I was going to convert my 1340 Lathe to a two axis cnc.
This will be my first cnc conversion and will use Mach 3.
I was going to install servos and was going to direct drive the X and Y axis.
Is there an advantage if I direct drive the servos to the ball screw or if I use some kind of pulley/belt reduction? (Please explain).
The reason I am asking this question is, I was going to buy servos from Kellings and was really going to direct drive the servos. Kellings responded to me on email me a link for nema23 servos.
I emailed back and asked them if the nema23 are strong enough to drive a 13 X 40 lathe.
They responded and asked me what kind of gear or pulley reduction I plan to use.
I emailed back and told them that I was going to direct drive but if they have any suggestion about any gear or pulley reduction, I will consider it.
I never heard back from them. I am ready to buy but I guess they don't want to help customer and sell their products!
What size servos will I use for a 13 X 40 Lathe?
Is a nema 34, 1100 oz-in peak servo too strong or just enough for this size lathe?
Thanks in advance for your help!
I imagine that you are replacing the axis screws with ballscrews?
The lead and dia, of a ball screw is essentially a form of reduction that has to be taken into account, any increase in dia. or decrease in lead. (distance travelled/rev), will increase the torque of the motor by the degree of reduction. Just as any timing belt would.
The advantage of servo's is the maximum usable rpm which allows for higher lead ball screws.
I am helping my son CNC a 9x30 Lathemaster and we are using 400w Nema 23 AC servo's, with a .2 lead B.S. on the Z and a .1 lead BS on the X, I found a B.S. small enough to replace the X axis screw directly, this will be driven direct, the Z axis has a 2:1 timing pulley reduction, with the servo motor tucked back in the web below the tail stock end.
We have not yet reached the point of testing the performance.
I would tend to look at something higher torque for a 13x40.
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