cnc spindle drive(how to) question

[compositepro]

hi guys

ive just finished machining up a spindle cartridge after being advised to make my own, someone showed me a picture of a simple one they had made
mines more of a cartridge with gamet precision bearings in either end and its oil cooled with r8 spindle tooling

now im stuck in that the theory was to buy a vfd and a 2hp motor and geardrive the thing using the vfd for stop , start and reverse

how ever researching into this has led me to the fact that belt drive from the motor to spindle are supposedly smoother and quieter

my intention was to use direct gear to gear ie motor gear to spindle but now im thinking more belt to a first pinion gear then direct to spindle

im troubled by how and if this could work being that reversing th motor woullead to some delay in spindle response and the associated forces which would be put through the belt

does anyoneknow or arethe vibrations so small direct drive that it doesnt matter how do they do this on industrial machines

regards

mike

thank smike

[rfdoyle]

Many (if not all) industrial CNC mills use a timing belt to drive the spindle. Even machines that rigid tap. With correct sizing of timing belt I wouldn't think you should worry about it. It you need to gear up/down, I would try to do it with the timing pulleys.

My $.02
rfdoyle

[RICHARD ZASTROW]

compositepro. I do not know what you are going to be cutting but in general I would reccomend timing belt / sprockets. No lubrication problems; when installed properly, no stretching on modern timing belts; Goodyears Eagle belts with herringbone teeth do not even require flanges; and they are quiet. A bit of warning though, be sure the spindle bearings can handle the radial load of the belt tension.

[compositepro]

thanks guys precisely what i needed