Sounds like Dave has a different setup, perhaps simply a sump and water pump, as he mentioned adding a frozen water bottle to assist with cooling.
Does your laser have the ability to turn the A/C on/off on demand? Mine has a USB output which controls a relay to cycle the A/C. I’m sure you’re aware the A/C is only required when your actually cutting with the laser.
Michael
If you used a reg, air compressor you could use a simple solenoid on 120 volt to open and close it, hooked to your fan switch, so if on is on the other is on.
go to Burdens surplus center , they usually have them pretty cheap.
Michael Glavin said:
Sounds like Dave has a different setup, perhaps simply a sump and water pump, as he mentioned adding a frozen water bottle to assist with cooling.
Does your laser have the ability to turn the A/C on/off on demand? Mine has a USB output which controls a relay to cycle the A/C. I’m sure you’re aware the A/C is only required when your actually cutting with the laser.
I concur; that is, I think Dave’s setup uses a pump so send the water to the cutter’s tube, and the outflow pours back into the exterior reservoir. Is that right Dave?
Dennis Rayon said:
If you used a reg, air compressor you could use a simple solenoid on 120 volt to open and close it, hooked to your fan switch, so if on is on the other is on.
go to Burdens surplus center , they usually have them pretty cheap.
Good point Dennis. I might do that for the “permanent” fix, once the compressor supplied with the cutter burns up.
Cliff - just ran across a web page that talks about adding an amp meter
http://lensdigital.com/home/?p=1453
A clear explanation.
dave
Thanks Dave, that was hugely helpful. I have that same ammeter coming, and have the various wiring products in hand. I also have a small plastic j-box for the ammeter, which I’ll park on the side of the laser for now. And with this link you just sent, I feel like I’m all set to dive in. So thanks again!
[edit] I need to confirm the 20mA target-max. My tube is nominally 60A. How can I tell what voltage the PS puts out? (I haven’t taken the machine apart or examined its guts yet, but perhaps you know a quick answer that doesn’t require that).
Best,
Cliff
Back at it today, getting more bits and pieces together, including the ammeter. Looking for a little more info on tying it into the laser’s wiring, I ran across this series on using Chinese lasers. I found this particular video pretty instructive on how the tube works, its connections, and safety issues.
https://www.youtube.com/watch?v=4tDK3yOhN3E&index=26&list=PLInTrkIbj69kPO_UP81yxX-xov4SVyPlD
Pretty cool Cliff. What will be your first project?
Hey Bruce, thanks. I’ll start with some small stuff like sheds & etc. to learn the processes. But my main aim is to build certain mine structures that my layout has been designed around. I tried a version in '13 using 1" foam board, but I’ve been looking to this laser tool for more precision and thinner materials and less time to cut the pieces. That’s the theory at least.
See you in a couple weeks!
Cliff
Today began with getting the vent system window feed-through finished. Here are the parts.
And here is the finished assembly. The blue hose is exterior, white interior. Both pop off the thru-window coupling, which I’ll make an insulated plug for.
Too cold to install it and have the silicone set up properly, so I’ll wait for a bit warmer day for that. Such funny weather, we had 70’s last Thursday, and but 30’s today with a foot of snow coming Tuesday they say!
The next thing on the list was the ammeter. I got the bits in during the week; and once I fully understood where to tie it in, and what the (unmarked) ammeter polarity was, things went fine. I installed it in a small jbox, which was screwed to a side door. It’s nice that the cutter’s door panels are easily removable.
Final physical install steps should be fairly easy, e.g.,
ground wire to new copper rod outside
replace a broken pushbutton switch
hook up the air pump & chiller
install the vent window
Then comes operational testing and figuring out the software, woo hoo!
Today I finally completed the hardware installation (I think), including:
It’s been a month since I got the crate, so I’m glad to finally get to this point. Time to get into the software and operations of this thing.
Thanks everyone for all the helpful suggestions and encouragements.
===>Cliffy
I want to say a few things about sound levels. I’ve indicated that I was worried about that all along, since the thing is completely parked inside the house (in the basement). Thanks everyone who assisted me with thinking through those issues! Now that it’s DONE, here’s some measurements.
These are all taken from the same place (about 30" away from the cutter).
Laser cutter on, with only its small vent fan on: 43dB
Switching on (adding) chiller and air pump: 57dB
Switching on (adding) main vent fan: 63dB
Here’s an oddity though. With ONLY the main vent fan on (and nothing else), from the same position, the reading was 62dB. I had expected thigns to be somewhat additive, so I re-ran the test and came up with the same results. Basically, when the main vent fan is on, turning everything else on didn’t make a difference. Curious, but good news.
The next good news came when I measured the clothes dryer upstairs: 70dB. So being less than that means I’m good.
My wife said it was fine! And that was the main thing. We were able to stand close to the thing and talk without raising our voices. Makes sense, because conversation at 3-5’ is in the 60-70dB range per the following chart.
http://www.hearnet.com/at_risk/risk_trivia.shtml
I also measured the main fan outside, from 30" away:
Not bad; but I’d sure not want it indoors! Bottom line, the inside stuff isn’t worse than the clothes dryer, and I’m very happy with that.
Anyway, I just wanted to report on all this to you guys, in case someone can find some useful data points.
===>Cliffy
Cliff Jennings said:
Laser cutter on, with only its small vent fan on: 43dB
Switching on (adding) chiller and air pump: 57dB
Switching on (adding) main vent fan: 63dB
Here’s an oddity though. With ONLY the main vent fan on (and nothing else), from the same position, the reading was 62dB. I had expected thigns to be somewhat additive, so I re-ran the test and came up with the same results. Basically, when the main vent fan is on, turning everything else on didn’t make a difference. Curious, but good news.
===>Cliffy
It is additive. But recognize that dB are based on a log rather than a linear scale.
43 dB (10^4.3) + 57 dB (10^5.7) + 62 dB (10^6.2) = 63 dB (10^6.3).
Cliff you need to hurry up and make something(http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cry.gif)
Logarithmic, makes sense Todd. I don’t quite follow your math but I take your word for it.
Dennis, this morning I’m reading the lit and reviewing the software, maybe this afternoon!
Sound levels are generally expressed in decibels, which are logarithmic and so cannot be manipulated without being converted back to a linear scale. You must first antilog each number, add or subtract and then log them again in the following way:
For example, adding three levels 94.0 + 96.0 + 98.0:
Thanks Todd. Way over my head, but I’m sure others will get it. I feel it though. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)
Been at it all day, trying to understand mirror alignments, software, proper mA to run it at, etc. You Epilog dudes have it easier I think…! But, I made my first test cuts.
Here’s what it took to get cut-through on .21 acrylic, using the 60W (?) system, while staying at 20mA:
58% power, running at 3mm/sec.
That seems mighty slow, but OTOH I have no experience. What speed / power do y’all use for, say, 3/16" or 1/4" acrylic?
On the Epilog, for speed, on a scale of 1-100, I would run 0.21 acrylic at ~8…, and that may not even get it. Also, we cut all acrylic, regardless of thickness, at full power and a frequency of 5,000 Hz (fastest). The Epilog is a 50-watt machine. So yes, acrylic is slow.
I don’t know how the 1-100 relate to mm/sec, but perhaps you could find it on-line at the Epilog site or elsewhere, if you so desired.
To do 3/8" I run at 4, twice and sometimes that doesn’t get it.
If you leave the paper on the acrylic, you get better edges.
Here’s my first part, woo hoo! It’s the start of a V&T logo, about 2.5" high.
This was cut in .165 material, still at 58% and 3mm/sec. But since the gaps were wider I think it could have been run faster.
Anyway, I’m thrilled to see something cut!
The idea is to run it as fast as you can so that it cuts all the way through, cleanly, including the bottom paper. The slower it runs, the bigger the discrepancy between the diameter of the hole at entry and exit and ultimately, the fit of your parts.
