20 Diode Modules

[Stuka]

I just want to see the array going full blast.

Yeah - what he said!!!!

[planters]

I've been in Boston for a few days and it will be some days before I take some beam shots. However, I was successful with the retaining spring replacement on both the large first stage arrays and they work very nicely. Even so I expect that beam combining will be a bear. 20 diodes through the first stage to 4 parallel groups then 4 groups stacked by the 4 mirrors of the second stage array to one beam then reflected through a reducing telescope to less than 8mm to fit on the scanner and then repeat for the second module. Oh boy.

The water blocks that back up the TEC coolers are probably optimal as they are. The Iwiki pump, an RLT 20, has a MEASURED flow through the two parallel heads of 5L/min. each. This is 80cc/sec=320W/C. So even with the blue module maxed out with 200W/diodes+600W TEC+30W environment=830W or a delta of 2.5 C. The step difference between the two sides is only 1.25C and so the difference across the smaller region of the diode array is somewhat less than this. This is relatively insignificant. Nevertheless, if you wanted to reduce this number further then the best method would be to increase the flow. Simply enlarging the 3/8 tubing to 1/2 inch would more than double the flow and cut the differential proportionally. I chose not to do this because of the increased weight and stiffness.

[LaNeK779]

thank you very much for all this info!!

[planters]

I am making steady progress, but I was correct that aligning 20 diodes would take some time. The new tension springs are much easier to use and are very stable. Except for one or two of the knife edge mirrors where the set screw threads were cut less carefully and have approximately 200u rad. drift. The knife edge arrays are very stable. The alignment process is iterative. First you fine focus each diode's collimation lens on a far field screen, then place the first knife edge array and group each five diode horizontal strip at right angles to the module and spaced the same 18mm vertically apart as are the diodes in the array. Next, insert the second knife edge tower. Bring the four groups down to the right angle and out to a far field mirror (second surface bathroom tile) and then project the far field image back to the module. Now it is much easier to see and adjust small errors in focus and alignment and so you begin the process focus/align focus/align etc...

The Vashio 532 is operating at 1.0 watts (measured) as a comparison to the 445 array operating at 7.0 watts (estimated). The far field patterns are similar and at 36 meters on the side of the tree are approximately 75mm in diameter.

As you can see, the array is still operating at room temperature and will need a 2:1 reducing telescope to fit on the scanner. Next comes the red module which will also need a similar reducing telescope (optics ordered). Although it seems like a lot of work, this is a LOT of fun.

More pics:

[flecom]

[allthatwhichis]

HOLY sweet Jesus!

[buffo]

It's already been asked, but seeing as there hasn't been an answer yet, I'll ask again:

Is there any chance we'll be able to see this awesome rig in person at SELEM this summer?

Adam

[mophead]

I don't think I can make SELEM this year, **BUT** i might drive straight there, have a look and go straight back home in time for work if you will bring that monster.


c'mon, plz.....

[planters]

I AM planning to come to the SELEM unless something unexpected comes up. I will have to fly out of Logan and as this projector was designed to be a semi-permanent installation it's bulky. And maybe a little delicate? I just don't think it is practical to bring it. I will continue to post pictures and maybe if there is ever a LEM near Boston I can bring this projector or version 2.0. Thanks for your intense interest; it's fun to read.

[laser_freak]

Another reason for a NELEM!