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ArcticMyst Security by Avery

Meredith 5.6mm adaptor Question

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Is there a easy way to get a diode into the adapter without having to hammer it in at the expense of ruining the diode? a small vise maybe?
 





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Sigh. Does anyone bother reading these threads? I've already answered this question.

I use a couple of long nose pliers to do this. One end of the jaws on the brass diode flange, the other end on the bottom of the adapter. Push one end in a little first, then the other, 180 degrees apart. You don't need to get the diode all the way in, try to get at least 3/4 of the brass bit of the diode in. It's more important that the diode be pushed in an even amount so it's not pointing at an angle.

You don't want to push from the top of the diode - the diode can and window are fragile. Push the brass diode lip/heatsink - near the back.
 
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i do read. i even tried to search it. thanks though guys.

and on a second note, depending on the diode, it does need to be pushed all the way in. Ive already done exactly what you've just explained with two sets of needle nose pliers. However, with a 803t diode, it needs to be all the way up for the lens to be able to focus the beam to infinity.
 
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Huh, can't say I've had that problem. I got most of the diode in, but the brass part was not completely flush with adapter in my case. I'm using the Meredith glass lens.

You might try flipping the spring in the assembly. Sometimes it catches on something and makes it hard to screw the lens assembly in enough to get focus @ infinity.

The Meredith stuff can be a little finicky - once you get it dialed in it works great. Also, I thermal epoxy the adapter to the back of the housing. This way is stays centered and does not rotate or squirm when you focus the unit.

Brass is soft metal, in the worst case you may have to increase the diameter of the adapter with sandpaper or a knife.
 
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good call on trying to open up the inner diameter of the adapter. works alot better. can i just buy thermal epoxy at radio shack?
 
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Oh, I also dab arctic silver around the brass diode bit and the top lip of the assembly, thermally mating the two (in addition to arctic silvering the adapter to the back of the case, centered). I figure this will help heat get out of the diode into the brass adapter, which is your first and most important heatsink.

My 803t diode, running at 85mA, does not have a duty cycle. I can leave it on, and after about 15-20 minutes the housing just gets slightly warm. I'm using the $5.00 Meredith aluminum mounting block as a heatsink around the LDC-2 adapter, thermal paste between the two. My opinion is proper heatsinking is very important is you want a long lived diode.
 
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TheGr8Revealing said:
good call on trying to open up the inner diameter of the adapter. works alot better. can i just buy thermal epoxy at radio shack?

Some radio shacks have it. I had to order the 'arctic silver' online. I really recommend it, it's an excellent epoxy in addition to being thermally transmissive. You can get thermal paste at ratshack, not glue. That would work also.

Look here:
http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm

I ordered from:
http://www.outletpc.com/c2019.html

Really recommend the arctic silver. It's permanent however. If the diode does die it's still possible to reuse the assembly, though it requires some brute force and sanding to gets the pieces apart and functional again :)

My biggest gripe with the Meredith stuff is I had trouble with the adapter not staying centered and squirming when I focused the unit. Glue will definitely fix this, though a thermal paste may work as well. Good luck.
 
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wow. Great. thanks for all the links Flogged. i'll post up my DIY when its pretty enough to be up here among the best. lol
 
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How far are you pushing the diode into the adapter? Here's a picture of how I've been doing it. This is my first 803t diode, now dead after cap discharge. It's easy to get the focus set to infinity this way, and I can usually get the focus down to 6-8 inches before the spring loaded assembly pops out. I just push the brass diode bit flush with the top of the adapter. You'll note the thermal epoxy to aid heat getting out of the diode to adapter.

803t_diode_in_meredith_adapter.jpg


See this thread also: http://www.laserpointerforums.com/forums/YaBB.pl?num=1212123438/0
 

daguin

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flogged said:
How far are you pushing the diode into the adapter? Here's a picture of how I've been doing it. This is my first 803t diode, now dead after cap discharge. It's easy to get the focus set to infinity this way, and I can usually get the focus down to 6-8 inches before the spring loaded assembly pops out. I just push the brass diode bit flush with the top of the adapter. You'll note the thermal epoxy to aid heat getting out of the diode to adapter.

803t_diode_in_meredith_adapter.jpg


See this thread also: http://www.laserpointerforums.com/forums/YaBB.pl?num=1212123438/0

I haven't installed a Merideth yet. I have two here now. However, that is NOT how I envisioned using the adapter. Here is the diagram from Merideth

Merideth-1.jpg


Notice that the 9mm diode is facing into the spring with the legs of the diode facing the rear of the module.

Here is the picture of the adapter
MIadaptor.jpg


Notice that the adapter is roughly shaped like the 9mm diode. I envisioned the 5.6mm diode being pressed into the adapter with the can INSIDE the adapter.

With it installed the way you have it pictured, It seems like the diode would be pressed up against the diode retainer and/or the lens!

Peace,
dave
 

jayrob

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daguin said:
With it installed the way you have it pictured, It seems like the diode would be pressed up against the diode retainer and/or the lens!

Peace,
dave



The adapter has a wide bottom, and a narrow top. The top points in the direction of the beam output:
5.6mm adapter.jpg

About getting focus, I have found that it is a good practice to shorten the adapter top (a little) before pressing the LD in place.

Take a look at my notes on the Meredith at the bottom right of this document: ;)
http://www.sonic.net/~jayrob/MXDLHeatsinkTips.doc
Jay
 
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Yes, definitly is backwards, which would explain why you didnt have to push your diode all the way in to get it to focus to infinity
 
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Wow, I feel stooopid. Yup, I've been plugging them in backwards! That would explain all the problems I had with the thing squirming around when I focused it - hence the need to glue the adapter into the back of the ldc case. I should have known better as the first two meredith assembies I worked with I was using 9mm cans, and the adapter is in the shape of a 9mm can.

Well, it does work the way I've been doing it, though glue is required ;)
 




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