That's the reduction ratio of the unit I'm building for an X axis power
feed for my mill . Input will be an HF 18v motor from a drill powered by an
18volt wall wart thru a PWM controller for speed control . Gearset is
loosely copied from a Logan reduction gearset in my QCGB . 16t input gear
drives a 48t which is pinned to another 16t which drives another 48 . Input
and output are concentric , I'll be copying the drive dogs on the leadscrews
for both in and output . So far I have the gears made and sideplates
machined . I still need to make an axle and bushings for the 16/48 pinned
pair , bushings all 'round , and the input and output shafts .
I'm using 20DP gears cut from a JD tractor (from my 317 , badly worn)
axle for the small ones and from a piece of 4140-type stock that used to be
shipping bracing for a 5 x 12 foot CNC router table . Side plates are 1/2"
aluminum stock , holes drilled then final machined with a shop-made boring
head . In a little while I'll be out in the shop getting started on the
in-out shafts and bushings .
This will give me enough low speed torque for smooth slow feeds , with the
top speed at 100RPM's at the output - I tried this motor directly coupled ,
but low speeds were jerky . Not all that fast , but a lot less work that
cranking tha wheel by hand . The big benefit here will be much more
uniformity in feed speeds and therefor much better surface finishes . Final
configuration for controls hasn't been decided yet , but I do have
everything but a DPDT reversing switch in hand . Coming next will be a belt
driven feed for the Z axis , for those times when I use the boring head and
need a very smooth finish .
7 years ago