So I have the 18" Beseler on its way. I am about to start building my box, but I am at a total loss on how I should attach the lens to the box...

First, I should cut a hole in the box?
Then I should put my junk in the box?

Wait, no... sorry, thats something else.

But seriously... I am going with a simple projector box (that I plan on hanging from my ceiling). How do I get this big lens to...
a ) not move around.
b ) have enough give so I can focus it. (It can't be permanently fixed because eventually I plan on moving the projector's home to a new room).
c ) for extra credit, be able to adjust the throw?

A knob for adjusting would be nice for the final solution, but I will take what I can get on this one.

Thanks for your help,
~EToreo

I did a box in a box design.

Basically I built the smaller box 6"x6" and at each end I cut the 5" hole for the Beseler. I inset the end pieces about 1".

Then I inserted the Beseler with a little sewing "tape" around each end where it fit the hole. This made it a snug fit.

Then I cut a 6.1"x6.1" whole in the main box. I added a piece of wood as a slide rail on three of the sides inside the box and slid the focusing box in.

The picture below is with the Pro lens but I just modified it a bit for the Beseler.

jonjandran,
I looked at that picture before posting and it left me even more baffled. To the naked eye, it looks like your boxes have a lot of wiggle to them. What is keeping them in place? Also, is that tape you used strong enough to prevent the lens from slipping out (or in) if an earthquake hit? Not that I think it would happen, but boy would it suck to have a 18" Beseler fall on your head while your enjoying some 1080p.

Thanks for your knowledge,
~EToreo

Inside the box are sliders on threes sides that the focus box slides on. No wiggling.

I cut the holes a little small and forced the Beseler in, believe me it would take an act of congress to get it out

Build a motorized focusing function. il roughly explain it to u. You get the lens, you build a set of rails(similar to inside a dvd burner where the laser optics slide on a set of rails), you mount the lens at the correct height to something which will slide on the rails. You then use a very long bolt as the runner which has a nut attached to the base of the lens mount. You use a high torque motor with slow RPM to turn the bolt and slowly focus in and out. You can make this thing as long as you need and make it go two ways. Once you construct the structure you can then mount a two buttons on the side of your box, one to + adjust one to - adjust.

Wow. So a few more questions...
1) Whats the tape for if its so snug?
2) Do you think I could/should hot glue the lens in place once its in the small box?
3) What are the other two larger boxes for before the main box?


As for the motorized one, that looks really cool and I might try something like that once I have my box up and running. Baby steps.
Do you think I could use a servo for that? (I have an old RC plane with 4 or 5 servos in it).

Thanks again,
~Eric

1. Why have airbags if you have a seatbelt?
2 If you want to
3. Design. I wanted it to look like an old camera.

Thats good point, I will disable my airbags. I was goign to say that it looked like an old camera, but did not want to offend you if it was not meant to be. Thats on awesome look.

A servo will work, that way you can go one step further and keep the remote controlled function and have the unit's focus remotely adjusted! The only problem with a servo is its voltage, i think most run at around 3 - 5vdc but you might be able to get some for a 12v so you don't need another inverter. Also you servo should be geared so that it can produce alot of power and spin at a nice speed. If its too fast you wont be able to focus well, if its too slow, its gonna take long, if the gear ratios don't are insufficient, as you know the beseler is quite heavy, it wont be able to twist the bolt and adjust the lens.