lab pin set Question

by **John McElreath** » 1 Nov 2005 3:07

Why are there different size top pins sizes used in some locks on the pin chart?

by **Chrispy** » 1 Nov 2005 3:38

So that the pin stacks have comparitively equal heights. For example, a chamber with bottom pins 1,2 or 3 will have a long driver pin. Bottom pins 4,5 or 6 will have a middle driver pin. Bottom pins 7,8 or 9 will have short driver pins.

by **Chrispy** » 1 Nov 2005 3:40

Ahem, comparatively. :oops:

by **Keyring** » 1 Nov 2005 3:40

Using different and complementary top pin sizes is a good safeguard against the method of fully compressing each spring in turn with a probe wire and thereby measuring the pin lengths.

by **Dimmy Locks** » 1 Nov 2005 3:58

John McElreath wrote:Why are there different size top pins sizes used in some locks on the pin chart?

Shame you didnt link to the chart in question, it would have been helpful, I tried a search but came up with nothing connected with a Lab Pin Chart.

So I'm guessing here as to what you are refering.

Some locks have limited space and as such restricted drill height allowance. as a result the TOTAL pin stack heights (including spring when compressed) are all the same height for all the stacks.

i.e. if the drill size is limited to 10mm, and springs when compressed are 1mm, the overall pin stack (top and bottom pin) cant exceed 9mm, Lets assume the deepest cut no.9 is 6mm for bottom pin, the top pin cant exceed 3mm (10mm=1mm+6mm+3mm). The shallowest cut No.0 is 2mm, the top pin can be upto 7mm.
(For the more technically aware, I've ignored sheer position within the drill hole in these calculations for simplicity, although obviously that imposes further pin stack sizes).

Vehicle pin locks are often these type of locks. Where space is an issue, whereas padlocks have no such space limitation so the top pins can be all the same size, making production cheaper.

hope this helps.

by **John McElreath** » 1 Nov 2005 11:32

Why is it then when i take the lock apart all the top pins are the same size on a new lock?

by **digital_blue** » 1 Nov 2005 11:35

Cheap lock?

by **John McElreath** » 1 Nov 2005 11:36

Why is one pin set have a different top pin size from another one when it has the same bottom pin?

by **Mad Mick** » 1 Nov 2005 18:58

John McElreath wrote:Why is one pin set have a different top pin size from another one when it has the same bottom pin?

Did you read this?:

Keyring wrote:Using different and complementary top pin sizes is a good safeguard against the method of fully compressing each spring in turn with a probe wire and thereby measuring the pin lengths.

by **John McElreath** » 1 Nov 2005 19:11

Thanks for all the answers and full explanation. :P