Exact spec of lens27

[-bart-]

Using a aluminium baseplate with brass mounts, with steel screws might not be the best way to start.

[Solarfire]

Using a aluminium baseplate with brass mounts, with steel screws might not be the best way to start.

For one.. (Unequal thermal expansion/contraction)




Temperature stabilization is probably the most important factor in multi diode setups. Using the base plate as a heat sink for TEC’s is actually not a good idea either. Here I use the natural law of physics (heat rises, cold falls) and place the TEC on top of the diode mount (cooling side down) with an extra heat sink on top, a much more effective setup. Placing the Diode, NTC and TEC in very close proximity to one another is also very profitable.

For that matter, any punctual thermal inductance into the base plate is a no, no! Less critical is an ambient temperature change, unless it gets out of hand.

[sbk]

For one.. (Unequal thermal expansion/contraction)

Temperature stabilization is probably the most important factor in multi diode setups. Using the base plate as a heat sink for TEC’s is actually not a good idea either. Here I use the natural law of physics (heat rises, cold falls) and place the TEC on top of the diode mount (cooling side down) with an extra heat sink on top, a much more effective setup. Placing the Diode, NTC and TEC in very close proximity to one another is also very profitable.

For that matter, any punctual thermal inductance into the base plate is a no, no! Less critical is an ambient temperature change, unless it gets out of hand.

I'm not sure a single heatsink to cool a TEC on top of the diode mount is sufficient... After an extended period of run time, the heat sink will get too hot to sufficiently cool the hot side of the TEC, and then the TEC will not be efficient any more. I will at least add a fan on the heat sink.

You will not have any problem if you cool the base plate which is used to cool your TECs

[Solarfire]

I'm not sure a single heatsink to cool a TEC on top of the diode mount is sufficient... After an extended period of run time, the heat sink will get too hot to sufficiently cool the hot side of the TEC, and then the TEC will not be efficient any more. I will at least add a fan on the heat sink.

You will not have any problem if you cool the base plate which is used to cool your TECs

There’s actually not any major cooling going on here, thus very little heat dissipation. The key here being that the diode, NTC, TEC are properly located and aluminum mounts are used (since these have a low thermal resistance). The diodes used here (no matter if 660s, 445s or whatever build in a 5.6 can) barely generate enough heat to do anything except to throw everything out of alignment if not dissipated away from the base plate. For this propose I use 15mmx15mm TECs (max 3.9W) on the same sized mounts where the heat sink covers 8 of these, It’s basically the lid to the module. Works fine without extra ventilation, the heat buildup is close to none.

It takes much more power to temperature stabilize the base plate. It’s much easier to stabilize the heat source and to keep heat from reaching the base plate then the other way around.

[Badpip]

Indeed, these lenses I have give a spot size at aperture of about 1 x 1.5mm with about 1 mrad divergence, however the catch is the diode's position relative to the lens needs to be tweaked to stop artifacts around the main beam.. I guess it's a inherant issue with any lens with such a short focal length..

I have all the hardware to achieve this here, however there was a bit of a issue with one of the parts.. Rather than wait another few weeks for a replacment part, I made up a jig to allow me to remachine these bits without too much pain.. After remachining, it is pretty easy to get a very nice beam profile.. Hopefully I'll have all the bits tidied up in the next few days :-)

Once I get a chance, I'll take some pics and post them here :-) Chris, I bet your itching to see ;-) I'll try to get some pics later today :-)

Any news on these Dave?

I'm building a triple LOC, those beam specs would be perfect for matching a 532 and 473 - 2 diodes knifeedged and 1 through a pbs would give a 2x1.5mm beam

/Thomas

[JohnYayas]

What's the word on the tip top lens?

[badger1666]

What's the word on the tip top lens?

awesome! thats the word on these lens.
they give a 1mm x 1.5mm beam , i just put 6 x 640nm knife edged
and got a 3x3.2mm @.98mrad beam
but there is a down side , you have to use a special diode mount that dave has
as the lens need perfect center to work properly,and daves mounts allow you
to shift the diode around a little to get the beam perfect, they are a little fiddley
to setup but its worth the trouble

[badger1666]

Any news on these Dave?

I'm building a triple LOC, those beam specs would be perfect for matching a 532 and 473 - 2 diodes knifeedged and 1 through a pbs would give a 2x1.5mm beam

/Thomas

you wont need no pbs with these lens , loc beam is 1mm x 1.5mm
3 loc diodes = a 3x1.5 beam

[p1t8ull]

.. and these lenses also give a very clean beam, cleaner than the 27 and better than any other short FL collimator I have tried.

[andy_con]

are they bare lens or are they mounted?