Jobo CPP-2 + XTOL 1:1 Agitation?

Discussion in 'Darkroom Equipment' started by analog65, Feb 14, 2014.

  1. analog65

    analog65 Member

    Messages:
    125
    Joined:
    Jan 24, 2014
    Shooter:
    Large Format
    Curious if there is any data on a suggested motor/rotation speed for processing black and white films using XTOL 1:1 in a Jobo CPP-2? I will be using the Jobo 3010 Expert drum to develop up to 10 sheets of 4x5.

    I reviewed the XTOL data sheet and didn't see any specific recommendations regarding agitation and rotary processing.

    Constant agitation for black and white films is probably not the best idea in general because it puts the fresh developer on the densest areas in the negative which ultimately produces a faster buildup of highlights. My gut tells me the slowest possible rotation speed is likely the right answer.

    I do plan on testing for my films EI and development times using a densitometer, however it makes sense to poll the knowledge of everyone here as a starting place regarding agitation in the Jobo.

    Thanks in advance for your input.

    Andy
     
  2. karl

    karl Subscriber

    Messages:
    199
    Joined:
    Jan 17, 2003
    Location:
    SanFrancisco
    Shooter:
    ULarge Format
    It works very well. Xtol 1:1 in the Jobo is my standard operating procedure. I use speed setting 4 with expert drums and P with the 2500 series drums.
     
  3. wildbill

    wildbill Member

    Messages:
    2,851
    Joined:
    Nov 28, 2004
    Location:
    Grand Rapids
    Shooter:
    Multi Format
    What he said.
     
  4. analog65

    analog65 Member

    Messages:
    125
    Joined:
    Jan 24, 2014
    Shooter:
    Large Format
    Thanks guys for the quick response, I appreciate it.
     
  5. karl

    karl Subscriber

    Messages:
    199
    Joined:
    Jan 17, 2003
    Location:
    SanFrancisco
    Shooter:
    ULarge Format
    There is a lot of information on the Jobo web page. If you search for something Jobo related via Google you generally get the Jobo site as the first hit.
     
  6. Sal Santamaura

    Sal Santamaura Member

    Messages:
    1,510
    Joined:
    Nov 21, 2005
    Location:
    San Clemente, California
    Shooter:
    Multi Format
    Optimum is around 45-50 rpm. In order to know how you can achieve that, it will be necessary to consult the following, which I transcribed from a printed copy of a Web page Jobo no longer makes available.

    How do I properly set the rotation speed for my CPA-2 or CPP-2 processor?

    For many years, JOBO has recommended rotation speed settings of 4 for use with our 3000 series drums and P for all other tanks and drums, to properly set the rotation speed. Now there are two different sets of speeds which need to be listed based on the type of motor in use in the processor. The following processors need to follow the new speed settings.
    • All CPA/CPP processors with serial numbers greater than 22000.
    • All CPA/CPP processors that have been upgraded with the new rotation motors (93026).
    Both of these categories can most easily be identified by the screw head in the center of the cog on the rotation motor shaft. If there is a hex-socket screw (it uses an Allen key to turn the screw in installation) then it is the new style motor.

    All older motors, using a slotted screw in the center of the cog on the motor shaft, still use the old speed settings shown below, and as listed in the instruction manuals that accompanied them.

    Old Settings
    0 - Off
    F - 25 r.p.m.
    3 - 40 r.p.m.
    4 - 50 r.p.m.
    P - 75 r.p.m.
    6 - 78 r.p.m.
    7 - 80 r.p.m.​

    *New Settings
    0+ 25 r.p.m.
    F - 46 r.p.m.
    3 - 70 r.p.m.
    4 - 86 r.p.m.
    P - 86 r.p.m.
    6 - 86 r.p.m.
    7 - 86 r.p.m.​

    *These speeds are approximate and variations of 10-15 r.p.m. will not show up in your processing results

    If you want to determine the proper speed settings for your processor, put a drum on the processor filled with an appropriate amount of water to simulate normal processing loads. Then swing the three-fingered switch out of the way, so the drum will only rotate in one direction, and then begin timing and counting the rotations of the drum. (Only use the single direction rotation for determining the correct speed dial settings. Always use bi-directional rotation when processing film or paper.)​

    This was published by the old Michigan-based Jobo USA folks. Enjoy.
     
  7. analog65

    analog65 Member

    Messages:
    125
    Joined:
    Jan 24, 2014
    Shooter:
    Large Format
    Thank You! I am amazed at the collective knowledge of the group here. Thank you very much.
     
  8. Rolfe Tessem

    Rolfe Tessem Subscriber

    Messages:
    211
    Joined:
    Jan 16, 2006
    Location:
    Egremont, MA
    Shooter:
    Multi Format
    If you use a five minute prewet you can use pretty much any time published for inversion processing. The five minute prewet just about exactly cancels out the speedier development from continuous agitation. It also gets the drum and film to temperature.

    Back when Jobo was still in the analog business, the company used to emphasize this on it's website.
     
  9. StoneNYC

    StoneNYC Subscriber

    Messages:
    8,201
    Joined:
    Aug 5, 2012
    Location:
    Connecticut,
    Shooter:
    8x10 Format
    Do you know if there is a way to adjust the motor speed of the CPE (original, not CPE-2). I can't find a manual anywhere...

    Looks like this...
     

    Attached Files: