Cambo rail knob sticking

[George Collier]

I have a 4x5 Cambo, the one with the square rail and round standard uprights (it's a lower end model). I've had it for about 30 years, with no problems. There are two knobs each to move and lock the front and rear standards, one tightens and one moves the standard. Lately, the rear standard tightening knob is harder to turn, like it is dirty, but it also tries to move the standard while tightening it, so it's difficult to tighten the standard after finding the right position. It still tightens, but it also will move the standard while doing so, unless I hold the moving knob just right while tightening. There is some play in it also.
Anyone know what I should do? Seems like something I can do myself, but I wouldn't want to clean or lube with the wrong stuff.

 

[John Koehrer]

If you can remove the knobs lube them with candle wax.
If the locking knob slips it's most likely a plastic or fiber pad between the knob and rail that's worn.
Just replace it with a similar material. Sometimes a visit to the local craft store is in order.

 

[George Collier]

Thanks, John.

 

[BrianShaw]

I'm curious... how does one remove those knobs?

When my Cambo started getting tight I removed the standard from the rail and cleaned the dust/dirt/debris from the nylon gizmos that adjust the standard to fit the rail. Try that too. I think it is basically a nylon screw, but can't tell becuase the know has to be removed to adjust/replace it. Hence my first question.

 

[John Koehrer]

Oh Poo! You mean the screws are captured?
Check around the top & bottom of the focusing block for a screw set into the block.
I was under the impression they would simply unscrew. Silly me.