Ok i am getting ready to add spindle control to my Harbor Freight Mill. I have looked into putting a REV function on it but cant really see why that would be a big deal or not. When i say big deal i mean using it... Are you folks tapping in CNC program? Tell me why i need the REV?

Hi,
when I built my mill I shagged around putting a REV on it as well but never use it.

Unless you have left-handed tools or drill bits why bother?

If you are doing rigid tapping that's another ball game altogether I wouldn't bother with REV.

Craig

same here, I did it all with relay logic and being 3-phase it was fairly simple. it's got a spindle brake and a timer so that I can program m3, m4, m3, m4 all day and it doesn't crash but I have never, ever used it in 15 years.
Edit: my 300th post, I should make a cake to celebrate

Thanks guys what i thought...

I just use reverse for machine tapping with my tap holder.

I also regularly use reverse on my manual mill when machine tapping (which I do all the time).  Also there is a Hemingway design for a spindle speed increaser using an epicyclic gearbox which reverses so you need to run the mill in reverse to get correct spindle direction.  If you're using a VFD it's a simple low voltage control option, why not do it?