Help mounting 300mm Ronar

[G Benaim]

Hi All,

Just got a 300mm ronar off ebay, looks like this one 280016841797, and am not sure how to mount it. It has one flange, no holes for screws like others I've seen, and the flange hasn't budged to my careful attempts at unscrewing it. So, firstly, does it unscrew? Secondly, what's the best way to unscrew it if it does? Thirdly, if it doesn't, how do I mount it? The good part is the glass is intact. It says stat-king on the barrel, FWIW. Thanks a lot for any help,

GB

[Steve Hamley]

GB,

Looks like it should unscrew. BTW, Stat-King was a brand of reproduction camera IIRC.

You could simply hot-glue the flange to the lensboard - others have. here are some other options depending on your mechanical skills.

First, remove the glass and tape over the openings. I'd drill two tiny holes in the flange for use with a spanner wrench. Try the spanner and see if it will budge. If not, you could use the two holes to simply bolt the flange to the lensboard and reinstall the glass.

If you're more adventurous, put a tiny bit of penetrating oil around the threads/joint and let it warm in the sun for a few hours and try the spanner again. If that doesn't work, and you're not mechanically inclined, you're probably at the point of needing professional help.

A bit more risky is taking a very small hammer or other solid metal object and start LIGHTLY tapping (not hammering) the ring, especially if you can tap in the direction that would remove it. Never tap hard enough to make indentations. There's some risk of loosening internal parts this way, but it usually works, sooner or later.

Of course, the "Easy Button" is to let S.K. Grimes or someone skilled in lens repair do it for you.

Steve

[G Benaim]

Thanks Steve, that's all very helpful. How reversible is the hot glue option, and how sturdy? That seems the easiest way to go if it won't budge easily. Also, would you remove the glass before trying the oil? Thanks,

GB

[Steve Hamley]

Hot glue would be "reversible", but you probably wouldn't want to! It should be very sturdy. Yes, I'd remove the glass and tape the openings before doing anything really. If nothing else you're going to be handling the lens a lot and there's of couse a chance you'll drop it or drop something on or in it.

Steve

[Neal Wydra]

Dear GB,

You don't say where you live, but if it is near a major metropolitan area you should have no trouble finding a repair shop to remove the flange for you. Heck, you might even see something to photograph on your way to the place.

Neal Wydra

[Ralph Barker]

There are several methods that might be used before resorting to drilling holes for a spanner wrench. The first would be to place a rubber mat on the work surface, and then press the flange into the rubber while turning the lens. Next up in terms of torque would be a "strap wrench" - essentially an adjustable, heavy rubber strap formed into a loop, with a handle. You can also find "lens wrenches" at specialty tool stores, which look like pliers with large, curved jaws with rubber padding. I'm not sure about available sizes, however - they might be too small for the flange.