Yashica Mat 124G focus knob grinding

Discussion in 'Medium Format Cameras and Accessories' started by Joe Galloy, Jan 28, 2018.

  1. Joe Galloy

    Joe Galloy Member

    Messages:
    23
    Joined:
    May 28, 2017
    Location:
    Missouri
    Shooter:
    Multi Format
    A Mat that I bought a couple of years ago has just started to exhibit a slight but noticeable "grinding" feel along with resistance when the focus knob is turned in certain places. Has anyone experienced this and know what the cause is? Thanks.
     
  2. BrianShaw

    BrianShaw Member

    Messages:
    8,218
    Joined:
    Nov 30, 2005
    Location:
    Los Angeles,
    Shooter:
    Multi Format
    If the camera had not been dropped or the like, I would guess that, at a minimum, the lube in the focus mechanism has failed.
     
  3. Dan Daniel

    Dan Daniel Subscriber

    Messages:
    974
    Joined:
    Jul 4, 2009
    Location:
    Vermont
    Shooter:
    Medium Format
    A few things can cause this. A bent axle or a bent side plate- one reason to always store a TLR in the infinity position; I even rack it back in walking down the street to avoid it being bumped. Sand or such in a variety of spots.

    Focus in and out and watch the lens unit very carefully. Watch for any wobble or binding in the movement. Lightly rest a finger on one side then the other while focusing to see if you can feel variation. This is the important issue and a sign of real trouble. Grit or binding in itself is annoying and not good in the long run, but having the lens moving erratically out of alignment should be looked at soon.
     
  4. OP
    OP
    Joe Galloy

    Joe Galloy Member

    Messages:
    23
    Joined:
    May 28, 2017
    Location:
    Missouri
    Shooter:
    Multi Format
    Thanks for the suggestion - the camera hasn't been dropped or knocked since I've had it, and although I'm the second user the first appears to have barely used it (almost factory fresh condition).
     
  5. OP
    OP
    Joe Galloy

    Joe Galloy Member

    Messages:
    23
    Joined:
    May 28, 2017
    Location:
    Missouri
    Shooter:
    Multi Format
    Thanks for the suggestion. I'll look for variation while moving the lens unit and report back!
     
  6. shutterfinger

    shutterfinger Subscriber

    Messages:
    2,845
    Joined:
    Feb 25, 2013
    Location:
    San Francisco Peninsul
    Shooter:
    4x5 Format
  7. OP
    OP
    Joe Galloy

    Joe Galloy Member

    Messages:
    23
    Joined:
    May 28, 2017
    Location:
    Missouri
    Shooter:
    Multi Format
    Dan, I did check this last night. There is no visible wobble, and my attempts to find any variation with light pressure didn't go anywhere...until I noticed that the focus knob was turning smoothly with no grinding feeling. I worked it back and forth and it was gone! My hopes were instantly dashed when I applied light pressure to one side and found that the issue returned. It only grinds around one spot, roughly where the 3.3' to 4' marker is on the knob.
     
    Last edited: Jan 30, 2018
  8. OP
    OP
    Joe Galloy

    Joe Galloy Member

    Messages:
    23
    Joined:
    May 28, 2017
    Location:
    Missouri
    Shooter:
    Multi Format
    Thanks for the manual. I wasn't aware that one was available. I've leave this to a professional because I'd likely turn it into a hunk of junk. I see that Mark Hama has been a popular choice. Does anyone know of others who service Yashica Mats and have a good reputation?
     
  9. paul ron

    paul ron Subscriber

    Messages:
    2,677
    Joined:
    Jan 22, 2004
    Location:
    NYC
    Shooter:
    Medium Format
    take the view finder off and you can see the focusing axle. while in there, remove and clean the mirror.
     
  10. jnanian

    jnanian Advertiser Advertiser

    Messages:
    24,532
    Joined:
    Jun 21, 2003
    Location:
    paswonquitte
    Shooter:
    Multi Format
    both zacks camera repair ( apug advertiser ) and midstate camera repair in RI are be good choices. they both take
    cameras through the mail. and both most likely work on yashicas.. zacks has an in house machine shop in case he has to fabrcate parts ...
    good luck !
     
  11. OP
    OP
    Joe Galloy

    Joe Galloy Member

    Messages:
    23
    Joined:
    May 28, 2017
    Location:
    Missouri
    Shooter:
    Multi Format
    Thanks!
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies. If you have a Photrio account, please log in (and select 'stay logged in') to prevent recurrence of this notice.
,