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Build an image projector/enlarger from an over head projector.

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A warning before you start this. if you follow these directions on converting your overhead projector it will probably no longer work as an overhead projector. But on the major plus side you'll have an inexpensive image inlarger.
 
My main goal with this is for creating artwork stencil paterns and other such things. that and not paying $300 dollars for an enlarger from an art store.

Theres a couple ways you could modify a part so it could be used for both transparency and overhead projector probably of  course. so i might include that

tools/materials
Electric drill
# drill bit
#" philips screw driver
Locking pliers
 4-5ft long 7/8ths square steel tubing   or 3/4 aluminum  edging for plywood if using the original bracket the 4 foot long piece is good  5 foot would be need to attach to frame without the bracket and still be able to shrink the images.
wood
wool blanket.
#" double sided velcro
sewing machine.
overhead projector $20 at goodwill
wire caps
zip ties
  
 
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Step 1: The tricky bit

Picture of The tricky bit

If the pipe on your projector  is the same as mine you'll need to get a 7/8ths piece of square tubing. This is the first thing you need Do this before you do anything else or you realy are going nowehere fast.
there are a few companies that make the stuff. but i didnt get any response to my inquiries for a single piece of pipe.
3/4" angle iron joined with another piece facing it to form a tube is 7/8ths so i had planed on trying to weld two pieces together. a 7/8ths piece of pine is two soft and frnkly a bit flimsy any way  to take wieght of the head and to hold up to the roollers inside. Also it needs to cut pretty truly to not have the rollers loose there grip.
what I ended up using is this. A piece of aluminum edging 4foot long. Its a channel ment to be put over the edge of a 3/4" piece of plywood. I had intended on uning two of them.sourounding a piece of wood. cut 3/4" - 5/8"  4 feet long.  and to the length of the edging.  I was going to use two piece  cut of the excess and fit them together over the wood. I ended up using one instead. I had some scrap wood cut from a differnt project that fit perfectly so didnt feel like cutting off the exess metal. if I end up haveing problems I'Il go back and do that later
just put the edgin on your cut wood and test the fit on your projector head. Its a little tricky getting it in theres a sliding wedge that likes to fall out and mis algin itslef. you have to push in place and up to have enough room to ge the arm. (yours and the original)  If the fits to tight to roll up and down easily plane the wood thiner or sand to fit (only use a planer if your planer will take of paper thin shavings) be careful if you make low spots it wont grab and you'll have to start all over again. Smooth the wood with some fine sand paper. dont take of much wood your just making a smoother surface here.
once i got the fit righ and snading done i rubed a little parfin wax on the back of the wood to act as a lubricant
 add a screww to at least two points throught the metal into the wood. if you couneter sink the holes for a scwerhead to fit in you"ll have eonugh clearance to get all the way to the top of the. the second spot will have parto the bracket on it so you dont have to worry about the second screw right now. If you want to glue it in i have no problem with other than that i dont know how long the aluminum will hold up against the steel roller and if the glue changes the thicknes you have more work to do thining it out. again.

i like this idea, the extended arm solves my focus problem while trying to use a projector as a negative film enlarger. thanks. (however, have you never heard of an elmo? why not use a video projector and take a picture of what you want to blow up?)
Wazzupdoc2 years ago
Well, I'm a bit baffled by this project or it's intent. An overhead projector IS an image enlarger. What does this add to our tool belt? These are useful platforms, but I don't see a lot of progress with this project. I'd stare at it for a week or so over glasses of wine or beer, then leap onto something really new.....then go forth! Keep going!
8footape (author)  Wazzupdoc2 years ago
An over head projector only works with Transparancies and only enlarges whats been printed on them or written on them. this works with anything you put in its fiels of view.They physicaly do the same thing but to a different end and are different tools all together.
It's called an Opaque Projector. Still available to project non-transparent material. I know some artists who use them to blow up sketches for larger works. Still seems a shame to blow up a perfectly good overhead.
9ale72 years ago
sorry i say this a lot around here,
but a picture or a video of your self using it would make a big difference!

i do get the idea, but would love to see it in action ( more as how good is the projected picture??)
thanks
8footape (author)  9ale72 years ago
added a pic of a ninja turtle being projectd on the wall.
9ale7 8footape2 years ago
Not bad ! looks good without a dark room.
Nirgal382 years ago
It's what used to be called an opaque projector. When I was in elementary school (longer ago than I care to admit), our teachers would sometimes use something like this to project pages from books. I remember the large dark brown wrinkle finish paint on the thing, the hum of its enormous fan and that giant lens like a huge glowing eye. It was actually pretty cool especially if you put your hand on the projection stage. You just didn't want to leave it there very long because it would get HOT!

It allows you to project a printed page without the need to turn it into a transparency first.
8footape (author)  Nirgal382 years ago
exactly.
I am glad to see someone telling about what one can do with these projectors. School district warehouses are full of them and they are auctioned for little or nothing, usually a dozen of them on a pallet. I suppose many are gone already. It's better they get used than for scrappers to get them for tin weight.

I would appreciate a description of what the device modification does that an unmodified projector cannot do. For example, if I want to enlarge an image, I put it on a transparency, plop it on the regular projector and ...wah lah...it is enlarged on the screen/wall, ready for tracing or whatever.
8footape (author)  onlylooklikepackrat2 years ago
An image projector can project an image of whatever you put in its field of view.the light source is above the image or object instead of bellow as for a transparancy. Now be it a picture or something youve drawn or any object say an orange or a screw driver like i have in one of my pictures on here,or an action figure. or your hand, or a candy wraper,etc. You put it on the bottom under the light and you can project it on a surface.
If you tried to use an overhead projector without removing the glass and the mirror an all that an you put any of these objects on the glass to try project the image on a wall or something, all you get is a shadow.
also my mod lets you shrink what your projecting. This gives you around a 10 foot image or 2inch image and anything inbetween. The regular arm length doesnt allow this range. you dont have to put anything on transparencies and you get the color of the object without have to deal with things like printing.
Now the image quality isnt the sharpest and the bulb isnt idealy postioned so that doesnt help probably. but this was an overhead projector. there not known for thier clarity. I consider it adequate overall. and compared to the image projectors they sell at art stores that have the same size capacity for the object/image being used for enlargeing this cost me $30 instead of the $300 for theirs.
Beergnome2 years ago
no offense, but Im trying to understand what this modification does that a stock overhead projector doesn't do already?
8footape (author)  Beergnome2 years ago
An overhead projector uses transparencies. whatever you draw on them or have printed on them projects on the wall.The light passes up through it all. other than that an overhead projector really isnt all that useful if you dont have or want to use transparencies. An image projector however can project an image of whatever you put in its field of view.the light source is above the image or object instead of bellow for a transparancy. Now be it a picture or something youve drawn or any object say an orange or a screw driver like i have in one of my pictures on here,or an action figure. or your hand, or a candy wraper,etc. You can project it on a surface.
If you tried to use an overhead projector without removing the glass and the mirror an all that an you put any of these objects on the glass to try project the image on a wall or something, all you get is a shadow.
also my mod lets you shrink what your projecting. This gives you around a 10 foot image or 2inch image and anything inbetween.

agis682 years ago
I have the same projector without the arm with the lenses.....I bought for 10USD in an auction.....its fuctional and i need that sided arm.....anyway your mod is neet if u do comics......
sweet!!
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