Packard Shutters - Part 3
Adding Flash Sync to a Non-Sync Packard
Liz and "The Green Monster"
In Part 1 of my series on Packard shutters, I described my method for front mounting the shutter onto the lens barrel. This is an excellent option if your lens requires a shutter larger than can comfortably fit behind the lensboard, or if you wish to use the shutter on different lenses. While I could have bought a smaller Packard for this lens (a 305mm f/9 APO-Nikkor) and fit the whole shebang behind the lensboard, I happened to have an extra Packard laying about and thought that this would be an excellent time to experiment with different ways of adding flash sync to a non-sync'd shutter.
Prior methods that failed miserably...
In Part 2, Building a Box Lensboard, one of my illustrations showed a microswitch mounted to one side of the shutter that was activated by the shutter's piston. While it sounds good in theory, in actual use the lever on the microswitch imparts too much drag on the piston. Maybe a roller type switch would have worked better, but I wound up replacing that shutter with a sync'd #6 of the same size and have had no problems with its operation since. Still, there had to be a better way...
Microswitch = Bad Idea
My next disaster was to try to mount a small microswitch inside the shutter, located in such a way as the top blade would trip the switch. I don't have any pictures of that horrible disaster to show, but rest assured that a shutter blade hitting a switch lever is not conducive to reliable operation.
My next attempt was to make a sliding switch from brass stock inside the shutter housing. I won't go into too many details, but it involved gluing a paper insulator to the back plate of the shutter housing to which a sheet of brass was attached (super glue is our friend), and gluing another contact to one of the shutter blades. The theory was that the contact on the shutter blade would slide along and connect with the contact glued to the paper. Well, it worked, but only when the camera was level or pointed up. When the camera was pointed down, the weight of the contact glued to the blade would make it fall forward and not contact the stationary piece of brass.
Success!
Being one who never says die (though I do occasionally tell things I drop to "lay there and bleed"), I wasn't about ignore the problem - THIS was a challenge!
I had mounted my 305mm f/9 APO-Nikkor to a board for my Calumet C-1 "Green Monster". I was digging through the magic equipment closet to see what I had in available Packards when I came across a 6" square #6 non-sync model. While the shutter is too big to go behind the lensboard, it's perfect for a front mount job. The problem of course is that the shutter doesn't have flash sync, and this was going to be used extensively in the studio.
This time, the solution came over dinner... Could it have been the Chardonnay?
I decided divorce myself from the idea of using a commercially made switch, and to forget about doing anything internal to the shutter. Instead, I'd make the front mount with an extension to one side and use the shutter's piston itself as part of the switch.
This approach has a couple of advantages and only one disadvantage. The disadvantage is that the entire switch and wires are exposed to the world, so it's necessary to exercise some caution that things don't get bent or wires broken. The advantages outweigh that though, as it's very simple to make adjustments to the sync without taking much, if anything, apart. Let's start with the general layout...
Here you see the finished project with the shutter in the closed position. Note that you don't see any mounting screws for the Packard to the mount. I elected to attach the back plate of the shutter to the mount with 1/4" #4 wood screws, then reassemble the Packard on the board. The reason? If it's ever necessary to clean the inside of the shutter (I like to use furniture polish on the inside metal surfaces of the shutter housing to protect them from rust), it's a simple matter of removing the four 2-56 machine screws to remove the front plate of the shutter to access the mechanism.
Here's a close up of the business end of the sync switch.
Starting with the shutter apart, I soldered a strip of brass into the piston. The strip is about 1/4" wide and .016 thick. There was nothing magical about this size, I just happend to have some strip brass of that size handy. Prior to bending and soldering, I used a pin vise to drill a 1/16" hole for the contact wire.
The next part of the switch was a bit trickier to pull off. I decided that I would use a brass contact on a pivot, set up so that the piston wouldn't have much extra work to do when using the shutter in the "I" mode. I had decided to use a 1.5" long 8-32 machine screw as the axle. Starting with an appropriate size length of brass tubing, I soldered a length of the 1/4" .016 brass and shaped it as shown in the photo below.
Before you yell and scream at me, yes, I went back and re-soldered my connections. I didn't notice until I shot these pictures how bad the joints looked (these are larger than life-sized).
The 8-32 machine screw that forms the axle is secured to the mount with nuts on each side, adjusted so that the brass tube is free to rotate. The nylon spacer shown serves two purposes, it limits the downward movement of the contact arm, and provides a path for the wire attached to the piston to get to the rear of the mount so that it may connect with the terminal on the lower portion of the shutter mount.
In my initial test, I wasn't getting consistent flash discharges. I suspected that either the pivoting brass tube wasn't making good contact with the 8-32 machine screw, or the strobe was having problems. Not wanting to dig into the strobe, I elected to solder a length of wire to the moving contact arm. The other end of the wire is secured to the machine screw with the front-side mounting nut. As it turned out, it was the flash that was having problems, not the switch. I elected to leave the wire in place because it actually tends to act like a weak return spring, ensuring that the moving arm returns to the rest position against the nylon spacer.
This view from the side shows the connections on the rear of the mount being brought down to the machine screws and wing nuts on the lower right of the mount.
A few more pictures...
Here we see the moving contact arm in it's uppermost position - the shutter has fired in the "I" mode and is closed, but the piston has not yet been released. Notice that I drilled out the "nub" on the face of the shutter so that I could insert a high tech paper clip instead of using the stock retractable pin (which would have been a pain to use in this case).
Notice that I adjusted the switch so that when the shutter is opened for focusing (no pin installed), the switch contacts are still open. There is a slight amount of piston movement available before the blades start to close, so it's possible to set the switch up in this manner to allow for focusing without firing the flash units.
Packard Shutter Has Moved!
Recently, the owner of Packard Shutter retired and his son took over the business. As a result, the entire operation was moved from New Jersey to California.
Packard Ideal Shutters are available from:
The Packard Shutter Company
PO Box 1
Fiddletown Ca 95629Tel: (209) 245-5719
Fax: (209) 245-5701