JJ- Lower Sprocket Pad Roller Arm Piviot Tension?

[Jim Cassedy]

The the lower sprocket pad roller on one of the JJ's I work with won't stay open
when you flip it up. It's a little annoying when threading & cleaning the JJ.
The one on the other projector snaps up & stays open till you close it.

> Is there a way to tighten up the friction on that pivot shaft, or something?
JJ_PadRoller.jpg

THANK U!

[Steve Guttag]

What holds it open is the metal shaft that you see to the right of your arrow (with the knurled end). That is held into the main casting with a suitable screw. If that is loose, then the whole unit is now pivoting in the casting. When you open/close...does the knurled part move (it shouldn't). As I recall, there is a hole in the front of the projector that aligns with the screw that holds the assembly from moving (and being removed).

[Jim Cassedy]

Thanks, Steve. I'm off today, but I've got a busy film schedule over the weekend, so I'll takalook
at it Friday morning, since it's a minor annoyance I'd like to fix. Also, one my Zipper change-overs
isn't as zippy as it should be. I'm pretty sure It's a mechanical, and not electrical, issue. It's still works
OK 99½% of the time, but sometimes it doesn't quite close all the way. I may just need to clean
some gunk out of the guide rails the c/o shutter blade rides up & down in. I'll deal with it Friday. . .

[John Eickhof]

jim, steve is correct that you can reach in from the front either with a long flat blade screwdriver or allen wench (depending on the set screw ) there is a drilled indent in the shaft that the setscrew locks into, it correctly positions the arm and there is a spring loaded detent ball built in to that sets the friction / hold device, i would remove the assy by loosening the setscrew, then test it by holding the portion that mounts into the frame with a pair of pliers, then operate the pad roller open / closed to make sure the detent is working, if it is then leave it in the open position and re-install it while aligning the drilled indent by slightly rotating the assy until it lines up with the setscrew, then tighten the set screw down and then check proper spacing of pad rlr against film. if the detent is not working internally, the arm will easily flop back and forth and will need to be replaced as an assembly as the mounting / detent portion is pinned to the shaft itself and is not fiels reparable, if you need a replacement assy, let me know, i may have a new one.