Another Internal Combustion Engine

Rdean33422 · Nov 19, 2024

Jojo said:
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

a41capt said:
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 · Nov 19, 2024

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 · Nov 19, 2024

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 · Nov 20, 2024

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 · Nov 20, 2024

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 · Nov 20, 2024

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

Steamchick · Nov 21, 2024

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 · Nov 21, 2024

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 · Nov 21, 2024

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

olf20 said:
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 · Nov 21, 2024

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 · Nov 23, 2024

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

Danuzzo · Nov 23, 2024

Looking great.

Rdean33422 · Nov 24, 2024

Thanks Dan

I put rubber feet on the bottom of the base board.
Couple of pictures with the engine mounted on the base.

Ignition will be next on the list.
Thanks for looking
Ray

Nerd1000 · Nov 25, 2024

Looking great!

Rdean33422 · Nov 25, 2024

Thanks Nerd1000

The electronics box is complete with a polished top and a off/on switch.

I adjusted the ignition timing and the valve timing.

Fuel system is next.

Thanks for looking
Ray

Sparky_SC · Nov 25, 2024

Looking great. What do you use for a ignition module with that hall sensor?

Rdean33422 · Nov 25, 2024

They are from China there are several suppliers but I don't recommend any specific seller.
Thanks

Ray

Rdean33422 · Nov 26, 2024

It's the little things seem to take the longest to make.
The carburetor parts ready for assembly.

And installed on the engine.

Gas Tank next.

Thanks for looking
Ray

Steamchick · Nov 27, 2024

But surely, part of the pleasure is the result from making the little things?

Rdean33422 · Nov 27, 2024

Yes you are right K2 but after dropping almost all of them on the floor at one time or another and then trying to find them can be frustrating.

The outside of a piece of round aluminum stock is skimmed to get a consistent OD.
The inside is then drilled out to remove the waste.
This shows cutting the lip for the end pieces of plexiglass to fit into.

Cutting the end pieces to size using pressure from the tool post only to hold them in place.

All the gas tank parts before assembly.

Thanks for looking
Ray

Another Internal Combustion Engine

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