Author Topic: My somewhat take on Chuck's John Deere  (Read 1385 times)

Offline galland

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My somewhat take on Chuck's John Deere
« on: April 28, 2018, 05:44:31 PM »
I put this in my own design but Chuck Fellows definitely gets credit for getting me started on it. I had considered building his for several years and finally got sketching things last fall. I did start out with the crankcase using dimensions similar to his but ended up changing things from there. I think of Chuck as the Godfather of 4 stroke air powered engines with his unique ball and spring in the head design. Of course with that design you need a intake valve but no exhaust valve and I decided to see if I could go with both and get the job done. That does complicate things because you need to keep the exhaust valve open for 3 of the 4 cycles or roughly 540 degrees of crankcase rotation. Thankfully with the cam moving at half speed that gets it down to 270 degrees and that seemed possible so I built a small jig with a degree wheel on it and started testing various camshaft lobes pushing a lifter up and down. After three attempts I got a lobe that appeared to be doable (Maybe). I hate it when your not sure if something will work or not. Well anyway I now need to try and get everything timed right and see if it will run. The 4 cam lobes are on locking collars so they can be adjusted and then locked down. Here are some photos.
    Gary

Offline kuhncw

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Re: My somewhat take on Chuck's John Deere
« Reply #1 on: April 28, 2018, 06:27:05 PM »
Nice work.  I'm looking forward to seeing a video when you get it running.

Chuck

Online Johnmcc69

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Re: My somewhat take on Chuck's John Deere
« Reply #2 on: April 28, 2018, 11:57:59 PM »
Yes indeed, very nice work.

 John

Offline cfellows

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Re: My somewhat take on Chuck's John Deere
« Reply #3 on: April 29, 2018, 03:40:31 PM »
Nice job!  It will probably run with a lower pressure than a ball valve requires.  However, it may not create as much sound. 

Chuck
So many projects, so little time...

Offline galland

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Re: My somewhat take on Chuck's John Deere
« Reply #4 on: April 30, 2018, 09:37:11 PM »
Now that spring finally arrived here have been busy outdoors. Finally set the cam and made a video this afternoon.

     Gary[youtube1https://youtu.be/Q1JsrRhK9BQ][/youtube1]

Offline galland

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Re: My somewhat take on Chuck's John Deere
« Reply #5 on: April 30, 2018, 10:05:21 PM »
I get the feeling something went wrong. I hit copy and then paste between the brackets of the 2nd youtube but don't see the video. I will do it one more time. If it doesn't work.........Help.

      Gary

Offline zeeprogrammer

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Re: My somewhat take on Chuck's John Deere
« Reply #6 on: April 30, 2018, 10:17:49 PM »
Works for me.

Sounds great!  :ThumbsUp:

It's a very interesting design. Congrats!
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Brian Rupnow

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Re: My somewhat take on Chuck's John Deere
« Reply #7 on: April 30, 2018, 11:53:45 PM »
Very nice Galland. You've done a great job on that engine. Chuck Fellows was and is a master of the air powered engines, and is always willing to help if you run into a hard spot in your build. I know what you meant in your first post about "Disliking to build something that you are not sure whether it will work or not." I do that a lot. I have great ideas that SHOULD work---but you have to build the darn things to find out if you were right or not.---Brian.
« Last Edit: April 30, 2018, 11:57:39 PM by Brian Rupnow »

Offline b.lindsey

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Re: My somewhat take on Chuck's John Deere
« Reply #8 on: May 01, 2018, 12:49:16 AM »
That sounds great Gary. Would love to have seen more of the construction and machining though. Really clean design and a very nice runner.

Bill

Offline galland

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Re: My somewhat take on Chuck's John Deere
« Reply #9 on: May 01, 2018, 02:48:54 AM »
Thanks guys for the kind words. Brian, I truly didn't know if I would get the exhaust lobes to have the long duration I needed for it to run and it was a fingers crossed event when I turned on the air. Bill, I tend to be rather slow at building because of other things going on so haven't done a build on here but I sure enjoy the guys who do.

  Gary

Offline galland

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Re: My somewhat take on Chuck's John Deere
« Reply #10 on: May 01, 2018, 04:53:52 PM »
One last thing guys. If anyone is contemplating building a 4 stroke air powered engine with 2 valves per cylinder I did not go with a conventional valve and cage. That works fine for the exhaust side like on my 5 cylinder radial but would not work on the intake side with the light springs used in these engines. Just like the air pressure pushing the ball bearing aside in Chuck Fellows design the air would push the valve off its seat and the engine would not be capable of running. So I did go with piston valves with a groove in the center for the air flow but that also raises a concern. Unlike in a steam engine where the bore for the piston valve is open at each end my bores are sealed at each end. That of course means the valves can't move back and forth because of the compression and vacuum they create. In the photo of the bottom of the head you will see the eight .040 relief holes at the ends of the bores allowing the pressure to escape.

   Gary