workinonit
Elite Member
3 phase ampacities reduce by the square root of 3 or 1.732 at the same voltage.
I do use a DC motor and controller on my round column mill/drill but it doesn't have much torque at low speed. I'm told that inverter powered three phase will have more low end torque than DC but not sure if that's true.Another option would be a DC motor and controller.
Very nice work on the control console!I converted my Craftsman drill press to a 3 phase motor and VFD a couple of years ago, and love it. No more moving belts around, just dial in the speed I want and drill holes. I used a Teco 510 VFD and a Connex 1 HP 3 phase motor I picked up at a local motor repair shop, made a new control panel and added a tach display to it.
I'm looking at doing the same to my Jet B920N lathView attachment 780201e.
View attachment 780198View attachment 780200
This is true for the motor itself. But 1hp is 1hp whether 1ph or 3 ph and since you're generating that 3rd phase with the VFD, the single phase side will need to deliver the same amps as before and the breaker size requirement won't change. Amps between the VFD and the motor will be lower but amps between the breaker panel and the VFD will likely be a little higher as the VFD isn't 100% efficient.3 phase ampacities reduce by the square root of 3 or 1.732 at the same voltage.
I do use a DC motor and controller on my round column mill/drill but it doesn't have much torque at low speed. I'm told that inverter powered three phase will have more low end torque than DC but not sure if that's true.
I've found that low end torque is needed on a mill for operations such as large hole sawing, boring head etc. There is the option of changing belt position on the stepped sheaves for more torque but that is the reason for retrofitting variable speed in the first place.
True.When comparing the same size motors, DC motors will always have more low speed torque than AC motors. Torque is proportional to armature current.
Yes and this is a good thing to list in the "pros" section when comparing AC and DC motors. DC can also do field weakening but only if it's a wound field motor and those are not common anymore in the 1HP range.Also to add to strantor's comment ... almost all VFD drives will allow motor speeds approaching twice the motor's rated rpm. This will allow you can run a higher gear reduction to get more torque at the same spindle rpm with a higher motor rpm.
Thanks, I 3D printed it on my QiDi Tech printer that has two extruders, so I could print the white lettering on it.Very nice work on the control console!