[hackerspaces] laser cutter revenue

[Nathaniel Bezanson]

So far, the one at i3 Detroit hasn't been the focal point of any big
classes (though as soon as I get two software quirks figured out, I want
to change that!), but there's a box on the wall next to it saying "laser
time $10/hr". Most users round up to the nearest dollar, even for jobs
only lasting a few seconds, so it generally does alright. I don't have
dollar figures handy.

To James' points: The water chiller that came with this machine had flow
and temperature alarms, which originally weren't connected to anything. We
wired them up so they'd inhibit the laser tube power supply if anything
was amiss. The cabinet originally didn't have any sort of safety
interlocks, so we added some and wired them to the same inhibit line. So
far, nobody's ever forgotten to start the chiller (it's on the same
switched power strip) or close the machine's cover, but we're protected
against that eventuality.

The lens air-assist compressor is also on the same power strip, but I
don't trust the hose to remain unpinched forever. I've got some parts and
just need to sit down and implement the airflow sensor in that line. The
last main vulnerability is the exhaust blower, which is switched
independently and has no automated feedback. I'd like to put a
flow-sensing vane in that duct, too. Pie-in-the-sky wishlist also includes
a (magnetic?) sensor on the fire-extinguisher mount, so the user must
remove and then replace the extinguisher (reinforcing awareness of its
location) to start the machine.

Point being, idiot-proofing is also me-proofing, and all of it helps
reduce the chances of an accident being costly. On top of that, there's a
kitty to fund repairs or eventual tube replacement, and I think if the
bill were to exceed the savings, enough of us appreciate the machine's
value to just pony up the rest out-of-pocket. Hopefully once we start
running classes, those contributions will max out the laser kitty quickly
and the overage will go to general space goodness.

Sorry I couldn't be more help on the accounting side. ;)

-Nathaniel-

> I know several spaces have laser cutters and some use them as a
> revenue source.  I would like to see hard numbers on operating costs
> of a laser cutter and revenue they bring in.  Could any spaces provide
> this information?  It would be much appreciated.
>
> Raymond