Possible to manufacture a Horseman 970 Rangefinder Cam?

[ivan35mm]

might also be wise to just trace it on a piece of paper, and scan that.

this way you avoid shadows (which is common when scanning 3d objects on a flatbed)

try to trace as close to the object as possible (mechanical pencil), and then you can scale a traced drawing quite easily in any program

 

[ags2mikon]

@ivan35mm Have you used sendcutsend.com before? That looks like an interesting idea.

 

[ivan35mm]

@ivan35mm Have you used sendcutsend.com before? That looks like an interesting idea.

yes. great company. i prefer to bulk order with them, however. they don’t have a “minimum order” per se, but if you order 1 item it’s like $30. if you order 20 items its like $35. so it makes sense to stock up. i’ve used them for laser cutting aluminum & steel. they have plenty of good materials and thicknesses to choose from. Sendcutsend is very fast, as well.

I also really like Xometry. great material selection for 3d printing / machining. little bit slower, but always high quality work.

 

[Chuck1]

I received the 90mm cam: it's exactly 40mm in width, and approximately 1mm in thickness.

Are you using a recessed lensboard (like from the super topcor 90mm)?

 

[loccdor]

Are you using a recessed lensboard (like from the super topcor 90mm)?

Haven't used the lens yet, it comes to me soon. I ordered a standard copal 0 80mm flat lensboard for it.

 

[ags2mikon]

You can use a 90mm on a flat lens board with a horseman. The designers used a recessed board so that the same lens stops could be used with the 105mm 3.5 lens.

 

[loccdor]

You can use a 90mm on a flat lens board with a horseman. The designers used a recessed board so that the same lens stops could be used with the 105mm 3.5 lens.

Sounds good. It seems like with a flange focal distance of 97mm I'm going to need to adjust the infinity stop about 5-7mm farther out vs the Topcor lenses. My horseman is missing two of its five pairs of infinity stops, but that should be no big deal.

 

[ags2mikon]

If you don't have enough lens stops you can make spacers that go between the next lens stop and the standard you are curently using. Someone here once brought this up. I don't remember who but I used his idea. So speak up if it was you.

 

[mshchem]

Do you know if each factory cam is the same? I read somewhere that Graflex adjusted each cam to the lens provided with the camera. I would be surprised if this is the case.

 

[mshchem]

Making Graflex Super Graphic RF Cams

graflex.org

 

[loccdor]

I was able to confirm that the 90mm horseman cam does accurately couple the rangefinder for the Nikkor 90mm SW f/8. Tried all rangefinder distances with a ground glass and loupe. Looks like it will be a nice lens for this! Although you can't close it up.

 

[ags2mikon]

Nice! Chunky little cameras. I don't know if you noticed but the 970 has a small finger grip inside the body and the 985 didn't. All metal knobs and latches too.

 

[Lachlan Young]

It shouldn't be too hard to work out the required curve for most lenses - once you know if it's a 1m or 2m min focus for that particular focal length. Widest point of the cam is infinity, narrowest is 1m or 2m (with a ramp off at the end of the 2m ones, presumably to ensure that the cam disengages and re-engages smoothly as you rack in or out past min RF focus). Length of curve seems to be defined by rack travel required for that focal length to traverse from infinity to 1m or 2m, multiplied by the scaling of the RF linkage (which seems pantograph-like and in the order of 2x). Once you have the relevant data, it should be pretty straightforward to design and make them for any given FL (within the limits of the mechanism).

 

[loccdor]

One interesting aside: I did a couple hours of calculations and apparently the hypothesis is that a 270mm Tele-Arton f/5.5 lens has the appropriate focus throw to work with the Horseman 180mm cam within a few mm of inaccuracy. I'm going to test that...

 

[ags2mikon]

I may be wrong, but I don't think that will work. I have a 270mm Rotelar, a 240mm Tele Xenar and a 300mm Fujinon-t and none of them are even close to being able to use the 180mm cam. Also the minimum focus would be about 12 feet?? Trying to use front tilts and swings will drive you to drink. The best thing I found for the long glass like that is the rotary back with the angle finder. Almost slr like. Almost but not quite.

 

[MMfoto]

Super interesting thread.

Just wanted to throw out here that this would be a good item to have cut by a CNC laser.

Also, photogrammetry might be more accurate than a scanner for something this small.

 

[loccdor]

I may be wrong, but I don't think that will work. I have a 270mm Rotelar, a 240mm Tele Xenar and a 300mm Fujinon-t and none of them are even close to being able to use the 180mm cam. Also the minimum focus would be about 12 feet?? Trying to use front tilts and swings will drive you to drink. The best thing I found for the long glass like that is the rotary back with the angle finder. Almost slr like. Almost but not quite.

I'll give it a try - if nothing else I can use it as a fixed focus portrait lens. Its flange distance is around 150mm, and the camera can rack to 250mm, which should be about 0.4 meter focus (rangefinder doesn't go that close though). The 240mm Tele-Xenar apparently has a focal distance of around 220mm from what I'm seeing and the Fujinon 195mm so it's a much weaker telephoto effect.