Motor runs but not under load

[Angellos]

Hi. What I have is a 3 phase 5hp GE motor 1170 rpm (pretty old). It has been set up with some electronics (I have no idea how this works) that convert the single phase into 3 phase. My father in law used to run it under no load and had an extension cord running off of it to run some 3ph equipment. Worked awesome. I have taken this motor and hooked it up directly to a Little Giant Power Hammer via a 4" canvas pulley. The power hammer specs call for a 2hp motor so this 5hp 3ph should have tonnes of torque. As soon as there is the slightest load it just hums and then stops. Even hand turning the belt doesn't help.
I have tried super minimal tension (can slide the belt on and off) and still no go. Is it likely that the motor just needs a tune up or am I most likely going to need to get a proper roto-phase convertor? Really hoping to get this motor working as I've just spent almost $300 on a making a 4" belt and pulley to match.

Thanks for your help!!

 

[Angellos]

Should also add, I bought this hammer recently and I really need it working asap for a job I'm in the middle of. Cheers!

 

[Minder]

It would seem the device to produce the 3rd ph is a little primitive, if so this is probabally why it refuses to start even when under a light load,
You either need a proper phase convertor or a VFD.
M.

 

[Angellos]

Shoot, I was afraid of that. Thank you

 

[GPG]

run it under no load and had an extension cord running off of it to run some 3ph equipment.

Possibly http://www.theautomationstore.com/3-phase-electrical-power-from-single-phase/

 

[Angellos]

Thank you!

Possibly http://www.theautomationstore.com/3-phase-electrical-power-from-single-phase/

So if I read this correctly I need to use my set up the same way it was used before. Use the 5hp as a generator and get a second motor to run the machine. It doesn't seem to need that 110v motor to start so maybe that's an unnecessary complication?