DC motor drive current

Hey, any DC motor experts!
Got a question for you.
I'm rebuilding a power hacksaw for making robot parts, and attached a
big 48 volt DC motor. The amperage is not listed on the motor. I measured one coil at 4 ohms, and the "instantaneous" resistance when it's across 2 coils is 2 ohms. So is the maximum current draw 12 or 24 amps?
In terms of providing voltage, could I just use 110VAC into a half-wave bridge with a capacitor, giving me around 50V DC, or is a "regular" power supply a better option? A 48 volt regular power supply is pretty pricey, especially if it has to provide 24 amps.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.