Messages

91

General Mach Discussion / Re: Z Axis loosing steps in the up direction only.

« on: January 24, 2014, 03:39:17 AM »

Thanks for your thoughts Hood.
I've played around with Acc and Vel, going from one extreme to another and all points in between with no change.
I have looked at all my wiring terminals and came up empty handed.
There are IDE cables running between the BOB and driver boards. I have changed them all around, but still no change.
I've changed key boards over. No change.
I have the same result when jogging with the Mach3 pendant callout.

I have the hard drive out of the computer at the moment as I'm seeing if I can sustitute it to another PC. I'll post up the XML as soon as I can.

I was going to try fitting a PCI parallel port card to my PC and see if the mother boards port is at fault.
Do you think that would be worth a try? They are pretty cheap and if they work, then that may be a better way to go rather than replacing the mother board.
Unfortunatly we have a public holiday here this weekend, so all the shops will be shut.

Thanks again.

92

General Mach Discussion / Z Axis loosing steps in the up direction only.

« on: January 23, 2014, 08:51:49 PM »

As the title states, my trusty router has developed a problem with it's Z axis motor loosing steps in the ^UP^ direction only.
This started after I gave mach3 a command to GOTOZ whilst doing some rotary carving on my 4th axis. It was a very stupid command to give, as that drove the cutter all the way into the job and ruined it. I have the Z zero alinged with the center of my part and I've only just started experimenting with the 4th axis. Lesson learnt.

Seeing that my project was ruined, I decided to complete the run and confirm that the job was going to turn out as I'd liked. This is when all my dramas started.
While running the rest of the code the Z axis started making strange noises and proceeded to drive deeper into the job.

I decided that I must have damaged the axis somehow, so I pulled it apart expecting to find a rough bearing or ball screw, but everything looked fine. I then ran the stepper without it being connected to the ball screw and found that jogging in the down direction the motor runs perfectly, but jogging in the up direction the motor jerks and moans and looses steps. Sometimes it even runs the wrong direction. The DRO appears to cycle as per normal and the soft limits were still working as they should.

I have changed motors and driver boards around and the problem still exists only in the Z axis UP direction. I have checked all my motor tuning settings and every other setting that I can think of and they are all set as they have been for years. So nothing has changed in the program that I can see.

My machine is running Probotix BOB and stepper drives, as well as their motors and power supply.
I've been running X Y & Z on 1/4 steps without a problem, and the rotary axis is running 1/8th stepping.
Could I have a bad BOB or parallel port pin? I have had the computer mother board go bad before and that made me suspect the BOB, but with some help from Probotix I was able to diagnose that the mother board had failed. The current board has been running fine for the last year or so.

Could anyone please help shine some light on the possible cause of my problem as I've run out of ideas?

93

General Mach Discussion / Re: external e stop requested

« on: December 30, 2013, 05:44:39 PM »

Try connecting a 0.1uF ceramic capacitor across your switch wires at the breakout board.
I had trouble with this early on in my build. I was having to run a very high debounce value and after fitting these caps, I don't run any value and don't get false triggers.
I don't run any shielded cables for motors or switches.

94

General Mach Discussion / Re: z axis gaining height with vcarve toolpath's only

« on: December 30, 2013, 05:26:17 PM »

Just a thought.
When you save the toolpath, what post processor do you use?
I was just thinking if your Mach 3 native units are set to metric, but you save the toolpath in inch, could that cause this issue?
Are your steps per calculated correctly for the Z ball screw, as you state that the Z has a different pitch/start to the other 2 screws.
I use Vcarve 6, Mach 3 and Probotix boards, drivers and motors and have done a huge amount of engraving without any problem.

95

Video P*r*o*b*i*n*g / Re: Copycat questions.

« on: September 20, 2013, 11:05:28 PM »

Thanks Rich.
I downloaded the users guide after I posted the question. I'm working my way through it.
I'll look into some programs for backplotting.
Solidworks may have some thing that will do it. I'll do some searching.

Ozy.

96

Video P*r*o*b*i*n*g / Copycat questions.

« on: September 19, 2013, 10:43:10 PM »

I am fairly new to the world of cnc, but have managed to build my own cnc router with good success.
I'm using Mach3 to run the machine and Vcarve Pro and Solidworks for my cad work.

I just recently mounted a camera to my spindle. This is mainly going to be used as an origin finder for when I place the stock onto my table.
However, I would like to use the camera for more than just that.
I frequently design stuff the old fashioned way using cardboard templates. Because of this, I've been looking at getting CopyCat and digitizing these patterns.
By digitizing I'm only refering to a profile outline and some holes etc. I'm not wanting a 3D representation of the object.

Now my question is this.
Once I have traced the pattern using CopyCat and generated the gcode, can I open that gcode file in say Vcarve Pro for further editing or modifing, or am I limited to only having the gcode file?
I realise that I can edit the code but this would be time consuming.
Is there a different way I can do this, that is better maybe?

I have found many good topics relating to CopyCat, but haven't come up with an answer to my question.
I appreciate any help.