Key cutting problem

[peterwn]

Had two keys cut for a local church organ console recently. The lock
was a 50+ year old cylinder cabinet lock (British made). Maker
(Century) long since defunct (-> Yale - > Racal -> ASSA Abloy), so
ETAS (similarly defunct) standard cylinder blank (Silca ETA1) used
with top edge shaved down (the plug diameter was slightly larger than
the usual 0.4in for cabinet cylinders). The lock had been re-keyed
using ETA1 blanks several years ago. New keys did not fit properly, so
I removed and dismantled lock. Pins on shear line OK, but noticed
bottom of blank below plug level just at front.

The problem was that top of key was not shaved right back to shoulder.
When key was inserted this forced forced plug upwards reducing shear
line tolerance on front pin to zero as well as causing lower pin to be
just above shear line.

A few strokes with a file near the shoulder and keys worked OK.

[Ralph A. Schmid, dk5ras]

peterwn <pet...@paradise.net.nz> wrote:

>The problem was that top of key was not shaved right back to shoulder.
>When key was inserted this forced forced plug upwards reducing shear
>line tolerance on front pin to zero as well as causing lower pin to be
>just above shear line.
>
>A few strokes with a file near the shoulder and keys worked OK.

Yes, a common small error, causing a big nuisance :) In such cases I
mill the blanks down with a desktop milling machine, so I can achieve
much more precision.

-ras

--

Ralph A. Schmid

http://www.dk5ras.de/ http://www.db0fue.de/
http://www.bclog.de/