Has anyone tried this adjustable lens focus mod?

Lasers
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1

Has anyone tried this adjustable lens focus mod? Any thoughts on it? https://www.youtube.com/watch?v=CC9kGOlxlHs

2

This is a neat mod

3

One problem however is that both sides of the lens are open to the air, will probably get dirty very fast.

4

Would be neat to make it as a telescoping tube mechanism to handle the dust problem, then the air nozzle could also be integrated. If I have some time today I might try to 3D model a concept of that

5

It really isn’t adjustable focus.The focal lenght remains the same, it just allows you to place the lens as clocse to 50.8mm as you can without a z table.

6

Exactly

7

I completely agree with the telescoping tubes. This is how it works with my machine. However, you might be able add a small air tube the blows clean air onto the surface of the lens to keep it from gettting dirty.

8

I was just thinking that I could design the tube in such a way where the lends snaps into position, but I wonder if the chinese lens gets hot and might melt the 3D print lol. I guess if the lens is clean it should not heat up, what do you guys think ? if it works then I could 3D print a lens marker on the outside of the tube to reference for aligning the focal point easily since I would want the air nozzle under the lens.

9

i got one of these off ebay works great

10

Moving the lens vs moving the table.

problem is with this system is you still need to lower the table by the material thickness. so not a solution for our K40. (not much space to move the lens up)

11

That’s a good point about not being able to move the lens up very much. But even a few millimeters should be helpful for cutting different thickness of plywood, for example.

Here’s a relatively small adjustable head with air assist (maybe the lower part could be 3D printed and attached to the existing K40 head): http://www.aliexpress.com/item/CO2-Laser-Head-Laser-Engraving-Cutting-Machine-Engraver-High-Quality/32355361516.html

Someone started to make the holy trinity of adjustable lens height, air assist, and dual laser pointers: http://www.thingiverse.com/thing:781204

I see plastic lens holders on Thingiverse so I don’t think it should be a problem. I should be getting a K40 later this month and want to try this mod :slight_smile:

12

I did think about all that when I design my air assist last year. (3 functions in 1)

13

Hey cool! I’ll give it a try, thanks.