Author Topic: Another casting set found!  (Read 4828 times)

Offline 10KPete

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Another casting set found!
« on: November 27, 2017, 11:57:56 PM »
Geez, digging in my shop heap yields more treasure! This is a Stuart twin. The drawing is for the Launch engine but the cylinder casting and the ready-made piston rings indicate it's the Compound Twin...  complete with reversing gear!  :cartwheel:

I had totally forgotten about these. Jo is probably shaking her head that someone could possibly forget about casting sets... :embarassed:

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline b.lindsey

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Re: Another casting set found!
« Reply #1 on: November 28, 2017, 12:01:42 AM »
Keep digging Pete...looks like you found the mother lode :D

Bill

Offline tvoght

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Re: Another casting set found!
« Reply #2 on: November 28, 2017, 12:18:40 AM »
. ..that someone could possibly forget about casting sets...

Pete
It's better that way. You experience the joy of discovery every time you dig them up.


--Tim

Offline Walsheng

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Re: Another casting set found!
« Reply #3 on: November 28, 2017, 01:03:32 AM »
"We'll be friends until we're old and senile...Then we'll be new friends"
Don't know who said it but it came to mind.

John

Offline Jo

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Re: Another casting set found!
« Reply #4 on: November 28, 2017, 06:59:48 AM »
I had totally forgotten about these. Jo is probably shaking her head that someone could possibly forget about casting sets... :embarassed:

 :hellno:  :disappointed:  :ShakeHead:  :facepalm:  :old:  :old: 

What's the last engine you've made Pete? Clearly too much time has passed and its time to show us their swarf  :).

Jo
Enjoyment is more important than achievement.

Offline 10KPete

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Re: Another casting set found!
« Reply #5 on: November 29, 2017, 09:18:01 PM »
This is my first, running, steam engine. And I'm proud of the outcome. It took 55 years to go from dream to reality.

I've been building this engine in my mind since 1962. That year Popular Mechanics magazine ran an article on making a little steam engine. It was the Stuart Oscillator. I was not ignorant of this sort of work but had never attempted anything as demanding.

Within a month I had in my hands a catalog from Coles Power Models. This was like being in a candy store! But an expensive candy store to me.

Fast forward to 2002 and I ordered the Oscillator kit directly from Stuart. Finally!!

We were still getting settled in up here so in 2008 I unpacked the kit, fondled the heck out of it and started. I probably put in 8-10 hours over the next few weeks to the point of assembly. But I couldn't get it to run very well at all and then only in one direction.

Well, life happened and I didn't touch it until last week. I was convinced I knew why it wouldn't run. Well, here's the story of what I found:

Stuart Oscillator Autopsy and Rework.

Piston fitted way too tight. Took about .002" off the piston. Now the o-ring centers the piston in the bore without the piston rubbing.

Pivot axle way off square wrt the back of the cylinder. Musta bent it somewhere in the mucking about trying to get it to run. So, the seal surfaces had a gap at the top about .003" wide. Well that doesn't help it run. So gripped the axle in the lathe and indicated the seal surface. About .005" TIR. OK, so mark it up and then do the gentle bend-it-only-at-the-threads-don't-bend-the-rod routine a few times and end up with less than .001" TIR. Good.

But the winner of the prize of the year is that there was no air connection between the right hand, looking at the seal face of the 'standard' (pillar?), main port and the lower right face port. Yup, some solder had plugged the hole. So drill out the soldered-in plug, drill down with the smaller drill past the plug, and out comes the solder chips!!
Cleaned it all out and all is now clear. I don't know why I didn't check this stuff when I built it. Well, I do, but that's another story…

I discovered the blocked port while lapping the seal surfaces. This after straightening the axle. Got the seal lapped really well with fine TimeSaver and was cleaning the gunk off the parts and ports. Compressed air for the passages and that's where one hole didn't produce air. Ta-Da!!!

The item I really worried about having goofed up was the spacing of the ports in the standard. Every time I had thought about this engine in the last 6 years was centered around those holes being way off. Nope. They are exactly on spec. as close as I can measure under magnification. Not bad for a blind old man with a tremor!!!  Why didn't that luck work on the rest of the features…..????

The last thing is the finish of the bore. It's not too bad but it should be better for the o-ring. It isn't rough so much as uneven. Like I didn't actually bore it but maybe I thought the reamer finish looked good at the time.

I thought of ways to hold the cylinder without disturbing the axle and they were all too complicated. So, I just put the cylinder in the 3 jaw and it landed true within .0015" TIR. Unbelievable!!  Pure  luck. Went over the boring tool carefully and made sure it was perfect. Fast and fine .001" DOC yielded a beautiful bore. A very light polish with some 600 g. Al-Ox powder on a wood stick made it super slick.

The piston fit is much looser than it was and is just right.

Clean and reassembled, the little rascal will start and run on about 3 psi.  And 10 is all she wants!  Lube is  ISO-10 spindle oil. The o-ring and brass love the stuff.

Now to build a boiler!!
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline crueby

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Re: Another casting set found!
« Reply #6 on: November 29, 2017, 09:33:57 PM »
Very nice Pete! Great that you got it all sorted out, without remaking everything.
All we need now is a video!!

 :ThumbsUp:

Offline 10KPete

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Re: Another casting set found!
« Reply #7 on: November 29, 2017, 09:44:38 PM »
Very nice Pete! Great that you got it all sorted out, without remaking everything.
All we need now is a video!!

 :ThumbsUp:

Yeah well, I'm working on that. I've never made or posted a video before!!

Thank you!!   ;D

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Online Kim

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Re: Another casting set found!
« Reply #8 on: November 30, 2017, 12:15:34 AM »
Very nice looking little engine there Pete!
Kim

Offline b.lindsey

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Re: Another casting set found!
« Reply #9 on: November 30, 2017, 12:47:39 AM »
That's a beauty Pete, regardless of how long it took. Looking forward to the video.

Bill

Offline Dave Otto

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Re: Another casting set found!
« Reply #10 on: November 30, 2017, 01:13:05 AM »
Nice little engine Pete!
Isn't it amazing what a few (or many) years of experience and knowledge will do?

Dave

Offline 10KPete

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Re: Another casting set found!
« Reply #11 on: December 01, 2017, 04:23:58 AM »
Pardon me for the change of orientation part way through. I was doing well to get the darn thing on here!

so try this:

[youtube1]https://youtu.be/vxJlN6UF_E0[/youtube1]
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Online Kim

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Re: Another casting set found!
« Reply #12 on: December 01, 2017, 06:11:50 AM »
It sure runs well,Pete!  Great job getting the video posted too! :)
Kim

Online Roger B

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Re: Another casting set found!
« Reply #13 on: December 01, 2017, 07:18:35 AM »
Excellent  :ThumbsUp:  :ThumbsUp: A little persistance always pays off  ;)
Best regards

Roger

Offline Mike Bondarczuk

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Re: Another casting set found!
« Reply #14 on: December 01, 2017, 09:52:56 AM »
Excellent little runner Pete and I purchased the same kit some years ago and have yet to start it but your video may well be the stimulus I need.

Mike  :o
"Everything I can't find is in a totally secure place"

 

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