Fixing / Adjusting Kalart Rangefinder

[Zaitz]

Yes I know there are a lot of threads with info on adjusting the Kalart rangefinder on a Speed Graphic. My problem, I think, is a little different. I've searched for many hours and looked at all the walkthroughs and seen the old manual many times. The adjustment procedure seems pretty simple and I was going through it ok, perhaps just a bit tedious for some. I was just seeing how the adjustments went with a 135mm Xenar on an Anniversary SG before I got my Aero Ektar on it.

My initial problem was that I could not get the rangefinder images to coincide at infinity. The moveable image was too low. Turning the eccentric screw back/left could not get it high enough at infinity. They wouldn't match up. I had read that the arm that is located UNDER the prism/mirror board might be out of alignment. So I removed the one small screw in the middle to take the main plate off and see the Kalart's internal mechanisms with the cams and a spring and whatnot.

While lifting the board up the spring part popped off so I am not 100% positive I have it back together right but it really only seems to go one way. Does anyone have a photo of the internal mechanisms? Not the mirror part but under that. I cannot find one anywhere online. The closest is this:
http://lommen9.home.xs4all.nl/kalart/new.html

But that only shows the arm attached through the camera side/body to the big silver follower arm that follows the eccentric screw. I also am not 100% sure I have the little metal spring/wire set up right on that main internal arm. It's the one in that link in the 3rd image. How I have mine on there it just doesn't seem to do much of anything.

I've set the whole thing back up a many times now with how I think it is supposed to fit together. But with the rails racked all the way back (so the rangefinder should be at/near infinity) the images only coincide at about 10ft. Moving the rails out obviously lowers the image which doesn't help the infinity problem. Also sometimes the moveable image will not start to move down (while turning the focusing knobs and extending the rail) until a few turns of the focusing knob. It just sits steady and then begins to move after a second or so.

Also wondering how far is the max adjustment supposed to go? By that I mean how far out (so close focus) on the rail? I've read it can only focus accurately maybe down to 6ft. The follower arm on the eccentric screw stays in positing for quite a while after that point with the rails racked pretty far out but the internal mechanism doesn't look like it can go any further on its adjustment with the way I have it set up.

A bit wordy but I can't really find anything close to what I need elsewhere online. All the old threads do is mention the standard procedure and point to the old manual which doesn't help with the internal mechanisms at all. I guess I just need a picture of the internal cams/springs to make sure mine is set up right and then to know why the infinity moveable image is so low.

My rangefinder also seems a bit different. There is no 'loosen' screw to unlock the long-scale rear adjustments. I can just push both the long-rear and short-front adjustment sliders with a small screwdriver. Don't think that matters but haven't seen any photos of one exactly like mine.

[Leigh]

The instructions that you linked are in error, specifically as regards the calibration distances.

The Kalart is designed to be set at infinity, 15 feet, and 4 feet. That is stated quite explicitly in the instructions.
The military LM-63A collimator, designed by Kalart for adjusting the rangefinders, has targets at those distances.

There are several different linkage arrangements for the Kalart, and different configurations of the rf itself.

I normally set the infinity position a hair (~1mm) forward of the mechanical stop, to allow for thermal expansion.

Here's a PDF of my instructions (~38MB) http://www.mayadate.org/pix/Kalart_instr.pdf

- Leigh

[Zaitz]

Yes the link was just used to show the image.

I did manage to fix it and calibrate it for the 135..for now. There were a few problems that were preventing it. One was the mirror assembly was not angled perfectly and I had to loosen and re-tighten it. This moved the moveable image up a good ways. Two was a small screw on the internal mechanisms preventing reaching a good infinity setting, it was inhibiting the last bit of movement of one of the internal arms. I was also starting the main internal arm (attached through the body to the big silver arm) too far to the left. Lateral coincidence was off by a good ways too. Probably because of not adjusting the mirror assembly perfectly. I got the height of the moveable image I needed but didn't move the lateral image enough, I think. Too much adjustment was needed via the main lateral coincidence screw. Back together now and it seems to be working well and the moveable image was actually a bit high at infinity. Moving the eccentric screw made it perfect. Some screws were bit rough so someone had been in there before.

With the housing back on the image is faint as heck, not sure if it was all the grabbing and whatnot I did. 50/50 beam splitter and mirror on the way from Edmund Scientific, not Edmund Optics. The beam-splitter was over 3 times as much at Edmund Optics.

Well that was fun. About 6 hours a night for the last 3 days. But at least I learned something. It'd be nice if I had spare parts around, then I wouldn't have worried so much about breaking/losing something. Like the small spring/wire on the mirror assembly that flew off. Took about 30min to find that in the carpet .