Pulled up 45PSS's instructions on making rangefinder cams. The section listing cam height for several distances has these mid-range numbers:

15 feet - .664
10 feet - .647
8 feet - .638
7 feet - .634
6 feet - .618

Is the 8 and 10 feet height numbers correct? Plotting these on an X-Y curve, it looks like they should be a bit higher. The curve of dots on graph paper with the X axis being evenly spaced "feet" numbers and the Y axis being cam height, all the "feet" numbers except 8 and 10 plot a good curve. Maybe I'm wrong, but it looks odd to me.

I'm getting a Graflex 90mm Optar in a Wollensak shutter and will make a cam for it using these instructions.

At the time I made the measurements I had 3 Super Speeds with factory matched cam/lens. 2 of the 3 camera/lens/cam combos has the same cam number and the third a different. The rangefinder was removed from a 4 th. body and used to make the cam measurements. All I had to do was position the cam according to scribed lines and measure between the follower and housing (cam base). I have made cams for a 100mm WFE, 162 Paragon, 203 Ektar, and 254 Wollensak. My crude cutting/grinding resulted in cams that are within .001 bed travel of perfect.

I too would like to hear from others if they have used the procedure/measurements to make cams from scratch.

So, yes I'm 99.99% sure the measurements are accurate.

Thanks, 45PSS, for the confirmation. I scanned my P34 cam from my SSG and sized it to 1000 dpi at full scale. I'll use it's X and Y values to check it's profile.

Your numbers just looked a bit off, but after reading your reply, I think I need to remeasure.

Now I made my first cams more like graflex would made the first cam ever
and that is to start at a target at 300' focus on the ground and make the
cam right there then I set a target at 5' making my cam right there
then I put a line from 300' to 5' and ajusted it every 5 ' up to 75' ,150',,,300'
so focusing a target on the ground every 5'
this takes some time BUT my cams work out bether then the cams that come
with my next Super Graphic + I didn't find the right cams to work some of the Newer Lens that I have I now have cams that work from my 90mm upto
my 250mm
I never tried to use a X - Y curve

banjo

1banjo wrote:

Now I made my first cams more like graflex would made the first cam ever ......banjo

That's good, but did you "make" the cam by grinding it's curve at the point where the rangefinder arm point contacted it when focused at each distance to get coincidence?

yes it end up smoth as 5' increments aint like 1/2mm apart on the cam