Swift historians (1 Viewer)

Mystery solved. In the lower end of the focus-knob, there is a metal piece that is threaded and can with the help of a finger be either screwed in deeper in the knob, or the other way, screwed outwards. This solved the problem with the gap.
Now it is just the problem of fine tuning the knob itself as close-focus depends on how much I screw the knob (don't get any nasty ideas here ) before fastening it with the screw in the bottom.
Fine tuning is delicate!

Ysterkvisten said:

Mystery solved. In the lower end of the focus-knob, there is a metal piece that is threaded and can with the help of a finger be either screwed in deeper in the knob, or the other way, screwed outwards. This solved the problem with the gap.
Now it is just the problem of fine tuning the knob itself as close-focus depends on how much I screw the knob (don't get any nasty ideas here ) before fastening it with the screw in the bottom.
Fine tuning is delicate!

Click to expand...

This is very interesting. I wonder whether anyone can confirm that this is the same focus mechanism as my 804 HR/5? I have managed so far to remove the entire center post/bridge assembly/occulars, but this is as far as I have dared go. It looked to me like a special tool was required to disassemble the hinge, so I stopped at that point, and simply re-greased the focus helical. I make my own thicker-than-usual grease by warming and combining heavy duty differential oil and candle wax. I wonder if anyone knows of a thick enough grease to replace the original thick, sticky lubricant used in most older binoculars? Most modern grease is significantly thinner than the old stuff, resulting in too little resistance in focusing and diopter adjustments.

Angelo

I successfully regreased the focus helical of a pair of Asahi Pentax 8x30 binoculars with some red grease I was kindly given by Rob at Marshall's cycle shop in Stevenage. I have a bad memory, but I think Rob said that it was the grease he used to service Rohloff hubs (Rohloff is a maker of 14-speed internal hub gears). I'd describe the resulting movement of the focus wheel as acceptable but stiffish and a bit slow. But the pitch of the helical screw of the binoculars rather than the viscosity of the grease may have been responsible. Certainly I used the same grease to re-grease the diopter screw, and the result was that the diopter moved far too freely.

Stephen

PS I paid £19 for the binoculars, but the focusing was so stiff that the binoculars were unusable. It was uneconomic to pay a repairer to open them up. There are no binocular repairers near where I live who might have told me what grease to use, and who might have supplied the grease to me. So I had nothing to lose by using the red grease. Your position may be different ... !

Glad you sorted them out.