Author Topic: Tumbler Shaft Clearance  (Read 1175 times)

Offline jonboyb

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Tumbler Shaft Clearance
« on: September 10, 2020, 04:12:13 PM »
Just disassembled lock to start inletting plate on new build and noticed a little wiggle to the cock as I started pulling it apart.  Started measuring and looks like the tumbler shaft hole through the plate is slightly oblong and shaft has .002-.005" clearance.  Anyone ever measured before and seen numbers like this or should it be tighter?  Easy fix if I need to close the gap....but thought I'd ask before tear my other locks down and check.  Thanks.

Offline 44-henry

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Re: Tumbler Shaft Clearance
« Reply #1 on: September 10, 2020, 04:32:20 PM »
I would send it back to the maker if possible, that is unacceptable. The hole should be reamed. A standard chucking reamer should give repeatability to .0005".

Offline smart dog

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Re: Tumbler Shaft Clearance
« Reply #2 on: September 10, 2020, 04:45:58 PM »
Hi,
There should not be any slop in the hole through the plate and the tumbler spindle hole in the bridle.

dave
"The main accomplishment of modern economics is to make astrology look good."

Offline jonboyb

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Re: Tumbler Shaft Clearance
« Reply #3 on: September 10, 2020, 05:05:27 PM »
I've had this lock sitting on the shelf for 10 years or better so I'd suspect I'm out of luck sending back.  Certainly something I can correct on the bench without much effort.  Lesson learned though....confirm all new parts day 1 not 10 years later.  Thanks for the info....seemed too loose to me but not something I'd really confirmed before.  Just pulled a Chambers Late Ketland apart I have for upcoming build to confirm.....FAR better tolerances.  Live and learn.

Offline Bob Roller

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Re: Tumbler Shaft Clearance
« Reply #4 on: September 10, 2020, 06:42:00 PM »
That's what is called "perduction"work. >:(and 44 Henry is right about the chucking reamer.
Bob Roller

Offline Scota4570

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Re: Tumbler Shaft Clearance
« Reply #5 on: September 10, 2020, 07:23:28 PM »
You could make a bushing.  Make it with a shoulder.  Open up the hole in the plate.  Silver solder it in place then dress off the extra.  One issue might be that once you have the hole in the plate fitted that bridle will not be in line and the tumbler will bind. 

I recently has the same issue.  The tumbler was sloppy.  I made a new plate.  The tumbler hole was as cast.  Other locks from that maker I have used had as cast tumbler holes.  If one cares about such things it may be necessary to not use certain locks. 

Another option is to ignore it and move one. 

Offline FlintFan

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Re: Tumbler Shaft Clearance
« Reply #6 on: September 10, 2020, 07:23:31 PM »
When I build locks I keep clearance between .001-.0015.  Any less than that can make it difficult to properly lubricate the tumbler shaft.

As mentioned above, bushing the hole would be a good choice.