Hello Guest it is October 14, 2019, 07:25:37 AM

Author Topic: Strange Behaviour  (Read 3625 times)

0 Members and 1 Guest are viewing this topic.

Offline comet

*
  •  315 315
    • View Profile
Strange Behaviour
« on: February 11, 2007, 09:22:22 AM »
Hi,
  got a bit of a quirk on my machine,can anyone advise?
Ill describe the machine first
Computer:
Pentium 4, 3 gig,  256 ram, XP pro
onboard graphics, sound with netmos PCI parallel card.
latest licenced Mach3 running 25mhtz

machine:
home brew servo'ed Denford triac.
Gecko 340's
600 steps per mm acc/decc set at 150. max feed about 90% of available.
 There is bags of power from the servo's
Homan VFD spindle card
all slides free and easy, correctly adjusted with no stiffness or ware.
 shielded cables and earthed where needed
good driver test,dont suspect noise.

Problem:
  I use the machine daily in my buisness with alot of different
programs (small tool/pattern making)
  Very occasionally when halfway through a program it will kick out the y drive,
when doing a G00 x&y right at the end of the move.
 This problem is 100% repeatable at that point in the program.
The only way to stop it is to make that move seperate Xthen y,then its happy!
  Now the strange thing is if you program it to do the problem move only in a seperate little
program going back and forth,its fine it will do it all day,without kicking out.
  Any Ideas? ive seen this sort of thing with steppers (resonance problem)
but its got me beat,could it be something to do with the amount of ram being used by
the lookahead setting,mines set to the 20 lines?
  could it be that each axis has diferent gearing X3:1  Y4:1  Z3.5:1 (max reduction tooth wheel in available space)?

     Thanks in advance
   Tony

Offline comet

*
  •  315 315
    • View Profile
Re: Strange Behaviour
« Reply #1 on: February 11, 2007, 09:55:54 AM »
Sorry,
    bit of confusion.
steps are X 600  Y800  Z640 per mm
   Cheers
Re: Strange Behaviour
« Reply #2 on: February 11, 2007, 10:06:21 AM »
Are you running any feed override? try setting the FRO to about 90% and tell me if that makes it happen.

Could you please post the 2 G code lines that will make this happen? I will see if you are getting an over accel.
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com

Offline comet

*
  •  315 315
    • View Profile
Re: Strange Behaviour
« Reply #3 on: February 11, 2007, 10:26:54 AM »
Hi Brian,
  here is the segments of the programs that causes the program.

G00 X-90.5 Y0.
G00 Z1.
G01 Z-1.
g04 p.75
G01 Z-6.5
G00 Z1.
M05
M09
G00 Z60.
M06 T2
M00 
M03 s2200
M07 g43
G00 X-71 Y45. (problem at the end of this move, servo drive faults)
g00Z1.
G01 Z-2.5 F60.

also with this segment in another program:

g00 x-130 y50
M06 T4
M00 
m03 s1200
m07 g43
G00 X-121.5 Y81.775 (problem at the end of this move, servo drive faults)
g00 Z1.
G01 Z-9.35 F200.

  I cant remember if I had overide on I tend to mess about with it,
these are the only two programs its done it on.
I will run them both tommorow when I get in the shop and advise
   Thanks for your interest
    Tony

Offline comet

*
  •  315 315
    • View Profile
Re: Strange Behaviour
« Reply #4 on: February 12, 2007, 11:31:23 AM »
Brian,
  had a play yhis morning and found that if I overode  80% things were fine.
I then tried lowering both the max rapid and the accel,individualy and found that
I had to drop 50% before things were ok.
  In the end I went up to 35khtz and alls well again.
I think Ive been sailing a bit close to the wind on the clock speed as my encoders require
1000 steps .but the reason I went to 25k is because I found Mach sometimes reverted back
to 25k on program start up  ???
    Cheers
    Tony
Re: Strange Behaviour
« Reply #5 on: February 12, 2007, 02:59:57 PM »
What is in your help /about  licence name? I bet you see demo mode :(
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com

Offline comet

*
  •  315 315
    • View Profile
Re: Strange Behaviour
« Reply #6 on: February 12, 2007, 03:16:17 PM »
Brian,
   no my name comes up there as it should.
  not sure about that one,it hasnt reverted today
prehaps that was some freaky glitch?
  Ive actually put it up to 45 khtz,to see how it goes
while keeping max rapid rates the same.
  I'll keep an eye on it this week to see what, if anything happens.
  Tony
Re: Strange Behaviour
« Reply #7 on: February 13, 2007, 10:56:13 AM »
IT was not saving your XML... if you change a setting exit mach3 and it will back up your settings :)
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com