120mm fans 8 of them

[LaserGuy216]

over kill or good idea?, I have it looking as four on each side with one set sucking air in and the other set sucking air out. my projector layout is double decker with power on the bottom and lasers on top, the lasers optics will have a small box of a housing that covers my RGB's laser lens & dichros... dust free!!!

the top & bottom (4) fans that bring air in will have filters, the other four no filters just covers for all. so my only question is do you guys think that the 8 120mm fans are over kill or should I just use smaller & save abit of space & money..

it seams that its a good idea with the 120mm fans to me

[QUAZAR]

I would have thought 2 would be plenty.

[The_Doctor]

Few as possible. Otherwise all you have is turbulence instead of airflow. And fans make heat too, specially 8 of them. Planning airflow from the start of a design is the answer.

[buffo]

Almost certainly overkill.

I've got a pair of 4 inch exhaust fans on my RGB projector (650 mw max output power), and I have twice run into situations where the blue laser's power output DROPPED because the cold outside air (38 degrees) was enough to cool the doubling crystal and reduce the efficiency. In both cases, blocking the inlets to the fans solved the problem within a minute or two.

So excessive cooling is a possibility, if you ever plan to use your projector outside (like in your backyard, for example). I think a pair of fans is more than enough for most projectors in this power range. Lower power solid state lasers don't really get that hot to begin with.

Adam

[Things]

... Lower power solid state lasers don't really get that hot to begin with.

Adam

Yup, its the PSU's and drivers/scanner amps that generate most of the heat usually.

[buffo]

Ok then - the PSU's and drivers for lower-power solid state lasers don't really get that hot to begin with either. That better?

Seriously though, the hottest component in my projector is the heat sink on the scanner amps, and it never gets above 100 degrees. (It's mounted to the case, so that helps remove heat too.) A small fan is all that is required to remove that heat. I've actually considered removing one of the two fans on my projector altogether. (For sure I'm going to install a switch to turn them off when they're not needed.)

The driver modules for my lasers are always cool to the touch. My Lasever green head actually does get warm to the touch, but my Lasever blue does not. Both Maxyz modules remain at room temperature, as does the main power supply that powers everything inside the projector. Likewise, the ScanPro-50 scanners themselves never rise much above ambient.

I think a lot of new hobbyists build their projectors with excessive airflow. This just means you have to clean out the insides of the projector more often (especially the optics, unless you've isolated them from the cooling airflow), it doesn't improve your performance at all. And like I mentioned above, excessive cooling can actually cause power instability problems with your DPSS blue laser if you operate the projector in a cold environment. So in that case, excessive fans could turn out to be a real problem.

Adam

[LaserGuy216]

I would have to agree that I do know that my scanner amps do get get the hottest, all of my lasers are lasever and have fans built on to them except for my 300mW 532nm, my 100mW 473nm & 300mW 671nm have small 40mm fans.....

So all in all I now think that I should only use maybe 3 fans tops?
one(80mm)with filter to bring in cold air, one small (40mm) to cool my scanner amps, & one (80mm) to bring the warm air out.....

I think I'll even use a switch to turn off the 2 (80mm) fans, but install a digital temp display to watch the temps in side...... but the scanner amps fan will stay on 24-7-365..... Sound better guys?

[SilentShaddow]

Alot of modern moving heads have variable fan control based on temperature sensing. Maybe this is something you could think about implementing? My reconning was on the basis that you are thinking about temperature sensing and some form of output to a read out.

It would enable you to have aa nice quiet runnning laser but reduces the chance of cooking you compotents if ambient temp rises
Carefully documented with lots of pictures ofc...

[allthatwhichis]

To be honest I like the 120mm fans because they are quiet. I plan to have one for inflow and one for outflow... if I ever put fans in. I have found even 80mm fans can get lout. this fan on the LW Blue is almost an argon fan.

[flecom]

you guys should have all your fans pointing inwards, to pressurize the case, then you only have one entry point for dust, have vent fins on the other side for the air to escape, and put filters in front of your intake fans (womens pantyhose works really well - dosent restrict airflow much)

also you might want to consider putting a filter on the interior side of the fan also, most of these fans can spit tiny amounts of oil from the bearings that in a computer dont make a difference, but when you have shiny optics begging to get dirty, it makes i difference lol

i think for any reasonable sized projector a pair of 120mm fans should be fine, i would recommend running them at ~7vdc... if you have a +5/+12 PSU hook the fans + to the 12v and the - to the +5v and you will get 7v difference

i have been cooling very hot PC's and servers for years, and this configuration has been my most sucessful over time