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Author Topic: Gib key removal  (Read 2333 times)

Feb300

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Gib key removal
« on: July 06, 2023, 02:23:30 PM »
Hi, I have just joined the forum.

I have a Lister D 2.5 hp stationary engine, I cannot remove the gib-headed taper key from the shaft to release the fly wheel.

I have tried many methods without success, can anyone recommend where I could take it, I am in the Cheltenham area.


Powdermonkey

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Re: Gib key removal
« Reply #1 on: July 07, 2023, 12:28:58 AM »
Please bear in mind that "heat" provides for expansion.  It MAY well be that the gib key is "very" driven into the keyway, or that it MAY be rusted in place. 

As for me, I've removed them several ways:  a series of wedges, a strong-back, and one time, I actually had to drill out a particularly stubborn key.  Word to the wise:  IF you must drill it out, have a machinist make you a steel "guide" for the drill-bit.  The guide should be the width of the keyway, and place the centerline of the hole as appropriate for drilling out your stuck key.  I've made one of these such guides, and it's quite easy to do.  Further, such a guide will prevent your drill-bit from entering the nether regions of your key, and into the abyss of the actual crank material....

Feb300

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Re: Gib key removal
« Reply #2 on: July 07, 2023, 08:32:51 AM »
Thanks for the info.

ajaffa1

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Re: Gib key removal
« Reply #3 on: July 07, 2023, 08:33:01 AM »
Heat, shock, penetrating oil and persistence will win in the end. Drilling really is the very last resort, difficult to do and likely to damage the shaft or flywheel. Butch (38 ac) swears by applying a significant outward pressure to the gib key while beating the flywheel in the opposite direction with a very very large hammer, I trust his experience and knowledge.
Good luck.

Bob

Powdermonkey

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Re: Gib key removal
« Reply #4 on: July 07, 2023, 11:27:49 AM »
Regarding drilling...I too considered it "last resort" until I actually did it.  It turns out that the designated keys are of standard dimensions and construction, and CAN be had off the inter web for reasonable price.  Or, if such a man exists who considers himself unashamed in his pursuits of metal removal from a substrate, Machinery's Handbook contains the taper and dimensions...

Building the drill-jig was simple, and employing said jig was also simple.  I just happened to have a drill of sufficient length to finish the task.  I'd assume that the Amazon gods would shine favorably upon anyone seeking such endeavors....

A simple electric hand drill was employed for twisting power.  A reasonable estimate of intended depth was utilized, in attempts to NOT drill through the back-angle cut into the shaft keyway.  I was easily able to prevent such dastardly results. 

Yes, the drilling took some time.  In total, an afternoon from noon till ~ 4pm was burned (including the making of the drill-jig). 

BUT...now having done it, and in possession of said jig, if I were to encounter another stuck key....I'd snicker after a few good whacks with a drillers hammer and some wedges, walking from said Listeroid, muttering something to the effect of, "....you have no idea what kind of violence I'm about to visit upon your insistent soulless life."

And...should a brother find himself entirely destitute, in need of moral and physical support, I'll allow the borrowing of said jig.  But....I'm not so keen on same, for the drill bit. 

Feb300

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Re: Gib key removal
« Reply #5 on: July 07, 2023, 12:52:34 PM »
Thanks for all the info.

Feb300

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Re: Gib key removal
« Reply #6 on: July 07, 2023, 01:00:33 PM »
Heat, shock, penetrating oil and persistence will win in the end. Drilling really is the very last resort, difficult to do and likely to damage the shaft or flywheel. Butch (38 ac) swears by applying a significant outward pressure to the gib key while beating the flywheel in the opposite direction with a very very large hammer, I trust his experience and knowledge.
Good luck.

Bob

Thanks Bob.

AndyD

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Re: Gib key removal
« Reply #7 on: July 09, 2023, 11:23:52 AM »
It took me many weeks to get my Gib Key out.
Strong-backs, wedges, heat, cold, big hammers, penetrating oil, etc.etc.
Eventually bought a Gib Key remover and that eventually got the job done but I think the constant trying over a period definitely helped.
(Picture of the type used attached)

cobbadog

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Re: Gib key removal
« Reply #8 on: July 14, 2023, 05:26:10 AM »
I too had some challenges removing old gibb head keys. In both cases the head broke off one level with the crank the other just inside. In the end I drilled them out as they are only a type of mild steel so easy to drill. Once I had it looking like swiss cheese I collapsed the remaining parts and picked it out.
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