Hello Guys,
I am very green here. I've just bought a very nice looking 4 axis foam cutter. Unfortunetely the guy that made it for me cannot help me with the problem.
So, running mach3, everything is done, all axis are working, limits are set, motors are tuned (no dfference in DROs and mms that the tool has gone), but when I start something to be cut axis are not moving as they should, the DROs however show that the axis are exactly where they should be.
I am using profili pro for the g-code. At the begining the Ys are supposed to go from the bottom to the middle of the foam twice and after that the cut to start, but what I am getting is - one Y goes always up and the other Y goes half of the way of the first, lets give some numbers - the foam block is 5cm thick, just before the cut starts one Y is about 5-10 cm aboive the block and the other Y is 3cm above the block and they are supposed to be in the middle of the block.
Also sometimes one X is going different direction.
What I have messed up? What should I check... or uncheck 

Thank You Guys!

A picture of your machine may help - I assume you have 2 slaved stepper motors for the X axis and 2 slaved stepper motors for the Y axis.

Are you using the parallel port or ethernet / usb to communicate with the machine?

Tweakie.

Hello Tweakie,
Yep, I will provide a pic, but later today. All the axis are independent - the main purpose is to cut swept wings. I am using parallel port.

When you post the picture it would be a good idea to post your .xml file (it is located in the Mach3 folder and named <your profile> .xml) it is typically called Mach3Mill.xml - this will enable us to check your set-up and hopefully be able to make suggestions as to how to resolve the problem you are having.

Tweakie.

OK,
here is the machine and the xml.




https://drive.google.com/file/d/0B-L4pwEDBy4kemFHZjgwMjBNcHc/view?usp=shar

Excellent looking machine.

Velocity and Acceleration settings look good.
The only thing I have found that you need to correct;     Config. / General Config. - Uncheck A-Axis is angular.

Tweakie.

Thanks Tweakie, written from a moderator this really makes me happy
Do You think that when I fix the A axis to not angular it will run as it should be.
I can post a video of the problem if it still exists, may be I am doing something wrong...

THX again!

Just because I am a moderator doesn't mean that I know anything. 

If you still occasionally get one axis going in the wrong direction then I would suspect that the axis direction signal is not being recognized correctly.
One cause could be that the voltage output from your computer’s LPT parallel port is to the 3.3volt TTL standard when your breakout board / controller is expecting signals which meet the 5volt TTL standard. If this is the case then fitting another PCI parallel port card (which does have 5volt TTL output) is probably the easiest solution.

Tweakie.

Tweakie,
I did that (with the A axis) what happened is that the two axis are going symetrical, so its a start but I still have problem with the machine, I've uploaded a video to show.
https://drive.google.com/file/d/0B-L4pwEDBy4kVzlhcXRhYnZ2UGM/view?usp=sharing
Notice, that according to mach 3 the axis/tools (DROs are changing symetrical and at the beginning go up and down) are where they are supposed to be.
For me it is strange, for You may be not, but when I hit "reff all home" the axis are going this order - Z, Y, X, A is this something in relation to the problem or not?

It took a while to download the 950MB video but, as you say, it does show the problem.

Use a voltmeter to measure the voltage on any LPT parallel port Direction pin (between one of the pins 3,5,7 or 9 and one of the Pins 18-25). If the voltage is approx. 0v to 3.3v (dependant on jog direction) then it may well be a voltage issue as I mentioned in my previous post.
If the voltage is approx. 0v to 5v then it is not the parallel port voltage that is causing the problem. This will at least eliminate one possibility.

The Ref All Home button contains a script which is intended to act individually on the axes just as you describe.
In your case you have 2 pairs of axes and each pair should act together so it will mean altering the button script to perform the required action.


Tweakie.