Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

MXDL Question

Joined
Oct 28, 2007
Messages
2,631
Points
48
okay, so I got my MXDL light today, waiting on my 7135's...

just to clarify, i take this little thingy out (the pcb/star thing):

img2894ap2.jpg



but I leave this thing in:

img2893qh4.jpg



and why are there 2 areas marked positive, and 2 marked negative? just being safe and doubble checking, Im thinking one set of polarities is for the LED, one is for input?

regards,

amk
 





H

Hikari_V

Guest
nope, what you see there is just 2 sides .. one is + the other is - !! ;) there is some extra markings on the star itself, but in reality 2 contact points.. case and hot.

The thing you see there is the star.. it is an aluminum heat sink on which the emitter rests.

under the star there will be a resistor to control the current.. this gets VERY hot.
:eek: :eek: :eek: :eek: :eek: :eek: :eek:
 
Joined
Oct 28, 2007
Messages
2,631
Points
48
jayrob said:
amk, are you trying to use the MXDL for a laser with a DDL driver? Or, are you talking about the Cree mod?
http://www.laserpointerforums.com/forums/YaBB.pl?num=1194770080
DDL has some great pictures of inside the MXDL and what to do with the driver on this first page of his DIY Laser Torch thread:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1186966870
Jay

sorry for not clarifying, I am gonna do the MXDL laser mod, only with an AMC7135 and an open can. (in my signature). I was just wondering, all I gotta do is replace the LED/PCB-resistor with the amc7135, and do I do anything witht the thing under the heatsink...
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
I would recommend the DDL driver for the MXDL and open can. Two reasons:
1. The MXDL is made for 2 X cr123 batteries. For the DDL driver, you would use RCR123/3.6 volt batteries.
2. The 7135 drivers not only take a different battery supply, but they also require the LD to be isolated. The negative side of the battery cannot make a direct connection to the negative side of the LD. Or, it would just be by-passing the driver, and run the LD directly off of the battery supply.
Also, using the open can diode, you will probably want at least 350mA current. So, you will need a heatsink as well. 350mA will give you about 200mW with the acrylic lens, or about 250mW with a glass lens...
Check out the bottom of this page:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1199846835/30
Gazoo helped me diagnose this issue. Read on in the thread to see the 'HOT' set up for an MXDL/open can...
Jay
 
Joined
Oct 28, 2007
Messages
2,631
Points
48
jayrob said:
I would recommend the DDL driver for the MXDL and open can. Two reasons:
1. The MXDL is made for 2 X cr123 batteries. For the DDL driver, you would use RCR123/3.6 volt batteries.
2. The 7135 drivers not only take a different battery supply, but they also require the LD to be isolated. The negative side of the battery cannot make a direct connection to the negative side of the LD. Or, it would just be by-passing the driver, and run the LD directly off of the battery supply.
Also, using the open can diode, you will probably want at least 350mA current. So, you will need a heatsink as well. 350mA will give you about 200mW with the acrylic lens, or about 250mW with a glass lens...
Check out the bottom of this page:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1199846835/30
Gazoo helped me diagnose this issue. Read on in the thread to see the 'HOT' set up for an MXDL/open can...
Jay

jay rob, ive already read that whole thread, I thought that would be clear from me posting there during the process of gazoo troubble shooting your problems/occurences.

I already ahve ordered the 7135's, and I am fully aware that the diode needs to be isolated. Also, i believe it was you who directed me to drill out my MXDL to fit one 18650, instead of CR123's, which would be good for the 7135.

from your thread, you say that the star thingy can be replaced with another one for the cree mod, i was wondering weather its the same for the 7135...

regards,

amk
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
sorry for not clarifying, I am gonna do the MXDL laser mod, only with an AMC7135 and an open can. (in my signature). I was just wondering, all I gotta do is replace the LED/PCB-resistor with the amc7135, and do I do anything witht the thing under the heatsink...

But if you are determined to use the 7135 driver with the MXDL, it can be done.
First, you would have to drill out the body of the MXDL on a lathe using a 3/4" drill bit so that it would accept a single, protected 18650 battery.
Then, you would remove the emitter as well as the MXDL driver. The new driver goes in place of the stock MXDL driver.
Last but not least, you would have to make sure the module/or LD, is isolated from the body of the MXDL. Because the Body of the MXDL, is also the negative side of the battery. The 7135 driver, has it's own 'negative to LD' that must be isolated.
That is why I recommend the DDL driver...Just like DDL first posted it! He knew what he was talking about. Some of us have only 'pumped up' the current and added a heatsink. For the open can, I like a 3.0 ohm resistor at the LM317. This will put out about 420mA. For the open can, this is the 'sweet spot'. Edit:(It may be a little 'HOT', but it's awesome) As long as you have TEC. Or, in the case of an MXDL, a thick heatsink. And, of course, short duty cycles...
Jay
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
I already ahve ordered the 7135's, and I am fully aware that the diode needs to be isolated. Also, i believe it was you who directed me to drill out my MXDL to fit one 18650, instead of CR123's, which would be good for the 7135.  

from your thread, you say that the star thingy can be replaced with another one for the cree mod, i was wondering weather its the same for the 7135...

regards,

amk

Ok....I know you posted on the other thread. But, just wanted to make sure you were understanding...
So then, the 7135 driver will replace the stock MXDL driver. You will remove the emitter, as well as the driver. (but save the stock MXDL driver in case you ever want to use it for an MXDL/DDL set up)...
Jay
 
Joined
Oct 28, 2007
Messages
2,631
Points
48
jayrob said:
sorry for not clarifying, I am gonna do the MXDL laser mod, only with an AMC7135 and an open can. (in my signature). I was just wondering, all I gotta do is replace the LED/PCB-resistor with the amc7135, and do I do anything witht the thing under the heatsink...

But if you are determined to use the 7135 driver with the MXDL, it can be done.
First, you would have to drill out the body of the MXDL on a lathe using a 3/4" drill bit so that it would accept a single, protected 18650 battery.
Then, you would remove the emitter as well as the MXDL driver. The new driver goes in place of the stock MXDL driver.
Last but not least, you would have to make sure the module/or LD, is isolated from the body of the MXDL. Because the Body of the MXDL, is also the negative side of the battery. The 7135 driver, has it's own 'negative to LD' that must be isolated.
That is why I recommend the DDL driver...Just like DDL first posted it! He knew what he was talking about. Some of us have only 'pumped up' the current and added a heatsink. For the open can, I like a 3.0 ohm resistor at the LM317. This will put out about 420mA. For the open can, this is the 'sweet spot'. As long as you have TEC. Or, in the case of an MXDL, a thick heatsink...
Jay

well, that got me thinking, if 420 mA is the sweetspot, could I use the LM317T driver with a 3 ohm, and then use the flashlight body itself as the heatsink (with the fender washers and such)?

and with the 3/4" drill, I could jsut use my power drill and a vise... or do I have to use a lathe?
Isnt a lathe like a thing that rotates stuff (like a pottery wheel) so that you can make designs and stuff??

thanks for your help,

amk
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
420 is the 'sweet spot' only if you have an open can, and only if you have good heatsinking. Probably better than washers. (by the way, the stock MXDL resistor is a 3 ohm resistor, which would give you the 420mA in a DDL dirver) Now, you could probably get away with drilling out a chunk of aluminum with a vice and drill. (for a heatsink) And, if you go with the DDL driver, you won't have to worry about drilling out the MXDL body. But, if you go with the 7135 driver, and need to drill out the MXDL body, you would definitely need a metal lathe for this. Because, it must be precise. After drilling it out with a 3/4" drill bit, there will only be a little more than 1/16" thickness of the body left! (at the threads) Doubt it could be done without a lathe...
Jay
 

Attachments

  • MXDL_18650.jpg
    MXDL_18650.jpg
    24.1 KB · Views: 95
Joined
Oct 28, 2007
Messages
2,631
Points
48
jayrob said:
420 is the 'sweet spot' only if you have an open can, and only if you have good heatsinking. Probably better than washers. (by the way, the stock MXDL resistor is a 3 ohm resistor, which would give you the 420mA in a DDL dirver) Now, you could probably get away with drilling out a chunk of aluminum with a vice and drill. (for a heatsink) And, if you go with the DDL driver, you won't have to worry about drilling out the MXDL body. But, if you go the 7135 route, and need to drill out the MXDL body, you would definitely need a metal lathe for this. Because, it must be precise. After drilling it out with a 3/4" drill bit, there will only be a little more than 1/16" thickness of the body left! (at the threads) Doubt it could be done without a lathe...
Jay

i meant use the washers, which are connected to the body, i presume since the washers are connected to the body, the body would aid in the heatsinking? or not?

considering the 1/16" thickness thing, i might not want to go with 7135's anymore, but what to do with the drivers now??

regards,

amk
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
They are great drivers. I have some extra ones too! They were cheap enough. They could be used as test circuits. Or, to build a 'labby'. Or, box style laser. As far as the washers, I'm no expert. I suppose it makes sense that they connect to the body, and in turn the body is also the heatsink. Use very short duty cycles and see how it does. Or, maybe try a 3.3 ohm resistor. This would give about 375mA. And should be pretty good for an open can. Make sure to post your pictures and findings!...
Jay
 
Joined
Oct 28, 2007
Messages
2,631
Points
48
jayrob said:
They are great drivers. I have some extra ones too! They were cheap enough. They could be used as test circuits. Or, to build a 'labby'. Or, box style laser. As far as the washers, I'm no expert. I suppose it makes sense that they connect to the body, and in turn the body is also the heatsink. Use very short duty cycles and see how it does. Or, maybe try a 3.3 ohm resistor. This would give about 375mA. And should be pretty good for an open can. Make sure to post your pictures and findings!...
Jay

man I wish I had a lathe so I could make a heatsink like yours...

then again I also lack the chunk of aluminum LOL....
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
I'll tell you something about my heatsinks. I don't like pressing the AixiZ modules in place anymore for the heatsinks that I make.
heat sink2.jpg

The reason is, when the module is 'pressed' in, (with a vice) and you need to replace the LD, you have to press it back out. (I now drill them out to fit, and put a set screw for the AixiZ modules) I guess the 'pressed in' style is not TOO big of a deal to change out, but much better is the 'set screw' style that I have for the Meredith modules as well!
MXDL 300 1.jpg

Also, the Meredith module may cost more in the beginning. But, I think it is worth it! Not only does it make it very easy to remove if you need to change out the LD, but it also allows the easy changing of lenses. Once you have a Meredith module with the heatsink, it will be the only module you will ever need for that laser.

The 1st picture above, is an extra heatsink that I have. It already has a Senkat diode installed in a AixiZ module with the silicon diode and the cap soldered on, along with lead wires. And again, this heatsink is made specifically for an MXDL, nothing else. I would sell it to you for $45 bucks plus shipping. (heatsink/module and lens/LD/components) The Sony diode is hardly used. I would run this with a DDL driver using a 4.3 ohm resistor, which would give around 294mA current, driving the diode at, or above 200mW.

If you wanted me to make you an MXDL heatsink sized for a Meredith module. (including set screw/no module) I would ask $20 bucks plus shipping...
Jay

As another idea, you could start a thread asking if any of the machinists out there would make one for you for less. Here are the exact measurements for a perfect fit to the MXDL: http://www.dealextreme.com/details.dx/sku.4171
heat sink.jpg
 
Joined
Oct 28, 2007
Messages
2,631
Points
48
i dont need an extra diode/module,

so how about 1 heatsink made for an aixiz module for $20? (just like your second offer only instead of for a meridith module it is for an aixiz module)

I already have the opencan inside an aixiz module, and so Im guessing all I have to do is press it into this heatsink and put it into the MXDL (with driver)?

regards,

amk
 

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
amkdeath said:
i dont need an extra diode/module,

so how about 1 heatsink made for an aixiz module for $20? (just like your second offer only instead of for a meridith module it is for an aixiz module)

I already have the opencan inside an aixiz module, and so Im guessing all I have to do is press it into this heatsink and put it into the MXDL (with driver)?

regards,

amk

Yes, you could solder the silicon diode and cap to the LD with leads. (like the picture of the heatsink with the AixiZ) This is how DDL showed it in his 'DIY Laser Torch' thread. Or, you could build the driver with the components mounted on the driver circuit. (like the picture of the heatsink with the Meredith) Either way, you must first check the 'head room' inside the MXDL using the heatsink. It will be kind of limited. But, not a problem. Just kind of tight in there, so you have to check it.

Tip: You will have leads from the driver sticking out of the MXDL, then the last thing, will be to solder the leads together to the leads from the heatsink/LD and use heat shrink tubing. Then carefully wind/place the small amount of excess wire inside using a small screw driver if necessary as you set the heatsink in place. (Making sure none of the components are 'smashing' into each other) Then just screw the retaining ring on...
Jay

P.S. You can see from the picture, that the threaded aluminum piece that held the original driver and emitter, has been modified. (drilled/grinded) The top (flat) part that the emitter rested on, is no longer there. This is to make room for the LM317 and components. (Which you will mount on the original round circuit)

PM sent...
Jay
 

Attachments

  • MXDL_attach_heat_sink.jpg
    MXDL_attach_heat_sink.jpg
    28.2 KB · Views: 117




Top