# Im designing a box for the ceiling to hide a projector



## steve b (27 Jan 2017)

ive designed a box for the ceiling to hide a projector, its also going to throw some light out of the sides to try to make it look pretty. when its all closed up.

currently i have my projector on standard hanging bracket form the ceiling, but its on show and looks a little ugly.

My first design was simple enough











the problem here is the projector is too close to the screen, with the box in the center of the ceiling placing it further back in the box would cut off the bottom of the image, so it basically doesnt work.

my second design is more complicated but gets me around that issue, hinge a flap at the back that pulls down its simple and should give the projector a clear view of the screen














or i could go for the following instead










have the whole door pull down to a height where it can shine at the screen easily.

the issue im having is, i dont know what to use as a mechanism to raise and lower either the flap door approach or the lowering shelf approach.

for the flap door approach i know i could use steel wire so the door cant open too far, but how to i lock the flap in the up position that isnt too fidgety to open. if i do open it, how do i stop it dropping down and hitting full extension of the wires too hard? (i kind of want to to push closed and open smoothly. and the weigh of it all would be fairly substantial

with the lowering idea, what could I use to lower the door smoothly that will also hold it in place when closed, i looked at a few parallel hinges used for kitchen cabinets, but i dont think they would be strong enough to hold the 1/2 or 3/4 inch plywood and projector in the up position.

any idea what might be out there?


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## Bm101 (27 Jan 2017)

I'm probably misunderstanding the whole situation (  ) Gas strut and magnets might work?


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## MattRoberts (27 Jan 2017)

I would probably use something like this for either design: https://www.windowware.co.uk/upvc-parallel-window-hinge

A loft hatch catch should also do the trick to hold it closed


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## Stanleymonkey (27 Jan 2017)

I would go for the third design in terms of airflow. I take it the vents are on the sides as any top and bottom vents would be obstructed.


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## Brentingby (27 Jan 2017)

How much farther back do you need to shift the projector to get it to fill the screen?


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## sunnybob (28 Jan 2017)

you should find something useful here.
http://storagemotion.com/wardrobelift/


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## sunnybob (28 Jan 2017)

or this one
https://www.youtube.com/watch?v=03SZ6NW8I5s


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## Rorschach (28 Jan 2017)

I can't offer much advice in regard to this but something to bear in mind when designing, try and make it as flexible as possible in terms of size. I have known people buy/make brackets for a very specific projector only to have it break and then a new one not fitting. Lifespan in these units is limited with replacement parts often costing as much as a whole new machine, try not to limit yourself too much.


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## Eric The Viking (28 Jan 2017)

If you are struggling to get the projector far enough away, you might consider using mirrors to bend the light path around. Ideally they need to be front-silvered, which are commonly used by DIY astronomy telescope makers, and were used in the more up-market overhead projectors too (if you can find one or two in a junk shop). Using two will let you keep the image the right way up/round, but many projectors have a "flip" feature for back projection, meaning you can get away with just one. 

The extra distance you can gain is limited by the size of the bigger mirror and how far away you can get it from the projector. If you draw out the layout to scale, you can work it out. 

Doing a vertical "U" will need smaller mirrors than horizontal, because commercial films can be up to 2:1 aspect ratio. It will also reduce the need for keystone correction a bit, giving you sharper pics with less colour fringing, but obviously it hangs down more if you go under the projector! The mirrors can get fairly dusty between cleans, which is OK, because they're not in focus, but if there is a smoker in the room they will collect tar and nicotine, which is hard to clean off. 

Finally allow for cooling. The top of the room is the warmest part. Note the power consumption of the projector and compare that to a kettle to give you an idea of how hot it gets. It's almost all waste heat, and has to be kept within a certan maximum to protect the electronics (just like a PC). If it has a USB port, you might be able to power a small PC fan (@5V, but most of them are 12V, which won't work) - best thing is cut one end off a ready made USB cable and wire that to the fan.

Of course, you might also apply the two-mirror trick to make an actual periscope, allowing you to keep the projector say in the top of a HiFi cabinet on the other side of the room. That would make cabling easier too.

[edit]Just looked at the Sketchup room - looks like there is no place to project from at people height! Be aware that if your projection wall is opposite a window, even some distance away, and you have any light pollution at all, it will have a huge effect on how good the "screen" looks. Also it needs to be as matt white as you can get it - absolutely non reflective and not at all grey nor tinted. "Caucasian" skin tone is considered light in colour, but photographers will tell you it only reflects about 17% of the light falling on it. If not the brightest, mattest white, the screen will waste a lot of the projector's power.


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## nev (28 Jan 2017)

Forget the box. 
get one of these or similar ... http://www.screwfix.com/p/manthorpe-gl2 ... oCnwTw_wcB
fit some chains/stays/etc to halt hatch opening at correct tilt.


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## thegsey (4 Apr 2017)

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## thegsey (4 Apr 2017)

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## lurker (4 Apr 2017)

I assume you have made allowances for how hot these things get?


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## thegsey (4 Apr 2017)

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