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View Full Version : Lens/Lens board problem.....Will someone help?



durr3
17-Apr-2017, 14:09
Sorry if this is off subject, but can anybody help me with a Lens/Lens board question? I have a Rittreck View 5x7 LF camera and just got a beautiful Wolly Verito 9" f4 lens mounted on a nice "regular" Wolly shutter. I had a Rittreck lens board that I took to a machine shop to have drilled out to fit....so far so good. THEN, he had to mount the flange to the lens board withs screws, which worked fine....BUT, now the lens does not screw on to a correct angle for it to work!! Any ideas or experience with this problem? Thanks
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Leigh
17-Apr-2017, 14:22
You have to tell the shop exactly how you want the ring oriented when you ask them to mount it.

Take it back, show him the problem, and ask him to change the mounting.
He'll charge you for the re-work.

- Leigh

durr3
17-Apr-2017, 14:32
That figures! I rotated the flange over two holes and it helped enough to use. Not perfect, but useable. Thanks for the advice.

Jac@stafford.net
17-Apr-2017, 14:33
Leigh is probably right. In the meantime you might remove the fasteners and turn the mount two holes, and try it again. It might come out close enough.

Michael Dodd
17-Apr-2017, 14:34
If the holes are spaced the same you might be able to rotate the flange one hole and get the placement close. I think I would try that before I spent any more $

Mike

Jac@stafford.net
17-Apr-2017, 14:42
Machinists today other than Good Old School Machinists, like Leigh, machinists (lower case) just do what you ask. The very worst are not machinists at all but just CNC operators. My favorite face-to-face consulting machinist retired and is now looking at end-of-life issues. We are all fading away.

My go-to guy is glenview (http://glennview.com/). He specializes in photography fabrication. Glen corrected a specification I thought I had done my best to make. He saved me from myself. (And he suggested that I get a new caliper. :) I got a Mitutoyo and all is better.)

LabRat
17-Apr-2017, 15:17
On many mounting flanges, the hole spacing on the circle is not always exact in all rotational positions... Be careful to find the point where the lens orients correctly, and mark it for that point...

One can add a small spacer of film, paper, thin metal, thin o ring etc on the lens seating area (between the flange), for trial & error testing to where the rotation stops when you screw the lens on the flange...

Good Luck!!!

Steve k

Mark Sawyer
17-Apr-2017, 15:29
The first thing to do is screw the lens into the flange and put a pencil mark at the top of the flange for reference. Between rotating the lensboard 90 degrees at a time and rotating the ring on the lensboard 72 degrees at a time, you should get it pretty close.

Leigh
17-Apr-2017, 15:55
On many mounting flanges, the hole spacing on the circle is not always exact in all rotational positions...
It's much worse than you might expect.

Many of these were drilled by hand with no particular pattern.
The flange was placed in the hole in the lensboard, then holes were drilled through both.
The tech (not a Machinist) knew where the holes should be, sort of.
That's as close to a locational specification as they cared about.

- Leigh

John Kasaian
20-Apr-2017, 14:47
Machinists today other than Good Old School Machinists, like Leigh, machinists (lower case) just do what you ask. The very worst are not machinists at all but just CNC operators. My favorite face-to-face consulting machinist retired and is now looking at end-of-life issues. We are all fading away.

My go-to guy is glenview (http://glennview.com/). He specializes in photography fabrication. Glen corrected a specification I thought I had done my best to make. He saved me from myself. (And he suggested that I get a new caliper. :) I got a Mitutoyo and all is better.)
Is Glen still in business?

Jac@stafford.net
21-Apr-2017, 06:02
Is Glen still in business?

He was last year when he made me a special round lens board. In fact, he saved the day by recognizing that my measurements were slightly off. Since then I have replaced my caliper.