4651
General Mach Discussion / Re: Confused about Steps, Pulses calculations
« on: April 27, 2010, 09:23:57 AM »
Similar to marking your stepper shaft you can mark you hand wheel. Your just magnifying movement.
If the handwheel is say 3" dia then circum is 9.424". So you wrap a piece of tape around the hand wheel and then with a razor blade cut it. If you remove it and put a mark say every .050" along the tape then relative to a stepper ( 9.424/200=.047" dosen't take into account the screw ) but you get the idea. Thus you can see steps roughly or linear movement depending on how you mark the tape. You can even make a big paper circle wheel.
For backlash rough check, you just tighten the gib and rotate the handwheel one way and then the other and you are seeing the backlash from the screw and bearings with the pointer set on mark. If you tighten the bearings / add preload and there was play due to them then you can see the
the adjustment affect of preloading the bearing. Idealy you would be checking the torque while you turn the handwheel but it's a poor mans way
for isolating things and seeing what is influencing the lack of movement.
Here is another example:
6" disc=18.85" circ
18.85 / 200=.09425" one step of motor on the disc
Thus you can see affect of one step to movement.
You can put one on the motor and one on the handwheel and compare them if you wish.
Probably clear as mud....FWIW,
RICH
If the handwheel is say 3" dia then circum is 9.424". So you wrap a piece of tape around the hand wheel and then with a razor blade cut it. If you remove it and put a mark say every .050" along the tape then relative to a stepper ( 9.424/200=.047" dosen't take into account the screw ) but you get the idea. Thus you can see steps roughly or linear movement depending on how you mark the tape. You can even make a big paper circle wheel.
For backlash rough check, you just tighten the gib and rotate the handwheel one way and then the other and you are seeing the backlash from the screw and bearings with the pointer set on mark. If you tighten the bearings / add preload and there was play due to them then you can see the
the adjustment affect of preloading the bearing. Idealy you would be checking the torque while you turn the handwheel but it's a poor mans way
for isolating things and seeing what is influencing the lack of movement.
Here is another example:
6" disc=18.85" circ
18.85 / 200=.09425" one step of motor on the disc
Thus you can see affect of one step to movement.
You can put one on the motor and one on the handwheel and compare them if you wish.
Probably clear as mud....FWIW,
RICH