How to change Symmar from Sinar to other board

[Dirk Rösler]

Hi --

so I impulse-purchased this Symmar 240/5.6 "Convertible" (great for summer, I thought :) ) for a few thousand today. Comes with a bit of Schneideritis and some fog, but that's OK.

But it is mounted on this Sinar board. How can I get it off there (no retaining ring on the back) and what size shutter am I looking for? The shop said it needs to be custom-drilled, but are the Compur sizes that non-standard?

Thanks for advice

Dirk

[dominikus bw]

Dirk,
It's already mounted to compur shutter, I think it's equal with copal 3. Try to turn the shutter against clockwise, maybe the lensboard have mounting thread direct to the compur shutter.

Do you have pictures of rear element or the back of lensboard?
And what other board do you plan to use?

[Peter K]

The Symmar 240mm is mounted in a Compur II, EX-CII/5, shutter. Remove the back part of the lens, than you will see the retaining ring.

[Ole Tjugen]

For the dimensions of the shutter, see the thread linked to in my signature - click the link, then "show thread" in the top right corner. :)

[Dirk Rösler]

Hi all,

thanks for your reply. Attached a pic from the back. There does not seem to be a retaining ring. Only a thread is coming through from the front. I guess you could put a retaining ring on it, but there isn't any. Could it be that this is directly screwed into the board? There seems to be something bolted on at the front? But if so, how do I unscrew it? It seems pretty tight.

I am thinking of Wista style board. Do I need to have it custom made?

Regards

Dirk

[Jerry Flynn]

It probably is a number 2 Compur. You'll have to get a board drilled. Number 2 is a non-standard size. I have exactly the same lens and I have had to get boards drilled in the past.

I may be mounted to a flange that was attached to the front of the board (mine was). You'll have to unscrew the rear cell, and unscrew the shutter from the front. It could be tight after all these years. You can then use the flange as a retaining ring. Don't lose or wreck it -as I said, it is a non-standard size (not compatible with Copal 0, 1 or 3).

[Dirk Rösler]

It probably is a number 2 Compur. You'll have to get a board drilled. Number 2 is a non-standard size. I have exactly the same lens and I have had to get boards drilled in the past.

I may be mounted to a flange that was attached to the front of the board (mine was). You'll have to unscrew the rear cell, and unscrew the shutter from the front. It could be tight after all these years. You can then use the flange as a retaining ring. Don't lose or wreck it -as I said, it is a non-standard size (not compatible with Copal 0, 1 or 3).

Thanks for that Jerry. I have tried twisting the shutter in front (anti-clockwise) but no movement. It is hard to get a forceful grip and I don't want to accidentally damage the control levers in the process. There seems to be a ring with an indent behind the shutter, wonder if that's for a special wrench. Perhaps I need to give the whole board to a mechanic to transplant it.

[Ole Tjugen]

That looks like a flange mounted with three screws, from the front, doesn't it? In that case the whole shutter should simply unscrew from the flange. If that doesn't work you can try drilling out the three screws - but that will make it even more difficult to remove the flange from the shutter since there's less to grip...

[Dirk Rösler]

Thanks. Do you think it's clockwise or anti-clockwise turn?

[Peter K]

When you look at the front lens, turn the shutter anti-clockwise.

[Dirk Rösler]

Thanks. I can't move it at all and I am afraid to do damage trying to hard. After 40 years together, they don't seem to want to part.

[Peter K]

Drop some rust solving agent in the thread of the nut from the backside of the lensboard but not in the shutter. After some time you should be able to turn the shutter.

[Dirk Rösler]

Thanks, good idea. Can you give me a reference product name for this? I need to find an equivalent in Japan.

[Jan Pedersen]

Dirk, You could try some WD40, it never fails to impress me and i don't think there would be any rust there anyway. Thin oil is the trick.
If you can find it, spray some out in a plastic cup and apply with a little brush and let it sit overnight.

[ic-racer]

A lot of good suggestions to a sticky (pun intented) problem.

It is probably wise to avoid a lot of torque on the shutterspeed ring, as the 'pin stop' could shear off. So, if this were sitting on my bench I would try my rubber 'jar-lid-remover' and use it to just grasp the body of the shutter to unscrew it. If I really felt the shutter ring was in the way of a good grip on the shutter body, I would remove the shutterspeed ring to get a good grip on just the body. However, if the shutter threads are really stuck that bad, the retaining ring for the shutterspeed ring might also be stuck.

Maybe there is some way to modify this present board for your planned application? Heck, for the price of machining a new lensboard and retaining ring for this thing, you could probably just buy a camera that will fit this board...:p http://cgi.ebay.com/Lecom-Sinar-Alpina-4x5-Large-Format-View-Camera_W0QQitemZ270213010372QQcmdZViewItem?hash=item270213010372

[Dirk Rösler]

Thanks for all the tips. I tried the WD-40 method and gave it a good soaking on the thread, but to no avail. This boy does not want to move.

Time to switch to Plan B and look for a fitting camera. :)

[Jan Pedersen]

That's to bad. It is possible that whoever put it on the board could have use Loctite or another thread glue, if that is the case oil will not help. Only heat will and that is a bad aplication for heat.
Hope somebody shows up with a mirracle up the sleve.

[Dirk Rösler]

Thanks -- I was thinking of putting it into moderate sunlight and see it something loosens when it gets warm...

[Struan Gray]

The back of the flange looks like bare aluminium, in which case the shutter and flange my be locked together by oxidation and/or galvanic corrosion. If that is so, you're going to have a really hard time exerting enough torque to unscrew them from each other without damaging the shutter.

I would drill out the three bolts and take a look at what's currently hidden between the shutter and the lensboard. You then have the option of making a radial cut in the flange and peeling it off the shutter threads. You could also just tap the holes in the flange and use bolts from the rear of a new lensboard to hold it in place.

If you don't have a drill press, a second option is to try and cut a slot in the end of the bolts so you can get a jeweller's screwdriver in and turn them from the rear. You'll have to back them out a little at a time so that the flange comes off the lensboard evenly, but with patience it will work. You can cut a slot with a Dremel or similar tool and a small cutting wheel.

The real bodger's solution hasn't been mentioned yet though: cut down the existing lensboard, drill some holes in it and use it as a flange. If you cover the shutter so swarf and filings can't get in you can do the job with hand tools.

[Peter K]

With the lens cells removed you can carefully warm up the shutter with a hot-plate.

Some time ago I've done this with a Copal 3 glued with two component cement. I could remove the shutter but the glue was all over the diaphragm blades. So I had to disassemble the whole shutter to clean it. After all the shutter works fine.

[Dirk Rösler]

Thanks guys. I am in the process of buying a Sinar camera to fit the board (assuming boards have not changed since the 60s). A bit more expensive option than drilling etc. but I bought the lens for a future 10x8 camera anyway...

[Jan Pedersen]

Dirk, Both Phillips and Chamonix cameras use Sinar boards and perhaps more than that so you don't need to be stuck with a Sinar camera.

[Dirk Rösler]

My Chamonix 45 uses Wista/Linhof boards, are you sure?

Anyway, in the process of closing the deal on a Sinar 8x10... my first time bigger than 4x5.