hate maths...really hate it... g540 motor tuning RPM

just reading a thread or two bought something up i never really sat down and thought too hard about...

and not seeing it mentioned, seems that either its rudimentary or noone actually bothers....


the gecko manual from memory states the steppers should spin at 200rpm.

so. question...

the procedure would be this, im guessing?

undo the steppers, so they arent driving anything. i havent got enough travel to frig around for a few minutes at rapid feeds!

i have the 0.2" lead ball screws...

so to get a motor to spin at 200rpm, it would be... um, um...lets see...

5 turns an inch...so 40 ipm?

convert to decimal cus im AUSTRALIAN. sorry, i cant help where i was born, and havent won a greencard yet :(

erm roughly 1000mm/min. slightly more because of that pesky lil 0.4 extra per inch... seriously, when they devised the metre, why didnt they just base it on whatever its based on then simply round it to suit what was already in use? think of all the headaches it would save!!!!!! thats the french for you... making life hard for EVERYONE! :p a solid 25mm to the inch rather than needing 127 teeth and all that sort of nonsense...sheesh!

then rather than write the gcode, id set the motor speed via motor config (i use mach3) to that figure, the 1000mm/min, and just hit rapid feed for whatever axis im working on?


correcticles?

i might actually tune them properly now... :)

It sounds like you're talking about a couple different things, but I'm not entirely sure.

I think you're trying to adjust the trim pots? The manual says 2rps, or 120 rpm.

Where'd you get .2 lead ballscrews in Australia? All the Chinese ballscrews are 5mm pitch, I believe.

For tuning the trimpots, I don't think it's that critical. 120rpm / 5 turns per inch = 24ipm, x25.4mm = 609mm/min

So you can use MDI and simply type G1 X300 F609

Or, you can change your motor tuning velocity to 609 and just jog around at 100% jog rate.

nope, the one thing only. just the rpm. i just tend to prattle on...sorry :o


2 rps, 120 rpm. my bad.

i havent looked at the manual in a good 2 years... so much for a photographic memory?


sure enough, taking 120 rather than 200 ends up at 609mm/min as you say.

never really seemed critical to me ever, actually :) ive tweaked the pots before a few times but never really "sunk my teeth in" so to speak.

i just know ill have to release at least the drive coupling so i dont hit the ends of my travel. 300mm at 600 may be 30 seconds, but i sure havent got that much on the Y!


the 0.2" leadscrews were what the cnc fusion kit came with... china isnt the only source ;) i didnt feel it necessary to say its on a sieg X2... if they arent 0.2" then somehow the machines still accurate! default units are inches... certain wizards i have since learnt dont include g20/21! ouch!


cheers :)

might get round to it when i tear it down again...