Hello,

After having had my eyes on a Graflex 5x4 camera for a few years, I’m super happy to finally have gotten my hands on one. It is a Crown Graphic with a side mounted Kalart rangefinder. Unfortunately, the rangefinder is incorrectly calibrated. In fact, the arm is incorrectly installed, as it is forced beyond its possible movement when attempting to move the rails all the way back.

I’m trying the reset it, but I do not have the correct tool for the two set screws. I don’t even know what tool to look for. It looks like the driver tip should be a straight cross, and not tapered like all the Philips and JIS drivers I’ve seen. I think someone has already been at it with an incorrect screw driver, as one of the screw heads is partly worn down. The cross indentation is so deep, however, that it should still work fine with the proper tool.

Does anyone know what sort of tool I should be looking for?

Best wishes,
Nils

The Kalart service manual describes them as Bristow screws, but I had no luck finding anything about those.

https://phsc.ca/repair/Kalart/kalart_rangefinder.pdf

I had to adjust the set screw on mine and recall using a Phillips screwdriver, and I managed to break the head off the screw when I retightened it at the end. It’s soft brass. Please be careful.

Thank you! I didn’t have any luck finding something when googling Bristow either.

I’m afraid a Phillips screwdriver will most likely not work in my case, given the state of the head. A flathead screwdriver seems to get a better grip, but I’m really worried that I’ll ruin the screw.

Provided I can get it out, do you think it would be possible to find a replacement with another head, or is that out of the question?

Actually, as I recall now, I think I may have just gripped an exposed part of the Bristow screw that was above the level of the screw hole with pliers. You don't have to remove it; just loosen it enough to turn the shaft inside, then retighten. I broke the screw after retightening too much, so at least my rangefinder is useable; just not adjustable in the future. The instructions I followed for calibrating the rangefinder were on Jo Lommen's website.

Probably Bristol screws. McMaster-Carr lists them here:
https://www.mcmaster.com/products/bristol-screwdrivers/. They seem to be real oddballs. Good luck!

Nils_pn wrote:

Thank you! I didn’t have any luck finding something when googling Bristow either. I’m afraid a Phillips screwdriver will most likely not work in my case, given the state of the head. A flathead screwdriver seems to get a better grip, but I’m really worried that I’ll ruin the screw. Provided I can get it out, do you think it would be possible to find a replacement with another head, or is that out of the question?

On p. 18 of the Kalart instructions, screw MS-21 is listed as a 5-40 x 1/8" set screw. McMaster-Carr lists a variety of head styles on this page: https://www.mcmaster.com/products/machine-screws/

Amazing, thank you!

I have managed to remove the screws using a flathead screwdriver and being very careful. Given the information you just gave me (5-40 x 1/8" set screws), would that be enough to find replacements? Perhaps this: https://nettorc.com/en/p/8f32db467af9461fb334a6830109339c/stoppskruv-5-40-x-18-in?srsltid=AfmBOooRfW8G_q46qfMqdp5NNEVubUgg8PcIb59IevPGm1XohiX0e-Ox

or this: https://www.accu.co.uk/imperial-cup-point-setgrub-screws/31039-SSU-5-40-1-8-A2

I feel replacing them would be the simplest solution, but I'm concerned the threads won't be compatible....?

Henry wrote:

Nils_pn wrote: Thank you! I didn’t have any luck finding something when googling Bristow either. I’m afraid a Phillips screwdriver will most likely not work in my case, given the state of the head. A flathead screwdriver seems to get a better grip, but I’m really worried that I’ll ruin the screw. Provided I can get it out, do you think it would be possible to find a replacement with another head, or is that out of the question? On p. 18 of the Kalart instructions, screw MS-21 is listed as a 5-40 x 1/8" set screw. McMaster-Carr lists a variety of head styles on this page: https://www.mcmaster.com/products/machine-screws/

Looks like either of those sources would work. I like the ACCU example, as it clearly shows the hex key opening. Also, it costs less. Good luck, and let us know how it turns out!

I can now happily report that I have a fully working and calibrated range finder Thank you so much for your help! I ended up going with the other screws simply because the store that sold them is actually not all that far from where I live, so I didn't have to bother with import fees and shipping and all that. They fit perfectly and so far seem to be doing their job brilliantly.

The shutter has returned from the repair shop as well, where it was given a much needed CLA, so I got to test that as well as the range finder today. Now I'm very eager to start using it for real, and not just for doing test images of focus patterns and such.

Henry wrote:

Looks like either of those sources would work. I like the ACCU example, as it clearly shows the hex key opening. Also, it costs less. Good luck, and let us know how it turns out!

Terrific! Glad you had success. It's always satisfying to get these old devices back in operation, to prove their worth in this "modern" age.

Now if I can just keep my '02 Prius going for a few more years, I'm home free!