Hello Guest it is October 24, 2021, 02:16:36 AM

Author Topic: Really need help  (Read 29820 times)

0 Members and 1 Guest are viewing this topic.

Offline ger21

*
  • *
  •  6,293 6,293
    • View Profile
    • The CNC Woodworker
Re: Really need help
« Reply #50 on: August 15, 2009, 08:34:26 AM »
I believe Mariss from Gecko is the designer of the Centent drives. It would be interesting to hear what he thinks about your findings, as I was under the impression that Geckos are far more advanced than the Centent.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline RICH

*
  • *
  •  7,419 7,419
    • View Profile
Re: Really need help
« Reply #51 on: August 15, 2009, 08:52:47 AM »
Tom,
Sounds good to me. When confident the signal is good you can then continue
to develop applicaton of Mach to your project. LOL

RICH

BTW: Suggest next time you start a topic, post in the context of what your after.
         There is a difference between a software problem, an application of the software,
         clarification for understanding, etc.
      

Offline simpson36

*
  •  1,369 1,369
    • View Profile
Re: Really need help
« Reply #52 on: August 15, 2009, 09:39:54 AM »
I believe Mariss from Gecko is the designer of the Centent drives. It would be interesting to hear what he thinks about your findings, as I was under the impression that Geckos are far more advanced than the Centent.

Are Mariss and Marcus the same person?  I had email exchanges with Marcuss Freimanis (may have spelled that wrong), but I ocationally see 'Mariss' mentioned.

If the Gecko is far more advanced, it would be quite a bargain at half the price of the Centent. I found no discrenable difference between the two drives with small (NEMA23 400oz-in) motors.

Offline simpson36

*
  •  1,369 1,369
    • View Profile
Re: Really need help
« Reply #53 on: August 15, 2009, 09:57:27 AM »
I believe what VMAX  refers to, is the proper selection of a component  . . . .

That is my question. How does one go about selecting, identifing, determining a 'well engineered' component. A statment was made, I'm just asking it be expanded to a useful point. Exactly how does one go about matching these components together as you correctly point out must be accomplished. I see a recurring contradiction whereing stepper systems are consistently touted as being 'easy', 'uncomplicated', etc, yet there is a never ending stream of posts with 'missing steps' or something similar as part of the subject line and then a pile of shot-in-the-dark suggestions on how to diagnose the problem. Not unlike this very thread.

Therefor, the logical conclusion is that this is not so simple as it's made out to be.

It's a serious question. I've done a ton of research on these topics and I don't reacall finding any clear advice on exactly how to select a 'quality' component from the vast choices available in the world of steppers. i.e. is it all down to getign a consensus or recommendation from existing users, or is there some way to be proactive in interpreting a spec, graph, or other perfomance documentation?

I.e., starting with a clean sheet of paper, what are the caveats to avoid and what is a logical path to sucess in setting up a stepper system. I'm asking for the benefit of the OP and others, as I am not planning to use steppers again.

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: Really need help
« Reply #54 on: August 15, 2009, 09:59:40 AM »
Brothers I believe.
Hood

vmax549

*
Re: Really need help
« Reply #55 on: August 15, 2009, 10:15:50 AM »
YOUare right IF I just wanted to drive around town showing off I would buy the sports car those speeds shure are impressive.

BUT IF I wanted to actually do some work and actually MOVE the dirt I would BUY the dumptruck every time.

with 40 years of driving dumptrucks there comes experience(;-)


TUNING ??? (;-)  THe dump truck requires you to ?  do NOTHING no tuning required turn the key and fire it up

, THE sports car YIPES what is a ocilliscope anyway, PID what does that do???  Have to tune it with the machine in motion? why? WHy is it I turn one knob and it effects the other settings too HUH?

I have done both many times (;-)


(;-) TP
« Last Edit: August 15, 2009, 10:30:51 AM by vmax549 »

vmax549

*
Re: Really need help
« Reply #56 on: August 15, 2009, 10:49:28 AM »
OK this says a lot:

When this lathe ran under DOS (and the BASIC programs were outputting the pulse train directly at the correct speed), the stepper motors followed faithfully. If the conputer had to be replaced, then the timing loops that controlled the rate of data flow, had to be adjusted to deal with the new processor speed. This has always been sort of a nusiance, but it did work.

Can you tell us WHAT has changed in the lathe setup.  Same drives and motors?  DID the DOS version run from the lpt port or a motion card that interfaced it to the drives? DID it run from a SERIAL port??

SOunds like you may just need to find the proper pulse width of the signal that makes the drives happy. UNLESS the BOB is distorting the signal?? OR the drive requires a really ODD signal to begin with.

IF you supect the BOB just as a test wire it straight to the port, eliminate the BOB to test. THen you will know for sure.

Obiviously this machine ran from a PC before . Now it is a matter of elimination to find the source of the problem.

Just a thought(;-) TP
« Last Edit: August 15, 2009, 10:59:43 AM by vmax549 »
Re: Really need help
« Reply #57 on: August 15, 2009, 11:04:25 AM »
OK,

I have a db-25,  screw terminal board... no LEDs, no isolators.   I could easily transfer the four stepper lines coming from the drive to this board.  I can do this Monday.  My parallel cable can then plug into this terminal board  I just thought using a simple terminal board without any isolation was an absolute "no-no".

vmax549

*
Re: Really need help
« Reply #58 on: August 15, 2009, 11:20:56 AM »
I just looked at the manual for these drives. THe inputs are opti isolated so NO further isolation is needed you can safely hook them direct to the port.

The MIN pulse width is 25 micro sec and the max pulse rate is 20Khz so that is good to go.

Depending on the exact drive (F or M) it will be either full/half step  OR Micro step. ( VERIFY the switch settings)

ALSO it can take either step/dir OR CW/CCW signals  Really need to verify this setting to be sure. ( CHeck the manual verses the switch settings)

As to the RELAYS I would simply get an opti isolator for those inputs OR double check the manual for the boards it may already have it(;-)   NORMALLY you would NOT double up on isolation as the signal CAN degrade for each LOOP thought the isolator media.

THat should get you on your way to finding the problem(;-)  GOOD luck and check back if you need help, We are always here(;-)

(;-) TP
Re: Really need help
« Reply #59 on: August 15, 2009, 11:44:28 AM »
OK,

The drive almost HAS to be the  "F" Drive. It is the only drive which offers full-step. The lowest resolution for the "M" drive is half-step.

This brings up another question...  Is there any advantage in setting this drive to half-step? I would think all I need to do with Mach-3, would then be to change my "Steps/mm" from 50 to 100.  No other changes should be necessary.  Hell, it might even eliminate my missing steps?  It certainly couldn't hurt...

What thinkts thou?