AC or DC For Variable Speed Application.

[Bib Overalls]

I'd like to convert my drill press from it's current single phase (110/220 AC) motor and replace it with a motor that will accept a speed controller. Since I will need to acquire a new motor which option is best from a performance point of view - AC or DC?

 

[dogdog]

3phase AC motor with proper single phase to 3PH VFD....

 

[wyliesdiesels]

AC 3 phase motor

forget DC

 

[Norcal]

AC 3 phase motor

forget DC

I have a DC motor on a horizontal band saw, it works but a 3Ø motor combined with a VFD will be the easiest way, the DC drive was salvaged from a decommissioned dish machine, even recycled the 5 KVA transformer so I could have 120/240V output, 120V for the controls & a future coolant pump, & 240V for the DC drive, but that was done 20+ years ago & was cheap, now as others have said VFD route combined with a 3Ø motor is the way to go as AC drives are cheap & plentiful now. 1 HP & smaller AC drives are even available with 120 volt input, but they do not work well with GFCI's.

 

[grounded-b]

Tubelcain on YouTube ( mrpete222 ) had a few videos regarding this exact question. In the end, he found that smaller DC motors do not have enough torque at slow speeds, to work effectively for drill presses. Get a single phase input VFD for three phase AC motors.

 

[rsanter]

DC is best but most expensive
Good deal is 3 phase with a VFD

Bob

 

[Falcon67]

BUT - source an AC motor that is build with variable speed in mind. Most regular motors (and most China sourced units) can get hinkey once you get about 20% over/under 60 hz. Chatter, noise, overheating, etc.

 

[theoldwizard1]

Tubelcain on YouTube ( mrpete222 ) had a few videos regarding this exact question. In the end, he found that smaller DC motors do not have enough torque at slow speeds, to work effectively for drill presses. Get a single phase input VFD for three phase AC motors.

Concur ! Their is a reason why most drill presses use multi-step pulleys. Cheap and effective !