Inconsistent Engraving

[dmotiempo]

Sometimes my k40 laser doesn't engrave portions of anodized aluminum correctly. Other times, using the exact same settings, it'll engrave perfectly. I'm looking to upgrade some parts but am not sure if this is a software problem, power supply (mine is the original pwm), or a tube issue.

I'm leaning towards power supply since I've seen some other issues with it but I could see it being software too (using corel laser). There is a known problem with the tube - the cooling water will shock the shit out of you if you touch it when the laser is firing. I do believe the problem was present before the tube issue though.




Not sure why the image isn't displaying but here's the link: http://imgur.com/fe9m1pr

[DonL]

I had shock issues with the water but it went away when I improved the ground connections. This could also be why you are getting inconsistent engraving, I suggest that you make sure the amp meter connections are good, as that is the tube ground, and that your cabinet is grounded. If you have a poor ground anywhere, all kinds of weird things can happen. I also tuned of PPI as I found it affected engraving so I was getting light and dark areas because the power output was changing. Unchecking PPI stopped this issue and I seldom cut anyway.

[dmotiempo]

Ahh thanks, I guess I really need to check the grounds. I engrave 99.9% of the time, have you upgraded to dsp and if so did this also help with the quality of your engravings? I'm currently using the stock software (corellaser) and I dont think there is an option to uncheck ppi.

[DonL]

Ahh thanks, I guess I really need to check the grounds. I engrave 99.9% of the time, have you upgraded to dsp and if so did this also help with the quality of your engravings? I'm currently using the stock software (corellaser) and I dont think there is an option to uncheck ppi.

I upgraded to the LO-X7 and it has improved engraving because I better control, I also have Network Ability now, the improvements in engraving are mainly because I can use a rotary table to engrave cylindrical objects, and the resolution is slightly better plus I have a Z Table now so I can raise and lower the table, before I had to remove the fixed table then shim up the object to the right height, it was crazy. The clamp in the table was a waste of time, jammed up all the time, too small to hold much and was useless, the Z Table is mainly why I upgraded.

I am looking an RDCAD based 60 watt 500x300 system with a Z table that can travel 13 inches and is 4500DPI for my next machine or just build my own bench model, with the experience of upgrading I know I could design and build my own using products sold here...

[dmotiempo]

Checked the grounds today - all wiring within the machine seemed perfect except for the actual plug and receptacle. Reseated the plug and the shocking seemed to have gone away. Gonna replace it with a high quality one (salvaged from an old HP printer) tomorrow and see what happens.

[DonL]

Checked the grounds today - all wiring within the machine seemed perfect except for the actual plug and receptacle. Reseated the plug and the shocking seemed to have gone away. Gonna replace it with a high quality one (salvaged from an old HP printer) tomorrow and see what happens.

Let me know... You can also run a wire from the cabinet ground terminal to a cold water pipe if available or to the screw on the cover of your wall plug as the metal housing inside the wall should be grounded but you never know
A good cord ground will help I am sure.

[dmotiempo]

Grounding made no difference at all! Checked the building grounds - everything is perfect.

[DonL]

Grounding made no difference at all! Checked the building grounds - everything is perfect.

Bummer... You do have a ground wire on the case not just the ground in the power cable right?
also, the ground from the laser tube has good connections, and if you are using a digital milliamp meter, try bypassing that for a test, it seems to me that you are loosing ground somewhere, could even be in the power supply. also make sure that you are in focus, I had a few cases where the image was mostly OK but had faint areas and it was the focus. it is better to be short on focus than long. What I mean is, if your focal length is 38.1mm and you are at 38.5 you can get weak areas, but if you are at 37.5 it will be consistant.
this is because there is no columnating after the focal lense.

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