three phase input VFD, but then you will need to upsize the VFD power at least 1.7x if used on single phase since a 2hp three phase input vfd will not be able to handle the current from a single phase source and give you 2hp output.
You will need to modify the controls a bit, the spindle drive lever needs to go through a relay that prevents the vfd from starting if you get a power failure and leave the lever in a drive position. Basically, you will remove all the existing relays and rewire through the VFD. It’s not difficult to do, just takes a bit of time and some control relays. There are plenty of people here who have done this and can help with questions. There are VFDs with internal programming capabilities and you can do relays through programming instead of physical relays, but you would need to dig through the manuals to make sure it has sufficient inputs to do that.
A vector drive VFD is able to operate the motor at full torque at very low speeds, but I’m not sure the motor that comes with the lathe is up to running as low as a true inverter rated motor could do. The motor is custom and no information is readily available on it. I have been using mine for a year and a half without any issues, so I don’t feel there is a need to change the motor unless you are pushing it beyond normal operation. I haven’t oversped my motor yet like Mark recommends, and I don’t even have a speed pot installed. I set my vfd up differently than most and use it more as a soft starter than to vary the speed, so changing gears is necessary. I also used the coolant switch to change to a fast braking for threading, as well as reducing the speed to 50%, this way I get the low speed and high speed ranges at the flip of a switch. I do mostly metric threading, so I need to stop the spindle and reverse for each pass. I will probably add a speed pot at some point so I can fine tune the speeds to better match the machining conditions, and also try the expanded operating range of the motor that Mark suggested above, but so far it has not been a priority. I want a tachometer installed before I do that so I know what speed I am running at. I did not add a braking resistor and my Teco CV7300 vfd can stop the 4 jaw chuck from 500 rpm in a half second, so for my uses, a braking resistor is not needed. If you wanted to brake quickly from full speed, then a braking resistor would likely be needed.
You will want a VFD with single phase input and 230v for your rated motor power. You can use a three phase input VFD, but then you will need to upsize the VFD power at least 1.7x if used on single phase since a 2hp three phase input vfd will not be able to handle the current from a single phase source and give you 2hp output.
You will need to modify the controls a bit, the spindle drive lever needs to go through a relay that prevents the vfd from starting if you get a power failure and leave the lever in a drive position. Basically, you will remove all the existing relays and rewire through the VFD. It’s not difficult to do, just takes a bit of time and some control relays. There are plenty of people here who have done this and can help with questions. There are VFDs with internal programming capabilities and you can do relays through programming instead of physical relays, but you would need to dig through the manuals to make sure it has sufficient inputs to do that.
