Mah lens is too big... mah lens, is TOO BIG! 610mm nikon tries to mate with Sinar

[snuck]

Ok, anybody remember Don Hertzfeld?

Ok, I have this issue. I have just recieved a truly amazing lens, a 610mm Nikon multicoated from John Schneider. But now I'm trying to think about how to mount it. I use a Sinar Norma, and the lens is huge at 4.5" insertion diameter. The flange itself fills the standard Sinar lensboard at 5.5". Have any of you dealt with this lens and machining out lensboards? Is there anybody in the Toronto area adept at chopping some really huge round holes in aluminium?

Cheers

[john wilton]

Why not just let skgrimes.com do it? Rhode island not too far from Toronto.

If an OEM lensboard won't mount on the camera with flange attached, they will drill and thread a hole in your lensboard in short order. They can also supply a thicker lensboard if necessary (probably not.)

[snuck]

Wish I could, but I am trying to economize by screwing it up myself.

[BradS]

Any competent machinist could accomplish this in not much time. I have a guy at work who would probably do it on his lunch break for a small token of appreciation (a case of good beer).

[John Powers]

Any competent machinist could accomplish this in not much time.

…and a few incompetent retired software salesmen. If you have a portable power drill you can do this with little expense. Go to a large hardware store (Lowes or Home Depot in the States) and buy a 2 inch drum sander accessory that chucks into your power drill. Also buy a package of three 2” sander refills. You will need an artist’s compass or dividers, not a navigational compass.

Start with a lens board that already has a Copal 3 hole. Scribe the correct size hole to use as a target. Make sure the scribed hole is equidistant from all edges. Lock lensboard in a vise using a rag on either side to protect the finish. Start grinding away. Frequently check to see the hole is growing in a perfectly round shape using the dividers at different positions on the board. Total investment, less your time, is $10-$15 in tools you may be able to borrow. Wear safety glasses to protect your eyes from flying aluminum chips and dust.

Got to get on with my retired incompetence. The dogs need a hike.

John

[snuck]

…and a few incompetent retired software salesmen. If you have a portable power drill you can do this with little expense. Go to a large hardware store (Lowes or Home Depot in the States) and buy a 2 inch drum sander accessory that chucks into your power drill. Also buy a package of three 2” sander refills. You will need an artist’s compass or dividers, not a navigational compass.

Start with a lens board that already has a Copal 3 hole. Scribe the correct size hole to use as a target. Make sure the scribed hole is equidistant from all edges. Lock lensboard in a vise using a rag on either side to protect the finish. Start grinding away. Frequently check to see the hole is growing in a perfectly round shape using the dividers at different positions on the board. Total investment, less your time, is $10-$15 in tools you may be able to borrow. Wear safety glasses to protect your eyes from flying aluminum chips and dust.

Got to get on with my retired incompetence. The dogs need a hike.

John

Not bad at all. Although if any of you have stumbled across a sinar board with an irregularly large hole, even if it doesn't match, I'd be game for taking it off your hands.

[John Powers]

Not bad at all. Although if any of you have stumbled across a sinar board with an irregularly large hole, even if it doesn't match, I'd be game for taking it off your hands.

Thanks,

The Labs liked the hike as well.

A carpenter friend showed me how to do this after another friend did a board with a power hacksaw. That was not a tight fit. The carpenter had a $150 drum sander with five different size drums, but he said the big hardware stores had the drums for power drills. It worked for me to mount Ilex #4 and #5 shutters increasing the hole size from Copal #3.

John

[eddie]

buy a big hole saw close to the size you need. put the board on a block of wood. add two wood screws per side to hold it in place, so it does not spin. drill hole!

i do this with all my boards. works fine.

eddie

[Pete Roody]

You will have to clip the flange so the board can mount to camera. You may also have to add a spacer to allow for mounting or if you plan to use a Sinar shutter behind the lens.

[Alan Davenport]

An alternative to the simple hole saw, is a flycutter. I use flycutters for all of my lensboard holes up to 1/8" aluminum boards. Believe it or not, Harbor Freight sells a nice flycutter that has a cutter on both ends of the bar; more difficult to adjust but well-balanced and cuts fast. Of course you MUST use a drill press. Run the thing as slowly as possible, feed the cutter slowly and keep your hands clear.