Friday, December 31, 2010

New Years - LASER Fire

As some of you know, we have a 35 watt laser engraver that we use to create artwork, build prototypes, and sometimes make a few extra dollars doing wedding glasses and such. The primary rule of the laser is to NEVER leave it unattended when it is in cutting mode.

Engraving mode could have some problems, but the laser is firing tiny blasts of power to create a pattern on the surface of the material. When in cutting mode however, it is usually running at full power burning it's way completely through the material. On a lightweight material it can overheat and catch fire... usually you can just blow it out. But what if the machine was being run with nobody around to watch over it?

Bad things happen.

This is what I found when I came home from working in Connecticut. (I also had a bad case of kidney stones while there... so it's been a rough month.)

This is what the laser looked like when I opened the top... full of ashes, badly burned interior, and the optical head would not move more than an inch [25mm] in either direction. (Normally it moves 24 inches [600mm] in the X-Axis.)

You can click on any image to get a larger view.

I knew that the unit sustained high temperatures and that the X-Axis gantry contained not only the lens assembly to focus the laser on the target, but the electronics and optical encoder system that allows the precise positioning of the unit. I was hoping that the optical encoder was intact as it is an expensive part due to the accuracy needed to produce it.

After opening up the gantry cover I saw what I was really up against. The cooling hose had completely melted and had to be cut away... this gave me an idea into just how much heat had been generated... it was not a small fire in there.

The optical encoder which is pivotal in the overall accuracy of the machine was melted in a couple of spots... one bad area will throw off the entire machine so it needed to be completely replaced.

The ribbon cable which carries the power and position signals to the processor sustained major damage and also needed to be replaced, but the socket it plugs into was intact. If the rest of the lens assembly was in good shape it wouldn't be too expensive, but would take a good deal of labor. (I have the skills needed.)

When I examined the auto-focus switch, a plunger assembly on the bottom of the lens housing, that's when I started to get a bad feeling. It was frozen in place which meant that the unit probably melted in place. I would need to pull the lens assembly off for shipment to Epilog Laser for repair or replacement.

After looking closely at the lower lens, I saw that it had sustained heat in the fire too... and if it has any materials fused to it, the assembly will need to be torn down and the lens replaced. That is likely expensive and will also mean that I will need to do a complete alignment on the machine.

I'm still hopeful that they won't need to run a calibration on the machine... if they do I have two choices... fly a tech here or ship the machine to Golden, Colorado. The best price I can find right now is $300 shipping each way.

So for the moment it looks like this is the shopping list for the replacement parts... but I won't know until Epilog reopens in January and I speak with the tech there. I'll send him (or her) this blog so they can evaluate it better.

I also have images posted on Photobucket so they can take a closer look.

Replacement Parts List

* X-Axis Belt Assembly
* Top Cover
* Cooling Hose
* Optical Encoder Strip
* Ribbon cable Assembly
* Plunger switch
* Lower Lens (possibly)
* Optical Encoder Sensor (Possibly)

Stay tuned for more information as I find out.


  1. ouch that sucks big time,
    but why use the laser without being there

    i was vector cutting acrylic without air pressure and catches fire,
    Thats when i thought lets not use it unattended

    well good luck restoring it

  2. I you are not going to restore it, I could use a few parts... I really need a new x axis/mother board.