mach3 not working, will emc2?

I have a knee mill I retrofitted from an anilam crusader to pc based controls. Im trying to get mach3 running but no luck and haven't found the answer on their forums. Here is what its doing. I am using a digital readout to check table travels. I have it running the correct distance when I run x or y by themselves. But if I cut an angle using x and y in the same motion they both way over travel. Here is my questions. Can emc2 fix this? And since hardware is installed how long would it take to get it right? And how much help may be available? Thanks

Whether Linuxcnc will run the hardware would require knowing what the hardware was. If it is USB based then no.

But regardless of that if Mach is not moving your motors correctly as you describe then there is something funny going on.
Mach is not THAT bad

There is lots of help available here and other places. How long of course depends on a lot of things.
Describing things correctly and with proper detail as well as answering all questions asked of you speed things up.

So can you describe your machine a bit and what hardware you are using to control it

give us some information on the conversion and drives i.e analog 10v servos , stepperdrives etc ,
you say the drives over travel , by how much and how are you testing this ..

you say you are using a digital readout what type ... ?

at first look , your problem is nothing more than configuration ,
and would be the same problem no matter which controller you use Mach or Linuxcnc

given more information i'm sure it would not take long to find the culprit

Sorry it took all day. I have a Supermax ycm 40 knee mill. Took the anilam crusader controls off. Installed 500 line count encoders that do 2000 counts per revolution in quadrature. Installed dugong cnc drives and two breakout boards. The machine has a thread pitch of .200 on x and y and .18 on z. There is a belt reduction of 2:1. I mounted encoders directly to motors. The servos are sem 30M4-59. Max rpm rating is 2400. And says 142 volts 30 pulse amps. I am using a basic. Digital readout that is using glass scales and is .0002 on accuracy. On a move of g01 f10. X.5 y.5 it moved x.6994 and y1.176. Thanks

ok , the main problem appears to be , scaling , i would recheck the counts per inch you may have the belt reduction in reverse in your calculations , also having encoders fitted directly to motor shafts
when their is still a reduction gear to go , can give you false feedback information , it is far better to have the encoders fitted to the final shaft or ballscrew , also check for slack belts .

i presume your using the parrallell port , so recheck your latency timing , and pulse timing , the fact that the y axis is moving just about twice the requested movement suggests your values are 50% greater then they need to be , or you have a value reversed perhaps

I beleive you stated that the x and y axis moved the correct amount if only one axis was moved at a time which would suggest that the scale was correct.
Perhaps check to make sure all your hardware connections are tight, correct, shielded, grounded only at one end.
Double chech your configuration that you are not "sharing" any pins in the configuration.
Which breakout boards are you using? How are they set up?
Have you installed LinxCNC or are you still talking about your Mach setup?

Rick G

Im using cat 5 wires with line differentials so im hoping that would reduce noise. Im using a c11 breakout board and hdbb breakout board. Both came from cnc4pc.

Im still using mach3. Haven't tried emc2 yet

Hi Brad;

I'm sorry to see you are still having problems getting your machine running. I wish I could get up there to look at it - probably just a simple error - but I'm swamped at work (as usual).

Here are a few things to consider.

LinuxCNC won't fix what sounds like a hardware problem. The printer port squirts out roughly the same signals in both cases.

If you are using those 500 line encoders I gave you I hope you mounted the differential transmitters close to the motors and not in the cabinet. That would defeat their purpose.

Make sure you have the pin assignments in mach match the requirements for the HDBB. The default assignments are probably not correct.

Send me an email offlist. Perhaps we can trace down that problem over the phone.

By all means, get that thing done! I still have some work for you.


Doug