Any spindle drive experts here? Tweak my "haas power" system

[bob1112]

Basically I have an older VMC that uses a Magnetek open loop VFD for the spindle drive. The spindle motor is a Lincoln 7.5hp. The actual power from the machine into a cut is embarrassing. Like about 3hp.... no joke.... I get plenty of work done with it but tired of having to be so careful with it.

Haas does offer the vector drive upgrade 15/20hp but price is maybe too high for this machine. I have determined that there are some settings in the Magnetek drive that will allow a little more power but I am considering just installing the 10/15hp magnetek to see if this will at least give more acceptable levels of power.

I do understand how vector closed loop systems work and would be a much better solution here. In my experience though, open loop systems can usually be oversized to improve accel/decel and in cut power but I am worried about excessive heating. I realize I cannot really get more than 7.5HP from the motor but I want ALL of it.

What do you guys think? I will still be able to tune the max amperage in the drive as well as accel/decel. I do have a thermocouple on the motor for protection. I also understand Haas has been doing this for years where they use a smaller spindle motor and put a big drive on it for improved accel/decel/recovery/etc and they seem to work fine BUT that is a vector system which may just be increasing frequency rather than amperage.

[mactec54]

bob1112

If the drive is 7.5Hp & the motor is 7.5Hp & you are using 3Phase power then the drive will power the motor to the max of 7.5hp a bigger drive will not help if this is the case

The drive may need to be set up so it can run the motor to it's max, the drive can only do this if it is using 3 Phase