The neverending How-Tooo... This time we're back with friggin laser beams. We're still building our HD projector. Today we'll nearly finish up mounting all the components. We're almost done, soon we'll have our HD projector running, plenty of screen shots, and some sweet tweaks of our own. Oh, and if you need to catch up, check out:
Now, on to the show.
Last time, we clamped our enclosure together to get a rough idea of what it would look like. By clamping things together this way, we were able to position all the pieces just how we wanted them.
We lined everything up, drilled holes, countersunk for the screw heads, and locked everything down using two inch fine thread drywall screws.
We put two screws per side into the edge of each piece and got the clamps out of the way. We're not ready to glue things together until the end. We want to be able to disassemble things as needed.
To mount the lamp base we whipped up last time, we pulled the same trick - we drilled slots into the mount side of the base to keep the mount adjustable.
A pair of drywall screws equipped with washers serve perfectly to get the base mounted.
With the lamp in place, we need to mount the reflector. It needs to be just behind the lamp envelope.
We traced around the reflector, and drilled for holes into the rear panel of the enclosure.
To get screws the right length, we lopped off the ends of a few drywall screws.
We carefully used the screws to mount the reflector. It's a crude mount, but it should suffice for testing. (This looks like a great excuse to buy that new milling machine.)
Next we need to mount the projection lens. We marked the three screw holes when we test-fit the lens. Now we're drilling out those locations so we can lock things down.
We picked up a few 100mm m4 stainless steel machine screws and some washers to get the lens mounted.
It was a tight fit, but now our lens is mounted to the carrier. (Some lens cleaner might be an order -- we've managed to grab the glass a few times since we got going.)
To line up our drawer slides, we separated them and used our t-square to square them up with the carrier. We chose an arbitrary height, but we'd suggest centering them with the lens.
We had to measure the offset from the lens center to mark our mounting locations on the enclosure. Once done, we screwed the slides down with the screws that came in the set.
With the slides mounted, we slid the carrier into the tracks and the lens is ready to rock. We still need something to lock the lens in place for focusing, but we're getting there.
On one of our parts runs, we picked up a two foot by four foot piece of quarter inch birch ply at the hardware store. We'll be using it to cover the large open spaces top and bottom of the enclosure around the lens carrier.
We notched the top and bottom of the front of the enclosure.
Our 1/4-inch ply will rest in the slot we cut.
While we were at it, we hit the bottom of the enclosure as well.
Then we glued an some strips of plywood to the inside of the enclosure so we can solidly attach the panel.
To reassure ourselves, we double checked our alignment with a laser level. Everything seems to be on track for success.
As the projector progressed, we decided to revise our mounting system for the LCD and fresnels. Instead of mounting the frame to the enclosure, we're building it into a pair of thin plywood panels. We picked up a couple pieces of 8-inch by 12-inch 3/32 aircraft plywood at the hobby shop. We also snagged some slow CA adhesive (aka superglue, but in bigger bottles).
To make up for the thickness of the plywood, we used our tablesaw to cut 5mm of wood from the side of our frame with the shallower cut.
Now the frame and the plywood should fit into our 17.5-inch wide enclosure.
To line things up, we laid the plywood end to end and glued down the two small riser blocks that the LCD panel will rest on.
With those placed, we glued the frame panels in and a pair of thinner strips for the lamp side Fresnel lens and a piece of UV filtering Lexan.
The LCD fits our framing panels perfectly. Phew. We're not loading that thing back in until we're ready to leave it for good.
We scored a piece of Lexan from Home Depot. To cut it down, we clamped a straight edge (our plywood) and made several cuts with a utility knife. Once it was deep enough, we just snapped the piece cleanly away.
Test fitting yeilds a perfect fit. We might need to sand down the edges just a bit so it'll have room to expand when things heat up.
Since we'll be mounting the control electronics for the LCD to the outside, we decided to reuse the internal shielding from the display.
We traced around the upper piece with a pencil, then got cutting with our tin snips.
After some cursing and a sore hand, we came up with this. We mounted it with some machine screws left over from our last CNC project. Remember that one? (Here you go: parts
one,
two, and
three).
Using progressively bigger drill bits, we drilled a 3/8-inch hole through for the LCD cable to pass through.
With the wire passed through, we mounted the boards to the lower panel, and installed the cover. Not too bad looking -- just don't let the wife see that angle and you're fine. Plus we get access to all of the connectors. We're not done here, but the cover will stay on to protect the sensitive electronics.
Believe it or not, there's only one more part to the series. Next time we'll lock down our mounts, add the cooling system, finish up the enclosure and add some finishing touches. Then we'll walk our new photon cannon though its paces and see if she's got the right stuff.
posted Nov 21st 2006 8:13PM
jesus!!! ive been waiting for this shit for so long and its still not complete
This thing looks HUGE!
Hawt. Can't wait to see the finished product.
if it works i will do it
Hope the image quality is great!
looking good!
i want to do this!
This seems to be taking so long that I'm considering just buying you guys a projector myself. I hope you are keeping track of the total cost of materals as well as hours spent. It'll be intesting to know what the true savings is.
Eric, I agree.
So how big is the movie theater going to be? i bet you can seat 100 people all with a great view
that thing is gonna catch fire :/
This is a great idea if you want a subpar projector and make less than $3 an hour. Otherwise, work a couple hours of OT & buy a real one that doesn't way 123 pounds and is 2.5 metres long. Plywood lol.
I just bought a used Compaq MP2810 i(t's got DLP) on ebay, one VGA cable and One DVI cable, and a power cable, and I had it up and running, I can get 720p on it, and 1080i. It loks great on my old 8mm projector screen. So right now I have a 4 foot screen, and go go up to a 10 foot screen. It works for me, espically as a second monitor on my MBP. Anyways, a very nce project none the less. Can wait to see it when it's done.
I wouldn't think you would need the lexan as a UV shield given that single ended metal halide bulbs have an UV shield on them (the outer layer of glass). You really only would need a shield if you were using something like a double ended HQI bulb which is really nothing but the envelope and does need a separate UV filter. Taking out that lexan *might* give that little extra bit of brightness and clarity.
That being said it looks great. I picked up a few 19" lcds recently and will probably do something similar once I have a room.
SO, get done with the series already!
I nominate this the longest yet most interesting Engadget how-to ever! Ugh! you are killing us out here... We want to see the sexy-ness when it is finally done! If all goes well I might destroy my old laptop and make one of these... I just don't have a thousand bucks to get a decent video projector... but I might have $600.00 tho... Great Job Engadget! Keep the good content coming!
how good will this projector be when it's finally finished? Like what would be an equivalent model or price tag of an HD projector of equal caliber as this homemade one?
Funny how there is always the same discussion about the how-to's: you could get a better/cheaper/prettier/smaller/larger/more pink product from the store, or how adding to the expenses the time used, based on someone's imaginary salary, makes the whole enterprise not viable. Surely it's more about the journey, not only the destination? And if you're counting hours, surely this has nothing to do with the miserable feet-shuffling at the office: the hours spent hacking HD projectors and CNC-machines surely are free time, and good pastime as that. (With the obvious exception of those enviable folks at Engadget... :-) )
I, for one, am fascinated by these things, as it's interesting to see what goes in to one of these things, and how you _could_ do it yourself. The whole process of trying to work it out and then solving problems as they come are the salt and pepper of DIY. Great that Engadget extends the fun from coffee tables and bookshelves to electronics.
@ TH
Couldn't agree more. There's a sense of accomplishment in DIY. With this digital age we live in, most of us are loosing touch with some old fashion hands on work. This project combines both this current generations connection to electronic gadgets to some good ole callous forming work.
Hacking and DIY is cool but it really only pays when any of these conditions can be met:
1) You can do it for substantially cheaper than a store bought version
2) You want to add functionality not found in the original
3) You can create the thing in a more elegant form
4) ???
This one is not more functional, definitely not more elegant, and only marginally cheaper. In addition, will your homeowners/renters insurance cover damage done by a non-UL listed projector made out of wood with a several hundred Watt bulb stuck inside that catches the whole house on fire?
The CNC machine was cool because they're prohibitively expensive but extremely useful. That said, the project is fascinating and kudos to the build crew for such ingenuity and manual dexterity.
I really want to see how this thing looks, they did I beautiful job with the build, and if it looks good enough (Read: 85% of a storebought) then I think I might find a 1920x1080 monitor and do the deed.
Quite frankly, if you don't understand right off the bat why someone would build a projector instead of buying one, you probably never will.
To the comments that it's not cheaper than a commercial projector, ponder this.
If one were to purchase a 720p DLP projector off the shelf, one would spend approximately $1000-$2000.
If one were to build the projector for 720p projection like this one, the cost of the build is $750 with $300 towards an very pricey LCD panel. a 17" LCD with broken backlight can be had on ebay for only $100.
Total savings so far: $250-$1250 not money savings enough for you?
Consider what it would cost to own the projector. edmunds calls it the Total Cost of Ownership and it's rightly so. If you were to purchase an off the shelf projector, it would be unwise of you to purchase just the bare unit w/o the bulb warranty. The bulb is guaranteed to burn out in the ownership lifetime of the projector. Most commercial projectors are rated for a 2000-3000hour under optimal circumstances. The cost of a new bulb is $300-$400. So after a year of ownership, the cost of the projector has increased by 30%.
on a DIY projector, the cost of a new bulb is $50. I could buy a whole case of $50 bulbs for the price of a single commerical bulb replacement.
How about the life of LCD panel ?
No ones seems to be worried about this.
When comes part 6 ? :D