I found an old set of prints to machine a Shaper to use in the lathe. It uses a Bodine Reduction Motor. I have one here that reduces 1725 RPM to 96 RPM. Problem is it is for 115 VDC. Is there a converter from 115 VAC to 115 VDC ?
It's amazing how this dovetails with some other stuff I'm doing.
Get yourself a KBLC-19PM DC motor controller from ebay for $25-$50. It's a pro DC motor speed controller that takes in 115VAC, makes DC out of it, and controls the amount the motor gets to give you variable speed. YOu may or may not want variable speed, but electronically, full wave rectifiying 115Vac gives you peaks of 170Vdc.
This is what mechanicalmagic meant. However, the average of a 170V peak sine wave (i.e. what you get from the wall) when full wave rectified is 103-105V average. This is fine for the motor if it wants 115Vdc.
However, putting filter caps on it converts this to 170Vdc by charging the caps up at the peaks and them holding the peaks through the valleys. This will be something your motor probably won't like.
If a suitable choke cannot be obtained, the secondary winding of a step-down power transformer like the type used to step 120 volts AC down to 12 or 6 volts AC in the low-voltage power supply may be used. Leave the primary (120 volt) winding open
This is a bad idea. Transformers are designed for no DC current flow through them. Chokes are designed for DC to flow. Using a transformer secondary for a choke will saturate the core, and you'll get nearly no effective filtering from it unless you take the trannie apart and rewind/restack it with a gap. I used to design transformers and chokes for a living.
A choke is OK, but not great for a DC motor; the treadmills use them (I think!) for suppressing electronic noise emissions. The motor winding itself is a big choke electronically. An additional choke can make things worse by making the commutator and brushes arc badly...
I'm getting about a 3/4 " "flame" from the brushes that heats the end of the motor housing etc too hot to touch in less than a minute. Motor runs smooth and fast like I wanted but the excessive arc from the brushes can't work. Armature has wear grooves on it from former usage(seen also as lines in the brushes) and I am wondering if that sort of lack of smoothness is causing the arc.
It may be that the motor is being run the wrong direction. DC motors run both ways, but motors design for specific direction have the brushes cheated one direction to minimize wear and arcing in that direction. It's better than the purely balanced position for brushes in a reversable, but it makes arcing worse in the non-preferred direction.
What happens to the arcing when you reverse the DC polarity to the motor? Is it much less? If so, your motor is intended for the least-arcing direction rotation.