[Swansea Hackspace] Proposal: Laser Cutter

[Justin Mitchell]

On Wed, 2014-10-15 at 11:32 +0100, Alan Cox wrote:
> > This is a chinese import, the max object size is 300x200mm (more or less
> > A4), its a 50W CO2 laser which can cut several mm thickness of wood,
> > plastic, card, leather etc, and etch onto plenty of other materials. It
> > will not cut metal, that's a whole other league of device.
> 
> Check which plastics it does - a lot of them won't do styrene containing
> products as the fumes frost the lenses somewhat irreversibly, vinyls
> (gives off highly toxic fumes so needs special venting) or PVC (ditto)

Its a CO2 laser, and yes, certain plastics like PVC are best avoided due
to the fumes, we need to add suitable venting to it anyway, wouldn't
want all that smoke in the room, a flexible tube out of the window seems
to be the norm.


> > The device itself sells for £529 including shipping, there are cheaper
> > versions, but they have either a lower powered laser (slower, less
> > thickness of cut) or don't have the air-assist cutting head (blows away
> > smoke and debris from cutting point). We might get hit for some VAT /
> > Import Duty, but the customs declarations aren't usually the full value.
> > So total cost, with contingency for taxes, the venting and electronics
> > is upto around £700
> 
> And a fire protection system, so there should be a CO2 extinguisher with
> it and included in the budget.
A quick search says £20-30 for a 2KG co2 extinguisher.

> Sounds a pretty good price. Does it have CE approval with interlocks, is
> it fully enclosed and with safety cut outs sufficient to allow it to be
> used in an open space (or does it need to be in a room of its own with the
> operator wearing protective glasses). Good excuse for a flashing amber
> light on the door 8)
It claims to be "CE certified and FDA compliant" and a CE sticker is
visible in the photographs, but i would want to run some earthing and
wiring tests on it before allowing general use anyway.

It is a fully enclosed type, the acrylic viewing window is opaque to the
laser light from a CO2 tube. It will be necessary to keep a watch on the
device whilst in operation incase the material catches fire, or theres a
malfunction.

I would expect there to be safety interlocks, not all listings mention
them, and they are not obvious from the photos, if there aren't any then
a lid cut off is first on the list of things to add.


> Other big big question - is the laser tube a standard design, can you
> source replacements, how much, how long ? The tubes are basically
> consumables and quite pricy at the best of times.
The tube is rated for 1000 hours, the guy from reading said that can
vary quite a lot in practice. the tubes appear to be a pretty standard
design, there are lots of places selling replacements, and they cost
upwards of £150 depending on expected lifespan.
 
> The operating cost of a laser cutting is supposed to be £5/hr.
Ah yes, i should have mentioned that there would be running costs for
anyone using the cutter, to cover replacing the tube, and eventually
also the various mirrors and lenses in the beam path.

Although this may all sound like a lot of work it is the path than many
other spaces have taken before, and buying a truly turn-key ready system
seems to start at £3000 or more.