First… Welcome to my Plog… I hope to use this to keep track of my progress, and to perhaps bounce ideas/ discuss problems/ express frustrations/ find solutions for the PJ Which I like to lovingly call Backyard Warrior (Or BYW) .

Second… a little history… Truthfully the thought of owning a screen projector has never crossed my mind. As it is, we are one of those few families in America that watches very little TV (Except during football season). It wasn’t until I read the Popular Science article (Check it out here http://www.popsci.com/popsci/how20/be84637...ecbccdrcrd.html ) about a backyard projector that I started thinking…Hummm This sounds like fun… You see I have the perfect backyard for this!
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As you can see I have a natural amphitheatre that is surrounded by trees which provide a lot of light interference shielding, Ideal for the type of projector described in the article. Plus I want this to be an educational experience for my kids.

However in order to keep the wife factor low (meaning project stays under the wife’s radar as long as possible) I have placed a constraint on the total price of this project of < $300. This means I will have to do a lot of research/ improvisation and make use of a lot of stuff already available to me.

Currently I’m in my way of building the Hass enclosure (I will go in more detail in another post) I have spent a lot of time reading and learning from other peoples experiences and I have decided that this is in fact not one project but 5 smaller project put together in a larger final product. Following this rational I will divide the project into sections and address each one by its own merits. The 5 basic projects are:

Enclosure
Optics
Light source
LCD
Power

The Final Build will be the actual putting together of the pieces
Currently I’m not sure how I’m going to address multiple issues on each one of these but as I get answers to my questions I hope will each issue will be solved.

That, indeed is a perfect backyard. Good luck with the build.

Ok so far I have done most of my work on the enclosure here is a little status review:

Enclosure:

Well after much thinking I decided to go for a “Modified Hass Box” The reason for this is the final projector I have in mind will be attached to wheels. I also have decided to have the power for the LCD and the Light Source outside of the enclosure which will give me more space for tweaking but will require a bit of design of the electrical connections.

Here is a picture of the closure as it stands right now (To see how I get to spot just check out this< http://www.lumenlab.com/forums/index.php?s...amp;hl=Hass> I followed a very similar procedure )
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I used some old scrap red cedar ply wood I had in the basement for the sides, I experimented with the placement of the 4 dowels but decided to go back to the original design placement.

Like I said at the beginning of the Plog, my idea is to build a back yard projector. Something I can get in and out of the shed to watch movies outside in the summer. As a wheel base I’m using an old baby carriage that we inherited from our in-laws! Check out how the projector will sit in it:
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Here is another possible configuration:

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The first thing I thing I’m going to change is the front and back. I like the routed track for the top and bottom boards but the way it “Connects” with the front and back might be a little to much trouble to cut.
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So I thing I’m going to use some L chapped wooden track I have lying around from an older project and attached to the top and bottom edges of the back and front:

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Here is a picture of the L chapped mill work, you can get at Home Depot.


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Here is how it is going to look. Tomorrow I will cut them to size and attach them to the front and back. Once this is done I will build the top and back. I think I have an ingenious way of making these.

More later….

BYW PJ STATUS

Enclosure 75%
Optics 30%
Light source 0 %
LCD 10%
Power 0%

Final Build 0%

Your one of the first to make an outdoor PJ Do you have a screen size in mind?

That is a nice back yard.

Thanks Arizona,

(If you ever want to come and mow it for me your will be very welcome ) Actually, I have not decided on the screen size yet. It will depend on the light source more than anything. (I hope I can pulled off with the LL S15 Optics set) We will see. The biggest consideration is making it "Wind proof". I do like what some of the people have done in this web site : http://backyardtheater.com/

Hanamalu

i love the baby buggy, that has got to be the coolest idea ive seen on here yet. when your done you must trim it out with all the frills including a baby on top,fire retardent

The buggy is a pretty cool idea- are you planning to make the screen permanent or able to be taken down each night? I’ve been kicking around the idea of making an outdoor theater too, our back yard isn't as cool as yours, we live in town, but it'll do. We do have a lighted pool, which would be really cool to have a movie playing while we swim, but I'd have to come up with something I could take down easily.

Belive it or not this was my wife's baby carriage! (Who said you shouldn't keep stuff for more that 40 years ) About the screen. I have not decided on the design yet but It will be designed so I can take it down at night. I have a volleyball net (also DIY, I'll have to post pictures some day. The net is made out of plastic bags!!!) Anyway I thing I will hang the screen from these since the poles are very easy to set up. And when I'm done I just store the screen in the shed.

Hanamalu

Love the buggy look. All you need now are 22 inch chrome rims on the tires.

Folks,

Things where very slow this week. Keeping the wife factor low is really slowing me down. However today I have done some progress. The enclosure is almost completely done, just a few minor details I can finally start working on alighting the optics and building the Fressnel-LCD-Fressnel (FLF) housing, and lining up the triplet hole to the lenses. I’ll talk more about finishing the enclosure later.



BYW PJ STATUS

Part %Done Todo Next Issues
-------------------------------------------------
Enclosure 90% Paint in-out NONE
Cut air vents
Optics 30% Build focus Fresnel & Key stoning
for Triplet
Light source 0% Decide on bulb
LCD 10% Acquire new LCD
Power 0% Decide on wring
& Power box
-------------------------------------------------
Final Build 0%

This will a very good plog for outdoor use. You should have no problem firing a 20-25ft wide image using a ll pj. The light output is much higher than a crt but less than a digital pj.

If tried both versions and the crt is more than suitable for outdoor duty so again, no problem to you. Check out palpatims's plog on backyardtheater to see how big you can go.

There are a few deisgns utilized to minimize wind but the best is the plywood route. Unfortunately, this is beset by the obvious problems of weight and its permanent. But if you can jury-rig a semi portable design it might work.

Here's how I did mine
http://backyardtheater.com/forums/index.php/topic,207.0.html

Here's an example of a framed fabric design
http://backyardtheater.com/forums/index.php/topic,354.0.html

Good luck

Victor

Thanks Victor,


I have visited this site and got some great ideas. Did you make your own projector? I like the results you posted, great contrast!

Hanamalu

Folks,

Like I said things have moved slow. Good thing is I got an LCD from ebay! Check it out and is only $82! (Check it out: http://www.pcsurplusonline.com/viewprod.cfm?id=8213

I had acquired a refurbish Westinghouse but it had a dead pixel and am in the process of returning, which it is not an easy process when you purchase at e-cost.com!) But I digress… Keeping the wife factor low sure hinders progress! However I got some good progress in the enclosure, Thanks to all the people that have commented on the project, I had put my self a completion date of Sept 8, so pretty soon I will have to make some mayor decisions. More in the sections…

ENCLOSURE:

Well I spend some time squaring the enclosure because I realized my dowel holes did not aligned. I was able to make sure everything was 90 degrees. I built a new laser alignment tool for my table saw pretty sweet and it only cost $19! I used scrap wood for a sled and attached the laser level to the front fence, align the blade with the back fence cutting slot (you can see in the picture where the laser falls precisely where blade is going to cut) and there you have it! Check out the pictures…
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After this I worked on a method to bend the top and the bottom to a radius that would easily slide on the routed tracks on the projector’s side. I used the left over from the cuts I made for the sides and build a nifty “cradle” for the 3/16 ply I’m using. Next I just wet the ply, put some weight on it, let it dry under the sun and presto! A nice curved piece.

Here is the cradle
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Here is Ply soaking wraped ona wet towel
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And here is the actual bending process
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And here is the final product (Before and after pictures)!

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Here is how it looks installed

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Next I tried my idea for the end of the back and front and was able to get a nice fit with the L shaped mill work. Check how it looks
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And installed

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Also I started working solving the focusing the triplet issue. I got some stuff but I’ll talk about it later…

BYW PJ STATUS

Part %Done Todo Next Issues
-------------------------------------------------
Enclosure 90% Paint in-out NONE
Cut air vents
Optics 30% Build focus Fresnel & Key stoning
for Triplet
Light source 0 % Decide on bulb
LCD 25% Got an LCD! Not sure about FFCs
Power 0% Decide on wireing
& Power box
-------------------------------------------------
Final Build 0%

Nope- craigslist NEC MT820- sold to me as dead for $10- only to find bulb was seated incorrectly (and had 500hrs left on lamp)

Victor

Folks,

Some good progress to report this week. Got the triplet finally installed, after much thought I went with the tried and true “Shower drain” method. Cutting the hole was easy. The next major hurtle I encountered was deciding for a split VS unsplit set up. After lots of thinking and balancing pros and cons I settled for the unsplit design. This was mostly because since this is to be used outside, I would like to make sure image quality is best.
Of course this means that the projector will be aligned with the center of the screen, so for big images (120” or more) the projector will have to be placed in a pedestal. SO unless I figure a way to raise the projector while attached to the baby buggy, the buggy is out .
I also finished the frame for the fresnel lenses and tested them. I still need to make some very minor adjustments to the frame itself but that part of the optics is mostly done. Currently I’m trying to decide how to attach it to the box itself. I have some hardware at Home Depot but I’m not sure if it is going to be as easy as I though.
I’m still waiting for the LCD .
The next Major decision is going to be the light source (400W vs 575W) and how to configure it (Reflector? Light tunnel? Light Box with or without a reflector?)
The important things is that I’m making steady process, and I’ve been able to spend at least a few minutes each day working in the project. I’ll include some picture of the optics later.

BYW PJ STATUS

Part %Done Todo Next Issues
-------------------------------------------------
Enclosure 90% Paint in-out Fan hole
Cut air vents
Optics 60% Adjustable Frame Distance between fres and LCD
Light source 0 % Decide on bulb
LCD 25% Still waiting Not sure about FFCs
Power 0% Decide on wring
& Power box
-------------------------------------------------
Final Build 0%

You can tilt the screen slightly to help with keystoning. The screen may be taller than the seating so a slight tilt may help.

I made the strange shape of the megawatt base just for height adjustment and storage of the PJ. I also don't see what is wrong with using a table.

Sorry, couldn't you just have it held on four corners with a rigid sliding frame,
then have something underneath in the middle that would jack it up? Maybe
not an actual car jack (however cool that would be!), but I think it would work
with some kind of mechanical or hydraulic that shouldn't be too expensive to
build or buy.

Actually, thinking back to a car jack... what about a scissor jack?

I though about that, some kind of mechanical boom, the problem I have is weight and center of gravity. I have not given up yet, Arizona sujested doing the key stoning on the screen and not on th fresnel lenses. Once I have the projector working I will run some tests. (There is the intriging posibility of turning the projector 90 degrees (the triplet looking up) and using a mirror, like an OHP)


I HAVE NOT GIVEN UP ON MY BABY BUGGY YET!!!!!

Hanamalu

Hanamalu,

How's your baby buggy coming?

Cheers!

Fulcrum