p8324k Posted June 18 Share #1 Posted June 18 (edited) Advertisement (gone after registration) Hi, my M4 rangefinder arm is slow to return to its position, especially when focusing below 2m distance - it takes a second or two, sometimes it just gets stuck altogether and I need to move focus to infinity and back and then it slowly snaps in. It probably needs cleaning and lubrication. Problem is I'm traveling and won't be able to send it for CLA right now, but was thinking if there's a way to lubricate it myself from inside of the lens mount box, without having to remove the top plate. If I get a high quality watchmaker oil, can I just drop a single drop of the oil with precision needle into the cavity that houses the roller arm mechanism? Or is this useless or dangerous and I should wait for proper CLA. I don't want to mess around myself with removing the top plate - done that with cheaper cameras and it was always a pain putting back various springs for the winder arm and control wheels. I also tried moving the arm back and forth numerous times to see if it loosens up but it didn't help. Thank you. Edited June 18 by p8324k Link to post Share on other sites More sharing options...
Advertisement Posted June 18 Posted June 18 Hi p8324k, Take a look here How to lubricate rangefinder roller arm on M4?. I'm sure you'll find what you were looking for!
jerzy Posted June 18 Share #2 Posted June 18 not oil, but you may take small syringe with light fluid and drop a tiny amount into the space under the arm, where arrows points to. It shall help, intermediate, until CLA Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 3 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/422266-how-to-lubricate-rangefinder-roller-arm-on-m4/?do=findComment&comment=5819729'>More sharing options...
p8324k Posted June 18 Author Share #3 Posted June 18 Thank you, would 99% rubbing alcohol work as well? Link to post Share on other sites More sharing options...
DadDadDaddyo Posted June 18 Share #4 Posted June 18 Caution, caution... A tiny drop of a solvent means this must be, must be, the tiniest drip of solvent, or smaller, that your finest syringe can deposit. Really, really tiny. Like, almost invisible. But, that assumes that the issue is old lubricant becoming stiff. The solvent might, might loosen it, hopefully enough to free the mechanism, but not so much as to strip out the lubrication itself (which would only compound the set of issues). I had an M246 that exhibited sticktion similar to this, and the source of friction turned out to be not at the pivot visible in the lens box, but at a pivot internal to the rangefinder mechanism itself, that is, inaccessible without removing the top of the camera body. Had I pursued efforts to deal with this at the pivot arm itself I could have made a real mess, the sort that would have made it obvious to a knowledgeable repair person that someone had messed with the thing in an attempt to fix it, but absent the knowledge or understanding or experience or materials to do it the right way. Please have caution.... Link to post Share on other sites More sharing options...
pgk Posted June 18 Share #5 Posted June 18 You need to figure out the cause prior to trying to rectify it. If anything does not operate as it should there is a reason for it which may not be obvious. Inside a rangefinder camera is a precision mechanism and adding oil or solvents in the hope that they will solve 'whatever it is that's causing the problem', is an action of rather dubious merit. I'd live with it until you can get the camera CLA'd myself. Link to post Share on other sites More sharing options...
p8324k Posted June 18 Author Share #6 Posted June 18 Thank you everyone for your feedback. I'm going to leave it alone and send it for CLA when I can. Link to post Share on other sites More sharing options...
250swb Posted June 19 Share #7 Posted June 19 Advertisement (gone after registration) I don't think using a solvent is a problem, it will evaporate very quickly and may just unstick gummy grease, the issue is that after a few days the grease may gum up again. I'd just work the arm back and forth manually for an hour and see if that loosens it up. Link to post Share on other sites More sharing options...
George Collier Posted July 2 Share #8 Posted July 2 Not to be stupid here, but I can't figure out what this "roller arm" is - not from the picture either. I have an M4 and several lenses - roller arm? To do with focusing? Link to post Share on other sites More sharing options...
Carlos cruz Posted July 2 Share #9 Posted July 2 5 minutes ago, George Collier said: Not to be stupid here, but I can't figure out what this "roller arm" is - not from the picture either. I have an M4 and several lenses - roller arm? To do with focusing? Inside lens chamber on top of it. Picture looks a bit enigmatic as it seems to be taken with camera (?)partly disassembled. Link to post Share on other sites More sharing options...
George Collier Posted July 3 Share #10 Posted July 3 I get it, thanks Link to post Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now