Author Topic: Making Patterns for a Rider Engine  (Read 1306 times)

Offline vtsteam

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Re: Making Patterns for a Rider Engine
« Reply #25 on: February 06, 2022, 05:09:06 PM »
That's probably what I'll do Andrew.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline vtsteam

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Re: Making Patterns for a Rider Engine
« Reply #26 on: February 08, 2022, 04:54:04 PM »
This is a pattern for a piston. I just have the first coat of spray paint on it so far, but tomorrow promises to be a nice enough day to possibly cast something, and this may be the first trial of the newly lined iron furnace, final paint coat, or not.

This pattern is a single piece, rather than split. It is hollow and has draft on the outside and the inside of its semi-conical shape. These were turned into the blank by offsetting the topslide on the lathe.

Instead of a parting line along the horizontal, like the split cylinder pattern, it will be cast upright with the parting line at the widest end. The hollow is intended to produce a greensand core when making the mold, in lieu of a hard core. What looks like a core print on the far end is actually a feature of the intended casting, to be used as a chucking piece when machining the piston in the lathe.

So this piston pattern illustrates different features and approaches to casting requirements when compared to the cylinder pattern, even though they look similar.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline vtsteam

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Re: Making Patterns for a Rider Engine
« Reply #27 on: February 16, 2022, 09:19:41 AM »
I've changed my ideas for a piston pattern, and have made a new one, which looks quite similar to the cylinder pattern, and in fact takes the same core.

The difference is, it is substantially thinner, and I should be able to get two pistons out of one casting, The only unconventional part is that they will not have ends, which will be added later.

BTW this pattern was much quicker and easier to turn on the Gingery lathe because of the new spur center I added. Where before I had to change jaws once, and switch ends once as well as dial in during a turning of the same shape using a chuck, this time the entire pattern was made at one go, from rough rectangular 2x4 lumber screwed together.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg