Green lasers fan?

Is there a trick to turning on the fan on the green laser so that you can use the red laser? Usually you hit the button and it turns on. It has been a while since i have been here and the fan on the green laser will not turn on.

Flip the red switch on the back of the machine nearthe power cord.

This seems like a safety issue to me. The fact that one person has asked tells me that at least a couple of people have likely just said: “f*** it, I will just run the one fan that comes on with the red laser”

In fact just before I went into the hospital, there was an evening when a couple of people were using the red laser (Hare) with the main power to the green laser (Tortoise) off. At least one person working elsewhere in the building came out to the front to mention the strong Acrylic fumes throughout the building. I noticed breathing difficulty and once I saw the power switch situation I turned the Hare’s power main switch on.

The only explanation I heard for ever turning the main power off for the green laser was because it runs the electronics bay cooling fan all the time.

I propose we make this situation safer by either adding circuitry to make both of the vent fans always both come on when either laser front power switch is on, or rethink the ventilation system so that there is only one fan, and a safety airflow detection (vane) swiitch preventing the lasers from firing and lighting a light when either laser is operational but the vent fan is not sucking air out. In the interim, is there any real reason to shut off the rear (main) power to the green laser?

Mike B

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Couldn’t we just put check valves in the ducting? It looks like they’re about $20 each on Amazon.

Ideal-Air 736982 Back Draft Damper, 6"


There is a check valve in the green laser, but the system is not perfectly sealed. It is not a perfect seal, so there are some amount of back flow. The plan is to pull the back flow flap out so there are not any cleaning maintenance issues with it. This is a dirty, system with sticky residue with small chunks of things getting pulled through it. This causes problems with anything that has to close tightly. These factors is why it was decided to go with a dual activated fan when either laser is turned on. Then tied them together in the future.

The main problem I have had is that any off the shelf solution (blast gates, back flow check valve) that are made for vacuum systems or hvac systems are not designed to be leak proof, so they fail when you are pressurizing a system filled with toxic fumes. some of leaks out.

Ideally it would be best to put a second or bigger hole in the roof, and vent through that. If someone would like to reach out to the landlord about adding several new holes. Jewlery, lasers, paint booth, ac venting in the classroom, ect. That would be great. Until then we will have to make do with what we have.

There are also some leaks in the system. They need to be tracked down and sealed. If there are any volunteers please step forward and start tracking them down and tape them up. There were no major leaks when I connected up the system, but things have been moved since then.

I am planning to work on a solution to tie the two laser together over the holiday break. I can accelerate that plan if there are major issues, and do a simpler version that powers both exhaust fans off of the (rabbit) when powered on. That would stop this issue until the final permanent system is in place. If someone can point to an off the shelf product that would accommodate our needs step forward.

If there are safety concerns and the current dual activation is not working. Take one of the systems offline, lock it out, and break the venting, and cap it off. Nobody had reached out to me directly, so I have been working on the assumption that things are working well enough. I don’t monitor the forum daily. I have had other things going on, and I have not been down to the space.


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