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Even w/ proper driver circuit my laser diode fries

judogti

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Re: Even w/ proper driver circuit my laser diode f

Thanks I will search for that. This is what I built (I have under 20 posts so I cannot post links. Just take out all the spaces and to make the URL)

ww. instructables. com /id/ Laser-cutter - start - slicing - stuff -for-under-50-dol/

It uses 2 scanners for the axis' Works good so far except for the frying of diode :)
 

judogti

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Re: Even w/ proper driver circuit my laser diode f

Is it okay/recommended for me to place the Aixis housing into a heat sink? Or do I need to place the diode itself into a heatsink?

Thx
 

Things

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Re: Even w/ proper driver circuit my laser diode f

You can keep the diode in the aixiz housing. Another thing to watch out for: Is your lab PSU's current metre accurate? ::)
 

Bionic-Badger

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Re: Even w/ proper driver circuit my laser diode f

You'd have to drill out a heatsink to get it to fit that diode, so it's usually easier to get an Axiz module, press the diode into it, and then mount it to a heatsink somehow using some thermal grease or something.

I've been messing with using some heatsinks made for regulator ICs and then bending them to wrap around the module. It's not pretty though, since I have to bend and hammer it into shape. You might want to look into a ready-made solution like those Deal Extreme 100mW red stage lasers that have a heat-sink block. They're pretty cheap for what you get, some even less than the diodes that Senkat offers.
 

chido

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Re: Even w/ proper driver circuit my laser diode f

Things said:
You can keep the diode in the aixiz housing.
Things - He does need a heatsink. Read the other page, he needs to leave the laser on for 10 - 20 minutes.

judogti said:
Is it okay/recommended for me to place the Aixis housing into a heat sink? Or do I need to place the diode itself into a heatsink?

Thx
You need the aixiz module for collimation, so you place your diode in that and then you get a block of aluminum, you drill a hole through it just big enough to have the aixiz module fit really tight, (when I say really tight I mean that you need a vice to press the module into the heatsink) if you can't get a tight fit then just drill a hole where the aixiz module fits through and glue the module to the heatsink inside the hole using thermal epoxy.
 
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Re: Even w/ proper driver circuit my laser diode f

Have you considered spikes at on/off from your psu, even with the lm317 driver? Seriously, try batteries. ;)

With heatsinking, I have had success gluing the module to a flat, undrilled heatsink using thermal silicone glue from dealextreme. I've kept an open can on 400ma for about an hour with barely any noticeable difference in temperature on the module or the heatsink.
 

judogti

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Re: Even w/ proper driver circuit my laser diode f

Have you considered spikes at on/off from your psu, even with the lm317 driver? Seriously, try batteries.
pocketfluff - If Im still getting a spike using a decent quality benchtop PSU -> driver -> diode then all hope is lost and even batteries won't help. I do think the issue is heat given the feedback Ive recieved here. I thought the Aixis housing would provide enough cooling capability that I could run it for hours, but being a noob I've learned that one. :)

You need the aixiz module for collimation, so you place your diode in that and then you get a block of aluminum, you drill a hole through it just big enough to have the aixiz module fit really tight, (when I say really tight I mean that you need a vice to press the module into the heatsink) if you can't get a tight fit then just drill a hole where the aixiz module fits through and glue the module to the heatsink inside the hole using thermal epoxy.
Chido & Bionic-Badger - Thanks, Ill grab some aluminum this week and see what I can do. I have some old chipset heatsinks but I think they are too thin and wont make enough contact with the housing... I do see a post on here about a MXDL Custom Machined Heatsinks is this something I can consider (Ive just started to read that thread and there are 20 pages so it might say in the middle of it, but I thought Id throw it out there as long as Im typing..)
 

chido

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Re: Even w/ proper driver circuit my laser diode f

Yes, jayrob's heatsinks will work fine with this.
 




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