I enjoyed the video, Tony! I’ve been unable to get nice tight bends in my acrylic. Do you have any tips on that?
I clamped the plexi between a couple pieces of wood and heated it with my heat gun while using another piece of wood to bend it. Then, while holding it at the angle I wanted, clicked the heat gun to cool mode and cooled the plexi.
Another thing I did was build a dummy load to set the driver module. I used the info that I found at LPF and bought some parts at Radio Shack.
I got six 3A diodes p/n 2761144 and a 1 ohm wire-wound 10W resistor p/n 2710131. The small 2.7K resistor across both leads is supposed to discharge the driver capacitors so you don’t zap your laser diode.
I always like to let folks know that they can put their videos right in their posts. All you have to do is paste the link from the address bar directly into the text, no tags required. Like this:
@Leo69 …!!! You are awesome! Thanks to you I have a really really dangerous laser!!! I am very excited.
Everything In that pic is a mess but I promise I am wearing safety glasses!
I followed your instructions, super easy. When setting my current the LED on the drivers I have, they do not go out, even when turned all the way down? All the rest worked great I was really scared to hook up the diode without that LED off but it worked just the same.
Nice!! Looks like you’re building a few there. An army of Friken sharks with laser beams on their heads maybe? Did you turn the current adjust multiple turns? The LED should turn off after about 5 complete rotations (at most)but even if it doesn’t I guess it’s fine so long as the current is below 2 amps . Anything over that will fry the diode after a short period of time . I think that if you sell a kit with fitted connectors and a pre-tuned driver/laser it would definitely be a value for your customers and I’m sure you could design a nice enclosure with built-in eye protection too. Also, did you use the fan connection with a voltage divider or do the firmware mod? Just curious since I didn’t do the voltage divider myself but I’m pretty sure it would work.
Putting on my wetsuit so I can jump in the SF Bay and wrestle me some sharks right now!
I can turn the pots all the way to 0 current and the LED stays on. They say “good laser A-11” on the back, I guess I got the wrong ones.
Yeah I have 3 power supplies, Figured I would either screw one up or have some to put on the site. I hate waiting so I figured I will buy a handful and jut mark them up a $1-2 for those who don’t want to wait for china shipping.
I have writers/designers block right now. I spent hours designing a holder for this and got nowhere. You think the power supply needs to in the cooling chamber?
I used your pin edit because I don’t have an easy combination of resistors on hand. I will order some or head to fry’s when I get the orders packed for the day. I’m willing to be the guinea pig for that.
I have to say, playing with this laser is so much fun but I am genuinely freaked out by it. Is there much chance of a nasty burn while focusing it, seems like unfocused it really wouldn’t do anything? Should I print up a big easy turn ring?
Definitely a different board revision than mine but looks like it’s not a problem so long as the current is down to a safe level and the voltage is set before you start the current adjustment. Might have to revise the write-up to include your board version. I’ve run my driver for hours at a time and have never done anything special to cool it down. It’s rated to 3amps and we’re running under 2 so I guess it’s not an issue but a fan wouldn’t hurt either. The diode itself definitely needs a heatsink and a fan though.
I’ve found that the lens has to be unscrewed quite a bit to focus , even at 55mm. I have Teflon tape on my lens screw threads so it doesn’t move once I have it set. I start by setting the height of the heatsink at 55mm and then turn on the laser at the lowest possible power S1 to S3 will usually turn it on. At that power level I’ve adjusted the focus ring without ever burning my fingers. A big adjustment ring would make it easier though. I could screw my lens in further and focus at a farther distance but I’m sure there’s a trade-off in beam power as the distance increases. You also don’t want to be so close that the smoke from the material will foul the lens either.
I skimmed through your PDF file yesterday & thought this looks something I might do in the future. One item I saw missing from your materials was the laser goggles & they are not mentioned until page 9 in your document. For those of us that do not know much about using lasers, seems like this should be added at the beginning of the file & what type to purchase.
I am looking forward to see where this project goes.
I bought two pairs from different company’s, I’m a little paranoid about my new lasik eyes. They have seen enough laser for a lifetime!
Very good point. I should emphasize the eye protection requirement. I personally am using a $4 pair of goggles at the moment and they work fine but I have shielding on my laser housing too. I’m planning to revise the write-up fairly soon to include instructions for some other drivers (like Ryan’s) that will require a slight deviation from the current tuning instructions. I’ll be sure to add the eye protection on the BOM .
That tuning issue might be because I didn’t a small enough resistor for the ttl pin safety you had specified. I have some on the way and will run through it again. So maybe hold off because I cut corners…sorry
No worries. If you do find that the tuning procedure is different then just send me a good pic of the driver and let me know what was different and I’ll make the changes or you can make them if you prefer. Either way
I am done all the hardware setup, almost… but I have a really stupid question. ive always flashed my changed and flashed firmware on my printers threw Arduino.ino but I couldn’t get the file "pins RAMPS_13.h in the tabs. so I opened it with a text editor and changed the pin out as instructed. but now how do I flash it over? will the change be done if I do it threw Arduino.ino like i always do even if the pins_RAMPS_13.h is not listed in the tabs?
i too have the “good laser A-11” once i figure out how to upload my firmware i can begin tuning
header files aren’t listed In tabs but modifying with text editor is fine.the compiler will still locate and link the files together when you upload. Let me know how tuning goes. If the led light doesn’t turn off as expected then make sure you turn current adjust screw down a few full turns just in case.The light is just to confirm current is down to low level so you don’t fry diode when you connect for tuning process. Goo luck.keep us posted!
Hi
I´m trying to get the laser to work as expected.
The problem is that i can´t get the current below 0,18 A and the led is newer turned off.
And I can´t get over 0,70 A with the voltage set to 6,5V
I got a little different version of the TTL board but it´s looking similar to me.
Some good advice from someone would be nice.
@PeterT: I think Vicious has the same driver and noted the same issues with the light never turning off. The light turning off is nice because it indicates the current level is low enough to connect the laser diode for current adjustment without risk of burning it out. If your light does not turn off then just set the voltage to 6.5V as described in the guide and turn the current adjust screw counterclockwise a good 4 or 5 full turns. This should be enough to ensure the current is low enough for safe diode tuning.
You can’t get over .7 amps? Which step are you at here? Is the diode already connected and you’re doing the current tuning?
Same exact board as mine.
My LED never went off but all the rest of the steps worked perfectly. The LED might be because I didn’t use the safety resistor, yet.