[Frogblender]

Ok, it hasn't yet.... but I can't be the first guy to hook up a woodworking dust collector to the laser. The same dust collector is used for an active wood shop - tablesaw, bandsaw, belt sander, etc. And with the amount of spark/flame I see coming from the laser.... frankly I'm surprised it hasn't happened already.

Compounding the issue is the dust collector is up on the roof of the building (with 4" duct penetrating a skylight), inside a plastic home-depot plastic deck box. Being on the roof means I can't just look in the dustbin to see if it's a-burnin'.


Anyone have any bright ideas on fire prevention / risk mitigation (other than the obvious "don't connect laser to sawdust") ?

[ger21]

Anyone have any bright ideas on fire prevention / risk mitigation ?

Yes, never connect a laser's exhaust to a dust collector.

[Jim Dawson]

:idea: Maybe a 5 gallon bucket with a few inches of water in it, inlet configured so the airflow from the laser is directed down into the water, then connect the shop suction system to the lid. Don't forget to refill the bucket occasionally

EDIT: What ger21 said too!

[Frogblender]

:idea: Maybe a 5 gallon bucket with a few inches of water in it, inlet configured so the airflow from the laser is directed down into the water, then connect the shop suction system to the lid. Don't forget to refill the bucket occasionally

EDIT: What ger21 said too!

Jim Dawson = Dude of The Week. Thanks man! I did exactly what you suggested: Behold the picture:

5-gal bucket, half-filled with water (and cup of bleach to prevent stink).
Black hose goes to laser, grey hose goes to dust collector on roof.
A round piece of plywood with flanges (and a blast gate on the grey hose to moderate airflow, in case I'm cutting paper or something) on the bucket lid.
The black hose has a 4" extension down into the bucket, so the flaming bits blast in closer to the water. I drilled two 4.5" holes in my table.

Works awesome! As long as you remember to check the water level. I found the evaporation rate is maybe one cup per hour.

As a side note: I researched alot of "in-line spark supression" duct devices, used mostly for grinders (which have non-stop sparking). These devices consist of nothing more than sheet metal baffles which cause zig-zag airflow - the idea is the heavy spark particles (heavy compared to air molecules) can't negotiate the tight turns, and clunk against the baffles... and then it takes time for the spark to re-accelerate to airspeed, at which time it clunks against the next baffle. The goal is to delay the spark particle until it has time to burn out. Doesn't sound very foolproof to me....

Attachment 346998

[Jim Dawson]

Thank you for the kind words.

Looks Good! Happy to hear it worked out.

[godfrey]

Yes, never connect a laser's exhaust to a dust collector.

Some ship with most of the inexpensive larger chinese lasers, minus the bag, of course...but essentially that's what it is.

I had a small Delta AP300 on my cabinet saw years ago, 680 CFM. It would have sucked every small part off the cutting area if I attached it to a laser. I have my eye on a small hydroponics fan, think it's about 175 CFM, that I'm going to put on a speed controller. All it needs to do is draw smoke and fumes out.