Doorknob falls off

[Clairebear]

My perko doorknob for the head keeps falling off. Looks like maybe there should be a screw in the handle that’s missing possibly. Not sure if that’s the problem or what size screw to get. Anyone know how to fix this?

[Pandor]

Hmmm. That does seem tricky. You may be right about a missing screw. Perhaps it fell out of the circular hole on the side that is lined with spiral-like threads? I can’t tell exactly what size because your photo isn’t 1:1 scale. Can you try taking another at actual size?

[hpeer]

Perko parts are still available for reasonable price.

https://www.perko.com/catalog/catego...s_and_latches/

That is a VERY common arrangement in older house door hardware.

[rls8r]

Yep - it's a set screw.

West Marine has a sale on the whole "L" handle-knob-shaft assembly (Perko Part No. 0962000CHR) for $17.49. At that price I'd get an assembly just to have other spare parts.

Otherwise - just take the knob to a local Home Depot, Lowe's or other hardware vendor and try out set screws until you find one that fits (should be about $0.75 each, so get 2 or 3).

[Hudson Force]

I had this problem with the identical door knob and the post was too abraded to function with a replaced set screw. I simply drilled a hole all the way through and inserted a cotter pin. I curled the sharp ends of the pin back upon themselves and crimped them down. I know this wasn't a pure a fix as new parts, but it was fully functional and no loss to antique value.