Another DIY Rotary Film Processor

I finally put this project together after moving on to shooting 8x20 and could not bear manually rotating the drum. :)
Basiclaly it is made up of a roller base with 4 Rigid Wheels, a motorized arm with 2 wheels and a Arduino Uno box.
More details on the parts and components at http://sgwetplate.com/2016/10/diy-ro...ilm-processor/

https://c8.staticflickr.com/6/5530/3...a9b0732f06.jpg

https://c2.staticflickr.com/6/5518/3...3882a21758.jpg
The roller base with 4 Rigid wheels
I connected the 2 pieces of plywood using 2 brass rails (they were from a forsaken camera project). They are locked down using 1/4" bolts and nuts. This will allow me to adjust the distance between the 2 rolls of wheels for catering to drums of different diameters. At this point the drum should rotate smoothly and evenly by hand.

https://c4.staticflickr.com/6/5689/3...bf5522ae77.jpg
The motor and the shaft coupler
For now I am using a 12V 30 rpm motor. To mount the 3/8" threaded rod (again another piece I have sitting around) , I use a flexible shaft coupler which has a one 6mm hole what will fit the motor shaft while the other end is a 10mm hole that fit the 3/8" rod.

Very neat and simple. Good job!

Kumar

That's an elegant solution for a dry roller. Do you get much slippage from the skate wheels? These little microcontrollers and the interface boards make motor control so much easier these days.

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Originally Posted by Graham Patterson

That's an elegant solution for a dry roller. Do you get much slippage from the skate wheels? These little microcontrollers and the interface boards make motor control so much easier these days.

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Thanks!
The wheels has good contact with the drum. The drum tends to move forward(to the left as seen in the first photo) as it got rotated so I will have to get a barrier on the left to make sure it does not go too far off.

Maybe I missed it. Does it reverse or not?

Nice DIY!

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Originally Posted by Randy Moe

Maybe I missed it. Does it reverse or not?

Nice DIY!

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Yes.. the Arduino code will make change the direction of rotation every 30 seconds or so. I may finetune this along the way.

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You will need to be careful about leveling the drum (not just the base). You need to keep the depth of the chemistry constant. It's something you have to watch with Jobo processors, too.

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Originally Posted by Graham Patterson

You will need to be careful about leveling the drum (not just the base). You need to keep the depth of the chemistry constant. It's something you have to watch with Jobo processors, too.

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It's also a good idea to always put in a little more chemistry than called for just for "insurance" against things not being completely level. I've always added an extra 30-50ml and never had an issue, even though my Jobo isn't levelled to an exacting degree.

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Originally Posted by Graham Patterson

You will need to be careful about leveling the drum (not just the base). You need to keep the depth of the chemistry constant. It's something you have to watch with Jobo processors, too.

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One of my rotary units rocks slowly left and right which takes care of subtle leveling issues.

I use a 6"/150mm woodworking bubble level. Takes only seconds to check. I move my Jobo when it is not in use, so a check is advisable.

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Originally Posted by Graham Patterson

I use a 6"/150mm woodworking bubble level. Takes only seconds to check. I move my Jobo when it is not in use, so a check is advisable.

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Ah, ya cheat. :) I use a digital level, too.
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thanks for the tip on keeping the drum level.
I hv put up the Arduino sketch (code) on my blog. Be warned that I am no coder. I pieced the code from various sample codes and modified it to suit my needs.

http://sgwetplate.com/2016/11/arduin...ilm-processor/

Why the one second pause between cycles? if your 4.5 second rotation step is exactly reproducible in reverse (same number and fractions of a drum rotation) you risk a 10% increased development zone. Since you do not pause between forward and reverse, there does not seem to be a mechanical need for a pause. Otherwise I would have expected the pause time to be split between the two directions.

I am not saying you are wrong - I just want to understand why it is done this way, and if it has any effect in practice. My Jobos (a CPE and CPE+) both take a fraction of a second to reverse, and actually rotate a different number of rotations (the CPE is mechanically reversed and rotates less per cycle). There is also a slight drift between forward and back, so over a few minutes the tank progresses in one direction.

You are actually inspiring me to get my Jobo timed start and temperature reporting application up and running. The Raspberry Pi has all the hardware - I need to finish the code so I can remote interrogate it from the main house.

Ha good question. the part of the code was taken from another project I did earlier where there is a pause period before the motor reverse. So what I did was only to change the timings involved. I guess it can be easily change to remove the pause but I have not really run enough sheets through to see the impact of it.





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I think I would ensure that the rotation is something over two revolutions per direction, up to maybe 5. On the other hand, many people get by happily with a uni-directional drive. The nice thing is you have complete control, and room to experiment.

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Originally Posted by pound

I finally put this project together after moving on to shooting 8x20 and could not bear manually rotating the drum. :)
Basiclaly it is made up of a roller base with 4 Rigid Wheels, a motorized arm with 2 wheels and a Arduino Uno box.
More details on the parts and components at http://sgwetplate.com/2016/10/diy-ro...ilm-processor/

The roller base with 4 Rigid wheels
I connected the 2 pieces of plywood using 2 brass rails (they were from a forsaken camera project). They are locked down using 1/4" bolts and nuts. This will allow me to adjust the distance between the 2 rolls of wheels for catering to drums of different diameters. At this point the drum should rotate smoothly and evenly by hand.

The motor and the shaft coupler
For now I am using a 12V 30 rpm motor. To mount the 3/8" threaded rod (again another piece I have sitting around) , I use a flexible shaft coupler which has a one 6mm hole what will fit the motor shaft while the other end is a 10mm hole that fit the 3/8" rod.

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Hi Pound. I was really inspired by your project and made me want to build mine.
Based on your project, and willing to process color C41 films, I wanted to couple it to a heated water bath.
I already planned to recycle a old electric kettle to use the heater with an fish tank thermostat so this part would be easy.
But, as I never used an Arduino in my life, I wanted to know if you'd like to share your wiring schema with us ? The code part seems pretty clear to me, but I cant catch how you wired the moto to the motor shield, then to the arduino (and the same for LCD to arduino).

It has been a long time since you posted here, but I'll give it a chance ;)

(Excuse my english)

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Originally Posted by pound

Thanks!
The wheels has good contact with the drum. The drum tends to move forward(to the left as seen in the first photo) as it got rotated so I will have to get a barrier on the left to make sure it does not go too far off.

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Experienced that same very gradual movement of the drum. Fortunately it was always in the same direction, so I glued a piece of thin plastic to one of the insides of my darkroom sink. Place my Unicolor roller base with the JOBO drum's base a 1/4 of an inch away from the plastic. As it spins, the drum slowly creeps to be in contact with plastic which stops it from rolling off the Unicolor roller base. After dozens of time doing this, I have yet to see any wear on the bases of my JOBO drums.

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Originally Posted by NerdLabs

Hi Pound. I was really inspired by your project and made me want to build mine.
Based on your project, and willing to process color C41 films, I wanted to couple it to a heated water bath.
I already planned to recycle a old electric kettle to use the heater with an fish tank thermostat so this part would be easy.
But, as I never used an Arduino in my life, I wanted to know if you'd like to share your wiring schema with us ? The code part seems pretty clear to me, but I cant catch how you wired the moto to the motor shield, then to the arduino (and the same for LCD to arduino).

It has been a long time since you posted here, but I'll give it a chance ;)

(Excuse my english)

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hi there , just saw yr post.
For Arduino the shields just get stacked up. So the first layer is the Arduino UNO board, then I inserted in the motor shield on top followed by the LCD shield.
If you go to the my blog http://sgwetplate.com/2016/11/arduin...ilm-processor/ , I linked to the different shield pages(for example https://www.dfrobot.com/wiki/index.p..._(SKU:_DRI0001) and then from there you have to look at the documentation to see which pin should you use. The shield I used is pretty old so I am now sure how useful would be a wiring diagram be for you as newer shield might use different pins. Let me know if you still need one and I will see how I can get one done.

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Originally Posted by Greg

Experienced that same very gradual movement of the drum. Fortunately it was always in the same direction, so I glued a piece of thin plastic to one of the insides of my darkroom sink. Place my Unicolor roller base with the JOBO drum's base a 1/4 of an inch away from the plastic. As it spins, the drum slowly creeps to be in contact with plastic which stops it from rolling off the Unicolor roller base. After dozens of time doing this, I have yet to see any wear on the bases of my JOBO drums.

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thanks for the tip. I am building version 2 using a wiper motor as now I got a bigger drum. If I ever finish doing it , I will post it here.

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Originally Posted by pound

hi there , just saw yr post.
For Arduino the shields just get stacked up. So the first layer is the Arduino UNO board, then I inserted in the motor shield on top followed by the LCD shield.
If you go to the my blog http://sgwetplate.com/2016/11/arduin...ilm-processor/ , I linked to the different shield pages(for example https://www.dfrobot.com/wiki/index.p..._(SKU:_DRI0001) and then from there you have to look at the documentation to see which pin should you use. The shield I used is pretty old so I am now sure how useful would be a wiring diagram be for you as newer shield might use different pins. Let me know if you still need one and I will see how I can get one done.

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Thank you for your answer.
I'll try to build mine with this info and I'll keep you in touch whatever it goes :)

What developer are you using for 8x20?

Quote:

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Originally Posted by pound

thanks for the tip on keeping the drum level.
I hv put up the Arduino sketch (code) on my blog. Be warned that I am no coder. I pieced the code from various sample codes and modified it to suit my needs.

http://sgwetplate.com/2016/11/arduin...ilm-processor/

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Just a side note if you ever want to produce more...using an ESP8266 (even a NodeMCU format) can be had for under $5 at this point and it's dropping. This gives you WiFi along with the ARduino libraries. All you do is change the board being used and the pins will need to change. But you get the Wifi as part of the ESP8266. Then you can hook up an OLED board for another $5. Or, the newest ESP chip (ESP32) can be had in the same NodeMCU format for around $10 and that will give you both WiFi and BLE 4.2 to choose from and from the Arduino IDE you use now. The BLE libraries are not completely there yet but within 6 months they should be. I am currently working with a Nordic nrf52832 with gives me BLE but not WiFi for my LF projects but they are expensive ($20) so I plan on shifting to the ESP32 when the bluetooth BLE libraries are "more" stable. And the ESP8266/ESP32 chip/board format is less than 1/2 the size of the UNO.
The NodeMCU bord format will give you a USB to power it from your laptop for development. You can also buy the ESP8266 or ESP32 boards with a LIPO connector or even ones that have the battery right on the back of the board and you can read the battery voltage in code. With this, you can develop while connected to your laptop and then when in use, connect the LIPO and run off batteries. With WiFi onboard the chip, you can connect to your phone and display data in an app or send it to a server.

Sorry for butting in here, it's a cool project. I've been knees deep in C/C++ code on my project and thought I would add my pennies worth since I may produce my components in small quantities for testing on the forum.

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Originally Posted by Will Whitaker

What developer are you using for 8x20?

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I use HC110 dilution B for my FOMA (2 sheets of 8x10 ) or Shanghai 8x20 film.

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Originally Posted by gevalia

Just a side note if you ever want to produce more...using an ESP8266 (even a NodeMCU format) can be had for under $5 at this point and it's dropping. This gives you WiFi along with the ARduino libraries. All you do is change the board being used and the pins will need to change. But you get the Wifi as part of the ESP8266. Then you can hook up an OLED board for another $5. Or, the newest ESP chip (ESP32) can be had in the same NodeMCU format for around $10 and that will give you both WiFi and BLE 4.2 to choose from and from the Arduino IDE you use now. The BLE libraries are not completely there yet but within 6 months they should be. I am currently working with a Nordic nrf52832 with gives me BLE but not WiFi for my LF projects but they are expensive ($20) so I plan on shifting to the ESP32 when the bluetooth BLE libraries are "more" stable. And the ESP8266/ESP32 chip/board format is less than 1/2 the size of the UNO.
The NodeMCU bord format will give you a USB to power it from your laptop for development. You can also buy the ESP8266 or ESP32 boards with a LIPO connector or even ones that have the battery right on the back of the board and you can read the battery voltage in code. With this, you can develop while connected to your laptop and then when in use, connect the LIPO and run off batteries. With WiFi onboard the chip, you can connect to your phone and display data in an app or send it to a server.

Sorry for butting in here, it's a cool project. I've been knees deep in C/C++ code on my project and thought I would add my pennies worth since I may produce my components in small quantities for testing on the forum.

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Thanks for sharing. This is new to me. I think it would be nice to have an app to store the different development time for different film and send it to processer. I will look into it.

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I finally made a version 2 of it. I shifted the wheels to below the drum and use a stronger wiper motor instead. I have not complete the electronic portion of it so now it is basically a ON/OFF unit with no direction or timing control.

Take a look at this video if you need some ideas on how to make a rotary processor for up to ULF. Hope you can understand my English.
https://youtu.be/5RjhYHS7x3w