The Home Machinist!

Thought I'd share a project I have been working on for the past few months, the future owner of the final part might be a member here on Chaski - not sure.

The original casting of this steam dome cover (goes on a British 7 1/4" gauge design called Paddington ) was found to be too small for the boiler as it was built. A larger casting is needed in order for the center bore to be the necessary diameter.
Using the original drawings and casting for reference I re-drew the part in 3D CAD and then scaled it up to the required size. Getting the compound curves right proved to be quite a challenge. Once I managed to get it correct I turned it into a split pattern and 3D printed it. I also 3D printed a core box to go along with it.
Ran out of metal on the first try, oops! However I managed to get a good pour the second time around!

Nice job Frank.

So this is done for cope/drag greensand casting?
I have wondered about 3D printing for "lost wax/foam" type casts. Haven't had much to do with it.
Nice work though, piece looks good.

steamingdon wrote: ↑Sun Oct 06, 2019 6:52 pm Nice job Frank.

Thanks Don!

mihit wrote: ↑Mon Oct 07, 2019 12:54 am So this is done for cope/drag greensand casting?
I have wondered about 3D printing for "lost wax/foam" type casts. Haven't had much to do with it.
Nice work though, piece looks good.

Yes exactly, split pattern with core and petrobond sand, petrobond gives a very fine surface finish vs. greensand. (At least this is what I have been told.)

Yes you are correct 3D printers are also very suited for making lost wax patterns! Dick_Morris's build thread has a very cool example of this process here:
http://www.chaski.org/homemachinist/vie ... 9&start=24

I have been doing this for over two years now. I work with Marty Pinkston (FairWeather Foundry in Kent, Ohio). I design parts in MasterCam and Marty does the 3D printing for the pattern for the sand casting. It works great. So far only aluminum castings. But we are going to be doing other types of materials.

I was looking at building a DIY RepRap around 2014 but decided I already had too many hobbies and at that time complete ready-to-run printers were expensive.

I purchased my printer last year and wished I had bit the bullet a few years back, besides making patterns it is great for prototyping parts.

Keep up the good looking work.

Rob

I have passed off the casting to DMS where it is currently being machined:

Nice work Frank! Those cowls are goofy shaped at best! The ligan is looking healthier also!

elm53 wrote: ↑Sat Nov 02, 2019 2:40 pm Nice work Frank! Those cowls are goofy shaped at best! The ligan is looking healthier also!

Thanks Larry!

What is a ligan ? DMS