405nm Lens from Lasers4U

UPDATE 9/20/09 -- With me heading out on vacation and starting the new semester, it has taken a bit to get this straightened out. The delay was mostly from my lack of attention to the matter. However, I have finally received the new o-ring for the module. I installed it last night. The new module has completely dealt with the "looseness" of the module. The module operates smoothly and "tight."

Thanks for all your help, Will

**NOTICE THE EDIT BELOW IN THE "CONS" SECTION**

After a mention in another thread, I picked up one of these modules for the violet laser from "Lasers4U" on eBay

405nm Laser Module Housing with Glass Lens Knurl adjust - eBay (item 120452292619 end time Jul-26-09 07:18:36 PDT)

I left my camera at a friend's house so no pictures, but this will be pretty short anyway.

The module arrived in a small plastic bag inside a padded envelope. Shipping was fast.

The module is 10.5mm in diameter and 19mm long. The lens is set very deeply in the lens holder. It has to be in order for this short focal length lens to be close to the diode. The lens holder has an O-ring near the top that "seals" the lens nicely. The lens was clean and free of visual flaws. The diode seat is smooth, but "deep."

Pro's = This does appear to be the same lens that is being used by LarryDFW and Jayrob. I did not do a "switch" comparison because of the difficulty changing diodes and the lens holder is NOT compatible with the aiXiz module.

However, I built two 6X's and set both drivers to 200mA. The 6X with the acrylic lens puts out 175mW. The 6X with this module puts out 220mW. This is not quite the 26% increase, but they are not the same diodes. The beam profiles are visually identical to the other lenses.

Con's = The module is only 10.5mm in diameter. It is to thin to fit the heat sinks that are already being made by members here for the aiXiz. It does fit snugly INSIDE an aiXiz module. It required a bit of effort and the use of some channel locks, so it is a nice tight fit. This is how I installed it. I soldered leads onto the diode pins and snaked them through the hole in the back of the aiXiz rear portion. I left the "knurled" focus ring portion of the module sticking out.

The diode seat is very deep. I did not measure it before I set the diode. However, the diode is set so deep that there is about a 2mm recess left. This makes soldering to the diode pins difficult. Directly soldering the driver to the diode is impossible. I would also recommend that the leads be soldered BEFORE setting the diode.

**EDIT** I've discovered that the "loose" lens holder issue was simply that the O-ring on my particular module was damaged in assembly. JayRob's does not have this issue. I am obtaining a new O-ring. Based on discussion with JayRob, I believe that this will no longer be an issue.
Lasers4U is sending me another o-ring. Will is very pleasant to communicate with.

Bottom Line = Although it is a high transmission lens for less money the module appears to be too much trouble for the average user. After they are installed they are great. However, getting them installed requires "customization." Unless you are capable of making your own heat sinks and are competent with some low level "fabrication", I would recommend against getting these modules.

Peace,
dave

Thanks for the review, worth a rep (not that you need it)! This dealer never responded to my ebay messages (required to get a shipping quote as per his instructions); this review eases any fears that I might be missing out on something great.

Yeah. The lens is fine. I'll probably be selling the laser I built it into after it gets its week of test burning. However, it will be a pain in the butt to work with for most people.

Peace,
dave

I'm adding this to the review thread

nice review, I almost bought one from lasers4u, but now I'm glad I didn't. I'll just have to shell out the extra cash for one from jayrob.

bryce007 said:

Isn't the aixiz housing also 10.5mm in diameter? I know mine is.

Click to expand...

Check it again, Mate. AiXiz modules are ~12mm diameter (11.9mm).

Peace,
dave

Just to verify that the optical element inside that new module is indeed the same 405-G-1 glass lens element that I am using for my AixiZ modification...

In fact, I buy my bare lenses from Lasers4U.

It is also the same lens that LarryDFW uses. I believe Larry gets the lenses from the supplier that Lasers4U buys them from. But not completely sure. They are the same lenses though.

So we now have the same lens being offered in three different mounting styles.

One with a custom machined nut using glue to secure the lens,

One with this new 10.5mm module,

And one with a modified AixiZ glass lens nut that uses a spacer/retainer to secure the lens.

I would honestly say that there are pros and cons of each one.

My method allows you to easily take the assembly apart for easy cleaning if you ever need to. This is the best! (IMO) But I may be a little partial.
Jay

Jay maybe you can machine 12mm cases that fit the 10.5mm modules if people started buying that module more?
Just a small thought hehe

I have one of those modules, so if someone wanted a custom heatsink that is fit for it, I could size it with one of my host/heatsink kits.

The beauty of using the AixiZ nut, is that there are so many AixiZ builds already out there... (swapping the lens with different lasers, etc...)
Jay

daguin said:

Check it again, Mate. AiXiz modules are ~12mm diameter (11.9mm).

Peace,
dave

Click to expand...

You're totally right. That's what I get for using a crappy ruler that's falling apart. Sorry! Yea I agree with Jayrob, it is nice to be able to swap it between multiple lasers if you'd like. I'll be ordering one soon. Thanks!

daguin, in your review are you saying that when the module is adjusted so that it is focused, the rubber o-ring on the threaded lense holder is no longer inside the outer 'sleeve' and therefore allows some play in the assembly? thanks.

IanBuckwell said:

daguin, in your review are you saying that when the module is adjusted so that it is focused, the rubber o-ring on the threaded lense holder is no longer inside the outer 'sleeve' and therefore allows some play in the assembly? thanks.

Click to expand...

There are actually two O-rings. One is part way down the lens holder and one is right below the knurled top. The one that is part way down is "engaged", but it is not enough to stop the loose thread fit from allowing the lens holder (and thus the lens) to move around. This allows the angle of the lens to shift significantly in relation to the diode.

The lens must be held stable and "square" with the diode for such tight focuses. I accomplished stabilizing the lens holder with the addition of a cut down spring between the diode housing and the lens holder. I imagine it could also be accomplished with the judicious use of some teflon tape over the threads on the lens holder. I do not know how "tight" the tolerances can be when using threaded brass components.

Peace,
dave

Hmmm... perhaps just pressing the diode 'flush' would also work, but then if flush turns out to be not close enough to the lens, then it would not be able to get focus...
Jay

jayrob said:

Hmmm... perhaps just pressing the diode 'flush' would also work, but then if flush turns out to be not close enough to the lens, then it would not be able to get focus...
Jay

Click to expand...

As you well know, 2mm can make a HUGE difference with these lenses.

Have you tried a diode in yours yet?

Peace,
dave

Yes... I put a PHR diode pressed all the way in to test it, and it focuses just about right as far as the distance you must thread the nut into the module.

But I always thought that the PHR's are about the same for focusing as the 6X's and even the 8X, so I'm a little confused with your result. Unless there is some slight difference in the lens position between your module and mine...
Jay

jayrob said:

Yes... I put a PHR diode pressed all the way in to test it, and it focuses just about right as far as the distance you must thread the nut into the module.
But I always thought that the PHR's are about the same for focusing as the 6X's and even the 8X, so I'm a little confused with your result. Unless there is some slight difference in the lens position between your module and mine...
Jay

Click to expand...

With the diode set all the way into the recess and the laser focused at ~40', there is a space of about 1mm between the diode housing and the bottom of the knurled top. Even at that depth, the lens holder "wobbled" in the diode housing.

Peace,
dave