Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Yodawill2000 on November 01, 2006, 08:54:08 AM

Title: Manual Motor tuning
Post by: Yodawill2000 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 ??

Title: Re: Manual Motor tuning
Post by: Chaoticone 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
Title: Re: Manual Motor tuning
Post by: Yodawill2000 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 !!



Title: Re: Manual Motor tuning
Post by: Chaoticone 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.
Title: Re: Manual Motor tuning
Post by: Chaoticone 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.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 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.

Title: Re: Manual Motor tuning
Post by: Hood 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
Title: Re: Manual Motor tuning
Post by: Yodawill2000 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
Title: Re: Manual Motor tuning
Post by: Yodawill2000 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 ??
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 01, 2006, 08:24:30 PM
Do you mean it stalls out?
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 01, 2006, 08:28:38 PM
Yeah   It does all sorts of weird stuff .
I get Limit switch stuff when I dont get even have limits set ..
And I just realized My motor pully is slipping ..  ooiy ..
Gonna restock on locktight and try again tommorow .
I know Im getting close ..
Thanks man ..
Just frustrated so its time to shut her down and start again tommorow .
I'll get this shizz figured out and be making chips soon.
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 01, 2006, 08:37:11 PM
Once you get the pulley tight, if it still wants to fuss, play with your motor tuning. ;D
Title: Re: Manual Motor tuning
Post by: Hood on November 02, 2006, 02:18:45 AM
You may have to play about with the acceleration and velocity to get the motor running sweet.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 08:40:40 AM
Man   Steppers can be a PAIN !!!   lol

If I tune the z motor to run smooth , then the measurement calibration is off.
get the calibration right , then the motor stutters like a sick pig.
Im wondering If I need to up the Voltage ? Not sure where its at since it was preset way back.
The only trimpot I have on the driver board is labeled VR1 .
Is that the Voltage supplied to the A & B phase wiring ??
Also ,, I noticed last night that sometimes I would get a Limit switch warning
 when I wasnt even jogging the motor ??
What kind of Gremlin am I dealing with here ??   ???
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 03, 2006, 09:38:15 AM
Hey Yoda,
    I don't know about the pot. I'd have to be there. If your motor is not running smooth, it is skiping steps. That is what makes your cal. off. Slow your motor accel. and vel. down. I would try to get the voltage around 75V.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 09:58:00 AM
Thats what weird ..
I can tune it and it will jog smooth as silk ..
But when I go to the page wher I calibrate the steps per and tell it to move 2 inches ,
It moves maybe 1.25 inches.
I enter that into the how far did it move window then it sets the steps per.
From that point the motor stutters and pukes ???
From that point do I need to tune down the Vel/Acc ??

Also .. how can I tell what voltage the motor is getting ??
I have a hunch its way low..
Just have a DMM , no scope  >:(
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 03, 2006, 10:12:42 AM
Your steps per.... should stay the same. Write it down. slow down you accel. and vel. and manualy enter the steps per, see what that does. Be sure to hit save axis settings.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 10:18:51 AM
OK   I'll give it another whirl tonight..

so basically I shouldnt mess with the auto calibrate feature ??

Heres another voltage thought . I keep hearing that steppers run hot by design.
I was running the snot outta that thing last night and it stayed cool as a cucumber.
That a sign of the voltage being low ??
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 03, 2006, 10:34:45 AM
I don't know about the auto cal. I have never messed with it. I have a good calculator.  ;D

Yes, cool steppers would be a sign of low voltage. I don't know anything about your set up. I have 70 VDC supplied to my geckos (drive). From ground to each phase, 35 VDC. Don't be mislead by this post. I no nothing of your set up. To new to know if this is what you should have. I do know there is allways more than one way to do anything. ;D

See if this helps.
http://www.cs.uiowa.edu/~jones/step/
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 10:48:55 AM
I have the spec sheet of my drivers at home ..
They arent gecko's by any means , I have 320's on my servo's and wish I had the cash to get another Lo-Cog pittman and a gecko.
Much mo' user freindly  :)
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 11:25:35 AM
Quick voltage question.
If I send more voltage to my stepper will the RPM increase accordingly?
With no changes made in Mach motor tuning ?
I want to experiment with a driver I know nuttin' about.
If the RPM increases I will know Im tweaking the right direction :)
Title: Re: Manual Motor tuning
Post by: Hood on November 03, 2006, 03:22:21 PM
If you use the auto calc it will set the correct steps per unit, after that you may need to change the acceleration and velocity to get your motors running sweet but dont touch the steps per unit.
 What is the pitch of the screw? are your drives full, half or ???? stepping?
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 03:33:16 PM
Its driving the micro feed shaft on a Mill/Drill ..  no screw involved until I convert it to the ballscrew setup.
This is a temp solution.
Im not near the machine right now, cant remember the make of the drive.
140 Oz , 200 spr  eight wires coming out of it.

Lots of help I am huh  .. hehe 
If I auto calc it and tune to be smooth it takes about a minute to move an half inch.
Thats why I want to increase the voltage as Im sure its set to motor spec .
I keep reading here that you should set the voltage WAY above spec.
I suppose my frustration is the X and Y ballscrews are driven by some nice servo's.
Set those up in about 10 minutes !!  Spoiled me .. hehe 
Title: Re: Manual Motor tuning
Post by: Hood on November 03, 2006, 03:38:20 PM
After  you do  autocalc do you get the correct movement? If yes then all you can do is try and tune, no point in making the steps per unit larger/smaller as all that will happen is the axis wont move the correct distance.
 For the voltage, yes you want as much as you can (up to 20x max motor voltage) BUT be sure your drive can handle it, some of the smaller drives are 24V MAX.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 03, 2006, 03:43:40 PM
Gotcha !!
I happen to have 2 spare drives in case I blow it up  :)
I originally planned on going all Stepper but ended up buying a X/Y servo setup , After I bought the stepper gear. 
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 04, 2006, 10:06:24 AM
Getting closer here !!!
Got the z motor running calibrated.
The only Issue I have now is errant Limit switch errors when Im not
near a limit ?
It even happened once when no motors where moving ??
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 04, 2006, 10:41:54 AM
Hey Yoda,
Time To TS, not to be confused with BS. ;D Check your wiring, switches, are your cables shilded? Could be noise.
What kinda feed rate did you end up with?
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 04, 2006, 10:53:09 AM
All the cables are well sheilded.
This didnt start until I set up the z motor so thats where Im gonna start.
Connections are all correct and tight.
Might need to get a better stepper driver. But money is way tight right now  >:(
Title: Re: Manual Motor tuning
Post by: Hood on November 04, 2006, 12:14:54 PM
Set the debounce to 1000 and see if that helps.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 04, 2006, 02:18:13 PM
Its was  I went to 1250 and still get the limit issue.
Bumped up Mach to the latest version , still getting it.

need to check for noise .
I have everything grounded quite well.
Tweakage will continue ... 
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 04, 2006, 05:56:42 PM
Think I got rid of the noise.
Had all my cables tied together tight as a Tick ..
Must of had some induction going on.
Here's another one for the guru's out there ..
I can jog till the cows come home .. smooth as silk.
but when I run code (Roadrunner)
The z motor loses step sometimes .
By the end of the run Im barely cutting metal ?
Why would my stepper choke on a slow jog when it's gravy on a regular jog ?
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 04, 2006, 06:15:26 PM
Hey Yoda,
    Try slowing your vel. and accel. down some more in motor tuning. I would back these way down, ( you are pretty close though, I think ) and creep up until I got repeatability. Are you running in CV mode? What kind of tool are you running when it looses steps?

Brett
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 04, 2006, 06:27:25 PM
I get the Vel and accel down suggestion.
But what is CV mode ??
Im using a 1/4 inch bit  cutting in aluminum .
Just in the testing phase ..
Thanks Brett
I owe ya a beer or sumptin'

Not being alone in this challenge means alot to me.
Title: Re: Manual Motor tuning
Post by: Hood on November 04, 2006, 07:03:35 PM
CV = Constant Velocity
ES = Exact Stop
There is info in the "Using Mach3" Manual on both these modes.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 04, 2006, 07:13:08 PM
Thanks Hood
Will crack the manual open after supper ..

Title: Re: Manual Motor tuning
Post by: Hood on November 04, 2006, 07:15:56 PM
Just had a look, pg113 (10.1.16) has info.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 05, 2006, 12:15:32 PM
So whats the preferred setting ?  CV or ES ?
I will be cutting metal if that matters.
Its been in CV mode up to this point ..
Title: Re: Manual Motor tuning
Post by: Hood on November 05, 2006, 01:08:52 PM
CV is probably best for most things, if you are finding you are getting rounding at corners when it is supposed to be a sharp corner then you will have to use  Exact Stop, or you may be able to mess with the rounding compensation or whatever its called.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 05, 2006, 01:31:18 PM
Thanks ..
I think I might know why I'm having the issues with my z motor.
If I get it to jog fine then it stalls running gcode moves.
then I tune it to work with GCode and it stalls on jog !!!   OOiy

The stepper driver requires a 15V to 35V pwr supply .
Guess what the kit came with .. 15 !!!

lol   
Im gonna get a decent 30V supply and see if she acts better.
the motor spec is 2.5 V
Title: Re: Manual Motor tuning
Post by: Hood on November 05, 2006, 01:38:47 PM
2.5V motor will run a lot better on 30V but really should run fine on 15, if only a little slower. 30V PSU will certainly do no harm and can only do good.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 05, 2006, 03:29:26 PM
Here's my thoughts on this . Keep in mind I'm mechanically minded and a electronic retard . :)
I have the bench mounted Mill/Drill , a Rung Fu 31 clone from Harbor freight.
The quill is spring loaded.
Moving up is a tad easier than moving down as the spring is in play.
Im tweaking the spring now to try to equalize the effort.
But if the Motor had more UMPH , it wouldnt be a problem .
Sound Logical ?
I can mount the 460 OZ if I have to . but man that seems like overkill.


Title: Re: Manual Motor tuning
Post by: Hood on November 05, 2006, 03:50:28 PM
Yes that sounds logical, your name Spok by any chance ;)
Just out of interest what make driver are you using?

Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 05, 2006, 04:09:57 PM
lol

I get razzed alot about my use of "Logic"

All I know about the driver is its a model # U366B
Bought the kit on Fleabay a few years ago and It came with two 460 Ouncers and a 140 for the Z.
The power suppies are most simple.
3 transformers that feed through a Cap and to the driver .
Hey , I was totally ignorant to CNC when I got it ... LOL



Title: Re: Manual Motor tuning
Post by: Hood on November 05, 2006, 04:38:55 PM
Werent we all, and I still am ;D
I was just curious as I bought some drives off eBay and had endless problems with them, eventually went to Geckos and never looked back.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 05, 2006, 09:10:03 PM
If a better PSU doesnt resolve this I will do the same.
Cashflow permitting.

Have Gecko's on the Servo's and dont have ANY issue's there :)
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 09:48:53 AM
Anybody know off the top of their head what that Pulse step setting
in the motor tuning section does ? (0 to 5 option)
Im at work and dont carry the manual with me :)
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 06, 2006, 10:10:11 AM
Hey Yoda,
    The best I make of it is  It is the duration of time the step signal is sent. Mine is set to 7.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 10:14:45 AM
7 ??
I thought it was only 1-5
Maybe I should bring mine up on the stepper axis .
Its at Zero !
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 06, 2006, 10:19:16 AM
Yoda, I'll be honest, I don't know why it says 0-5. I do know that mine likes it at 7 though. I don't think it will hurt any thing to try.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 10:32:21 AM
I'll give it a shot..
For Hood.
Heres the specs on the driver

 Standard 5V TTL CMOS Enable, Step and Direction inputs interface with virtually all step and direction controllers including Microchip PIC, Atmel AVR and PC parallel port CNC software.

 This state-of-the-art, high power drive is very conservatively rated at 6 amps per phase.

 Maximum step rate for this drive is over 200 KHz.

 Connecting the Enable input to Ground disables the outputs of the drive so stepper motor shaft could be rotated freely.

 High quality screw type terminal blocks with sliding pressure plates (will not fall apart when wire is removed) on all inputs and outputs, make connection to this drive very easy and reliable.

 Half or Full step operation is set with an on board jumper.

 Stepper motor current is adjustable from 1.5 to over 6 amps via an on board trim pot. This drive does not require any external power resistors to set the stepper motor current.

 This drive features automatic stepper motor idle current reduction to 25% of full current. This feature could be defeated with on board jumper so the motor runs at full current all the time.

 Drive is mounted on custom designed, heavy yet compact, heat sink for cool and reliable operation.

 Drive has dimensions of 3.2" L x 3.0" W x 2.5" H.

 Drive is designed to perform, be efficient and last a long time.



Title: Re: Manual Motor tuning
Post by: Hood on November 06, 2006, 01:24:47 PM
Yoda
 the style of writing in that drive info sounds very familiar to me ;)

Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 01:40:38 PM
LMAO
Is that you selling the rig on EBay ???
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 06, 2006, 01:48:34 PM
Probably the same kind he got from fleabay once.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 01:52:18 PM
Dooh !!!
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 06, 2006, 01:56:24 PM
Not sure though. LOL ;D This stuff makes me laugh.
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 02:05:11 PM
I just hope its not a piece-O-Crap   nuk nuk

I cant even rub 2 nickles together right now much less spring for a Gecko !!

Im pondering putting the stepper drive on the 24V PSU I have for the servo's just to see
if it makes a differance.
Its unregulated and filtered , Same as the board specs.
It just makes me nervous as its a 20 AMP PSU .. And Im not sure it's "Linear"
Im an electronics dipstick.
Bad Idea ???  I can drop the amperage on the driver ..
Title: Re: Manual Motor tuning
Post by: Hood on November 06, 2006, 02:57:26 PM
They are not the same drives I had but by the style of writing and the language used in the description I suspect they may be the unipolar drives that the same guy sells. I had a few conversations with guys that bought the unipolar drives and they all reported that they worked, not brilliantly but they did work.
 Anyway as I said it is only the language that sounds familiar and more than likely it is NOT the same guy.
Hood
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 06, 2006, 02:59:10 PM
See if this helps Yoda.
http://www.campbelldesigns.com/how-to-build-a-power-supply.php
Title: Re: Manual Motor tuning
Post by: Hood on November 06, 2006, 02:59:39 PM
Oh and as to your question regarding the 20Amp PSU, it shouldnt be a problem. The 20Amp bit is what it CAN supply, not what it will supply. It will only supply what the drive draws.
Hood
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 06, 2006, 04:15:34 PM
I sorta thought that  :)

I'm gonna give it a whirl tonight .
Maybe I can sell enough of my 6061 stock to get a gecko !!
got about 100 Lbs of it :)
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 07, 2006, 08:27:43 AM
Shizzam !!!!!   ;D

Hooked up to the 24Volt PSU that stepper is Flawless !!!
Had a feeling it was a lack of tourqe thang'.
Thanks for all the help guys .
Title: Re: Manual Motor tuning
Post by: Chaoticone on November 07, 2006, 09:53:39 AM
Good Job Yoda :D
Title: Re: Manual Motor tuning
Post by: Yodawill2000 on November 07, 2006, 10:04:33 AM
Thanks ..  Glad the frustration is over   ;D

Heres a little tip for noobies Like me.
lol
To start the story I load the roadrunner and scale it down to fit on the chunk of aluminum I have in the vise.

After I realized all was well with the motor I decided to go to the Auto Step Cal thing to check distance ..  lol
Keep in mind I have the scale down setting still on the main page ..
LOL

I got to move the Z 2" and it moves 1/4" ?????  I say WTH ???
I tell it that it moved a quarter inch and it set the step's per at about a Bizzilion LMAO

Then when I jogged the motor just laughed at me ..

Then it dawned me that scaling down the axis is a Global Thang' !!!   nuk

Lesson learned.
when auto Calibrating the steps per be DAMN sure scaling is at 1.00      ;D
Title: Re: Manual Motor tuning
Post by: native34 on August 20, 2007, 03:22:19 PM
Anybody find out what that step/dir pulse (0-5) Thing is all about i have the same HF mill 33686 as you and am having problems with accuracy