Anything recommended on the safety front? / unattended printing ?

While I wait for some parts to arrive on my first RepRap build, thought I'd ask if any of you have felt the need to anything in particular on the safety front: smoke detectors? fire extinguishers? safety screens?

Does printing generate smells? I have a couple of potential sites for my Prusa, one of which is a basement where
smells would tend to linger.

Also what's the view on the safety of unttended printing, say in a locked room away from pets etc?

Mike

I only print when i'm home. I'm a bit scared of fire, but i'm more scared of something breaking.

ABS has acrid, unplesant smelling fumes. PLA has a sweet unoffensive smell and is better for an enclosed space.

I think PLA smells nice and it is pretty harmless, but I hear people prefer ventilation with ABS. The smell with PLA doesn't linger at all, unless you burn it, then it can smell a bit for a day or two. I generally don't notice any smell from my printers any longer (all using PLA).

Unattended printing is not for the inexperienced, you need to know your printer is totally stable in every aspect. The filament feed can be tricky unless you buy it on spools. I seldom leave my printer alone for more than 15-20 minutes at a time, even though I have no pets who can interfere with it's operation.

I have had good use of a double pole (safety) switch on the 12v and gnd line going to my printer. It's nice to be able to stop it instantly when something goes wrong.

Smoke detectors and fire extinguishers is something you should have in your house already.


With some precaution and common sense, RepRap is a very safe hobby.

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-Nudel
Blog with RepRap Comic

I leave my Mendel for several hours as some prints take a long time and I can't be running down to the garage all the time, the main thing for me is to make sure they are stuck properly and NEVER start up a power hungry device like a power saw while the printer is running especially if plugged into the same circuit as it causes the printer to miss steps

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Experimenting in 3D in New Zealand

Try putting an MOV on your AC line to your power supply. That should help with line noise a bit...at least spikes, won't help with brownouts though, you would need a UPS for that.

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www.Robosprout.com RepRap Mendel parts and accessories.
Message if there is anything you need...I have more than what is listed on my site.
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The most dangerous part of a reprap is the wiring to the heated bed. Constant movement can break the strands inside the sleeving.

If it is a low voltage - high current bed then the remaining stands burn out, potentially causing a fire.

If it is low current - high voltage bed then the broken wire arcs and melts the insulation, shorts the mains and explodes.

I have had both of these happen. Luckily the mains explosion didn't set fire to anything and I was around to witness the low voltage fire and blow it out.

On the new machine I have designed I use ribbon cable and a flexible strip of polypropylene to make the equivalent of a micro cable chain. So far that looks good. In any event you have to ensure there is no absolutely no flexing at the connections and any bending in the cable has a minimum radius that is related to the wire gauge.

Electronic components can always catch fire. They should ideally be enclosed in a V0 rated (self extinguishing) enclosure. Unfortunately printed cases are a fire hazard. I am not aware of anybody selling V0 filament. I think the additives for ABS makes the plastic more viscous, so it might be difficult to extrude.

I am thinking of putting automatic fire extinguishers in my machines.

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[www.hydraraptor.blogspot.com]

Guys, thanks for your advice on this.

Mike

Nophead, how many pins of ribbon cable do you need to carry heated bed current?

By using fire retardant wire (CL2 rated) and appropriately sized fuses, nearly all that risk goes away.

nophead Wrote:
-------------------------------------------------------
> The most dangerous part of a reprap is the wiring
> to the heated bed. Constant movement can break the
> strands inside the sleeving.
>
> If it is a low voltage - high current bed then the
> remaining stands burn out, potentially causing a
> fire.
>
> If it is low current - high voltage bed then the
> broken wire arcs and melts the insulation, shorts
> the mains and explodes.
>
> I have had both of these happen. Luckily the mains
> explosion didn't set fire to anything and I was
> around to witness the low voltage fire and blow it
> out.
>
> On the new machine I have designed I use ribbon
> cable and a flexible strip of polypropylene to
> make the equivalent of a micro cable chain. So
> far that looks good. In any event you have to
> ensure there is no absolutely no flexing at the
> connections and any bending in the cable has a
> minimum radius that is related to the wire gauge.
>
> Electronic components can always catch fire. They
> should ideally be enclosed in a V0 rated (self
> extinguishing) enclosure. Unfortunately printed
> cases are a fire hazard. I am not aware of anybody
> selling V0 filament. I think the additives for ABS
> makes the plastic more viscous, so it might be
> difficult to extrude.
>
> I am thinking of putting automatic fire
> extinguishers in my machines.

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www.Fablicator.com

I used one ribbon cable strand in each direction per amp and two for the thermistor, so 22 in total.

A fuse doesn't help much because as strands break the current capacity of the wired reduces to less than the fuse rating.

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[www.hydraraptor.blogspot.com]