I've got it bad, working on another host. (1.5W 445nm)

[CDDZ]

Every time I see someone do another build I get ideas and start thinking. I cannot remember who it was that used 10 watt resistor with a 5A LDO in a Mag light host. Anyway, I ordered some parts from Mouser :san: I picked up several LD1084V and a variety of resistors to set currents from 833-1838mA, and a handful of 10uF caps. I was a bit worried at first that I did not design the driver heat sink large enough in diameter to fit the 3 components. The driver heat sink is part of the battery cup adapter. It is 1.275in x .250in thick. When the adapter is inserted into the head/LD heat sink it leaves a 1.275in. x .500in pocket. It is a tight fit for this DIY driver, but it looks tidy. I used ceramic tile to sink the LD1084V, this also gave me a bit of room under the regulator to tuck wires out of the way. I used a 4-40 brass screw to secure the aluminum housed resistor and used this as a ground source. There is plenty of room for multiple parallel drivers to be installed.
I still have the battery sleeves, focus ring and tail cap to machine once I get the switches and M9x.5 tap in. Hope they show up tomorrow. . I will post pictures of the complete build when I am able to finish it up.

Thanks for looking!

Chad

 

[millirad]

Re: I've got it bad, working on another host.

Looks like a promising design. Nice and robust build. Kudos!

 

[CDDZ]

Re: I've got it bad, working on another host.

Thank you for your kind words!

 

[CDDZ]

Re: I've got it bad, working on another host.

Question...
I rebuilt this driver after finding some isolators for the LD1084V. I decided to install a .68ohm resistor to run it at 1838mA. I have my black laser running on a jib77 1.8A driver. Will this little bit of extra current fry this LD? Or is it one of those wait and see kinda things? I tested it on my "dummy load" it was reading 1850mA, but as the test load got warmer the mA would rise ever so slowly. The resistor and regulator are barely getting warm due to the size of the heatsink. Guess I am just curious if this rise effect has to do with the "dummy load" and not the driver build.

 

[Eudaimonium]

Re: I've got it bad, working on another host.

For which LD exactly, 445nm one?

Well, in my personal opinion, 1.8A is pushing it just a tad too far. People had their diodes die within some months on such high currents.

I'd personally reccomend going 1.5A max, that way your laser will last a very long time.
And difference in final output power will not be visible in practice, only measurable by LPM. So in the end, better to go with lower current and having it last.

 

[CDDZ]

Re: I've got it bad, working on another host.

For which LD exactly, 445nm one?

Well, in my personal opinion, 1.8A is pushing it just a tad too far. People had their diodes die within some months on such high currents.

I'd personally reccomend going 1.5A max, that way your laser will last a very long time.
And difference in final output power will not be visible in practice, only measurable by LPM. So in the end, better to go with lower current and having it last.

Yup, 445nm A140. I think I will LPM this diode at the 1838mA and then take it back down, it is easy enough to change out the resistor . Thank you for your input.

 

[CDDZ]

Re: I've got it bad, working on another host.

I mostly finished it. Insert was breaking down and I was too lazy to change it. Looking back I should have, not really proud of how the finish turned out, I suppose I could powder coat it.

I got my Laser Bee in yay! Decided to LPM this, I suppose it is not bad, I did change out the resistor to a .75ohm, wanted to run this a little lower than 1838mA, figured 1666mA was a better figure for longer LD life. It peaked at 1558mW, and settled to 1515mW.

As I said, I am not too proud of the finish, I really did not want to take any pics with it this way, but figured I would share. I think the head is lacking a bit. What do you all think I should do to it in terms of grooves?

I decided to spruce up the focus ring, make it a bit more aggressive. The focus ring rides on two 1.25in OD o-rings to take up for the slop in the lens assembly. I ended up using a copper module from a laser I had purchased on the classified here. Kinda had no choice, the axiz modules were off center by as much as .005in. That was enough to make the focus ring bind a bit. Next time I will clear it out a bit more to allow for this.

I used a Romsen tail cap switch, pretty standard 18mm. I did press this into the tail cap assembly, did not feel like waiting on another tap from Victor. I am really not proud of the way the tail cap turned out at all. I WILL remachine another when I get a chance. I had knurled it, I rechucked it to clean the thread face up a bit.... it slipped in the chuck:gun:

All in all I am pleased with the build, just not to keen on the finish I left on it. Any comments or suggestions are welcome.
:thanks:

Forgot the beam shot

 

[Eudaimonium]

It's pretty epic this way. I'd leave it as it is, or maybe knurl up the handle if there's time.

But great work! Plus rep from me.