P73 and 2FL lens

[neutrino]

Thanks.

Sorry the pics are not of better quality. I only had my phone to hand.

I actually ordered enough lenses to do the blues too. As I am actually happy with my two current blue satellites I figured I would use these extra lenses to build two more modules giving me 4 satellites.

Like I said these are for only beams.

I intend on dialing these in more so to make everything nice and tight - well, so at least the two diodes match.

I didn't take any near field measurements - I will do this tomorrow.

I have some heat shrink on order (ran out of what I had). Should be here in a couple of weeks then I can tidy everything up.

I'll try and do some more tomorrow, if not over the weekend.

Cheers
Rich

[neutrino]

What glue should I use to glue the lenses to the mounts? I have a hot glue gun - which would allow me to reposition if I really had to. I also have some 5 minute epoxy - which would be a permanent fix.

Cheers
Rich

[planters]

I am not a big fan of hot glue for optics for two reasons. Firstly, the glue hardens quickly and so you have very little time to adjust the optics on their mounts. Also,as the glue hardens, it does so before it completely thins out and so the resulting bulk often prevents a well machined mount from squarely supporting the optic.

Epoxy is not permanent. An optic held with epoxy can easily be removed. You can soften it with heat by contacting a metal mount with a soldering iron, a short blast with a mini torch or placing it in an oven for a few minuets. Or, if you're patient, apply a generous dab of methylene chloride ( paint stripper) to the exposed adhesive and it will turn to snot. Epoxy is widely used by most optics manufactures and although they probably use a higher grade ( like the epoxies marketed by Master Bond), the 5 minute type available from the big box stores is fine for amateur work. The gel type is easier to use.

I like silicone RTV when you are only retaining an optic. Although this is less rigid than epoxy, it is easy to push an optic out of it's mount with your finger and if the surface that had the silicone on it is not critical then scrape it off with a razor in a few seconds.

[neutrino]

Epoxy it is then. Thank you for the explanation. It clears up a few things I never knew about glues!

Cheers
Rich

[CDBEAM]

Nice design and build Mr.N !! That is the first I have seen Dave's new mounts in action. You MAY want to reverse your Plano Concave lens 180 degree. Although.... with the first lens in this " Plano facing the diode" orientation, the LD has increased exposure to back-reflection...I find one can get a better beam quality with that set-up......and I have had no problem with BR.

And YES...please cover the P73 +/- pins !!! I have sent a few diodes to the LED realm with a momentary disconnect...and a direct short would do the same thing !!! in about .001 seconds !! Yikes !!

BEAM

[neutrino]

ooops well spotted! good thing i haven't glued any thing yet. i'll swap it round tomorrow.
As soon as the heat shrink arrives they will get covered

cheers
rich

[planters]

Beam,
I haven't been too concerned about back reflections because the ROC of these short focus neg lenses is so steep that I suspect the intensity at the diode is actually lower from the curved surface than from the plano surface. However, regarding the performance, how noticeable have you found the difference in beam quality with the two orientations?

[CDBEAM]

Mr.P,

It has been quite some time since I was experimenting with this particular aspect of Plano concave orientation. IIRC....with the concave surface facing toward the LD....there was a slight more presentation of vertical wings....and MAYBE...the divergence was not quite as tight !!... I suppose I need to have better record keeping...but I DO remember that the Plano should face the LD. I would suggest that members try both orientations....and drop a note here.

I have found the distance between cylinderical lenses is critical....like =/- 0.1mm can make a difference. So....take your time....do not be in a hurry....you will locate the " sweet spot " !!

I have only run trials with the Kiyoukan GB 6X lenses.....but I have not noted this off-axis geometry with these optics.

BEAM OUT

[neutrino]

I have lost power on my P73! What currents are you driving these at safely? I don;t want to mess with TECs but will have a fan blowing over the module once completed.

I have one spare P73 I will swap out (well not really spare it was for he other projector - so I still need to order another) but I want to make sure the current is set properly first

Also what is a safe current for the A140 blue diodes?

Thanks
Rich

[badger1666]

the power on these dives like a rock unless you tec them, mine are tec cooled to 18deg,c and run at 1.2a no problem
you being in a hot climate dont think i would go over the stock drive current unless cooled