F I N K B U I L T

Today’s Ebay Item

missle tracker

Scale model cockpit FPV

fpv
cool scale cockpit video

Funny Zoo Snap

man enjoys elephant My wife noticed this in the family archives.

RC Nitro motorcycle racing

rc motorcycle Motorcycle racing in Lilliput.

Manned RC Multicopter

manned multicopter
Here’s an RC multicopter big enough to ride on!

Quadcopter FPV

Quadcopter FPV
Amazing remote first person view piloting.

Make: Talk 004

make: Talk 004
I had a fun time talking to Mark Frauenfelder in episode 4 of his new podcast, Make: Talk!

Helmets

retro vintage motorcycle helmets Pictures of boxes full of sweet vintage motorcycle helmets

One Man Basement Band

one man band
I feel like I could be getting more mileage out of my right foot.

Liberty

liberty vintage motorcycles An Etsy portrait. Thanks, Danny.

Tequila Sleeve

tequila the champs
Champs sleeve

Wolf-Stelzer Book Lamp

Book Lamp
My friend Tess just made the cover of ReadyMade with her cool lamp design.

Tree Stump Bug

null
Can this be for real? The design is so awesomely Thunderbirds. Via

The Nothing Box

nothing box

Thunderbirds

Thunderbirds are go
Are Go!




Opaque Projector

opaque projector

Here it is. No. 2 in my BelAir series of retro-feel homebuilt AV equipment (see No.1). I used a surplus copy machine lens to make this opaque projector for use as a drawing aid. (See this post for background info and plans) .

opaque projector

The projector is essentially a wooden box with with a lens, internal lighting to illuminate reflective copy, and a mirror to flip and invert the image so that it is projected right-reading on the screen. These projectors are great tools for enlarging images when making paintings, posters or other such artwork.

Materials

I was able to use quite a bit of scrap and on-hand materials for this project, which is always satisfying. I made most of the box out of some nice 1/4 inch plywood that I had lying around. The front panel is 1/2 shop grade plywood, also scrap. The mirror has been kicking around the shop for years, as have the ceramic light sockets. I made the lens holder from an empty cocktail peanut can, epoxied into a hole cut in the front panel.

I purchased the two 23 watt fluorescent bulbs, which are supposed to have the same light output as 100 watt incandescents. I also had to purchase the chrome toggle switch, the wrinkle paint, and the stylistic embellishments.

opaque projector

Finish

I painted the cabinet with black wrinkle paint from Plasticote before installing the chrome (1966) BelAir script and ruby red Fender amp indicator jewel.

opaque projector

opaque projector

Focus is achieved by simply twisting and pulling the lens in and out.

I still need to paint the bottom edge of the cabinet and make some reflectors for the lamps.

opaque projector

I got rid of the dimestore mirror and installed a trapazoidal front-surface mirror. If I were just building an opaque projector I wouldn’t worry about the ghosting that you see with a rear surface mirror, but since I have video projection ambitions for this project, I went ahead and upgraded the mirror.

To get a nice snug fit inside the peanut can lens holder, I wrapped the lens with several turns of black yarn. This makes for a nice snug fit, and keeps any light from leaking through.

opaque projector

Results

I’m pretty happy with it. I didn’t spend too much building it – less than I would have spent on a low-end commercial unit, which can typically only handle copy under 6 inches in size. The projector works great. The copier lens can take in really big copy. The BelAir handles 9 1/2 x 12 inch originals, looks cool, and was fun to make.

Future

If I can find a cheap portable DVD player with an LCD monitor, I want to make this into a movie projector.

UPDATE:

Following in the footsteps of Mr. Jalopy, I have spent lots of time on the immensely rich Lumenlab forum, and I am gathering parts to build the video projection base unit.

27 Responses to “Opaque Projector”


  1. Mcewan Says:

    This is a beautiful thing. Looking forward to seeing the next phase. Is that BelAir script the same as the BelAir script on your entertainment center? What is the source of this one?
    Nice
    Mcewanj

  2. Matthew Says:

    I have a 19″ LCD panel that I’d be happy to give you for building a projector. The backlight is dead (pretty sure it’s the inverter) but the panel itself works as tested using a flashlight.

  3. Steve Says:

    Hey Matthew,

    Nice thanks for the offer, but from what I can tell, I need a smaller panel. Something like a 7 inch would be ideal. But I have more research to do.

    Cheers,

    steve

  4. ECA Says:

    The LCD projector, has already been done, and its on sale for $500…
    You want the LCD that comes with a TV, not a laptop version…as no one will give you the Pin outs and control card for the laptop.

  5. Liam Says:

    Hey, any pics of the output of this? Would love to see how it works!

  6. Steve Says:

    Hey Liam,

    It works pretty well as opaque projectors go, but the output is quite dim. It really needs to be used in a completely darkened room, especially at higher magnifications, but that is par for the course with a reflected light projector.

    Since these photos were taken, I have painted the inside black to reduce stray light, and added reflectors to the lamps. This probably doubled the brightness of the image.

    I’ll post an update when I start the video projector leg of the project.

  7. RR Anderson Says:

    fantastic. the crinkle paint was a nice touch. Can we see it in action?

  8. curt thompson Says:

    hey! I really like the look of this project! I have a project I’m working on and i’m trying to find the same wrinkle coat finish… can you tell me where you found it? I tried home depot, lowes, and ace hardware… no dice.

    by the way, I’m in seattle too, one of these days maybe we’ll meet up, I have a bunch of projects I think you’d appriciate based on what’s here on your blog.

  9. Steve Says:

    Hey Curt,

    You can find the wrinkle paint at auto parts stores. I got mine a Autosport on Aurora, just north of Greenlake.

    cheers,

    steve

  10. curt Says:

    great! that’s right by my workshop, so I’ll swing in this weekend and grab some! thanks!

  11. eli Says:

    Hi I am a teacher and I need make one for my class, you can send me the messures thaks

  12. Simon Park Says:

    Great work! This has inspired me to build one, too. For my purposes, the commercial ones require too much fiddling around (making sure the picture is reduced to such a tiny size and all), and they all seem to be made of plastic. I want something large and sturdy, without having to spend megadollars.

    Many thanks!

  13. Jeremy Says:

    I purchased one of these lenses because I troll AS&S and, frankly, the lenses are just plain awesome (I plan to buy several more if money allows). I then came across your site because I also had the idea to build an opaque projector and Google (via Make) told me about your project. I was really happy to see the PDF link you gave us, but I think it has caused me more problems than I had trying to work it out on my own.

    I built a little proof-of-concept projector out of the lens, a fluorescent light (with work-light-type reflector), and an old cardboard box. It worked beautifully (though since there was no mirror everything was backwards/upside down). I decided to build a for-real box based on my stunning success. This was about the time I found your article, so I dug through the PDF you recommended and decided to go with the plans on page 14 (though it claims pg 12). I had to scale them up a little because our lens was much larger and my mirror was a good bit larger as well (8″ x 8″). Lo and behold it was worthless. I can do the math and the focal length of the lens lines up pretty well with the “document” being shown, the light from the lamps isn’t directly hitting the lens (because of blocking), and AT LEAST as much light is hitting the surface of the “document” as in my PoC. However, most of the light was lost inside the box and what light DID come through the lens was impossible to focus into an image (note: I haven’t painted my box yet).

    I guess what I’m asking is what the dimensions of your box are? I’m not sure what’s different from yours to mine (in terms of focal-length, etc), but I’d love to know (even rough) dimensions. Also, what did you use for reflectors?

    Thanks for your time and great article,
    -Jeremy

  14. Jeremy Says:

    P.S. your CAPTCHA is effectively worthless against real SPAMmers… you should check out reCAPTCHA.

  15. Jeremy Says:

    Aw hell… I’m on a posting spree so I’ll throw this out there. I had the idea of using black felt (as opposed to yarn, like you did) and it happens that if you give the lens a few turns of black felt it fits nicely into a piece of 4″ black PVC from any “home improvement” store. I liked this becaue I could glue/tape it down instead of having to tie it down (and I hadn’t thought of using yarn).

  16. Nathan Says:

    Hello!
    I am constructing one for myself and I wondered if you could give me the measurements of your box? I am trying to figure out at what angle to put the mirror.

    Thanks a ton!

  17. Nathan Says:

    Hello!
    I am constructing one for myself and I wondered if you could give me the measurements of your box? I am trying to figure out at what angle to put the mirror.

    Thanks a ton!

  18. charles Says:

    it did helped me a lot with our science fair.

  19. rich Says:

    I don’t see the lens everyone is talking about. Any idea if it’s the same as the ones showing now?
    (http://www.sciplus.com/category.cfm/subsection/21/category/188)
    ie., 27379 F:4 LENS 28mm F:4
    I’d love to try this, but I’m unsure where these lenses went.

  20. JIM D. Says:

    HELLO, I’VE HAD THIS OPAQUE PROJECTOR PROJECT IN THE
    BACK OF MY MIND FOR A FEW MONTHS, AND I CAME ACROSS
    YOUR VERSION. CAN YOU GIVE ME A CLUE ABOUT HOW TO
    GET THE LENS. IM IN PUERTO RICO AND THERE ARE NO JUNK
    SHOPS HERE LIKE I USE TO HAUNT WHEN I LIVED IN CHICAGO.
    THE LARGER 91/2″ X 12″ IS REALLY A GREAT ADVANTAGE.
    THANKS MUCH, RETIRED TOOL MAKER
    JIM D.

  21. Steve Says:

    Hey Jim,

    Well, I checked my source and they are sold out. Just search the web for “surplus copy lens”.

    steve

  22. Herb Klug Says:

    Hi, I just stumbled onto you web site and I like how you built your opaque projector. I recently bought a high end opaque projector for almost nothing because it didn’t work. Turned out it was just a loose wire! . I plan to use the projecter for tracing photos to canvass so I can do some oil paintings. I would rather have the projector overhead projecting an image downwards on a flat table rather than projecting it onto a wall. I was thinking about building some sort of wooden framework to hold the opaque projector up in the air and then using a mirror to cast the image downward. I am afraid that if I just mount the projector facing downwards that it might build up too much heat because it isn’t designed to function like that. Any thoughts on this? Is there a better way? Thanks. Herb

  23. Teacher Mary Says:

    THANK YOU so much for this! My budget will not cover the expense of an opaque projector and I really want one. I teach kids with learning disabilities and research shows that an opaque projector, used with other strategies, helps develop skills in reading. I can’t wait to make it and get it to my classroom!

  24. Kenneth Davis Says:

    I built an opaque project about 35 years ago that I have just recently set up again. Because of changing needs I would like to increase the magnification of the final image. I am wondering how to do the calculations to determine what lens to look for. Any help you can provide would be appreciated.

  25. Paul Jones Says:

    Sir:

    I’m looking at what appears to be a self made (but extremely well done job) Bel-Air #2 Opaque Projector.

    Is this item for sale? If so, how much and can parts (lenses and bulbs) be easily obtained?

    I am a professional artist and lost the bulb for my old projector and, naturally, it isn’t made any longer. I got one from the same art shop but it does not provide a focussed image (???)

    I need a projector that will take an 8 x 10 photo and project a sharp image on a canvas perpendicularly placed on an easel 30 x 40 inches in size. Projection distance would need to be sharp out to about 10 feet.

    If you don’t sell your item, can you recommend a reasonably priced ($250 + -) opaque projector? If you are at all interested in military aviation, current USAF, WWII or Vietnam, I have published numerous prints of F-15s, F-16s and collages honoring WWII and Vietnam. I’d be happy to send you a complimentary signed copy of anything I have for your help.

    Thanks,

    Paul Jones
    Lt Col, USA (Ret)

  26. Steve Lodefink Says:

    Hey Paul,

    No, I dont have this projector for sale.

    If I were you, I would attempt to retrofit your current projector with a different lamp and lamp base. Something that has been for sale more recently than your old one. Maybe something from a junk rear-projection television would work

    good luck,

    steve

  27. dave Says:

    great construction, i really love it. just been looking into picking one of these projectors up i didnt even know they exited . i need one quite soon so might buy but think i will try to build this also in the future . love the paint finish also .
    many thanks :)