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…Originally Posted by Jim C.
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.
Even monkeys fall from trees -- Japanese proverb
Cool!
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.
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:
Seems like banding is a common problem with these type of cameras.
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.
Last edited by malexand; 15-Apr-2024 at 15:10.
Even monkeys fall from trees -- Japanese proverb
Congratulations!
Tin Can
Fantastic. I admire your persistence.
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