Hello everyone. I purchased a KKMoon 30W laser that requires a 2A power supply with the hopes of integrating it for use with the DexArm (which will only supply 1.2A). As others have or are looking to integrate more powerful lasers with their DexArm, it seems this is the best place to discuss this hence my creating this topic.
What Voltage does that Laser use? 12V * 2A is only 24W - so if it’s running on 12V it cannot be a 30W Laser…
Can you post a link to that Laser?
Here is the link to the laser: https://www.cafago.com/p-e11602-4.html
30W is likely overpowering the laser but since they indicate it will do 5.5, 10, 20, & 30W I am happy to use it at 20W to avoid burning out early.
My original thoughts were to provide a separate power supply for the laser & use a relay switch connected to the Dexarm to control it (https://www.amazon.ca/PACK-AMP-Waterproof-Relay-Harness/dp/B074QV54V1/ref=pd_di_sccai_4/147-3054421-9281503?_encoding=UTF8&pd_rd_i=B074QV54V1&pd_rd_r=754ec54d-ab40-41b0-adeb-99b8babac47c&pd_rd_w=mz6k8&pd_rd_wg=qla3l&pf_rd_p=a5f9e780-487d-4881-a2b8-b9a00c4b0707&pf_rd_r=BWT5R453KW9QZ6BM1HJK&psc=1&refRID=BWT5R453KW9QZ6BM1HJK)
I’ve been privately communicating with ChrisWhite on Discord about this as my electronics knowledge is ancient & quite limited - he’s been an immense help. Today though I received a message from Bence asking about it since he purchased the same laser hence my creating this topic here to ease communication.
I emailed TomTop (KKMoon) asking for this laser’s data sheet as Chris has found another user who has a setup that may work with this one with a bit of tweaking. However we need the data sheet which was not provided. I emailed TomTop (KKMoon) for it & am now awaiting their reply.
Thats where things currently stand.
Not sure, what you are going to do with a relay…? Alexsanf has already a 3rd party laser working. He posted some data on doscord:
I have also ordered a KKMoon Laser for me:
And the opto coupler alexsanf also used:
My laser is announced to be delivered tomorrow - so let’s see…
Using a relay was part of my original idea (based on limited knowledge of electronics from classes I took 30 years ago). I didn’t know about PWM & thought the DexArm was simply turning the laser on & off very quickly to burn. I therefore thought I could use a separate 2A power supply to power the laser while the on/off signal from the DexArm was sent via relay. That idea has been since been nixed & I’m now officially out-of-my-depth - I’ve been relying on Chris’s knowledge & guidance.
ChrisWhite also mentioned Alexsanf’s posts & believes it’s the way to go but we need my laser’s data sheet as there may be modifications necessary (I assume due to the higher power output my laser can manage). I’ve emailed the seller yesterday & they said they contacted the supplier asking for said data sheet. That’s where things are now… waiting for a response.
Well - your idea isn’t generally wrong. Turning the laser on and off very quickly is exactly what PWM does. It’s just far too quick for a relay. I think the PWM frequency of the arm is 500Hz. That’s why Alexsanf uses an opto coupler. Also you might have to take into account if your laser needs the same PWM voltage as the original laser from rotrics and most PWM implementations reference agains GND whereas the Rotrics PWM references against 12V.
Sorry, nixed is the wrong word to use. Rather it is flawed, probably exactly in the way you described. I read up on the optocoupler yesterday & discovered it was a relay but much faster so same idea (I don’t think this kind of device existed when I took my courses way back when -or- it was something we never got to before I dropped out (decided electronics wasn’t something I wanted to pursue as a career)). The PWM voltage is exactly the info we are looking for now hence waiting on the data sheet. They didn’t list it in the specs but Chris believes it’s probably 5V. We want to be certain.
HI all, I am quite interested in cutting perspex with dexArm at some point, so I am joining the discussion;
Here are a few images on Discod from @alexsanf which should help anyone interested in the setup:
I wanted to add the direct link to discord but since its my first post here I am not allowed : /
Have you been able to test yet?
Hey Guys, my setup is working well, shout if you need any input, spent a lot of time figuring it out. Running a 7.5w Sainsmart laser for now with good results… 3 passes through 3mm ply with Lightburn and Camera setup.
Ordered this 40w beast from Neje…should arrived soon - will get that hooked up and post my findings
Used a DC to DC convertor to drive the 5V PWM signal (replaces the 5V supply in my diagram) supplied from the 12V of the arm
Cool! I hope it doesn’t get confiscated by customs… I heared, they are quite strict if they discover such things… I’m waiting for your report! If everything goes well, maybe I will get me one as well!
Does this converter work ok? I don’t trust these things since I had one that got incredibly hot at quite low power. Might give it another try if your experience is good.
Have had no issues with it, pwm does not draw much current, as it buffered.
Will let you know once i have it running… and delivered
Check Discord - 40W update there
Could you please repost it here too? Discord will see most of that go away, at least here it is a little more organized.
@alexsanf could you please drop some references of your working setup here? I quite like the display idea too