Cutting deeper in areas???

[alboy]

Hi Guys

Well here is a strange problem, having been cutting loads of plaques something seems to have gone somewhat haywire in that my machine is suddenly cutting deeper on the left side of the item being cut, very noticeable in the picture. you can see on the text that it has cut fairly deep from the top left to cutting so shallow towards the bottom right that it barely cuts through the paint mask.


The spoil board is nice and level and the material is of equal thickness.
The CNC uses the DSP controller, used vectric to design the plaque. Thought maybe it was a dodgy output file so remade the design with new tool paths etc but problem still there. Any Ideas ?

Cheers

Al

[Boyan Silyavski]

When all options are exhausted usually means Mach3 is broken. Uninstall, restart,fresh install and paste yourbackup.xml,restart again and should be working.

[EddyCurrent]

Skim the bed and/or spoil board.

[alboy]

Cheers Guys

I do not use Mach3 it's a DSP system using the nk105 pendant and NC file formats. Have already reset and reloaded the DSP OS.

The Spoil board has been skimmed and is nice and level. I double checked by lowering a cutter just touching the bed and jogged around the X.Y axis and all fine.

Hmmmmm.....

Al

[EddyCurrent]

If you have a Z probe I would take readings across the work piece to see if the top surface is level. Also in your CAM software is everything flat on the XY plane.

[alboy]

If you have a Z probe I would take readings across the work piece to see if the top surface is level. Also in your CAM software is everything flat on the XY plane.

Hi Eddy,

do not have a probe although I have one on the shopping list (amongst other items lol) although I am not sure the DSP system supports probes, trying to find that out. I redrew the design again making sure all was well on the XY plane and still the same problem, very odd.

I have cut other plaques with almost the same size text with no problem, I even tried changing fonts in case the font was causing problems but still the same.

Al

[routercnc]

Could it be the tool slipping up inside the collet during the engraving? I've had that happen once which was confusing at first.

Alternatively could be missed steps on the Z stepper - can you remind us of the machine you are using?

[JAZZCNC]

If machine as been working fine then suddenly started happening then Coupling on Z axis motor as probably come loose and is slipping. Does Z axis return to Zero after job is finished.?

Other than that then how machine is setup regards feeds etc could be problem. The DSP software could have gone tits up but I'm guessing at that.?

[alboy]

Hi Jazz

How are you doing. I haven't tried to cut anything with such a fine text before although I have cut smallish text in a different font which seemed ok but can't say for certain if the problem had been there before, the signs etc I had been doing were fairly big, min 1" text. I had notice a couple of times when cutting templates out of 6mm ply that sometimes it wouldn't cut all the way through in parts but put that down to the material initially. I will check the Z axis coupling again. I reloaded the DSP software just in case but it didn't make any difference. Thought I had another problem as well but it just the tip broke off the V bit Doh. All axis return to home position at the end of a job. If I rerun the job on the same workpiece it does the same, so I suppose it's repeat accuracy is good lol.

Cheers

Alan

[JAZZCNC]

No you need to set a Zero work position and return to that not Home position. Reason being that home position is referencing a switch so it will and should always return to that position.
Returning to Zero work position will tell you if you have lost position thru missed steps or slipping couplings etc.

But before all this have you Surfaced the Bed.? . . . . With fine engraving you can't have any error in the bed.!