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What do I need to fix this part of my laser

MarkR123

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My Sanwu pocket had a problem. As I was focusing the lens, I noticed it no longer focused. But as I continue turning my lens end counterclockwise, I actually unscrew the copper module from the stainless host. There is some gray residue on the threads. Do I need thermal adhesive here?? Any recs appreciated.
 

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Richie89

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I don't think you need any thermal adhesive if it wasn't already on there. Hmmm I know the residue is just shrap metal if that makes any sense, at least on all my flashlights the threads will accumulate this residue over time, it won't harm it. I have no idea why it won't focus :( hopefully someone can answer this question. Maybe the lens separated from the thread somehow? Unfortunately I'm not familiar with the sanwu silver series. Sorry I couldn't be more of a help.
 

94Z28

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That picture is dim so I cannot tell what you have on those threads, from my PC it almost looks like corrosion but obviousy that shouldn't be the case.

If your lens won't unscrew it may be from sanwu's extremely tight tolerances between the lens barrel and module; or it may be because the o-ring on his barrel has broken and seized in the module threads.

While the module is out, break the lens free... It's really the only thing you can do.. once the lens is free and moving, tighten the module back up.
 

MarkR123

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This copper module is threaded on both ends. One end has the lens which is adjusted by turning it counter clockwise. The other end screws into the host. There is more friction in the lens threads than the host threads. So if I try to focus the lens, the entire copper module unscrews.

I can still focus the lens, if I have enough copper showing that I can hold it with my thumbnail to keep it from unscrewing from the host. Then I can unscrew the lens.
 

RedCowboy

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It's helpful to include several pics of the item, from different angles, so we know what we are looking at, that and/or a more detailed explanation.

I could recommend bonding agents, thermal or not but I don't want to suggest the wrong thing.

-----edit-----

Ok you have the user grip unscrewing, you could clean the treads and use some Loctite on the part that is not meant to unscrew, I would use non permeant Loctite.

I don't know if there is any outgassing as the Loctite cures, but you may want to cover the lens or remove it if possible and use a temporary plug while the Loctite cures.

Lenses and diode windows are notoriously hard to clean and can attract airborne particulate.
 
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BobMc

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That exact thing happened to one of my pockets once. What I did was put a few drops of penetrating oil down the threads and than very carefully wrapped a whole bunch of paper towels around the threads and around the head ( lots made it really thick ) than took two pliers and squeezed and twisted both parts. Mine broke free did minor damage to the threads but not enough to stop them from screwng back in also put two small scratches on the head but very small so that's what worked for me? But be careful. There was no Thermo compound on threads so I didn't put any on. If that's works ( or something else ) when you get the head off , I took a plastic tooth pick and retighten the lens to the head. It's still gets loose every now and than but the tooth pick works again.
 
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RedCowboy

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A little Teflon tape could do the trick without a mess.
Also I have used the trick of scratching a line down the threads then using a bit of force, but that is not the proper way, cleaning the threads and a little Teflon tape sounds good, it's not a major part of the cooling surface is it? If so the a mounting type heat paste, I use Fujik B.A.B. 900

This goes on like thick toothpaste and dries firm like hard rubber.

http://www.ebay.com/itm/50ml-Thermal-Fujik-Silicone-Adhesive-Glue-Grease-Coupling-CPU-Heatsink-Compound-/231568498760?hash=item35ea8ee048:g:UmoAAOxyuDpSGZDl
 
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BobMc

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Oh, I forgot to mention after I got the head off I cleaned all the oil off didn't want it to get on the lens, it happened a couple of months ago and my pocket is alive a well. Hope that's helps!
 
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MarkR123

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So this pocket laser has 3 major components. The stainless host. The copper module containing the diode/driver. The stainless end cap containing the lens. The copper module is threaded on both ends as seen in the pics. The end that screws into the lens cap has an o-ring; therefore, this end of the copper module is under more friction.

When this is all assembled as in the first pic, I can adjust the lens for focus by turning the end lens cap counter clockwise. Since the lens cap has an O-ring on the copper module, it is under more friction. This causes the entire copper module to unscrew from the host instead of unscrewing the lens cap.

I need a way to increase friction on the threads in the host. I assumed it had to be thermal, but I am a novice with lasers. There is a gray flakey compound on the threads that Sanwu used. I'm not sure what it is. Do I need thermal compound? Can I put pipe sealant tape on here (will it hold up to the heat)? Can I use thread sealant the solidifies?

Any help is appreciated. That's the best I can describe the problem. Thanks guys.
 

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MarkR123

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So after messing around with this a while, I figured out I could snug the module down inside the host. I don't have a specific tool. I just used a tacky glove to hold the module and snug it tight. Put the lens cap back on and so far so good.

So should I still get a thermal paste for the threads inside the host? Thanks
 

ElectricPlasma

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The thermal paste is not necessary, I guess it could be useful as SS isn't as heat conductive as some other metals but the threading should be good enough for heat transfer. I would think that using the thermal paste would just create more of a mess than it's worth, I personally hate working with that stuff. If I were you I would use some rubber/rubber gloves to get a good grab on the module and thread it as far as it can go to keep it in place. That grey residue might be some kind of adhesive that Sanwu used to keep the module in place, but I have the same laser and never saw anything like that on my module.
 

RedCowboy

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That solidifying thermal paste is only for something that is meant to stay put, it's best to keep it as clean as possible around your lens and diode window, I was thinking that was a stainless steel skin over the thumb wheel that the lens stays screwed into.



 
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MarkR123

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Thanks for all replies and tips. Some of the gray flakes (whatever it is) was on the threads under the lens cap and some actually on the lens and down around diode. I carefully cleaned all of it. I took a low speed wire brush to all copper threads and made it shiny new again. Snugged it up with rubber gloves, put my lens cap back on and everything is fine. Thanks!!!
 

BobMc

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Glad it worked out for you, those pockets are great little lasers. Have fun,enjoy!
 




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