Stuart No. 9

[samc88]

JB weld works quite well, once sanded it does blend in (you can still see it though, I think its Tug / Ramon on here who uses it quite a lot in his builds.

Also I like the look with the larger flywheel

[crueby]

The JB Weld will be a close grey when sanded, maybe a little lighter gray, to get closer you could dry brush on a little darker gray paint. Use a small stiff bristle brush with just a little pa8nt, stipple it on some paper first till its just leaving little dots, the stipple on the patch. That should blend it so its not as noticeable.

[Double Dutch]

Great  job Michael,
The base looks good.
A larger flywheel looks much better.
I bought a No9 last year in an antiques shop during holiday in the UK.
As I have a spare set of castings, I have the plan to build it as a twin with a large flywheel in the middle she will run much smoother at low speed.

[Michael S.]

Thank you very much,

The original flywheel on the Stuart 9 is small, but has a wide rim. This provides enough flywheel mass to the crankshaft.

The base is now painted black, and we can continue soon.

Michael

[Michael S.]

Today I have time and can work on the engine.
I tried using primitive means to check how well the crankshaft bearing recesses align with the cylinder.
At a general overview, it looks good.
The previous owner of the cast parts had soldered the round and square parts together and drilled a hole that was too small.
I separated the parts again. The holes weren't exactly centered either. After machining, the lower parts fit well into the recesses.
Now I'm wondering how to make the upper parts fit. I have to adjust the sides. Maybe I'll solder the upper part back to the lower part and then drill the crankshaft bearings to the correct size.
Drill in the frame or machine each crankshaft bearing individually?

Best regards, Michael

[Michael S.]

I decided to solder the two parts together with soft solder.
With a heavy bar on the upper half, it won't shift as easily.
I drilled the threaded holes for the oil cups on the milling machine.
And milled off the excess.
The crankshaft has a diameter of 9.60 mm. The existing hole was approximately 8.90 mm. I carefully drilled it out to 9.60 mm in 0.1 mm increments.
It looks good for now. Tomorrow I have to transfer the holes for the two threaded bolts to the upper half and drill them. Only then will I separate the parts again.

Michael

[crueby]

That all worked very well! Good tip about weighting down the two halves so the top doesn't float around during soldering.
 

[Dave Otto]

Good progress! 

Dave

[Michael S.]

Thanks Chris and Dave.

I drilled the upper parts with holes for the threaded bolts and the holes were pretty accurate.
I milled pockets on the milling machine with a 7 mm cutter. Brass parts were soldered into them using electronic solder. Electronic solder is quite good for such delicate soldering work.
The flywheel is also finished and is attached to the crankshaft with a wedge.
I also lapped the crankshaft a bit with grinding paste. It's running quite well.

Michael

https://youtube.com/shorts/_0dn2fdDmG4?si=tUjfOehgH-AudMWE

[crueby]

Great  result!  Excellent  proportions  on that model.   

[Michael S.]

Thanks Chris,

Regarding piston rings........
I still have an old piston from my Simson moped on my workbench, and it fits perfectly into the bore of the No. 9 cylinder.
Now I know where to get the missing piston rings.
Or I can build a No. 9 as a two-stroke engine.......😉

Michael

[crueby]

That would be fun at one of the steam shows, hook up your No 9 to the boiler, get some steam flowing down fake pipes, then fire it up as a two stroke!   

[Dave Otto]

I like the #9, always wanted to build one but never got around to it, too many projects.

Dave

[Michael S.]

I had a few flywheel sizes in my collection that I could use as pulleys. So I tackled a flywheel, and there were some surprises in the cast iron. I had to glue a cast iron ring over it.
The three flywheels I still have also have this flaw in the same place.
That was my contribution to the construction of the Stuart 9 today and a little change from the other work that still needs to be done.

Michael

[Michael S.]

I spent the rest of today working on the cylinder. The floor in my house was being redone.
The cylinder already had threaded holes for the rear cylinder cover. If I leave it as it is, the hole for the exhaust exhaust will be at the top. I don't like that, even though the No. 9 is sometimes built that way. But if the exhaust is at the top, there are no cast bosses at the bottom of the cylinder for the cylinder drain valves.
So I'm turning the cylinder over.
I could leave the holes open, but I closed them.
On the lathe, an aluminum tube was turned to the size of the cylinder bore so that it fits tightly.
Then the front was smoothed. The cylinder flange was barely touched by the turning tool.
Next, I can work on the outer edge of the cylinder flange with the milling machine. The diameter is still too large.

Michael