Direct drive vs. Gear drive

[rodzilla]

Could someone please tell me the advantage/disadvantage of direct drive as opposed to Gear reduction as i see on the tomach website thier CNC mills are running Direct drive and in their movies they are running a 3/4" EM through 1" steel with no loss of steps and with my machine i have a 2.5:1 gear reduction and i can't run that without losing steps and i see on their website they have two flavors of motors one is 1200 oz/in for the Z axis and the X and Y are 640 oz/in. My machine i am running 720 oz/in for all three axis with Gear reduction am i doing something wrong please any help with this is greatly appreciated thankyou

[NC Cams]

You get power 1 of 2 ways - you either create it in/via the motor itself or you multiply power created in the motor via gearing - it is pretty much that simple.

It can be rather difficult to double the power of a motor without doubling the size or at least increasing the size or cost substantially. Yet, with a simple 2:1 gear or belt drive reduction, you double the torque/power output at the given RPM relatively easily and cheaply all things considered.

A simple comparision of physical motor sizes, overalll package costs, etc should fill in the blanks as far as why you'd use one method as opposed to the other for a particular situation. Something as simple as "packaging" may be why gearing is used as opposed to a bigger/more pricey motor....

[rodzilla]

I have got a HF 33686 Mill. the X/y have not been converted over to ballscrews yet i will be doing this soon. what Motors would i need to run my system direct drive and not lose steps i currently have 720 oz/in motors they are sanyo denki stepsyn motor 1.8 degree stall torque is 5.09 Nm 6A perphase would these motors be sufficient or would i have to go with a bigger motor say a 1200 oz/in motor. Right now the best i can get out of my machine is 10 ipm and i would like to get a least 60 ipm. how could this be accomplished with out breaking the bank