LPC-840 discussion thread

[Pman]

I completely forgot to do the measurement! So sorry guys, life has been intervening lately.
G2 with one of my LPC-826 builds 372mW.
Acrylic from Jordan modules 305mW.

 

[VirtueViolater]

Nice,
Thanks Pman. If I'm not mistaken, seems the acrylic are basically for reds. I have been, and will continue to use them for 500mw or less builds

 

[paul1598419]

Wow, considering the difference between our two measurements, I will do mine again with a different acrylic lens. Maybe I had a bad lens, IDK.

 

[Lifetime17]

Hi has anyone tried the 2 element lens for Reds i have about six of them ..

rich

 

[Pman]

I've never even heard of a 2 element for reds. The only 2 elements I've seen are the ones Jordan sells for green.

That's why I was so surprised at how much of a drop you had Paul. I've never seen that kin of percentage difference. Maybe flip the lens around? Have seen some big differences between which way a lens is installed but I haven't actually figured any % out. I'll have to try an acrylic both ways and see what happens. It's just a guess at the moment.
As I mentioned before I wish I knew where Eitan was buying those lenses from. Almost all of my single mode pen builds have them as they don't need correction and are worth getting the most out of.
By the way, I didn't see any difference in output between the G2 and an Eitan lens on that 826 I tested yesterday. It takes testing different wavelengths to see which lens works the best to achieve what you want with our beams and dots. Personally I like the cleaned up look over raw power as I'm not big into burning. If I feel like lighting a match or something I just use a cheap Ebay 405 or 650 that I've made focusable.

 

[VirtueViolater]

Ive read something about 'Meredeth" lenses being the best For red but haven't researched them

 

[icecruncher]

Ive read something about 'Meredeth" lenses being the best For red but haven't researched them

They are, but you can't get them anymore afaik.

Unless it is this one??? http://mi-lasers.com/product/5-6mm-laser-diode-press-fit-collimating-lens-glass-2/

THis isn't the same module they used to offer, so I'm not sure about the glass lens

They came with their old modules about same the time aixiz started producing modules. They were competing - in our minds on a number of hosts with jayrob doing versions of heatsinks for both modules, like the old MXDL

But they were significantly more expensive so most people didn't buy them and instead bought the aixiz ones.

The meredith modules had a slide in sleeve to allow EITHER a 5.6 mm or 9 mm diode in the module.

Aixiz didn't have 9mm modules until a few years later as there wasn't really a need.

(I still have an unused Meredith module sitting in a MXDL with heatsink ready for something - right next to the first laser I built, also a MXDL with the aixiz module. )

 

[VirtueViolater]

Just out of boredom,
I put an acrylic lens in my mits500 build and what do you know, the spot and beam characteristics improved over all the other lenses ive tried. Will keep a watch for melting but thinking it'll be fine as my driver setting is only
800 ma

 

[CaliKirk]

I threw an acrylic on a 209 build and it didn't seem to have any melting issues, although I only used it for about a minute. Same thing with a 2.3w m140, I wanted to see the dot difference between a g2 and acrylic. Turned it on for about 30 seconds, probably ridiculously stupid but fortunately nothing happened.

Earlier in this convo I wanted to go to a source of these number claims and asked DTR about the percentage numbers and exactly what lenses are being talked about.

From DTR- "The G-2 will give 25% over the three element lens with blue and 30% with 405nm. Don't have exact numbers but it is something like 15% over an acrylic but the acrylic can only be used with lasers under 200mW or they melt and really under 100mW if you never want to replace them but they are a single element lens and do have fairly good pass specially if you find the AR coated ones which I don't see often."

 

[bdgreenb]

be careful cali. I learned how to clean diode windows the hard way. Once the lens starts melting, the fumes will completely thrash the diode window.

 

[CaliKirk]

be careful cali. I learned how to clean diode windows the hard way. Once the lens starts melting, the fumes will completely thrash the diode window.

That was a loooong time ago and like i said it was ridiculously stupid. At the time of doing that I didn't understand about what could happen if the acrylic melts . But since then I have heard many horror stories about lenses melting and now i only use G2/G7 for anything over 300mw..

 

[VirtueViolater]

Wow,
Was checking the acrylic lens i put in my mits500 build for melting/heating and realized the barrel is actually metal. Is that normal? I know I've seen pics of melted acrylic lenses where the barrel was also melted. These lenses came with a 10 Pac of modules I got from existotem. These are the same modules with the really strong springs I posted about a while back