Loose Optic Presents As Mechanical Backlash And/Or Offset Issue
A loose mirror or focus lens can mimic mechanical backlash or scanning offset problems; this article explains the symptoms, root cause, and checks to perform.
Preface: A Loose Optic (Mirror, lens) can present itself as excessive mechanical backlash and/or scanning offset value issue. This article will address the symptom and possible causes.
Client was in the middle of engraving a water bottle on a rotary an noticed the double image effect as shown in the image below:
The client then disabled their scanning offsets and bi-directional was set to off for the fill layer. The project was then sent from Lightburn again and re-engraved on the same tumbler. The results improved, as shown in the image below:
The next test was to run some tests on the existing scanning offsets. The client set up a small rectangle engrave with a low LPI like 40 with bidirectional back on. The client adjusted the stock offset value from .105 to .8 with no noticeable improvement in the edge quality. The ends of each engrave line were also very curved which would not be an offset related issue.
While it looks like a scanning offset value issue, it was actually mechanical. The Focus Lens was not secure in the Laser Head. So, as the head traveled left and right to engrave, the Focus lens would shift in the head, shifting the beam and mimicking a large mechanical backlash or offset issue.
Mirror 3 was loose on the laser head.
In this video you will be able to hear what a loose Focal Lens sounds like.
Lets also check the mirror 3 retaining ring/plate, bearings on the laser head (Nova Series), and the that laser head is secure to the trolley plate (Grab the head and try to wiggle it).
Nova Series
Retaining Ring for Mirror Three Laser Head Tube Receiver Bolts For checking the bearings on your Nova series machine, please check out this guide.
Odin\Bolt Series
Retaining Bolts for Mirror 3 Laser Head Rear Mounting Bolts (Also check the Lens Plate Knobs on the front)
(Note that you must carefully remove the laser head from the gantry bar by unloading the spring loaded lower bearings to access the mounting bolts)
The bearings on your Bolt an Odin series machine are spring loaded and do not have an adjustable tension setting.
Still stuck?
Fastest response times in the industry from our US-based support team.