15cc Seal and 30cc Seal Major

[Alyn Foundry]

Hi Both.

Jason does have a good memory Jo....

But you're right, I've decided not to sell as I don't know what's hidden beneath the surface of these goodies.

Cheers Graham.

[Jasonb]

Did not remember what was in the photo though  , I now see bases for two CHUK varients there.

Out of interest what engine were the smaller curved spoke flywheels for and what diameter.

[Alyn Foundry]

Hi Jason.

As always, there's a story.

They came from a small atmospheric gas engine who's picture appeared in an article written in the Model Engineer circa 1905.

Dave Croft, a familiar face on the NW stationary engine rally scene acquired this very engine many years ago. He approached me because the delicate spokes had been broken just inside of the flywheel rim. I managed to repair one to be used as a pattern to replace the broken ones.

They are 5" in diameter with a rim depth of 1/2" but are quite light, ideally suited to non compression engines.

I used them for Nattie, my little National Gas engine " lookalike " flame gulper.

<a href="https://www.youtube.com/watch?v=2eorVwM7n64" target="_blank">http://www.youtube.com/watch?v=2eorVwM7n64</a>

Cheers Graham.

[Jasonb]

I always like story time, sent you a message.

J

[Jo]

Don't let him have any of the castings Graham 

You know what he says about castings 

Jo

[Jo]

A bit more on the Major rods. You will recall the holes top and bottom of the rods looked decidedly out of line relative to the castings - its time to fix that.

Using the bored holes to hold the conrods the outsides have been taken to width and given a bit of a running face. I have chosen to make the big ends 12.5mm wide rather than the 12.7 in the drawing because the drawings have no tolerances  A 12.7mm rod on a 12.7mm big end, when you think there are 4 of them doesn't leave any wiggle room same goes with the little ends - the drawings show the same width as the counter bored inside the piston 

I know, I know the rods still look all out of line but if you put two bars through the bored holes you can see they are in line 

The next part is mainly cosmetic. The bottom ends need to have their outsides turned to 22.2mm diameter (this still won't let them be inserted into the engine through the bore  ) and the rods need to be fettled so they all weigh the same.


  I wonder if someone has some new castings he would like to share with me 

Jo

[Roger B]

Looking much better than when you started on them  Not that long till the first trials     

[Jo]

Thanks Roger 

To turn the outside of the rods to the required 22.2mm I used the big end bolts to secure the rods to a piece of spare bar and proceeded to turn the outside of the big end.

Each big end cap in turn had the counterbore added for the screws and a slight step across the width added. The castings did not have enough material to round the cap like the drawings

The last stage took the longest as it involved lots of fettling: Partly to give them a better shape but mainly to get the small end to fit into the bottom of the pistons and to make sure they all weighed the same. The final rods are within 0.1g of each other 


I now have the joys of repeating this for the Seal rods, but as they are barstock they will be somewhat easier to do and will use a totally different machining process.

Jo

[Bearcar1]

WoW!! Nicely done Jo…… I Like it a lot!!   


BC1
Jim

[Jo]

Thank you Jim, nice to see someone else following along on these builds

Jo

[Jo]

I heard a startled noise and found a delivery driver being hassled by Surus    He clearly was holding an engineering parcel as it was held together by the duct tape on the outside  ..

Closer examination found it contained a set of castings with that patented special coating so I did not need to read the further clue on the base (which read "Chuk Alyn Foundry" ) to know where it originally came from 


Lets hope Surus is feeling generous and we can have a fondling session later 

Jo

[Bluechip]

 Hi Jo

      etc. etc.

Dave

[Jasonb]

Lets hope he is feeling generous and we can have a fondling session later 

I'm sure he would swap the licker for a Snicker

[Jo]

I'm sure he would swap the licker for a Snicker

I think you are underestimating Surus: I might get to fondle it for the time it takes him to eat the snicker 

He tells me something is missing the plans detail an A frame and he doesn't have any in his set

Jo

[Jasonb]

That is all I had to go on when I built Chuky, seven written sheets plus a couple of photos of Grahams. You can just about do him at 1.5 times and you will have a totally metric engine too if you can't manage without drawings.