Actually, ACME threads have a lower loss in their transmission of power. I haven't seen a breakdown of the various types of friction involved, but their higher transfer efficiency than 60 degree (allthread) screws would lead me to believe that, all else being equal, they'd run *cooler.*
Of course, if you're comparing them to ballscrews, that's a whole 'nuther matter. Those things have almost *no* friction involved!
-- Chuck Knight |