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18~20mm Laser head w/ air assisted

Posted: Wed Dec 04, 2013 5:32 pm
by TimAustinTX
I installed the new head and the lens is not much closer to the reflector than the head that came on the unit.

The new focus point is very high and above the exhaust intake.

Is there something I am doing wrong? I am concerned it is so high not that I can not laser items that are more than 1 inch thick.

Thank you!
Tim

Re: 18~20mm Laser head w/ air assisted

Posted: Tue Dec 17, 2013 4:36 pm
by Mangus
The new head moves the focal point closer to the head by 8-10 mm. Pull out the stock table and use something else to hold your part. A power (or manual) adjustable Z table is ideal. I like my LightObject table, except that it does reduce your work area by ~1.5" in each axis, but that's still more than the stock table allows.

Re: 18~20mm Laser head w/ air assisted

Posted: Wed Dec 18, 2013 9:39 pm
by TimAustinTX
The issue I had also was the focal point is raised up so high that the cross beam would run into the item I am trying to cut or engrave.

Is there a fix for that?


Thanks!
Tim

Re: 18~20mm Laser head w/ air assisted

Posted: Thu Dec 19, 2013 10:13 pm
by Mangus
That's odd; that indicates that the lens in your machine is of unusually short focal length. Did you test the focal length with test cuts? If it's true, and your laser head is assembled correctly,, I'd say the best fix is a different lens.

Re: 18~20mm Laser head w/ air assisted

Posted: Mon Dec 23, 2013 11:35 am
by Tech_Marco
Just a reminder, some K40 may comes with 38.5mm focus lens instead of 50.8mm
By replacing the new laser head, the focus point should be 10mm raised up because the barrel is shorter.
But if you add a piece of honeycomb, it should offset it and provide good enough focus point

Marco

Re: 18~20mm Laser head w/ air assisted

Posted: Fri Jan 17, 2014 1:26 pm
by rushmore1305
also make sure you put the lens in the correct way, there is a flat side and curve side, curve side away from mirror

Re: 18~20mm Laser head w/ air assisted

Posted: Mon Feb 10, 2014 3:57 am
by chuckels431
rushmore1305 wrote:also make sure you put the lens in the correct way, there is a flat side and curve side, curve side away from mirror
The original instructions for my k40 say to install the lens curved side towards the beam. This would put it towards the mirror. Which way is correct ?

Re: 18~20mm Laser head w/ air assisted

Posted: Thu Feb 13, 2014 4:36 pm
by TimAustinTX
So I just found out what my issue was.

When I took the head apart the head did not originally come fully apart and I had the lens up too high.

Pictures would be handy in the product listing, showing how it comes apart into 4 pieces.

Tim