Another Internal Combustion Engine

[Rdean33422]

Not often we get to see a governor on a model.
Nice job !

This will be my third engine with a fly ball governor.
Thanks Jojo

Looks great Ray, and I’m on pins and needles waiting for the first “pop”!!!

There is still a lot to do yet and I keep adding more features to the engine.
Thanks John

This is the head mounted on the engine.
What do you think?
Do you like the name?


It has proven to be abundantly clear to me that the flywheels I made are way too small. I have a pair of 8" round cast iron slugs from McMaster Carr with the certification papers to be free of voids and hard spots. Cost me some $$$ but the others were just too small for this long stroke engine.
Out of the box they weighted right at 11 pounds each and at this roughed in stage they are at 6lbs 12oz and there is still more to be taken off later.


Now to clean up the lathe and the rest of the shop.
They did machine nicely though.


Thanks for looking
Ray

 

[Danuzzo]

Ray, I have been whittling away for several days now at a flywheel for my first I.C., the Webster, much smaller than the ones you describe. I thought it was mild steel; but, it is much harder (rounded some of my HSS lathe tools). I still have one side of the flywheel to go, as far as the internal depth. I have learned that I very much dislike making flywheels from scratch.

 

[Rdean33422]

They are not my favorite either as I had been making mine from bar bell weights. Never again.
I will buy cast iron from a known source and pay the extra. The first flywheels I made for this engine gave me a fit for several days. Several carbide inserts and a tool post grinder to get them to where I would except them.
A heavy coat of paint hides many issues or it looks good at 6 feet away.
Ray

 

[Rdean33422]

I made up a couple of taper lock bushings and taped the holes in the flywheels.


I just can't have plain solid flywheels so over to the CNC mill for some bling.
Drew up some curves, added some width, and hoped for the best.
I think it came out just fine.


First one cut out but a lot of work left to clean it up nice and pretty.


The other flywheel will be the mirror image of this one so the pattern goes the same direction when viewed from either side.

Thanks for looking
Ray

 

[Sprocket]

I like the curves. Philip Duclos had a method for doing that manually. I never tried it, but it looks good. Sometimes I wish I had CNC.
Doug

 

[olf20]

What angle do you cut your taper loc hubs?
Thanks
olf20 / Bob

 

[Steamchick]

Excellent work, Ray.
Did you know that originally, curved spokes were not a cosmetic shape, but a countermeasure to the problems of straight spokes and rims that cracked or broke when the hot castings were removed from the moulds in the foundry. - Uneven cooling and spoke shrinkage distorting the rims, leading t cracking failures. Eventually, someone managed to master the straight spokes and still have un-cracked castings, and the industry moved on with straight spokes. - I think they kept them hot while the rims (heavy sections compared to spokes) cooled. The diagonal aspect from using curved spokes allowed the spokes to flex more, and reduce stresses as a result. But that also meant that for load bearing wheels the wheels were more flexible - then broke in use if overloaded. Straight spokes were "more efficient" in the use of metal - and foundries needed a lot of coal/coke per lb. of metal - so the development of straight spokes that didn't crack was a technological step forward. So "more modern" locos and rail waggons/coaches use solid wheels instead of spokes to help keep the rims true and round under load. BUT Flywheels do not have external rim loading, so easier to design and make work. Straight spokes are in tension only.
Interesting to have machined curved spokes to glorify the model.
K2

 

[Steamchick]

This table indicates the "low" tensile strength of Cast Iron, hence its poor suitability for flywheels, that are almost all in tension. with a bit of bending. (Compressive strength 4 x tensile!) It is better in compression (like concrete) due to its crystalline nature (I think?). Hence the "short life-time" when people used curved spokes on cast flywheels - until the materials and processes improved so they could use straight spokes.
https://www.engineersedge.com/properties_of_metals_strength.htm
But on a freelance model they do look pretty!

K2

 

[Rdean33422]

Thanks Doug the CNC is a way to make parts that I couldn't do manually or a least not look as good.

What angle do you cut your taper loc hubs?

I setup close to 5 degrees but it isn't all that critical as long as you don't change the angle until all the parts are cut.

Thanks K2

Ray

 

[Rdean33422]

I spent a lot of time filing around on the flywheels today to get rid of the sharp edges and gave them a good coat of paint.


It is supposed to get down in the 30s tonight so maybe they will freeze dry.

Between coats I polished up the taper faces.


Thanks for looking
Ray

 

[Rdean33422]

No shop time yesterday but I actually got quite a bit done today since the paint on the flywheels was dry.
I did weigh them with the tapers in place and they lost over half their original weight.
Started at 11lbs and now almost exactly 5lbs.
This shows the difference in size.


A few pictures of them on the engine.
These are better proportioned for the size of the engine I think.






I also installed the hall sensor and tested it.


The rest of the time today I cutout the base pieces.
Sanded, stained, and finished them.


Thanks for looking
Ray