I blame Brent..

Darren Wright

Administrator
Staff member
Messages
20,089
Location
Springfield, Missouri
So helping Brent out with his new little toy got me to thinking "That would be fun". I almost ordered one of the same engravers, but revisited a place that I had looked at once before that sells a laser kit for adding onto the Shapeoko and other cnc's.

Highlight-FDA-Laser-Kit-800.jpg
http://jtechphotonics.com/?product=1-7w-445nm-laser-diode-and-2-0-amp-adjustable-driver-kit

Well, it arrived yesterday and I had about an hour to play with it last night before heading to the house for bed. I was able to get it all connected and found I couldn't get it to turn on! ::bang: So, ran some checks on the power supply and it worked. There were LED's on the board that weren't lighting up, I was starting to get concerned that I had a bad board. Well, after some reading of the manual (last resort), I found this thing has 3 safeties on it. The main one that was giving me fits was that when the board loses power it must be reset to work again. Basically it's a latch relay that opens the power circuit to the board when power is lost to keep the laser from continuing to burn and start a fire, so this is a good thing. :thumb: The other two safeties are the power switch and the key switch, which must be both on for the laser to operate.

So after a few more minutes, I had it burning some cardboard, which I'm surprised at how fast it started smoking, almost instantly.
2015-08-20.jpg

Hopefully this weekend I'll be attaching the laser to a new mounting plate, which I can swap with the router mounting plate, I also have a mounting plate for my dremal...so just another attachment.

This laser has the TTL control connection, which allows the gcode to turn off/on the laser as needed as well as supports PMW settings for setting the intensity of the laser on the fly, so can gray scale photos onto wood/materials. Since it 's a little larger laser (2 watts), I should be able to cut out thin materials, probably with multiple passes.
 
Probably a dumb question.. but are you guys doing anything to provide airflow/smoke evacuation from these little units?

My vague understanding from lurking on some other forums is that smoke can ruin the lense pretty quickly as it builds up and refracts the light (and cleaning it appears to be a whole nother ball of wax).
 
Mine has both a cooling fan integrated with the heat sink blowing down, and I have a little pc fan I use when soldering pointed at the thing to keep the smoke away. It's probably not good for humans either, but then again I can't see across my valley today from all the smoke in the area, so it's kind of a moot point.
 
Probably a dumb question.. but are you guys doing anything to provide airflow/smoke evacuation from these little units?

My vague understanding from lurking on some other forums is that smoke can ruin the lense pretty quickly as it builds up and refracts the light (and cleaning it appears to be a whole nother ball of wax).

I've got a fan on order to cool the laser and blow the smoke away also. I was also considering putting a vent under the bed to pull the smoke down and away. I haven't gotten very far with mine at this point.
 
Well the new mount is overkill for the little laser, but thinking I'll mount the driver board onto it once I get things worked out, so it will be easier to remove it all to swap with the router mount.
2015-08-21 21.47.04.jpg 2015-08-21 21.47.13.jpg

I ran out of time tonight to get it going, had planned to test the spindle mode, but couldn't get Mach3 out of estop mode for some reason. Will report more tomorrow afternoon hopefully.
 
cool, i was thinking how long before someone without thinking makes something like this into a light sabre and takes it to comic con and causes issues.

any idea on how many hours of life these lasers have?

Sent from my SGH-I337M using Tapatalk
 
cool, i was thinking how long before someone without thinking makes something like this into a light sabre and takes it to comic con and causes issues.

any idea on how many hours of life these lasers have?

Sent from my SGH-I337M using Tapatalk

I've seen several hand helds that are about the size of a flashlight, as a matter of fact many are made with a maglight case.

As for hours, that will vary with wattage and type of use, but average expected life expectancy I've seen about 10,000 hours. Here is a doc I came across on the subject...http://www.bob-weber.com/downloads/pdfs/white_paper/WP_laserlife.pdf
 
Thanks for the link and info Darren. Now considering the housing of that laser and heat dissipation, might be worthwhile getting a thick piece of aluminum to use as a adapter plate and some of that heatsink paste.
I note one thing that affects them is temp, that housing looks like its designed to radiate the heat on those fins so your fan will work for the fin side but pretty sure they expecting the base to thermally conduct heat away too. Just an extra .

Sent from my SGH-I337M using Tapatalk
 
I finally figured out the issue with the spindle control, turned out the connections were polar, I had the + and - backwards.

I did a little testing with a file that Brent sent me for a circuit board.

First one is at 100%
2015-08-23 16.55.13.jpg

This one is at 70%
2015-08-23 17.03.01.jpg

This one is at 50%
2015-08-23 17.29.57.jpg

A comparison of those, top is 100%, bottom is 50%.
2015-08-23.jpg

Another but at 60%, but 1/4" higher from the work piece, seemed to have a little better focus.
2015-08-231.jpg

A little video of it in action through a spare set of safety glasses.
https://www.youtube.com/watch?v=2N3AvzhhpLs
 
Thanks Darren. Very interesting. The difference between a line cut when laser is on and moving versus the short on off bursts.
Can parameters sent to laser control be changed while carriage is moving.?


Sent from my SGH-I337M using Tapatalk
 
Very cool but..... Portrait mode video....? :doh::rofl: :wave:
Yeah, I know, didn't realize it until after I was back at the house posting it. ;-)

Thanks Darren. Very interesting. The difference between a line cut when laser is on and moving versus the short on off bursts.
Can parameters sent to laser control be changed while carriage is moving.?
In my current setup, the spindle PMW controls the intensity of the laser and can only be set on each command set, so for what ever distance the x/y are moving, it will be that intensity. I'm considering wiring up the z axis motor to control intensity, which could do the change on the fly, this may prove to be a little more difficult to working out with the software, but have read of others doing it. So for now I won't be doing any photograph engravings as each movement is only a fraction of a inch before needing to change the intensity. I was hoping to use it for line engravings, solid logos, and minor cuts anyway, so can live with the limitations. BTW, the limitation is with Mach3, doesn't sound like grbl controller or emc have the issue. I've got an EMC computer setup to run the cnc, so may just try using it for the laser also.
 
I took Rob's suggestion and added the heat sink. Also got the fan installed today, but may change the mount on it to be more over the laser. I did angle it a bit to help with clearing smoke away from the cut.

2015-08-29 17.42.25.jpg2015-08-29 17.42.40.jpg
 
Top