I've built this machine 100 different times in my head!!!

[JoeHarris]

Seems to me from reading (and that is all I can base this on) that both 5 and 10mm pitches will work pretty well on most materials if set up correctly. I was getting all worried at one stage that my 5mm pitch screws would mean I was going to be burning up the wood I was cutting due to the low feed rates then I remembered back to when I started getting into all this lark seeing machines that cut wood pretty reasonably being driven by threaded rod with pitches so small you can hardly see them! Reckon our 5mm screws will be all right. But I may live to eat my words...

[JAZZCNC]

I was getting all worried at one stage that my 5mm pitch screws would mean I was going to be burning up the wood I was cutting due to the low feed rates then I remembered back to when I started getting into all this lark seeing machines that cut wood pretty reasonably being driven by threaded rod with pitches so small you can hardly see them! Reckon our 5mm screws will be all right.

Ermm Ye understand what your saying Joe.!!. . . BUT don't be fooled.? . . . If truth was told there bull shitting you.!! . . . You'll see many examples of flimsy machines cutting Aluminium with dremels etc but what they don't tell you is the finish is shit and the machine/spindle curled up and died 2hrs after the video.!

Same goes with threaded Rod machines the finish is rubbish the cutters wore out in 30mins and the machine fell to pieces 10mins after that.!!

Your correct thou that 5mm will be ok if you already have them but if your mainly cutting wood then I'd look at gearing at least 1:1.5 or 2:1 has that will allow the speeds needed to cut MDF/plastics at correct feeds.