Mitsi g71 quad

[Galvonaut]

What beam specs are you hoping to achieve with this build Andy? That's a lot of red!

[andy_con]

Around 4mm @ 1mR

[badger1666]

those specs out of an 8 banger, that i want to see, i struggle to get that out of my 4 banger ,depends on what secret lens you use i supose

Around 4mm @ 1mR

[Galvonaut]

Around 4mm @ 1mR

Pretty tight. Looking forward to following the build

[p1t8ull]

That would work for me. But what about blue?

The blues are a slightly different beast to the reds and I personally prefer the G2 lens with prisms to tame the 445's, less fiddly than cylinders and very variable magnification to dial in the desired beam. Prisms didn't work so well on the reds when I checked, heavy power losses at the angles needed to get the higher magnification, but if you are not worried about losses they may be the solution..

[The_Doctor]

Good point. I suspect the fixed ratio of expansion/divergence with the cylindrical lenses either works, or it doesn't. As I have G2's now I'll likely use prisms for blue. I don't think a bit of loss there will bother me as much as with red. I suspect red will for some time be the colour where most efficiency matters (ignoring currently the transition to new green diodes, which I will not try for some time yet). I'm currently setting up a test rig to try a sample lens for red. Nothing to report beyond that right now, so I might yet have to rethink corrections for it. All I know is apparently it is less demanding of corrections.

[p1t8ull]

those specs out of an 8 banger, that i want to see, i struggle to get that out of my 4 banger ,depends on what secret lens you use i supose

Andy and I are working on some ideas using commonly available parts, theories need to be turned into metal yet tho
One thing is for sure.. work or not, alignment of this will be a total screaming bitch of a job!

[The_Doctor]

Ouch. That's the problem, what we all need is to figure out ways to reduce that trouble. For example, while one variant of Dave's mounts allows translating a diode across its axis, that seems to me like adding error to error. I'm not saying it's wrong, but I won't go there until I have tried myself to eliminate the original source of error.

[dave]

I'm not saying it's wrong, but I won't go there until I have tried myself to eliminate the original source of error.

I await your findings then

[The_Doctor]

They might be as you expect. Or worse. Doesn't matter though, I have to see for myself. Is why I bought stuff I can use anyway, it just helps me decide what will come next.. Like what Dan and I said recently in the 'Diode Quantification' thread, it seems unlikely that significant off-axis variation exists between diodes, so the main scope is in lens and barrel fit. I've solved stuff like that before, it just remains to be seen if I do it on this smaller scale. It's only three-fold smaller or so, so I'll take my best shot.

Edit: Do you know something you're not telling me? Specifically, is there known error in coaxiality between the diode mounting bore, and the adjuster threading bore? I don't know the order of machine operations, but I'm assuming that the parts were made with no need for re-centering between those operations. If this is NOT true, then now is a VERY good time to let me know!