Petter 1-1/2 HP Apple Top Engine

Folks I have a Little 1-1/2 HP Petter that I am desperately trying to get the flywheel off of in order to get to the governor collar on the backside. In my attempt to get the key out I have managed to break off the tang on the key. If you will type this URL address in your address line on your browser you can see pictures of my dilemma:

formatting link
The first picture is a picture of the engine, the second picture is a picture of the gib key when I started and the last four pictures are of the gib key as it looks now. I plan on trying to drill down the center of the key, tap it out for a 1/4-20 Grade 8 bolt and then use a slide hammer or make a puller to try and get it out. I am wondering if I start drilling in the center of the gib key on the outside edge will it continue to be centered as it goes under the flywheel hub assuming the drill bit is tracking straight OR does the key taper down under the flywheel. I am concerned that if there is a major taper that even though I start out in the center of the key I will end up drilling into the flywheel as the drill enters under the flywheel. Any thoughts on this?

Reply to
Paul Maples
Loading thread data ...

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!

Mart> Folks I have a Little 1-1/2 HP Petter that I am desperately trying to

Reply to
Campingstoveman

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

formatting link
Dave Croft

Reply to
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.

Reply to
Andy Dingley

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

Reply to
Roland and Celia Craven

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

Martin P

Reply to
Campingstoveman

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

Reply to
Dan Howden

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

Reply to
Roland and Celia Craven

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

Reply to
Andy Dingley

level.

_keyway_

method is to

Reply to
Uk.rec.engines.stationary

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:

formatting link
Thanks Guys, you are a great group of people.

Paul

Reply to
Paul Maples

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.