Restoring a pancake lock

wylk

I’ve never done much in the way of lock restoration but decided to give it a try with an Elm City 6-lever pancake lock. I do have the key but the shackle spring is broken (very common) and it will not lock.

After carefully drilling the 5 case pins and working the cover off, I discovered the locking problem was me being stupid. It requires the key to lock. Duh. Problem solved.

The spring is a minor challenge and I was hoping somebody might have some advice on making a new one, such as what shape it should be in the “unsprung” state so it will work well enough when put into the case. The old spring used approximately 1mm wire (.04 inch) and I assume music wire might work (being a little more findable than spring wire).

I assume I’ll have to drill out the pins to clear the holes in the case, turn new ones to a snug fit, and carefully hammer them to re-attach the case cover, then file them flat. Any advice as to technique here to avoid marking the cover (or the back)?

Thanks in advance.

oldbiscuit

Wylk, It seems that these pancake locks all vary from one brand to the next on the spring designs. I’ve made several springs, all different from spring wire. As to the case pins, I’ve had pretty good luck just annealing the pins with a small bench torch, then prying the two halves apart. After I’ve made my repairs I simply pressed the two halves back together and repeaned the pins flat. A slight buffing over the peaned area then I repatena. Bob Dix, I know when he restores locks will drill out the pins and tap them. He then makes new screw in pins that are cut off after tightened and filed flat. I wish I would have kept my old jewelers lathe, but I sold it years back before I got to this stage of my hobby.:8):

wylk

Mark, thanks for the reply. I believe the spring needs to be close to the shape shown in US patent 143,831. I’ll just have to experiment, I guess.

I also discovered that on this lock, and probably others, the pins are not pins. They are posts. That is, they are cast integrally with the case. Then they are cut down to the proper diameter before assembly. Since I have already drilled one out and partially drilled the rest for disassembly I guess I have to consider making some screws (what are the odds I already have “just right” brass screws!).

oldbiscuit

Wylk, Your right, I should have called them posts as they are cast with the one half of the case and machined as you said. I’m pretty sure Bob starts out with solid round bronze stock and turns it to the needed pin dia. Then he turns down one end and threads it to screw in the threaded hole in the cut down posts. Your talking some pretty small threads here, probably #4. Mark

Donnie

This is my first response to the forum : It may be redundant, but I find that if you are able to get the top off to make repairs by separating the two halves, if you counter sink the top on the inside just a slight bit , it will make aligning the 2 parts a lot easier when re-installing the top back onto the posts………..Donnie