Merideth Module: Is This Normal?

[daguin]

OK I built my first blu-ray with a Merideth module with a glass lens. I will admit that it is a BURNIN' BEAST, but is this limited focal distance normal?

The farthest I can get a focused beam is about 12 inches!! I sanded the adapter down to 4mm. I pressed the diode until it was flush with the back surface of the adapter. I have to screw the lens in all the way to get it to focus at 12 inches.

Don't get me wrong, the power is nice. I'm actually torturing this one to see what kind of output I can get for a later project. However, I like to shine my lasers around. I like to be able to focus to infinity. If this is what I can expect, I'll probably sell this one to someone who likes to burn stuff and build a new one for myself with an aiXiz (or a new custom IgorT lens).

Does the Merideth acrylic lens have the same focal distance?

Peace,
dave

 

[flogged]

Apparently it can be a problem. I've never had this problem.. but then it turns out I've been installing the diode backwards in the adapter (lol). See this thread, especially the second page:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1212443308

You may have to sand the 5->9mm adapter down more.

 

[daguin]

Apparently it can be a problem. I've never had this problem.. but then it turns out I've been installing the diode backwards in the adapter (lol). See this thread, especially the second page:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1212443308

You may have to sand the 5->9mm adapter down more.

I don't think that I would call it a "problem." It certainly is NOT a problem if you want to burn stuff. This thing is throwing photons! It is just not what I like to use my lasers for. I think this will be important information to know when counseling neophytes.

Peace,
dave

 

[flogged]

My opinion is not being able to focus to infinity is a problem. It's easy enough to fix, though the adapter needs to be modified depending on the diode. I think the Meredith stuff was originally designed to work with 9mm diode cans.

 

[daguin]

I think the Meredith stuff was originally designed to work with 9mm diode cans.

Yes. Hence the need for an "adapter."

The adapter could be sanded down farther or the diode could be seated more deeply in the adapter. Are there any other changes that could be made? Have others tried either of these options?

Peace,
dave

 

[Hemlock_Mike]

Re: Merideth Module:  Is This Normal?

Did you remove the lens? IgoreT says that the flat side should face the LD. I don't know.

Mike

 

[climbak]

Re: Merideth Module:  Is This Normal?

jayrob may be able to help. He has noted the need to shorten the adapter with his red builds.I am having the same problem right now, but my driver hasn't come in yet and I don't want to screw around with it too much until I have a stable connection to deal with.

 

[daguin]

Did you remove the lens? IgoreT says that the flat side should face the LD. I don't know.
Mike

I didn't remove it, but I checked it anyway. It is flat side to the diode. I even tried changing it with a lens from a different Merideth module. Same/same

jayrob may be able to help. He has noted the need to shorten the adapter with his red builds.I am having the same problem right now, but my driver hasn't come in yet and I don't want to screw around with it too much until I have a stable connection to deal with.

Well, you may be the one to try something else with the adapter then. Unless Jayrob comes in with the answer. It is a great burner. It has no distance.

It might still be me. I'm pushing this one pretty hard. It might not last anyway

Peace,
dave

 

[VW]

Re: Merideth Module:  Is This Normal?

What's it like under your smoke machine?

 

[daguin]

What's it like under your smoke machine?

I haven't tried it yet. My wife's allergies are acting up. Fog coming from the garage would not be good for her. I'll try it after she goes to bed.


I sanded the diode retainer down another .7mm. That allows the adapter to screw in closer to the lens. I figure the diode is now no more than 1.5mm from the bottom of the diode retainer. The lens surface is another .85mm into the diode retainer. That makes the diode 2.35mm from the surface of the lens. The focal point moved out to about 17inches.

I can't really make this one any closer than that. I would have to sand down the adapter with the diode in it. There is only about 1mm from the top of the adapter to the top of the diode now anyway.

So I guess, with careful measurement, That we could get the diode as close as 1.35mm from the surface of the lens. That is with having the diode protected inside the adapter. If we sand down the adapter far enough to allow the diode to protrude from the adapter, we could get it another .85mm closer (.5mm total distance). However, that leaves no room for error. It probably wouldn't be very good to smash the top of the diode into the surface of the lens. Plus, somewhere along in there, we are going to run into the height of the fully compressed spring.

Peace,
dave

 

[jayrob]

Re: Merideth Module:  Is This Normal?

[quote author=Hemlock Mike link=1212879018/0#5 date=1212881646]Did you remove the lens? IgoreT says that the flat side should face the LD.  I don't know.
Mike

I didn't remove it, but I checked it anyway.  It is flat side to the diode.  I even tried changing it with a lens from a different Merideth module.  Same/same

jayrob may be able to help. He has noted the need to shorten the adapter with his red builds.I am having the same problem right now, but my driver hasn't come in yet and I don't want to screw around with it too much until I have a stable connection to deal with.

Well, you may be the one to try something else with the adapter then.  Unless Jayrob comes in with the answer.  It is a great burner.  It has no distance.

It might still be me.  I'm pushing this one pretty hard.  It might not last anyway

Peace,
dave



[/quote]

Dave, it will be able to focus to infinity no problem. There's just a little extra thing you have to do....

First, you did shorten the 5.6mm adapter correct? Check here:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1212443308/12#12

Now, the 'skirt' (where the spring touches) on the piece that houses the lens, sometimes must be shortened as well. Carefully turn it upside down and let the lens come out like this picture:

Then machine/sand/or grind the 'skirt' about 1/16" shorter, or more....as long as the spring still has something to fit into.

I find that if your careful, the lens can be removed and replaced in this manner, without even having to touch it!
Jay

P.S. I am looking for another member who can verify my findings...that the Meredith glass lens will give you a 30% increase in power for a blu-ray, when compared with an AixiZ acrylic. (plastic cut away) - 20% increase with the reds. (Gazoo has found the same with the reds)

 

[TheGr8Revealing]

the 803T needs to be all the way into the adapter. it cant just be flush with the back of the adapter. Needs to be all the way into be able to focus to infinity.

 

[jayrob]

Re: Merideth Module:  Is This Normal?

the 803T needs to be all the way into the adapter. it cant just be flush with the back of the adapter. Needs to be all the way into be able to focus to infinity.

Doing that would solve both of the things that I do. Shortening the adapter, as well as shortening the 'skirt'. (which hits the 'inside bottom' of the module case, if not shortened) If you look inside the module case, you can see that it is beveled toward the bottom (where the 'skirt' would hit), not allowing the 'skirt' to go all the way down.

But since I always press the diode only flush with the back, I have been doing these 'optional fixes' with good results...
Jay

 

[climbak]

Re: Merideth Module:  Is This Normal?

How do you push the diode all the way in? It was a pain just getting it flush with the back. I'll have to look around for something to push it in with.

 

[TheGr8Revealing]

How do you push the diode all the way in? It was a pain just getting it flush with the back. I'll have to look around for something to push it in with.

i use a dremal and bore out the hole in the adapter slightly (to the point that the diode can just slip all the way in). Next i take my wire clippers and squeeze in three places on the brass part of the diode 120 degrees apart to cause slight protrusions from the diode. This allows you to push the diode in with enough of a tight squeeze that it wont slip out on its own. However you will still be able to remove it very carefully if you wish.

 

[daguin]

the 803T needs to be all the way into the adapter. it cant just be flush with the back of the adapter. Needs to be all the way into be able to focus to infinity.

This was the answer I was most afraid of. Disassembly and figuring out how to push it in farther.

Once more . . .Into the breach!

Peace,
dave