anyone have any leads of casting a knuckle?

jim@sdrm.org

> anyone have any leads of casting a knuckle?

Do you have a pattern? I think the big issue would be developing a pattern and attendant core box patterns for a complex shape such as a coupler knuckle.

I am assuming this would be cast steel, vs. grey iron or perhaps malleable iron. I guess you need to determine the material (alloy) first, either from testing the broken one or perhaps from old manufacturing or industrial records.

Then locate a foundry who pours that type of casting based on the alloy. There are many foundries still in business but few willing to pursue short runs or one of a kind projects.

If you do not have a pattern, most foundries work closely with a pattern shop local to them, but it is BIG bucks. And you need good drawings or the old part to establish dimensions and size. There is some experience necessary and some unique skills needed to construct the pattern, but in about eight weekends of work we have completed two patterns and a core box for new brake shoes for a special application. The work was quoted on the outside at $4,000. A coupler knuckle would be more complex and likely more bucks, maybe a lot more, for the pattern.

For the brake shoe project with us, over 2/3 of the cost is in the patterns. Depending on the type of knuckle you are trying to replicate, there may another preservation operation needing that design or be willing to share some of the fixed costs. But I expect you should have deep pockets for this one.

Bob Kutella


68trolley@comcast.net

What type of knuckle are you looking for? If you put the description on this site there is a chance someone may have what you need laying around and may be willing to sell or trade it to you.

Joe Mann
Niles Canyon Railway

http://www.ncry.org/
jmann@asyst.com

Very old, wooden trucked coach. I have the wooden pattern - I just need the foundry.

Jim

> What type of knuckle are you looking for? If
> you put the description on this site there
> is a chance someone may have what you need
> laying around and may be willing to sell or
> trade it to you.

> Joe Mann
> Niles Canyon Railway


Jim@sdrm.org

> Very old, wooden trucked coach. I have the
> wooden pattern - I just need the foundry.

> Jim

Best thing to do would be to search for foundry or castings in www.thomasregister.com . There is probably one near you.

Take care,

Rich

Connecticut Eastern Railroad Museum
rcizik5519@earthlink.net

> Very old, wooden trucked coach. I have the
> wooden pattern - I just need the foundry.

Is that a boarded pattern or a loose pattern? That can make a difference as to wheather a foundry will do the job or not.

Brian Norden

Hi,

The city of San Francisco uses a firm named Ridge Foundry, in San Leandro, Ca. Their phone #510 352 0551.

Sincerely,

Karl Johnson


karl_johnson@ci.sf.ca.us

A friend had some equalizer seats cast here in Michigan some time back, and the price was quite cheap for a simple flat piece attached to a board. There are a number of small foundries in this territory, used to doing experimental auto parts. Depending on where you are, a trip through the yellow pages could be sufficient.

I am no expert in this, but I get the impression that patternmaking is no longer the expensive chore it once was. There are several varieties of rapid-prototyping machines that will produce patterns from CAD files, untouched by human hands. One variety produces a stack of layered cardboard cross-sections of the piece, which are then glued together to form a pattern durable enough for short runs. Other machines will produce patterns machined from polyester. (The pattern for the steel mandrel used to make Nicholson thermic-syphon necks for PM 1225, Frisco 1522, and NKP 765 was made in this fashion, although I believe Johnny Cash's "One Piece At A Time" was playing in the background while this was done.)

But before casting a critical part like a coupler knuckle, you might ask,

Does the pattern match the drawing?

Does the drawing go with the drawhead?

Do we know how to finish the part after casting?

Are the rest of the coupler parts in good condition, or should we replace the whole thing with a current design we can get parts off the shelf for?

Depending on the severity of the service and whether the car carries passengers, control of the coupler dimensions could be safety-critical.

Aarne Frobom

You'll need a foundry which casts steel, not iron. For starters try Phoenix Iron Works, 499 Embarcadero, Oakland CA, 510-465-9900

There's also one in Berkeley of all places, but it doesn't seem to have a listing in the yellow pages (unless it Phoenix's or Macaulay's plant). I've seen this place cast discs for passenger car axles on numerous occasions.

Be prepared to spend money.