AC Infinity or Fan External Vent for Lack V2 Enclosure

In order to eliminate fumes I designed this replacement rear panel for the Lack V2 enclosure. An AC Infinity fan (you can use some other fan/controller) exhausts the fumes outside.  The fan is mounted at the top of the rear panel to minimize drafts.  A nice side effect of using this rear panel is that you can mount things to it such as a Raspberry Pi.

There are other designs available where the fan is vented outside the enclosure but that does not protect you from the fumes.

The model is fully parameterized and can be adapted to a different fan system and duct size.

There are 3 printable objects:

1. Panel Fasteners (Qty 4 needed)
2. Cable Door (depends on what you want, Qty 0 to 2 needed)
3. Adapter plate (Qty 1)

There is a non-printable item which is the rear panel door.  Use the provided measurements with a pinch of salt.  The measurements and fit will depend on measurements from your Lack V2 enclosure.  ½" or equivalent MDF or plywood would work for the rear panel.

You will need a window insert if you plan to exhaust to the outdoors. This will require:

1. Board that fits in window 
2. An exterior vent
3. Flexible hose
4. Two clamps
5. 10' adhesive foam strip
6. Four screws

The model files are setup for 4" dryer exhaust but it is parameterized to fit whatever is available locally.

Assembly of the rear panel:

Remove the existing rear lexar panel. The brackets on the rear of the enclosure need to be trimmed to allow the new rear panel to be centered on the slot.

Prior to modification the rear brackets look like this:

I used a Dremel, but files or whatever you want to use we need to trim back the chamfer so the brackets look like this:

Cut the back panel to the square dimensions inside the legs and top/bottom rails.  Hold the board up to the back of the enclosure and trace a line around the inside edge

You should end up with something like this:

Take one of the Panel Fastners and mark around the edges.  This is how far the full depth needs to be cut. i.e. the center of the saw blade must reach this point.  

Mark out the cable doors if needed

Using a table saw, or whatever method works for you cut a slot roughly centered in thickness of the board.  The exact measurement should be taken from your enclosure from the rear corner brackets that were modified.  The depth needs to be slightly deeper than the arm height on the panel fastener and must for the full length of the panel fasteners. It is much easier to do this before cutting out the panel corners. 

Now cut out the corners and cable pass throughs using a jigsaw.

Check the fit of the fasteners. I recommend putting the wingnut on the outside.

Make a cutout for the fan and mount it

Remove the four screws holding the exterior cover to the fan.  Mount the adapter plate using the four screws that were just removed.

Install the rear panel into the enclosure. And put the rest of the enclosure back together.

You need to measure the inside of your window to determine the thickness that is required to fit somewhat snugly.  In my case it was ¾".  I used some wormwood white oak that I milled from deadfall as the window insert.  The exterior vent is a standard dryer vent purchased at a local hardware store.  Mark where you want to mount the vent, make sure you include some extra room to allow the band to fit inside.  I also raised the mount up higher than center to allow the exhaust to be higher than the outside lip on the window.

 After cutting the hole, prime and paint using exterior paint.

Put the flexible hose through the whole, then attach it to the vent with a clamp.  Then attach the vent to the board.  Put foam insulating tape around the outside of the board.

Put the adapter plate into the window and attach the hose to the rear panel

I manually setup the fan, I run it at the lowest setting.  With the enclosure doors closed there is a negative pressure which means fresh air is drawn through the cracks and the fumes are expelled outdoors.  

If you are using ACInfinity here is a nice mount https://www.printables.com/model/374428-ac-infinity-controller-stand