View Full Version : Focus Knob Stuck on Wisner TF

Brian Vuillemenot
9-Feb-2004, 10:08
The focus knob on my 4X5 Wisner technical field is stuck and can't be unscrewed. It's not cross-threaded; I think there's just some grit or debris in there making it hard to turn. I tried using WD-40 to lubricate it, and it helped a bit, but still can't be turned all the way. Any advice on how to free it up? Thanks!

Michael Kadillak
9-Feb-2004, 10:55
This may be a really basic question, but are you sure that you do not have a locking knob on the other side of the camera engaged? Sometimes I would unintentionally engage a locking knob and that caused the gearing to be tight on my 11x14 Wisner TF.

If this is not the case, by all means be very carefull in approaching the situation. Did one of the cogs skip a gear and you are binding the rails?

Brian Vuillemenot
9-Feb-2004, 11:18
The problem is not with the gear and cogs that move the focusing rails. It's the focusing knob itself. I can unscrew it a little bit, and then it becomes stuck. I can also screw it back in a bit, but it becomes stuck before being tightened all the way. I don't want to use pliers, even after wrapping the brass in something to protect it, since that might leave a mark. Any thoughts?

Ted Harris
9-Feb-2004, 11:36
Sounds like some combination of the knob itself or the hole it goes into are crossthreaded or have stripped threads.

Michael Kadillak
9-Feb-2004, 12:12
I would give Wisner a call to see if you can get some assistance and if that fails, I would call Richard Ritter in Vermont. He is supposed to be a real problem solver and ex-Zone VI camera innovator and probably can ease your mind over the phone. Don't have his number, but he has a web site and seems like a really nice guy. Nothing more frustrating than a camera that will not function as intended for whatever reason.

Michael Kadillak
9-Feb-2004, 12:17
Richard Ritter is at www.lg4mar.net.

Phone (802) 365 7807

Roger Hein
9-Feb-2004, 13:45

From your description do you mean the left hand focus lock knob (as you face the back of the camera) can't be unscrewed? A friend of mine had the same problem - the thread on the axle the lock knob screws onto isn't cut far enough (or the washer between the knob and the body is too thin) so as you tighten the lock knob it's basically cutting into the axle (and seizing). You might be able to work it loose using those 'band' pliers (so you don't mark the knobs) and liquid screw - otherwise you'll have to send it back to Wisner for repair. Good Luck!

John R
9-Feb-2004, 18:19

It sounds to me like galled threads. Additional lubricant may help, try Corrosion X, a superb lubricant anti-seize. Used a lot with saltwater fishing gear and marine applications. It does wonders at times when you think there is no hope. Otherwise I agree that you should contact Ritter or Wisner.

Richard Rankin
10-Feb-2004, 21:30
This happens on mine regularly when I unscrew the knob too far. It's some sort of problem that happens due to an artifact on the screw part to keep the knob from coming completely unscrewed. I have always just used a pliers and carefully applied just enough force to unseat the jam. Then, I try to remember which way the knob screws and unscrews to prevent this happening again... but it always does. I always doublecheck the rotation of the other knob an the same side of the camera before applying any force, because a mistake in direction probably WILL ruin the screw threads. But it doesn't take a lot of force, just more than you can apply comfortably by hand. I'm pretty sure that Ron Wisner told me this, but you might phone him yourself and double check if you have any qualms about applying the needed force. Cheers, Richard