machine going crazy

[warrick]

I was using my machine today and went crazy. I had already cut a couple of pieces with no problems
It made its first cut and when it went to its second cut it jumped over about 2mm
It got half way around and then started going backwards and forwards then got back on track again.
I stopped it and you can see in the screen dump below that the position on the screen doesn't match the code displayed
I re-generated the code a couple of times but that had no effect.
Any ideas on what to check would be appreciated

Warrick


crazy.jpg

[rodm]

Hi Warrick,
Don't worry we are all crazy.

You can send me the file and I can check it running on one of my machines if you like.

Things that spring to mind are loose connection on the motor causing the direction signal to be ignored or reversed.
EMI noise so check your earths on the shielded cables. The most likely source of EMI is the spindle so do an air cut with the spindle turned off and observe what is happening.
What you need to confirm is it both X and Y or just one of those axes that is behaving silly.

Anyway send me your file and we can eliminate or confirm if it is the code. BTW the Gcode window reads ahead of the current position and buffers those lines so that the machine movements are smooth. I wouldn't be too concerned about that and by scrolling up the Gcode wondow you should see the DRO references somewhere in the code.

[warrick]

Thanks Rod,

I will give it another go tomorrow and let you know

Warrick

[warrick]

I went out to the shed this morning and checked the mechanicals and found nothing so I set about connecting an earth cable from the spindle to all metal bits on the x,y and z axises back to the main control box.

I then loaded the original file (I had tried different versions changing speeds etc which had limited effect) and ran that, cutting into a scrap piece of wood and it ran fine.
Hopefully that was the problem solved.
I will find out this afternoon when I have another go at a project for my son
Thanks Rod for your help

Warrick

[warrick]

The problem surfaced again, it seems the Y axis is getting stuck. I checked the tension on the rack and pinion and that was fine, then checked the electrical connection those all appear fine.
tuned the motor on the G540 and so far it has worked fine. I will have to find some more work so I can stress the machine to see if it is truly fixed, damn shame I will have to spend more time in the shed

Warrick

[maddog 62]

Warrick
i am no cnc guru
but iv had the same issue,
my machine is a chinese special, i found it was a broken wire in the cabling
replaced all the cabling and not a problem since, unless i created it by self
cheers Tony

[warrick]

Warrick
i am no cnc guru
but iv had the same issue,
my machine is a chinese special, i found it was a broken wire in the cabling
replaced all the cabling and not a problem since, unless i created it by self
cheers Tony

Thanks for the suggestion Tony,
I have checked the connections on the cable and I did use good quality cables so hopefully I didn't miss anything. Time will tell.

Warrick