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Re: New Cirkut-type pano-graflex build
Quote:
Originally Posted by
Jim C.
Nice job !
I think based on the pictures posted the teeth form on the gears aren't correct, that could be where your banding is coming from.
Me printer just doesn’t have the resolution for fine teeth. I reprinted the gears as helical, which certainly improved the banding but it is still present. Perhaps if I had a higher res resin printer…
Next test will be with o-rings and pulley wheels.
I may have to go with commercial gears but that requires a larger redesign so I’m exhausting all my 3d options before I go down that path.
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Re: New Cirkut-type pano-graflex build
Re: New Cirkut-type pano-graflex build
Quote:
Originally Posted by
malexand
Me printer just doesn’t have the resolution for fine teeth. I reprinted the gears as helical, which certainly improved the banding but it is still present. Perhaps if I had a higher res resin printer…
Next test will be with o-rings and pulley wheels.
I may have to go with commercial gears but that requires a larger redesign so I’m exhausting all my 3d options before I go down that path.
It's important to know that gear teeth aren't triangular, with involute spur gears there is a curve to them to allow it the tooth to clear the mating tooth,
the banding is very regular which makes me suspect the gear teeth aren't the proper form and or aren't clearing each other properly.
If you're using a CAD program to generate your STL file it may have a parameter dialog box where you can enter the pressure angle, tooth count, pitch etc.
O rings and pulleys might slip, which would be interesting to see the resulting image, you might consider timing belts and pulleys,
there are mini sized versions available or take apart a old inkjet printer, the ink carriage is driven by a timing belt and stepper motor.
An advantage with belts, timing or regular is that it will isolate any vibrations the gear motor may generate.
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Re: New Cirkut-type pano-graflex build
While researching some history at the University of Wyoming, I handled an early Circut camera used to take pictures around 115 years ago. The particular photographer was also a hunting guide, and one of his clients was George Eastman, and I read some of their correspondence. One of the letters, from Eastman, had suggestions on how to get rid of banding. Here is an example:
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Seems like banding is a common problem with these type of cameras.
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Re: New Cirkut-type pano-graflex build - SUCCESS
SUCCESS!!
Turns out the Banding issue was much more related to the size of the exposure Slit than the gears. While I did change to helical gears which improved banding a bit, some deep-dive research revealed the original Cirkut cameras had a slit of 3/16 in - nearly 5mm. Mine was initially 1mm which I've now increased to 4mm. That increase and the gear change has virtually eliminated the banding.
Other improvements include a battery pack, testing gears for the long focal length of my Rapid Rectilinear ~300mm with the front element removed. Working on a developing reel.
I'm really looking forward to playing with this over the coming months!
Below is about 1/2 of a full image - hit the limit for scanning with my phone...
6"x36" green X-ray, developed in dektol 1:10.
https://lh5.googleusercontent.com/Yp...oFv4mW-A=w1280
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Re: New Cirkut-type pano-graflex build
Re: New Cirkut-type pano-graflex build
Fantastic. I admire your persistence.
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Re: New Cirkut-type pano-graflex build
UPDATE
I've spent the past month or so working on refinements and all the other needed parts to ultimately make a decent printed image. The severe limitation of film and paper availability is in some ways a blessing, limiting many of the variables. Xray film, 1 or 2 RC B&W papers, and Alt printing is about all that is available anymore.
I installed a .2mm nozzle in my 3D printer which allowed finer teeth in the gears. Finer teeth allowed for more precise movement and control of the speed of rotation, improving the image quality.
Spooling film has been a steep learning curve. Cutting and alignment are critical. The spools are like big 220 rolls, and just like medium format they spool one to the other, the empty becoming the new take-up. I got a jumbo sized rotary cutter with strong magnetic guides for the precision needed to cut the film as well as the paper leader and follower.
However, a working camera as we know is only a part of the whole system if I want to make a print I can display.
I built a 40" long UV LED exposure box for Alt printing. Just as I was finishing it I realized I could also install white LEDs for contact printing on traditional photo paper. After adding a toggle switch and dimmer, it's working well for both - so far without any additional diffusion. My printing frame is 1/4" plate glass that I epoxied onto a piano hinge mounted on a 12" melamine shelf. A layer of thick shipping blanket gives it padding and the weight of the glass makes for good contact. Clamps can be added if extra pressure is needed for wavy paper.
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As anyone who has processed xray film will tell you, it scratches if you look at it wrong. My first tests were done see-saw style with poor results. I ended up constructing developing reels from PVC and 3D printed spirals. These work quite well in a tank, dip and dunk style. With minimal care, no scratches. I may look into a daylight type tank, but honestly probably not worth the effort.
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Re: New Cirkut-type pano-graflex build
UPDATE (continued)
Traditional B&W contact prints are made currently on Ilford Galerie RC Digital Silver paper - made more for photolab printers, it was the cheapest 6" roll I could find. It's pancromatic, so total darkness is needed. I built a light-proof dispenser box for it. Kind of like a giant 35mm cassette, I just pull out and cut what I need. processing so far has been successful with see-saw method in deep trays.
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Washing and Alt processing is accomplished in an 15"x48" industrial storage bin that I installed big PVC ball valve in one bottom corner. With the valve open, I can add an elbow to the inside to make adjustable the water level and drain. If I close the valve, I can use it as a X-large processing tray.
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Over all, I super excited at how well this project has come together. So many details needed to be worked out. At the start, I was curious if I could even make a recognizable image. Never did I expect the images to be coming out as well as they are.
Below are 2 recent contact prints using 2 of the lens I plan to use. The Optar 135mm is able to produce a full 360 degree view on 36 inches of film, the Rapid Rectilinear 170mm is apporox 270 degrees. The rectilinear is able to convert to about a 300mm, which makes about a 180 image, but I'm still working out some details of gearing and exposure for using it.
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Re: New Cirkut-type pano-graflex build
Amazing!
Where did you source the LEDs?