Check my math for a Knee Mill conversion...

[DaSnake]

I am not sure if this is the correct place to post this.
If not feel free to move it to the correct place
(this forum is MASSIVE)

I have a Hurco KM-1 cnc knee mill.
These are the specifications according to the owners manual.

200 line quadrature encoder
0.200 travel per rotation of ball-screw
250 IPM original high speed

So if I understand correctly, using the factory encoder in quadrature would
take 800 steps on a gecko style drive to rotate 360 degrees.

With Mach 3 limited to 45k pulses per second (I assume the extreme upper limit)
Then 45000[pulses per second] * 60[seconds] = 2700000 pulses per minute

2700000/800[steps per rev] = 3375[RPM]

3375 * 0.200 = 675 IPM


I remember somewhere, somebody stating that if I went to gecko/rutex....
that I would loose some speed on a simular setup.

Do the above numbers look correct. And FYI I do not expect to be able to
go faster. I just dont want to go much slower....

[Mickey_D]

I converted a Bridgeport BOSS machine that had 18x12 of travel. I used some 512 count encoders that I had and with an old laptop driving it I was getting 140 IPM rapids/cuts in plastic and that was plenty. That big table moving around that fast will make you a little nervous. Without a tool changer on the machine the lack of a super fast rapid is not going to make much of a difference in your part times. You switching tools are going to be the bottleneck.