Author Topic: AOGís version of the Stuart S50 Engine  (Read 1293 times)

Offline AOG

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AOGís version of the Stuart S50 Engine
« on: September 15, 2018, 11:27:18 PM »
Iím sitting here in my living room with the house buttoned up waiting for a hurricane to hit so I thought I would post the start of my next build. I am making a Stuart S50. I started by sanding the base until it sat flat on the surface plate.



Then the mounting feet were spot faced.



The casting was kind of rusty so I cleaned it up with some navel jelly. The casting was primed to prevent further rusting and the mounting holes drilled.



The base casting was mounted to a tooling plate and the various flats milled.



Next the bearing stands were cleaned up and the oil holes spot drilled to be the reference point for the centerline of bearing supports.



The base casting was flipped on itís side and leveled in relation to the vise.



The bearing supports were drilled and reamed to take a 3/8 Bronze bearing.



The bearings were center drilled and taken to size.



Then they were pressed into the base casting.

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Then the base was placed back on the mill and the bearings were drilled and reamed.



The last operation was to drill and tap the top of the supports to take some PMR oilers.



Thatís it for now. Till next time

Tony


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Online b.lindsey

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Re: AOGís version of the Stuart S50 Engine
« Reply #1 on: September 15, 2018, 11:43:02 PM »
Great start Tony!! Are you feeling effects of the storm yet. We have just had a slow steady rain today. Very little wind here but I am well inland compared to Savannah.

Bill

Offline 10KPete

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Re: AOGís version of the Stuart S50 Engine
« Reply #2 on: September 15, 2018, 11:43:52 PM »
Good start! I hope the storm misses you...

Pete
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Offline zeeprogrammer

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Re: AOGís version of the Stuart S50 Engine
« Reply #3 on: September 16, 2018, 01:01:33 AM »
I had no idea where you were. I hope all goes well.

I look forward to your new build.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline AOG

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Re: AOGís version of the Stuart S50 Engine
« Reply #4 on: September 16, 2018, 02:35:34 AM »
Thanks guys, I think Iím going to get lucky this time. The storm is tracking further north then expected. Hopefully if everything goes well, I can get the garage reconfigured into shop mode tomorrow and get back to work on this project.

Tony

Offline bent

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Re: AOGís version of the Stuart S50 Engine
« Reply #5 on: September 17, 2018, 06:37:58 PM »
Nice start, Tony.  Gotta get my garage reconfigured too, now that the rain has started...

Offline AOG

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Re: AOGís version of the Stuart S50 Engine
« Reply #6 on: September 23, 2018, 07:17:41 PM »
My shop time this weekend was something of a disaster. My original intent was to start work on the cylinder casting. Letís just say that after destroying 3 inserts and crashing my lathe I think that cylinder casting may be better as an AP round then as a cylinder so I ordered another one. After wasting the majority of my shop time on the aforementioned disaster, I decided to make the crankshaft with the time I had left. After truing up the parent stock in the lathe I turned the required boss and drilled and tapped the center of the crank.



The final shape for the crank was marked out and milled.



Then I spot drill the location of the crank pin. To keep it square to the crank, I wonít drill and tap the hole until later.



The crank was parted off from the parent stock and then I threaded the shaft.



The crank was mounted to the shaft. Then the assembly was mounted in the collet chuck and trued up. At that point I discovered that my parting tool had wandered and the crank ended up very thin.



Now that the crank face was true to the shaft I drilled and tapped for the crank pin.



Since the engine isnít going to run under load Iím not worried about the strength of the thin crank but I am concerned about the alignment with the cylinder bore. I decided to make a bronze spacer to correct the geometry. It was drilled and parted off.



So after a weekend worth of work, all I have to show for it is a crankshaft.



Maybe Iíll have better luck next week.

Tony


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Offline AOG

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Re: AOGís version of the Stuart S50 Engine
« Reply #7 on: October 04, 2018, 01:30:10 AM »
I got my replacement cylinder casting........ and promptly stuffed it up. Somehow I donít think this is right.



Oh well, time for another ten day wait.

Tony


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Offline jeff l

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Re: AOGís version of the Stuart S50 Engine
« Reply #8 on: October 04, 2018, 03:58:46 AM »
Nice start on the engine , I made this engine years ago and found the cast in bolts unattractive so I milled them off and drilled and tapped them for proper model engineering bolts .The extra work was worth the effort .Jeff

Offline AOG

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Re: AOGís version of the Stuart S50 Engine
« Reply #9 on: November 01, 2018, 04:14:40 PM »
Ok this build is officially cursed but letís get caught up first. While I was waiting for a replacement cylinder, I decided to make the eccentric and the strap. I started with the strap extrusion.  It was first trued up on the lathe.



Then it was bored out on the mill.



The holes were drilled and the strap was slit.



Then the eccentric itself was made. First it was turned to size and grooved.



The piece was offset and then drilled and turned.



The eccentric was drilled and tapped for a set screw. Then it was parted off.



Here is where we sit today.



Now for the cursed part. I have successfully botched cylinder number 3. At this point I have spent almost as much on cylinder castings and shipping and I did for the whole model. It will take approximately 2 weeks to get another casting but I think this is a sign that I need to get away from model engineering for a while. I donít know when Iíll be back

Tony


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Offline Admiral_dk

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Re: AOGís version of the Stuart S50 Engine
« Reply #10 on: November 01, 2018, 07:28:28 PM »
So sorry to hear that you have those disheartening problems with the cylinder - I hope somebody here can give you some useful advise ....

Best wishes

Per

Offline Jo

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Re: AOGís version of the Stuart S50 Engine
« Reply #11 on: November 01, 2018, 07:41:25 PM »
Tony can you let us know what the unintended features were with the cylinders? In case we could come up with some fix its...

That out of line bore could be sleeved  :thinking:

Jo
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Offline AOG

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Re: AOGís version of the Stuart S50 Engine
« Reply #12 on: November 01, 2018, 07:42:53 PM »
Itís not so much lack of advice as lack of attention to detail. Thatís the sign that I need to step away for a while until I can spend the time to focus on what Iím doing. I donít have to tell you how dangerous it can be in a shop if your not focused. Right now all I am out is money and time. The last thing I need is to get myself hurt.

Tony

Offline AOG

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Re: AOGís version of the Stuart S50 Engine
« Reply #13 on: November 01, 2018, 07:57:52 PM »
Tony can you let us know what the unintended features were with the cylinders? In case we could come up with some fix its...

That out of line bore could be sleeved  :thinking:

Jo

So far itís been the armor piercing casting, the misbored cylinder and the last one was too short on three faces and more importantly the drill wandered when drilling one of the ports. It chewed up the inside of the cylinder and damaged the port face when it broke through. Basically Iíve been going through the motions and not really paying attention to what I was doing. As I said before, that is potentially dangerous in the shop and a sign I need to get away from this for a while.

Tony

Offline Jo

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Re: AOGís version of the Stuart S50 Engine
« Reply #14 on: November 01, 2018, 08:20:51 PM »
:thinking: Maybe Tony you have three pieces to practise with.


The first one sounds like it has hard spots - chuck it in a fire and leave it in the hot embers for at least 24 hours to cool down. Then test the hard sports with a file.

How far out is the misboring on cylinder 2? It could be sleeved, or rather bore it out a bit more and loctitie in another bit (steel or CI or even bronze/brass) and practise boring in the right place. The trick is to line the bore up using the valve face and the outside of the cylinder - ignore the existing bore.  If you get it right you possibly could have a cylinder to use  :)

The cylinder with three short faces is a little trickier but it all depends on how much shorter they are if it is only 1mm you could probably get away with it. The port face can be recovered by machining the top surface off and adding an additional plate. As the valve chest is to be screwed on you can probably get away with securing it with JB weld  :-X


Don't throw them away, think about what caused the features, then use them to practise on and you never know you might find one is good enough to use, no one will be any the wiser  ;)

Jo
Usus est optimum magister