Castings for RR trucks

[Russ Hanscom]

Here are the patterns for several parts for a truss rod on a wood brake beam we are having cast for some RR trucks. One of the C&TSR members is an amateur pattern maker. The project requires about 12 different castings, some quite complex.

A foundry in Houston will do these in CI, DI, or steel as needed. The cost for these particular ones is in the $20 - 30 each range.

[Harold_V]

Interesting!

What purpose do the three holes serve, Russ?

Harold

[Russ Hanscom]

No clue as to the holes, I will have to ask the pattern maker. I know that he goes to great lengths to make cores and such non symmetrical so that they are truly fool proof.

You can see the completed parts installed in "Wood Brake Beam" in the Live Steam section.

[dolfa]

The holes are for plastic locators.

[Harold_V]

The holes are for plastic locators.

Thanks. Can I safely assume that they are used to align the cope with the drag, in lieu of pins in the flask? That doesn't make a lot of sense to me, but then I'm not a foundry person (but eager to learn).

Can you please elaborate on your response?

Harold

[dolfa]

Yes, they are used to align cope with drag. If the foundry is using Pep Set which is sand bonded with hardener they do not have to use steel frames with pins.
The mounted patterns with wooden frames made with 5 degree draft are filled with Pep Set and when the sand hardens it is dumped out. If the locators are self moulding - cope has female locators and drag male ones- then the mould is closed and ready for pouring. If they are not self moulding then sand cores are inserted in the locator imprints.

[Harold_V]

Thanks for the timely response. I've witnessed the Furan process, which is similar to that which you described, so your explanation makes sense to me.

Harold