September 2014 Email with Stefan

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Email correspondence between Greg Buckland (FeF) and Stefan Hechenberger (nortd Labs)

re: Open Source Ecology Lasersaur questions

On Fri, Sep 5, 2014 at 3:37 AM, Stefan Hechenberger <> wrote:

On Thu, Sep 4, 2014 at 5:44 PM, Greg Buckland <> wrote:
Thanks for the quick reply, Stefan! A couple quick follow up questions:

I checked on those, and shipping will take some time. Any concerns with these ones? They could get them to me tomorrow.

Look good.

Thanks for the tips about connecting the laser - i'll try a screw terminal connector and see what I can do (I also found this helpful thread after talking with you)

Another question re: ventilation. We have a 6"x6" square vent take-off similar to this one:

Vent takeoff.jpg

And then we have duct work that takes it to a blower and then out of the workshop. We are trying to figure out the best location for this take-off in the cutting chamber. The bottom in the center would seem to give the best coverage, but it's the least convenient. Does this takeoff seem about right to you? Any suggestions for location in the box?

We haven't really found a location that works exceptionally better than others. One feature that help is if there are inlets on the other side to create a nice draft. But this also requires a sort of overlapping gap to prevent laser radiation from exiting.

Left side or center rear base is probably the best location. If you find it inconvenient in the base I would go with left panel.

Thanks again for the help - we'll send you some pics when we get it cutting!


Greg Buckland

On Thu, Sep 4, 2014 at 3:35 AM, Stefan Hechenberger <> wrote:

Greg Buckland here at Open Source Ecology / Factor-e Farm. We are working on getting our beautiful Lasersaur up and running, and as we hook it up, we have a few questions:

Were CO2 laser safety goggles included in the shipment?
If so, we can't seem to find them. Do you have goggles you recommend? I was looking at these: 

Good find.

These don't specify blocking 10600nm (CO2 laser wavelength).

Any suggestions or thoughts on which goggles we should get?

Are the dark acrylic panels laserproof?
In other words, when the chamber is closed, do we need to wear safety glasses, or will the acrylic panels protect us enough?

Practically yes, a fully assembled and calibrated Lasersaur is designed to be safe without laser glasses. It's eligible to be certified as a class 1 laser in most jurisdictions. Yet without going through with the paper work it's legally a class 4 laser system. So legally you would have to wear protection glasses and only let trained personal use it.

How do we connect the 40W chinese laser?
The lasersaur shipped with a 40W chinese laser. It looks like there are two electrodes on the tube - and two wires from the power supply that are not hooked up. There is a thick red wire (which comes from the power supply) and a thick white wire, which connects to the blue wire (which goes into the power supply). Could you tell me a) how to connect the wires to the electrodes (do I just solder them with regular 63/47 solder?) and b) which wire connects to which electrode (left and right in the picture below)?

The 40W tubes don't have screw terminals like the 100W ones do. Soldering does not work well because the heat can break the glass/seal. Either use a screw terminal connector (careful about torquing the pin) or conductive glue.

The red thick wire goes to the rear of the tube, blue/thin to the front (where the beam comes out). The red wire needs to be insulted. It's important to not overdo the layer of insulation as heat buildup may cause the tube to fail.

Careful with the high voltage laser PSU. It often stays charged even after unplugging it from the AC lines.