My first build! (405nm pen from scratch)

[LazyBeam]

Ok, so it seems like I've taken forever to finish this... but since it was my first build I took it slow.
It's a pretty straight forward build with the SF-AW210 diode and flexdrive. I just added a little twist to be unique.
For anyone wondering... yes I destroyed my first LD harvesting it. Good thing I got 3 sleds

The SF-AW210 LD is seated in an Aixiz module that was turned down to 10.1mm and has a press fit step machined in the back. The back half of the module got pitched in the trash. The modified aixiz head presses into an aluminum sled that holds the Flexdrive, power board and the negative terminal (the host is case positive).

The host body is 12.5mm in OD and the front ID is 10.2mm and the rear ID (batteries) is 10.5mm. Unfortunately the body is a little tight on triple A batteries and the only AAA I get to freely slide in & out are Duracell alkaline... but they seem to work fine. The host body & battery cap are all 18-8 stainless and the buttons & sled are 6061 aluminum. The sled uses two M2.5x0.45 screws to stay secured in the host body. Even though the body is case positive, the battery spring is on the tail cap because it was easiest to do this way. I still need to attach the custom focusing to the body so that screwed all the way it's focused to "infinity". There's also still one or two machine marks I need to brush out of the body from some touch up machine work.

A custom power board (push-button switches, resistors, and hobby board) is interfaced to the backside of the flexdrive and set to supply either 65mA or 165mA. With aixiz 405 glass this should be around 40mW and 180mW. It's a tight fit so I had to use clear tape to insulate the electronics. I have pics of the power board and driver... but I misplaced them at the moment (remember when HDDs were only 100MB? lol). I'm still debating whether or not to coat the back of the LD in thermal adhesive. As it is now, it can be disassembled to fix any future problems.

When I figure out how to do a proper beamshot (safely) I'll post a video. The camera won't pick up the visible beam.
The clicking noise in the video is the crappy camera focusing mechanism...

Video: http://www.youtube.com/watch?v=W3fiLxBPb58

 

[laser_freak]

That looks like a great build, especially since it's scratch built!
I really like the dual power buttons. How did you get each button to set the driver for a different current?

 

[Asa]

Sick dual power buttons! Good stuff man.[:

 

[Morgan]

Always best to thermally isolate in such a confined, high output build than to electrically isolate, IMHO. What's the duty cycle on this one? Is the host, 'case positive', or, 'negative'? Floating?

I like the dual buttons though!

M

 

[LazyBeam]

Update: I found some stainless steel so I made the focus ring.
I'll have to focus it to infinity tomorrow and then glue the ring onto the lens.

I'll be brushing the body and caps tomorrow and then making the final assembly.

That looks like a great build, especially since it's scratch built!
I really like the dual power buttons. How did you get each button to set the driver for a different current?

The low power button supplies power to the flex-drive set at 65mA. Simple and straight forward. The high power button has a resistor with it and connects the power supply to the backside of the flexdrive's resistors. The high power resistor allows extra current of a predetermined value past the flexdrive's range-setting resistors in a parallel circuit fashion.

 

[LazyBeam]

Always best to thermally isolate in such a confined, high output build than to electrically isolate, IMHO. What's the duty cycle on this one? Is the host, 'case positive', or, 'negative'? Floating?

I like the dual buttons though!

M

The case is positive... so the diode case pin is clipped because the flexdrive (-) power supply runs straight through to the diode.

Thermally isolate? what does that mean? I'm probably going to add the arctic thermal adhesive to the back of the LD tomorrow.

As for duty cycle... I'm not even sure how to measure that. I only run the high power for a few seconds at a time. The nice thing about having the 65mA low power is that I can use that to aim, focus, and point around for entertainment. It does not seem to get hot no matter how long I run it in low power and I've not had to run high power long enough to heat it up.
However, I'm not sure how well the heat is conducted into the hose body. there is about a 1mm gap. I might use some arctic silver 5 between the aixis head and the case body before final assembly... but I'm not sure how freely it flows and if it leak back to the electronics.

 

[Morgan]

The case is positive... so the diode case pin is clipped because the flexdrive (-) power supply runs straight through to the diode.

Thermally isolate? what does that mean? I'm probably going to add the arctic thermal adhesive to the back of the LD tomorrow.

As for duty cycle... I'm not even sure how to measure that. I only run the high power for a few seconds at a time. The nice thing about having the 65mA low power is that I can use that to aim, focus, and point around for entertainment. It does not seem to get hot no matter how long I run it in low power and I've not had to run high power long enough to heat it up.
However, I'm not sure how well the heat is conducted into the hose body. there is about a 1mm gap. I might use some arctic silver 5 between the aixis head and the case body before final assembly... but I'm not sure how freely it flows and if it leak back to the electronics.

Do you know, I'm not sure I have the faintest idea! I do know I had a few drinks late last night so I may well have got my mucking fords wuddled!

I think what I was trying to say is that in a small build, with limited heatsinking, then using thermal paste just as you have pointed out, is more important than choosing to use the diode case as an electrical contact. In your build the diode case sounds to be floating as you have not connected the case pin. The case is positive because the positive contact for the Flexdrive input goes to the case, yes?

Sorry about the nonsense post. That is probably the first post I've come back to and thought, "What did you do with the REAL Morgan?!!!"

Again, my apologies...

M

 

[Eudaimonium]

Skilled machinist and knows his electronics.
That's totally awsome. Reputation given.

Just one thing that's itching me - what if one is to press both buttons at once?

 

[LazyBeam]

Skilled machinist and knows his electronics.
That's totally awsome. Reputation given.

Just one thing that's itching me - what if one is to press both buttons at once?

That is how high power mode works.

The button closest to the rear produces low power. Pressing both buttons produces high power. It is easy for your fingertip to cover both buttons. Pressing the high power button alone does nothing.

This makes activating high power more deliberate. It could VERY easily be wired for both buttons to act independently... nothing would need changed except the rerouting of traces on the back of the power board. I just didn't didn't end up doing it that way, that's all.

 

[Eudaimonium]

That is how high power mode works.

The button closest to the rear produces low power. Pressing both buttons produces high power. It is easy for your fingertip to cover both buttons. Pressing the high power button alone does nothing.

This makes activating high power more deliberate. It could VERY easily be wired for both buttons to act independently... nothing would need changed except the rerouting of traces on the back of the power board. I just didn't didn't end up doing it that way, that's all.

That's awsome , I though one button was low power mode and the other was high power mode.

I just flew over that text, didn't take time to visualise the schematic in my head, which hurts a lot today BTW, winegarden poisons tend to do that it would seem ...