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jasont
05-05-2011, 11:19 PM
After building my 8x10 camera I found that I needed a contact frame to make prints with. After searching around I found a page with something I felt like I could build.

http://cameraobscura.busdraghi.net/2007/printing-frame/

So, I decided to buy a router. After all, I can use it to make my own photo frames too! Man, I should have read up a little more on how to use it. I got a great lesson on projectiles! Fortunately, no fingers were harmed. However, a couple of strips of wood were. I'll keep you posted as I progress.

One question, though. I can't see any nuts on the bottom of the pressure bars, but I don't see how his setup would work without them. Can anyone illuminate this for me?

pinholeblender
05-06-2011, 12:24 AM
They are using a latch like what is on a lunch box. I have a frame that used rubber tubing that fit in groves in the side to hold the back in place. I think it was made by a company called Gravity Works. They used to make archival washers.

pinholeblender
05-06-2011, 12:31 AM
Just tried to find info on my old contact frame and found this, http://www.ohio.edu/people/schneidw/501/alternative_process.html might be an easy and cheap solution.

"The best solution found was also the cheapest. Two pieces of 11x14 plate glass with ground edges were obtained from a glass store and hinged together with electrical tape along one edge. Some sponge rubber feet were glued onto the bottom to make handling easier. The print and negative were placed between the two glass plates for subsequent exposure. Tests showed that the 1/4 inch thick plate glass provided nearly identical print times as the so-called UV transmitting Plexiglas in the Gravity Works unit. The actinic radiation must pass through the glass as easily as through the more expensive, flexible, scratch prone Plexiglas. The sharpness provided by the two very flat panes of glass was much better than the commercial print frames. The homemade print frame is vastly superior to the commercial versions, and is highly recommended."

jasont
05-06-2011, 08:03 AM
I know he's used latches, but he also says the pressure applying bits are adjustable to vary the pressure for different material thicknesses. That's the part that I'm uncertain about.

jasont
05-06-2011, 08:05 AM
And at this point I'm kind of set on making an actual frame. Ever since I started making my wooden pinhole cameras I've realized that I really enjoy the construction aspect as well.

Jim Jones
05-06-2011, 09:17 AM
. . . One question, though. I can't see any nuts on the bottom of the pressure bars, but I don't see how his setup would work without them. Can anyone illuminate this for me?

T-nuts or threaded inserts in the crossbars would work. Even when allowing for the translation, the whole cited article sounds more like a sales pitch than like good engineering. Pinholeblender's approach seems more pracitcal, although I wouldn't hinge the two glasses together.

jasont
05-08-2011, 10:22 PM
Well I spent most of the day working on the contact frame. Here's the finished photo.

http://farm3.static.flickr.com/2039/5701324759_41fa5141e7.jpg (http://www.flickr.com/photos/jasonthomas/5701324759/)
P1010865 (http://www.flickr.com/photos/jasonthomas/5701324759/) by jason_in_gboro (http://www.flickr.com/people/jasonthomas/), on Flickr

http://farm4.static.flickr.com/3516/5701324085_1985b13bdd.jpg (http://www.flickr.com/photos/jasonthomas/5701324085/)
P1010864 (http://www.flickr.com/photos/jasonthomas/5701324085/) by jason_in_gboro (http://www.flickr.com/people/jasonthomas/), on Flickr

renon
05-09-2011, 03:00 PM
Nice work, jason. I use simply cheap picture frames with standard glass. This works very well for contact copies.

jasont
05-09-2011, 07:46 PM
I never had much problem with a similar approach until I started printing on fiber paper. For some reason I couldn't get good contact, hence the contract frame route.