Petter 1-1/2 HP Apple Top Engine

Paul,
Yes the key should be tapered, if thats the case then go for a smaller bolt i.e M6 as long as your pulls are linear then the bolt should not fail. You could always weld alarge bolt to whats left of the key!
Martin P
Paul Maples wrote:

Hi Guys, Pauls full range of photo,s are at Dave Croft

You don't care too much about this - your care whether the _keyway_ tapers. Now I've seen plenty of keys with tapers on them, but I've never seen a boss with a parallel hole bored in it, yet a tapered keyway.
OTOH, someone who's actually had a Petter to bits will be along in a minute.

The taper is in the flywheel boss. The keyway in the crank is level. ttfn Roland (who's had Petters beyond count apart :-)

The stone was gently lifted away from the ground, and there he was busily taking one apart :-))
Martin P

A standard key taper IIRC is 1/8" in 1', or approx 1 in 100, so for the length of key you have there won't be much difference. Another method is to use a suitable piece of pipe (and a big hammer) to push the flywheel further onto the crank and release the key.
Regards
Dan

In this case a dork has put the governer collar on backwards and the flywheel is hard against it!! ttfn Roland

Ah - so there is an effective taper in the depth of the machined keyway ? About how much is it ?

level. _keyway_ method is to

Hello U.K. Engine List
Just wanted to take this opportunity to thank each of you who have responded to my inquiry concerning my efforts to remove the broken gib key in my Petter Engine. This morning I went out to the shop armed with a slide hammer, welder, drill bits, taps, Grade 8 bolts, drill motor, etc. I was determined to get the key out.
I was going to make a drill guide from new 3/8" key stock but once I saw that the width of the gib key was 3/8" but the thickness was a little more than 1/4" at the front end of the broken part and tapered down to less than a 1/4" at the end of the key I knew that what I had in mind would not work out. I decided to have a go at just free hand drilling. I took a 1/8" bit and first drilled about three fourths of the way through the broken gib key and I followed this with a #7 drill. I had planned on then tapping this hole for a 1/4-20 Grade 8 Bolt but soon realized that the bottom of the hole that I had just drilled was too close to the crankshaft keyway and the tap threads might have cut into the crank so I abandoned this idea. I then decided to just try and weld a 1/4" Grade 8 bolt to the top part of the remaining broken gib key.
I removed the hook attachment off of my slide hammer, I purchased a large nut that had the same thread pattern as did my slide hammer, I found a 1/4" drill bushing in my tool box (lucky here). I welded the drill bushing to the large nut and then welded the 1/4" grade 8 bolt to the drill bushing. Once I completed this I then screwed in my slide hammer to the pulling apparatus I had just made and gave it a go. The key moved about 1/8" on the first blow and two blows later it was out.
You can go to the URL address below and see pictures of how I got the key out:
Thanks Guys, you are a great group of people.
Paul