63" prototype coupled wheel castings?

[Mountaineer]

I've been looking but not finding. Does any supplier make castings for 1.5" scale 63" prototype driving wheels (like on a Mikado) that are not flat back. In other words full detailed spokes from two part pattern?

Thanks for info.

Mountaineer.

[FLtenwheeler]

Hi

What type of counter weights are you looking for? Take a look at these.

http://www.chaski.org/homemachinist/vie ... 7&start=48

Tim

[Mountaineer]

I did notice your nice pattern work (and great work on the rest of your project!) but couldn't tell if you'd made both a front and back pattern for each wheel? 1.5" or 1.6" scale?

Regards,
mountaineer.

[FLtenwheeler]

Hi

I am building in 1.6 scale. The driver centers are machined to 7.200" and then I put steel tires on.

Do you have prototype drawings for the wheels you what to model?

Tim

[Fender]

I believe Tim drew up the entire wheel in a 3D CAD system, and then had the entire wheel created in plastic by Shapeways. To convert this into a two-piece pattern for conventional sand casting, one would need to make separate repro molds for each side of the master (molds of each half of the wheel, front and back), then use these molds to cast the front and back halves of the wheel pattern in the repro material.
Or, I suppose you could get two wheels from Shapeways, machine away the front half from one and the back half from the other, and then mate them to have a split pattern.

[Mountaineer]

Fender, I don't think I understand. Is the plastic Shapeways wheel flat back or proper spokes on back as well? Is the idea to burn out the plastic on casting? (Like using styrofoam patterns) Haven't done any 3D CAD. And yes, to answer a previous question, I do have drawings for prototype (a 2-10-4).

[FLtenwheeler]

I believe Tim drew up the entire wheel in a 3D CAD system, and then had the entire wheel created in plastic by Shapeways. To convert this into a two-piece pattern for conventional sand casting, one would need to make separate repro molds for each side of the master (molds of each half of the wheel, front and back), then use these molds to cast the front and back halves of the wheel pattern in the repro material.
Or, I suppose you could get two wheels from Shapeways, machine away the front half from one and the back half from the other, and then mate them to have a split pattern.

Hi Fender

I used a backer board and did the wheels loss. So yes I have full detail on the back of my drivers when they are cast.

Tim

[Fender]

I don't want to try and answer questions about Tim's wheels. Just wanted to explain, from my own experience, how to go from a full (one-piece) wheel pattern intended for burnout in an investment, to a split pattern on a match plate used in sand casting.

[FLtenwheeler]

Hi Dan

There are other ways to do a 2 sided pattern with out splitting it and putting it on a match plate. I still have the patterns and backing plate so I can do more wheels if needed. I will see if I can come up with pictures on how it works. I saw a picture on an English site.

Tim

[Fender]

Agreed. My explanation is of one method (which I have done), but there are others.