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Author Topic: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)  (Read 24944 times)

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Offline Hood

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Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #10 on: March 30, 2011, 05:16:03 AM »
Ok your drives will be the limiting factor if their max is 125KHz.
The numbers I had above were motor RPM so at 125KHz your max motor RPM would be (125,000/4,000) x 60 = 1875rpm
Your axis travels 3.14 inch per rev so 1875 x 3.14 = 5887.5 IPM

Hood
Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #11 on: March 30, 2011, 05:32:51 AM »
I have a 10:1 gear reduction on each servo. So would it be 1875RPM/10=187.5 RPM x3.14 = 588ipm max?

Offline Hood

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Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #12 on: March 30, 2011, 05:38:30 AM »
Sorry doing to many things at once here ;D  it would be my number above divided by your gearing (10) so 588.75 IPM I think ;)

Hood

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Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #13 on: March 30, 2011, 05:44:49 AM »
Let me say it another way.

Ok we know the max RPM of the motor at 125KHz as it is  (125,000 / 4,000 ) x 60 = 1875 rpm
It takes 10 turns of the motor to turn the outoput shaft 1 turn  so 1875/10 = 187.5 rpm on the output of gearbox. Each rev of the output moves 3.14 inch so 187.5 x 3.14 = 588.75 IPM

Hood
Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #14 on: March 30, 2011, 06:14:45 AM »
Is there a way to calculate the gear ratio if i know my exact steps per inch?? I went out to measure the gear but cant really get to it, and even so i can't measure the Diametral Pitch, which is obviously less than the overall diameter which i estimated. With the following below is there anyone i can reverse calculate the gear pitch?

X axis: 3191.931756 steps per inch @ 700IPM (10:1 gear reduction) (1000CPR encoder)
Y axis: 2491.704346 steps per inch @ 499.98IPM (10:1 gear reduction) (1000CPR encoder)
Z axis: 10,040.73425 steps per inch @ 49.998IPM (No gear reduction directly linked to lead screw) (1000CPR Encoder)

Offline Hood

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Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #15 on: March 30, 2011, 06:41:56 AM »
Not sure exactly what you are wanting but heres what I think ::)

X Axis
CPR = 1000 X 4 = 4000 per motor rev
Gearbox is 10:1 so motor rotates 10 times for one output rev so that is 4,000 steps per output rev
3191.931756 steps are needed to move 1 inch so 4,000/319.1931756 = 1.25316inch per rev that the axis moves per rev so divide by Pi and you have the dia which is 0.399 inch.

Y Axis
Same encoder so
Gearbox is 10:1 so motor rotates 10 times for one output rev so that is 4,000 steps per output rev
2491.704346 steps are needed to move 1 inch so 4,000/2491.704346 = 1.605 inch per rev, divide by Pi and you get 0.511 inch

Z Axis

Same encoder so still 4000 per rev of motor, no gearing so again 4000 per rev of screw. 10,040.73425 per inch so 4000/10,040.73425 = 0.398 pitch screw

Think thats right ;)

Hood
Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #16 on: March 30, 2011, 06:54:24 AM »
Well i know my output gear for the x and y are somewhere around 1" i will have to measure them somehow. Really hard to get a caliper in where they are.

The z axis screw is a .1 pitch kirk leadscrew, its brand new.

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Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #17 on: March 30, 2011, 06:57:35 AM »
Ok so just going by the Z, 0.1 pitch with no gearing and 4000 pulse per rev encoder that would mean 4000 pulses move 0.1 inch so 40,000 would be needed for 1 inch. So something mixed up somewhere.
Are you sure you dont have some electronic gearing set in the drives?
Hood
Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #18 on: March 30, 2011, 06:58:41 AM »
Seems like if you divide 1000CPR/10,040.73425 you get .0995943, or roughly .100 leadscrew pitch which it was advertised as. My mind is fried haha.
Re: Mach 3 Driver test. Results for 3 computers, which is best? (PICS)
« Reply #19 on: March 30, 2011, 06:59:49 AM »
I will have to go check to see if i have the pins set for electronic gearing. I'm fairly certain i do not. be back in a moment.