marter1229
Member
Since the smaller lathes with VS have a DC motor and the belt flippers use an AC motor, which would have the more torque?
Lathe Torque?
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Since the smaller lathes with VS have a DC motor and the belt flippers use an AC motor, which would have the more torque?Signed-In Members Don't See This Ad
hdtran
Member
As a gross generalization, belt (or gear) reduced motors will have more torque. (Of course, we're assuming the belt won't slip).
As another gross generalization, the same HP AC motor can provide greater torque (at rated speed) than an equivalent HP DC motor.
That said, when turning a pen, it doesn't make a difference, as just about any motor drive will have more than sufficient oomph.
Last gross generalizations: AC motors are much less expensive to make than DC motors. DC motors + electronics are much less expensive than AC electronic drives.
As another gross generalization, the same HP AC motor can provide greater torque (at rated speed) than an equivalent HP DC motor.
That said, when turning a pen, it doesn't make a difference, as just about any motor drive will have more than sufficient oomph.
Last gross generalizations: AC motors are much less expensive to make than DC motors. DC motors + electronics are much less expensive than AC electronic drives.
Russianwolf
Member
And one more generalization..... Any of them have enough torque to cause serious harm to you and your body parts.
monophoto
Member
I've noticed that the dc motor on my variable speed lathe has a torque problem at low speeds. This is a handicap when trying to drill on the lathe, especially with a forstner bit. I've been able to get around the problem by cranking up the speed a little.
An alternate solution is to start to drill on the lathe in order to define an exact center for the hole, and then transfer the piece to the drill press.
An alternate solution is to start to drill on the lathe in order to define an exact center for the hole, and then transfer the piece to the drill press.
KenV
Member
Another generalization
Most all the variable speed lathes (even big ones) have 2 or 3 speed ranges set with belts. Setting the belts to the low speed setting increases the torque considerably at low speeds.
If you are having problems drilling -- I suggest raising the speed a bit, taking the feed a bit slower or sharpening the bit. (yup you can and should sharpen forstner style bits -- especially the big ones from time to time.)
Most all the variable speed lathes (even big ones) have 2 or 3 speed ranges set with belts. Setting the belts to the low speed setting increases the torque considerably at low speeds.
If you are having problems drilling -- I suggest raising the speed a bit, taking the feed a bit slower or sharpening the bit. (yup you can and should sharpen forstner style bits -- especially the big ones from time to time.)
ctubbs
Member
There are basically three different ways to wind a wound DC motor. Each one has it's own torque curve for the load it is designed to carry. Series, shunt and compound. The series has the most torque at start up and the shunt has the least at start with the compound somewhere in the middle. The starter on your car is series wound. Without a load this type will accelerate till its flies apart. The other two have limiting factors to limit the top speed they can turn. Then there is the PM style that uses permanent magnets for half the windings. This one is fairly good when used in small motors.
AC motors, generally, have less start torque than DC, but higher full speed torque, however, with the correct VF drive, that can be modified to the point where you can get somewhat higher low end torque from an AC motor. Hopefully I have totally confused you by now.
What it all comes down to is it depends.
Charles
AC motors, generally, have less start torque than DC, but higher full speed torque, however, with the correct VF drive, that can be modified to the point where you can get somewhat higher low end torque from an AC motor. Hopefully I have totally confused you by now.
What it all comes down to is it depends.
Charles
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