inaccuracy of cutting

[Martin Hladis]

Hello all,

We hit the problém with our Bodor laser, bodor bcl 1006xu. There is a problem with the inaccuracy of cutting. An example is the production of CWG coins for geocaching. (see picture faulty_geocoin.jpg in attachment)

When burning graphics on CWG coins, we use a pattern for inserting a larger number of coins (see picture pattern.jpg). When burning graphics, each subsequent row of coins shows greater inaccuracy than in the previous row and the image is not placed in its position. In each subsequent row, the graphic deflection is larger and larger. When the laser is restarted, the problem is eliminated and the laser starts cutting in the correct position, but again only the first line - the graphics on the next lines are again out of their correct position.
The problem of inaccurate placement of graphics on CVW coins manifests itself in both cutting and engraving process. In the case of CVG coins, this is only for cutting, because the engraving was applied first and in several steps, so the deviation of the location of the graphics was small.

Does anobody has idea, what can cause this behaviour? Thank you in advance for your tips.

[Pete Cyr]

There could be several thing impacting your issue.

1. With the machine off move the gantry and head by hand through the complete X and Y axis(one axis at a time) - it should move smoothly with out binding - the drag should be uniform in the pressure you apply to move the gantry and head
If it is not smooth - clean and lubricate the rails
2. Recommend you perform the calibration in this thread viewtopic.php?f=105&t=3528&hilit=100mm

[Dave Vigness]

I'll second double checking your calibration. For me, I make as large a square as I have bed size or paper for. Old wrapping paper works well. Cut as large a square as you can, and put a dashed line down the center,

Compare the X and Y measurements against the what it should be and input the data accordingly into RDWorks.

Now fold that big piece of paper on the dashed line. If the corners match, your gantry is square to the Y axis. If they don't, that's how much you are out of square by. That is a physical belt or gear adjustment, not a software adjustment.

[Martin Hladis]

Thanks a lot guys for your quick answer. We we'll check all your suggestions, step by step, and I'll let you know about outcome.

[Jeffrey Aley]

In addition, I'd check your speeds and accelerations. Try reducing your idle speed and acceleration (this is the accel and speed used when the head is moving between cuts). If it is too high, you could lose steps and therefore become increasingly inaccurate.