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Title: Prestolite MDY-7070 (Old School ) Post by: Misterouija on September 03, 2004, 12:29:30 PM (http://www.eternalrollerz.com/TechArticles/Hydraulics/MDY-7070Custom-2.JPG)
I love these motors ... very reliable... I had a four of them last 6 years at 48 Volts and only had to replace brushes once! Title: Prestolite MDY-7070 (Old School ) Post by: misterouija on May 03, 2005, 08:35:43 PM If anyone is interested in more information the the Prestolit motors I'll be happy to shar my knowledge with you guys...
The quality is there with these motors... the only real draw back is that Prestolite sold off their winch motor divison so this model, the MDY-7070 is hard to find.. expect to pay between 125-150 if you find them. One thing the prestolite motors have over the saco motors is the commutator bars on the armature... A saco comm bar is made from soft copper with mica that is very uneven between the bars... The prestolite motors have a silver / copper mix comm bar for less smearing and undercut mica dividers to prevent wearing down the brushes so fast.. Also about the brushes... Most saco motors use pressed carbon brushes that wear quickly and you'll notice the prestolite's brushes are pressed copper that seems to last longer... Just my 2 cents Title: Prestolite MDY-7070 (Old School ) Post by: Hydros on May 04, 2005, 08:57:35 PM This is some real good info.
I'd like to see if there were any successful hoppers uning that high speed high torque motor. I used to run that, but kept busting the old style couplings. Title: Prestolite MDY-7070 (Old School ) Post by: misterouija on May 05, 2005, 07:03:38 AM Gary May used to run them before he passed away. RIP
This particular prestolite can be modified to spin a little faster with a slight loss in torque.. See if you look in side the stator (case) you notice that there are 4 Feilds. Acually there are three feilds and a shunt. The shunt acts as a governor on RPM. Dissconnect the shunt. I'd rather break a tang style type key than destroy one of my hard to find Fenner pump heads. It's all in timing but with a little practice you'll get a feel when your stressing out the coupler too much... Title: Prestolite MDY-7070 (Old School ) Post by: misterouija on May 05, 2005, 07:08:16 AM I love getting into my motors and I like to fix dead motors... I can fix most motors as long as the windings in the armature are still good...
One thing I like to do to prevent arcing at higher voltages is to add liquid electrical tape to the brush holders. I learned about this after reading about Hugh Stillman and his tricks of the trade.. Title: Prestolite MDY-7070 (Old School ) Post by: misterouija on May 05, 2005, 07:10:03 AM :)
Title: Prestolite MDY-7070 (Old School ) Post by: misterouija on May 05, 2005, 07:11:16 AM :) This shows one with the treatment and one without...
Title: Prestolite MDY-7070 (Old School ) Post by: Hydros on May 06, 2005, 12:51:20 AM Edited for your viewing pleasure:
Title: Prestolite MDY-7070 (Old School ) Post by: Hydros on May 06, 2005, 12:52:32 AM again:
Title: Prestolite MDY-7070 (Old School ) Post by: Hydros on May 06, 2005, 12:55:28 AM Out of order:
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