Fanuc Alpha or Beta drive motors?

[Hermle UWF851]

We just bought a new VMC. Standard C-frame with Fanuc Oi MD. Nothing special. When it was delivered, a competing sales rep that we did not buy from came in to see what we bought. Of course pointing out the things his machine had better. One of the things was, our new machine has Beta motors and his has Alpha. I asked why Alphas were better and he clearly didn't know but assured me they were. He has higher horsepower motors and therefor more accurate. I'm not sure why more HP is more accurate. That can be a function with ball screw pitch and other things I'm sure.

So, do I have a crap machine that will barely make it through the rest of this year? What are the differences?

[Al_The_Man]

Sounds a bit like Salesman spiel, the Beta series are the smaller range of Fanuc motors, there are lots out there and presumably the OEM spec'd them in right, than you will not tell any difference.
There are many factors such as gearing and load inertia that comes into play when sizing motors, so he may be comparing apples and oranges!
Al.

[underthetire]

I believe the alpha motors have a higher poll count, I know the Alpha-i motors do for sure. This gives you a little better resolution out of the motor. This does not mean accuracy, just torque and smoothness from the motor. You probably won't notice any difference on 99% of the work.

[Hermle UWF851]

Thanks guys. I feel confident I bought the right machine.

[Rich 72]

you did. there is nothing wrong with the beta series motors. we have 3 lathes with the beta motors on the loaders that are close to 15 years old that still have the original motors, we have replaced a few of the drives over the years but I can only think of 3 or 4 of those. not bad for an inferior drive motor?