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Turnstile ratchet repair

making replacement pawl and pivot bolt

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ken king, King Design11/07/2018 11:24:42
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144 forum posts
239 photos

We've all, at some time, attempted to push through a turnstile which wasn't ready to allow passage, resulting in stress to both parties. At my son's local swimming pool the pawl had had enough, and shed its tip. The pivot bolt was badly bent and worn, so replacements were requested.

old pawl:bolt.jpg

The tip had been roughly reattached to give the shape required, whilst it had been necessary to tack a hex onto the chewed-up slotted bolt head to enable its removal. The hex seemed a good idea, and so was incorporated into the pawl design. The outline was traced onto !" thick plate, marked all round with centre punch dots, then a series if holes were drilled to facilitate cutting out the rough blank (this being my only means of doing so)

pawl 1.jpg

Thicness was reduced by 0.2" on the mill, then the pivot hole and 1" c'sink were added

pawl 2.jpg.

After completing the profiling process (quicker to say than do !) a new bolt was made, from three pieces to reduce machining. Contrasting new pawl and bolt shown below. Clickety-click !

new pawl:bolt.jpg

Michael Gilligan11/07/2018 11:39:38
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23121 forum posts
1360 photos

Elegant result, Ken

Just out of curiosity; was the original pawl a forging or a casting?

MichaelG.

ken king, King Design11/07/2018 14:18:07
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144 forum posts
239 photos

Hello Michael, yes, definitely one of those ! Sorry to be facetious, but I am unsure, though tending toward casting. It will be intersting to see how M.S. stands up to the job, otherwise guage plate or similar might be needed, with heat treatment. At that point I might decline, reluctantly of course,

Regards,

Ken.

Michael Gilligan11/07/2018 14:49:54
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23121 forum posts
1360 photos
Posted by ken king, King Design on 11/07/2018 14:18:07:

Hello Michael, yes, definitely one of those !

.

smiley

Samsaranda11/07/2018 15:22:22
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1688 forum posts
16 photos

Is this just half a topic or have I missed something, it doesn’t make any sense.

Dave W

SillyOldDuffer11/07/2018 16:27:04
10668 forum posts
2415 photos

Made sense to me. Good job Ken. We could open a book on how long the new pawl will last - I imagine it will have a tough time in a turnstile. My guess, 5 years.

Dave

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