Originally Posted by TravisR100  I contacted deselectric.com which some members here mentioned. Larry there is telling me that I need a minimum a 30hp converter and shoud use a 40hp. This seems like complete overkill for a super mini mill 2. No? He says if I don't use the larger size I'll never hit top speed and will have a problem on instant reversals such as when tapping. |
He could be (partially) correct, I think the reason is that when the converter is delivering close to its rated maximum the phases get out of balance and the machine is sensitive to that. I think it is the control electonics draw power across two legs of the incoming supply via a transformer so the machine needs these legs to be good.
However, you will be able to hit top speed, the problem shows up during spindle acceleration to 10000 rpm especially if you have the machine moving the table into position while the spindle runs up. Then you have the spindle motor and two servos drawing full power for a second or two.
It is less likely that you would have problems tapping because you are not gpoing to tap at 10000 rpm and the draw is much less accelerating to around 2000 rpm. But even then there is a work-around; there is a Parameter for maximum spindle load during acceleration which is set at 195(%) out of the factory. You can drop this as low as you like and all it does is take slightly longer to reach top speed. I run my Super and a TL-2 both at the same time from a 14.7 kva diesel generator and all I had to do was drop the Parameter to 100(%). The spindle on the mill takes about an extra 1/2 to 1 second to reach 10000 rpm and the lathe chuck takes about 1 to 1-1/2 seconds longer