Hi all, I have had my K40 for six years now, and up until yesterday it has been great, and most of all accurately repeatable.
Suddenly, when I cut a part, it is cutting it at 98% of the actual size, so unless I compensate the parts are all wrongly produced.
For info, my workflow is
produce basic design in QCad
Open .dfx file in InkScape, make sure line colours are correct, then save as .svg
Open .svg file in K40 Whisperer, connect to K40 and cut
Is there any potential explanation for this? The K40 otherwise is functioning perfectly, no funny noises when moving and all the mechanical parts correctly tight. The 98% is totally repeatable, so nothing is loose or wobbly
Also, you noticed it recently but do you make things which would have exposed this weeks ago had it cropped up slowly over time? ie interlocking shapes/designs is all you do so the change in scale would have shown up if it happened earlier.
I would cut a large square and a small square. Like maybe 20mm and 200mm. Then see if it’s the same percentage difference, or the kerf just got wider.
If the tube is shifting to TEM01* mode (“donut” mode), the beam will be wider. Also lower effective power, but if you were already cutting with more power than you strictly needed you might not notice the difference?
It has been working great recently, and the only issues I have had started two days ago. I checked the size thing using a 50 x 50mm square and allowing for the cut width I determined the (just under) 2% change.
I have been using it to cut shapes out to match previously printed items, and it has been exact, you position the printed page on the bed using the datums, and then it will cut exactly where it was supposed to. Now, unless I scale the Inkscape file to compensate, it no longer matches
Check to make sure your belts are still tight(but not too tight) and I would also check that nothing changed with the software generating the printed design just to be safe.
I was going to say that you would notice a power change if the laser moved out of TEM00 mode but cutting paper is very low power. As Michael mentioned, the TEM change might have made the kerf larger. Speaking of that, recheck your focal length( ramp test ).
It’s definitely not the laser itself, simply because the laser doesn’t control where the cut is made, the software and mechanics do. I line being cut 2mm away from where it should be is either control or hardware
So I re-installed InkScape and K40 Whisperer, and all the usual restarts, power recycles etc, and now the error is down to 0.45% (essentially the laser cutting a line of 199.1mm where it should be 200mm. I’ll reverify the belts and everything