I have a 90mm Horseman lens that I want to remove from its lens board. The only problem is the retaining ring too tight and no matter how much I try the tool that I am using eventually slips off. I have used two different lens span wrenches. One cheap and the other more expensive. The ring is really tight. Any suggestions.
Using your best spanner lock it in the the inside (center) of the retainer ring notches then grasp the shutter (front lens element may need to be removed) and turn the shutter to the left as viewed from the front while turning the spanner to the left viewed from the rear. The most turning force may need to be applied to the shutter while preventing the retaining ring from turning with the shutter to get it to break loose. The opposite was done to tighten it.
You can try freezing to see if the contraction will loosen it. Put in a well-sealed plastic bag and put in freezer for an hour or so. Remove and LET IT SIT in the sealed bag for another hour or more so you don't get condensation in the shutter.
If you have a bench vice use it to hold the board. Wood blocks and cloth can prevent marking.
People sometimes make their own spanner wrench. Drive two nails into a board at the right distance and use a grinder to shape the end of the nails.
im not sure about your shutter n how it mounts but most habve a small notch in the lens board that a small screw or pin on the shutter that registers with it to prevent the shutter from turning. if you force turn the shutter, you may do some serious damage.
post a picture of the retaining ring so we can see how its on there? it may be as simple as removing the rear cell to get better access to the ring's notches.
im not sure about your shutter n how it mounts but most habve a small notch in the lens board that a small screw or pin on the shutter that registers with it to prevent the shutter from turning.
A small percentage of shutters have a locating pin from my experience. If the lens board has a bump at the 3 o'clock position when viewed from the rear then the shutter may have a register pin or had one at some point in time.