Anyone worked with 90vdc motors?

[priderocks]

I am building a piece of equipment in which a 30" diameter steel plate needs to turn at 40-60 rpm. It takes too many pulleys to get down to this speed from a 1725 rpm motor, so I am thinking about a gear reducer, or using a 90vdc motor with a variable speed controller. I have never worked with a dc motor before. Do I need a special power supply/inverter?

[Topcat]

An Inverter from 110V to 12V to this might work?
Look at the others too.

http://compare.ebay.com/like/320793675152

[Bullitt-]

Have you looked into a variable speed switch for the motor you have along with a pulley/gear reduction?

[dodj]

Generally speaking, DC motors are expensive. Not too long ago, speed control was better using DC motors. AC is superior now and cheaper. What kind of horsepower are we talking about?