Hello Guest it is September 26, 2021, 05:02:45 AM

Author Topic: motor settings  (Read 9637 times)

0 Members and 1 Guest are viewing this topic.

Re: motor settings
« Reply #10 on: October 28, 2014, 10:12:02 AM »
Thanks Stirling
I guess its back to the old drawing board as they say. Not quite sure what to chack for losing steps especially on just one axis. It cant be from heat, each motor has a heat sink on it and the X axis also has a 12v fan blowing directly on it since it is enclosed in the gantry. I also have three 12v fans blowing onto each of my 3 drivers, they barely get hot.  I have 2 fans mounted on the box 1 blowing in the other sucking out, both with filers to keep the dust out. I have changed my BOB, checked and tightened all my electricial connections, checked all my settings within Mach3 they are still what was set from the begining.  In fact when I built my electronic box I soldered all my wire ends before connecting them. What else can I check? If my BOB was bad how could I tell? If the driver is bad, again how do you tell? I really dont want to buy a whole electronic package.
Safe machining everyone

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: motor settings
« Reply #11 on: October 28, 2014, 12:26:45 PM »
Is this your kit that we're talking about? (from a previous post)

http://kelinginc.net/CNCNEMA23Package3x.html
CNC 3 Axis Stepper Motor Kit with 425 oz-in motor and KL-4030 Bipolar Driver with 36V /9.7A Power Supply (110V/220VAC):
(3) 425 oz-in stepping motors, NEMA 23
(3) KL-4030 Drivers (3.0Amp 24-40 Volts, 1-1/64 microstepping)
(1) 36VDC/ 9.7A Power Supply 110VAC/220VAC
(1)C10  Breakout board
(1) 5V power supply

if so and these are your motors:

NEMA 23 BIPOLAR STEPPER MOTOR 425  oz-in KL23H286-20-8B

Then the motors are not the best match for those drivers and power supply. What do you have set in motor tuning for steps/per and max velocity?
Re: motor settings
« Reply #12 on: October 28, 2014, 05:21:55 PM »
Yes sir thats my kit.    My machine uses chain not Acme thread to drive the X and Y.
Settings are:
X Axis
Steps per 912.4659217
Velocity 250
Accel 5

Y axis
Steps per 1420.292255
Velocity 250
Accel 5
Safe machining everyone

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: motor settings
« Reply #13 on: October 29, 2014, 12:48:20 PM »
should have also asked for your microstepping value. I'm trying to see what rpm your motors would be doing at your max velocity.

Also can you describe in a bit more detail under what circumstances/speeds you get stalling.

The thing is I suspect you're attempting speeds that your motors just aren't capable of because they're quite "under-volted". They're very high inductance motors really and are not ideal. To get their optimum speed/torque they'd need a PS voltage of 84V. Your 36V means their max speed is less than half what it should/could be. As I said earlier those motors are a poor match for the drivers.
Re: motor settings
« Reply #14 on: October 29, 2014, 03:14:16 PM »
the setup on the driver is set to 1/16.    Sometimes the stalling is during a no load travel to my touch off fixed plate, this can be just as it starts to take off or after a few inches of travel or after 3 ft of travel. Sometimes it's during cutting and  the samething as the no load times.      There is no pattern to the stalling. In fact sometimes i can cut two or three things without a stall.      Also I dont take much of a bite when cutting sometimes 1/16 , 1/8 or 1/4 depth of cut depending on the size of my endmill/ V bit but nothing more than 1/4 even on a 1/2 inch endmill.        I find i get a better cut taking less of a cut.          
 I guess this is a dumb question but if the motors are a bad match for the drivers and the PS is less than half of whats needed why would Keling Inc package them as as ready to go kit. What Drivers would be good for the motors I have? And I'm sure I can find an 84v PS. Although this package worked OK on my small 2" x 4' machine for 2 yrs. No stalling of any kind.
Safe machining everyone

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: motor settings
« Reply #15 on: October 30, 2014, 06:00:56 AM »
Your X motor is doing just over 71 rpm at 250 in/min which is very slow and should be no problem at all. It may be that they're just underpowered for the job and running at their limit or perhaps you've developed some binding somewhere.

I guess this is a dumb question but if the motors are a bad match for the drivers and the PS is less than half of whats needed why would Keling Inc package them as as ready to go kit.

You'd have to ask THEM that.

What Drivers would be good for the motors I have? And I'm sure I can find an 84v PS.

It's hard to say without knowing the full details of your machine. It's possible that changing the motors - not the drivers and supply would improve things. As I said, these motors are 6.8mH Inductance which is very high and not really suited to the purpose.

First thing I'd try is check for any binding. Second I'd drop the microsteps to as near 10 as you can (probably 8 ) and of course half your steps/per to match.

Although this package worked OK on my small 2" x 4' machine for 2 yrs. No stalling of any kind.

Well - maybe so but why would motors that seem fine on a "small" machine lead you to think they'd be just as good on a different machine?

EDIT: changed 8 followed by a ) to 8 followed by a space followed by a ) to get rid of the darn smiley
« Last Edit: October 31, 2014, 02:13:13 PM by stirling »
Re: motor settings
« Reply #16 on: October 30, 2014, 07:58:58 AM »
Quote
Well - maybe so but why would motors that seem fine on a "small" machine lead you to think they'd be just as good on a different machine?

The place I got my machine from and about 2 dozen people that own the same machine and package, say that the electronics package I have works fine with their bigger machines.

You had mentioned you need more info about my machine, this is what I have and where I bought it..

http://buildyourcnc.com/blackFoot48v40.aspx

If you have any recommendations for what I can save from my electronics and what I need to change to that would be great.

I want to thank you for your help/info with this problem.
Safe machining everyone

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: motor settings
« Reply #17 on: October 30, 2014, 08:19:39 AM »
Quote
Well - maybe so but why would motors that seem fine on a "small" machine lead you to think they'd be just as good on a different machine?

The place I got my machine from and about 2 dozen people that own the same machine and package, say that the electronics package I have works fine with their bigger machines.

Well there's a contradiction here then. If they say the same package works fine it must be that yours has a problem that theirs doesn't.

If you have any recommendations for what I can save from my electronics and what I need to change to that would be great.

See the contradiction?

Have you tried what I suggested?
Re: motor settings
« Reply #18 on: October 30, 2014, 12:22:34 PM »
i have not change the motors or power supply.     when i jog the motors using the keyboard they run great.    
 
i have gone over all my bearings nothing binding there, inspected each link in the chains no bent or mis -shaped ones, checked every inch of my rails for bends, bumps or waves nothing there either. re checked all my plugs and connections all good.

i have even ohm tested each wire in the harness between the plugs all are good.

when my machine is turned off i have pushed the gantry the full length of my table both with the chain connected and without, it is easier to move without the chain connected to the motor, but suspect thats normal.

Not wanting to spend $500.00 to a $1,000.00 buying new electronic chasing phantom problem, i think i will continue to monitor my system and see if this problem worsens or developes a pattern.

Are you saying that this could not be a Mach3 software problem, that it has to be my electronics?

Again thanks for your help.
Jeff
Safe machining everyone

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: motor settings
« Reply #19 on: October 30, 2014, 01:54:06 PM »
Are you saying that this could not be a Mach3 software problem, that it has to be my electronics?

No I'm not saying either of those.

I can only suggest things based on what you say and when you say it. You have the machine in front of you - I don't so I can only go on what you tell me and when.

Your motors ARE a poor match. However if you say 2 dozen other people have exactly the same system and theirs work fine then despite the motor's shortcomings it may well be that all other things being equal, they are up to the job (though I still suspect it's only just).

Have you set your microsteps as I suggested? Do that first because 16 is pointless anyway so you might as well start with that.

Then I'd suggest you try the following - one by one:

1) find some toolpath that reliably exhibits your problem in air - a few rapids should do it.

2) lower your accel and max velocity by half and repeat. Does it still happen?

3) Because you've just mentioned jogging is ok, try turning your toolpath display off and see if things improve when you run a toolpath that previously stalls.