I have a VFD on both my 935TS and my 1340GT, and will say that the lathe is the more complex of the two to install a VFD on. I originally did my own install, but later bought a setup from Mark as I wanted his electronic stop.
You'll love having the VFD on the lathe. It just makes dialing in the cut so much easier.
I have the 940-TS and now the 1440-GT.
I did the 940 VFD on my own and it was not too bad.
I used the Fuji VFD on that one because I did not know Matt had such a good deal on the Hitachi, and that there was more info available on the Hitachi here.
I got the Hitachi for the lathe and I am thinking of just gutting the electrical system and wiring the lathe switches directly to the VFD, but I am only at the thinking stage so far.
I do have to say the Fuji manual is rather cryptic about a lot of the settings
I have not dug into the Hitachi manual just yet, only got the machine Thursday.
What are the advantages of keeping any of the factory relays/wiring etc.?
Also what is the "setup" you bought from Mark?
I do not recommend wiring the VFD directly to the spindle controls for safety reasons and you are also do not take into account the foot brake, E-Stop or any of the other safety features. I had previous outline a very simple conversion (basic) which uses the contactors to switch the VFD inputs and also maintains all the safety features of the lathe. Each 1440GT seems to have some variants on wiring, so you need to have a basic understanding of what your are doing in the conversion. With the foot brake, you should issue what is know as a free run command to the VFD which negates the VFD braking when using the foot brake. This requires replacing the brake switch form a single pole to a dual pole, one side trips the power realy (default) the other side issues a free run command to the VFD. Otherwise they will fight each other. Note, the VFD input run commands are completely separate from the machine low voltage circuit. The details of the conversion and programming have been outlined in the following thread: https://www.hobby-machinist.com/thr...he-contactors-to-switch-the-vfd-inputs.64965/
You must use an external braking resistor with the VFD on a lathe, there is too much momentum otherwise. There have also been other postings with suggestions as to VFD cabinets, venting, switch gear and fusing. If you can't find it send me a PM with your email and I can send the files.