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Author Topic: Manual Motor tuning  (Read 21779 times)

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Manual Motor tuning
« on: November 01, 2006, 08:54:08 AM »
Hey guys.
I finally mounted the z axis stepper on my Mill/Drill.
As it's a temp solution because I eventually will use a servo I just mounted it on
the side of the head with a belt going to the Micro feed knob on the mill.
Heres the issue.
Its a 140 OZ stepper as hardly any tourque is needed to turn that wheel.
its a 200 step per rev motor.
I tried to auto calibrate it like I did with my X&Y servo's but that dont float !!!
I set it to move 2 inches .. it moved like a 1/8 Inch so Mach set it to 10,000 steps per !!!  LOL
That little puppy doesnt have a chance !!!

How can I calibrate a stepper to move an Inch when I want it to move an inch ???

Is the problem that Im using the micro feed spindle adjustment ??
The step down ratio must be huge . When I jog up and down its pretty dang slow.
I can deal with Slow I just want it to be acurate as far as movement measure.
Any idea's ??

Offline Chaoticone

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Re: Manual Motor tuning
« Reply #1 on: November 01, 2006, 09:34:05 AM »
That is it Yoda,
 ¬† You have to do the math.
Quote
Is the problem that Im using the micro feed spindle adjustment ??
First, you need to know how many rounds of the micro feed = 1" of travel. Multiply this times the number of steps per rev. of the motor. Are the motor pulley and micro feed pulley 1-1. If not, this comes into play also. These will give give you your steps per inch. Or as you said, auto calibrate. That is probably a high ratio, ( the micro feed ) 10,000 steps per inch sounds reasonable.


Good Luck,
Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: Manual Motor tuning
« Reply #2 on: November 01, 2006, 09:44:26 AM »
LOL

Calculator time !!!

I have a 2 to one ratio between the motor and shaft.
then god only knows the ratio between the shaft rotation and one inch of travel.
Sounds like a cold beer and measurement night is in store !!!  lol

This is what Im eventually gonna make

http://www.homecnc.info/Pics/800z-axis-cnc-parts1.jpg
and this is after she's mounted
http://www.homecnc.info/Pics/800z-axis-installed.jpg

Kinda cool as the Ballnut spins ..  Not the Ballscrew !

Thanks Brett

Paul in GP Tejas !!



Offline Chaoticone

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Re: Manual Motor tuning
« Reply #3 on: November 01, 2006, 09:57:06 AM »
LOL, Good luck Yoda. I'd save the beer for the victory though. That stuff makes me forget the minor stuff like.................. where the shop is. LOL ;D

Had a look at the Quill drive. That should work. Looks good.
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!

Offline Chaoticone

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Re: Manual Motor tuning
« Reply #4 on: November 01, 2006, 10:18:05 AM »
Hey Yoda,
   Do you have a torque curve chart on that stepper? Might want to see at what RPM it falls on it's face.
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: Manual Motor tuning
« Reply #5 on: November 01, 2006, 10:55:45 AM »
I'll have to see if I can find one ..
I have a few 460 Ouncers if torque is an issue  ;D
Doubt it will though . you can turn that micro feed knob with your pinkie.

Hood

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Re: Manual Motor tuning
« Reply #6 on: November 01, 2006, 02:51:31 PM »
Yoda, I used a 260oz/in stepper on a full size Bridgeport  for the Z Axis, it was 3:1 reduction and it worked very well, never had any problems even when plunging a 20mm slotdrill into steel. Think yours should work out OK for a small mill.
 OH and also forgot to say the Bridgeport Interact CNC mills have the ballscrew stationary on both the quill and the X Axis so its not a new idea ;)
Hood
Re: Manual Motor tuning
« Reply #7 on: November 01, 2006, 02:57:25 PM »
Cool deal.

The majority of my jobs will be cutting about 1/8th" deep slots in Copper so speed of z doesnt bother me much ..
More time to sip a beer !!!   lol
Re: Manual Motor tuning
« Reply #8 on: November 01, 2006, 08:04:06 PM »
Still befuddled ??
I did the math ..
3680 step to move an inch .
If I use that in motor tuning my z motor pukes ???
What am I missing here ??

Offline Chaoticone

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Re: Manual Motor tuning
« Reply #9 on: November 01, 2006, 08:24:30 PM »
Do you mean it stalls out?
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!