EEEK flames ! why though ? ( SORTED NOW)

[Jani Pedersen]

Hi all,

SORTED !

Just had a mild panic moment as streaks of flames followed the design I was vectoring - any ideas why this would suddenly happen ?

I am using mirrored acrylic @ 12 speed, 100 power and 5000 freq - I switched off the machine immediately and then tried again over same design at 50 / 50 / 5000 and still had the flames.

Working with it mirrored side down, no backing on it and plain paper to protect the mirror side on the bed.

On the second attempt I also raised it from the bed ( honeycomb bed that is )

Suggestions please ? I am almost too scared to try again !

Thanks :)

[Jani Pedersen]

O M G how stupid can you get ??? It helps if I have air assist and fan on - that's what happens if you answer the phone as you start off a job.

Can't believe how dumb I am lol. And ... how lucky I am nothing more serious happened.

DOH

[Chris DeGerolamo]

O M G how stupid can you get ??? It helps if I have air assist and fan on - that's what happens if you answer the phone as you start off a job.

Can't believe how dumb I am lol. And ... how lucky I am nothing more serious happened.

DOH

did it wrong. lol

[Dan Hintz]

Meh, whenever I cut wood I get a nice 1.5-2" flame arcing up from the piece... no air assist. As long as it follows the carriage and doesn't continue to burn in one spot, I'm okay with it.

[John Noell]

Meh, whenever I cut wood I get a nice 1.5-2" flame arcing up from the piece... I wouldn't walk very far away when it is flaming like that. :)

[Larry Bratton]

Well Dan likes fire anyway..RE: In his signature "Flame Polisher (ooooh, FIRE!)"

[Dan Hintz]

I wouldn't walk very far away when it is flaming like that. :)
Guaranteed I (or someone) stand in front of the laser the entire time (I really need to get some more cushiony flooring in front of it, too).

[Jiten Patel]

I'm with Dan, when Im cutting card stock, there is always flame, sometimes even sparks like those from a firework when cutting metallic cardstock. Kick back and watch the show!

[Rodne Gold]

I NEVER get flaming no matter what I cut , I use very high pressure air assist which stops it dead , I would be VERY nervous If there was any hint of fire in my machines

[Mike Null]

If I get flaming that I can't control with air assist or machine settings I don't cut the material. There is very little that I've found to be a problem but I'm not going to risk my lens or a fire.

[Dan Hintz]

Mike,

I've been running "experiments" over the last several weeks to see how my machine holds up under different circumstances. I have engraved two large plaques (14"x19") with no air assist, along with a bit of vector cutting 1/16" maple ply. I would pause the machine from time to time and take out the lens, checking for any smoke damage. Due to some rough handling on my part, my 4" DC tube was much closer to a 3" tube... which explains the loss in pull I've seen the last few weeks :( Smoke would linger around the carriage a lot more than I would like. But even so, the lens is still as clear today as it was when I started. Same flames on the vector, same heavy smoke on the rastering, but no damage I can see (the back of the machine could use a good wipedown from the smoke residue around the exhaust port, though.

Needless to say, I'm a lot less of a nervous Nelly if/when my air assist dies in the middle of a run.

[George M. Perzel]

Hi Gang;
I'm with Rodne- I use air assist with virtually everything do not want to see any flame ever. Call it paranoia, if you must, after having small fire and melting one focus probe while trying to cut ebony (don't take that job, Dee!)
Best Regards;
George
Laserarts

[Martin Boekers]

Meh, whenever I cut wood I get a nice 1.5-2" flame arcing up from the piece... no air assist. As long as it follows the carriage and doesn't continue to burn in one spot, I'm okay with it.

Just curious Dan,

Do you have air assist with your machine, if so why do you choose not to use it.
When I had flaming it did char the surface a bit. Realigning the air tube got things
back on track.


Marty

[Dan Hintz]

Do you have air assist with your machine, if so why do you choose not to use it.
When I had flaming it did char the surface a bit.
ULS machines use air curtains over all of their optics to keep them clean... this same air eventually ends up as the air assist coming out of the cone. Taking the cone on/off from job to job was becoming an annoyance (air has to be on when the cone is), so I wanted to see what would happen if I left the cone off and left off the air altogether. I get a flame more often (not always, though), but other than a slightly darker edge (the true vertical surface only, not the surrounding horizontal surface areas), it doesn't appear to be an issue. Once on a piece of basswood with a tight curve and a piece of mask that was lifting I got a semi-sustained flame (the mask caught on fire)... it eventually put itself out when the flame hit the portion of mask that was no longer lifted form the surface, and it darkened the face in that area. Even then, the lens was okely dokely...

I have not had the brass cajones to try that test with acrylic...

[Martin Boekers]

Now I see, Thanks for the insight!

[Bill Cunningham]

Yesterday I did a bunch text and logos into 5" x 5 foot maple boards for Starbucks (they even brought me coffee):D. A little earlier, I had to make a minor adjustment to my exhaust piping. Unbeknownst to me, while making the adjustment, the first elbow in the line separated, opened about a 1" but could not be seen from below. I started the first board, and after a few minutes, I thought it was getting a bit smokey :(.. Then, it started to get a LOT smokey:eek: I discovered where the smoke was coming from, but I could not get to that section of the pipe without climbing on the table, and standing/moving/possibly bumping the board being engraved, it was sticking out the side of the laser. I opened the front and back doors to the shop (35 degF outside) and hoped it would clear before I got smoked out over the next 20 minutes needed to finish the job. Once the laser stopped, I climbed up and got it fixed, but my eyes were still burning, and the shop still smelled like a bushfire this morning. Where there's smoke, there's not always fire, but smoke by itself is pretty bad too:p

[Dan Hintz]

Bill,

There's no pause button on the Epilogs? That button alone has saved me hours of frustration...

[Jani Pedersen]

I'm not aware of a pause button on my epilog - if I open the top it stops the actual firing but I switched mine off at source when I had the flames. One question with regards to this, how would I get back to the point where I'd stopped the cut ? ie if I had a wavy lined box and had cut 3/4 of it before flames caused me to stop the process, is there a way to get back to the same spot to resume cutting without having to go over it all ?
Oh, another question, it made me realise I am not sure what type of fire extinguisher I should have on hand either - which should it be ?

[Dee Gallo]

Mine has a STOP button, which will immediately pause rastering, but it does not immediately stop vectoring.... it seems to keep going for a few seconds before stopping. But then I can press GO and it will resume right where it left off.

If you lifted the lid, it would stop the laser but not the movement so it would be pretty hard to get back to exact spot you stopped. You'd have to run the job again with the lid open (& red dot on) until it got back to the spot in question, then drop the lid and go on your merry way.

cheers, dee

[Jani Pedersen]

Mine will also stop but at the end of a line per se - perhaps it is in a timed mode - I'll have to test it. Will also test out lid lift and drop too. :)

[Bill Cunningham]

Like Dee's, the stop button will stop my laser raster immediately, but not the vector. It will continue on for a few more seconds. Stop, and then continue on again when you press go. But 'my' particular problem was in the piece of wood 5 feet long. 2 feet in the laser, and 3 feet sticking out through the hole in the side that I cut and fitted a door, so I could do things like this. I would have had to climb up onto the table and put my feet on both sides of the 'stickout wood' and wrestle a piece of vent pipe back together, duct tape it, step back over it and climb back down off the table without touching it even a hair.. I'm not a nimble little fellow, as a matter of fact, I'm 6'2" and 250 lbs, much like the dancing hippo's in a Disney cartoon. The chance of me being able to 'dance' around that board and not bump it are practically zero, so you can say I got smoked!:rolleyes:

[Chuck Stone]

[QUOTE=Jani Pedersen;1676003 One question with regards to this, how would I get back to the point where I'd stopped the cut ? ie if I had a wavy lined box and had cut 3/4 of it before flames caused me to stop the process, is there a way to get back to the same spot to resume cutting without having to go over it all ?
[/QUOTE]

I think on a vector you wouldn't have to worry so much about positioning. If it cuts
twice, it is still cut all the way through, right?
But raster is different. I had to do it yesterday. 18x24 sheet of mahogany, rastering the
Declaration of Independence for an hour or so while I did other things nearby.
The cord to the laser worked itself loose and eventually it shut off in the middle of
the job. ugh!
I dug out the heavy duty magnifier, pulled out the sheet and zoomed in really close
on the computer to identify where the rastering stopped. I was using Photoshop.
I dragged a guide to that position and then selected the part that was already
engraved and I cut it. Ran the job again and it was right on the money. Started
engraving right where it left off .. no overlap or space. But, I was lucky that the
text along the 24" length gave me plenty of spots to place the guide line. I put it
where I thought it should go and then looked really close at other letters in the
text at other positions to fine tune the placement. (stop halfway through that
letter "L" .. nudge a bit to get it right in the middle of the dot over that "I" etc..)
Oddly enough, the more intricate the image, the easier it is to place the guide
correctly.. it gives you more reference points. Cutting a straight line? forget it.

Dee mentioned, you could run the file again with the lid open.. but for me that
would be very hard. I just don't see that well inside the laser.

[Martin Boekers]

Mine has a STOP button, which will immediately pause rastering, but it does not immediately stop vectoring.... it seems to keep going for a few seconds before stopping. But then I can press GO and it will resume right where it left off.

cheers, dee

Dee,

I believe it goes to the next node then stops, must be a mathmatical thing.


Marty