castings, start to use them

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Kerrywil
Posts: 3
Joined: Sat May 23, 2015 12:19 pm

castings, start to use them

Post by Kerrywil »

Hi folks, I just bought a set of castings from Ken Schroeder for a 3 truck Shay. I have never used castings. How does one figure out where to start machining the casting. I look at them just not sure how to approach the finishing the castings to the finished measurements.

I am in the the Sacramento area if someone wants to "show" me

Thanks
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NP317
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Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: castings, start to use them

Post by NP317 »

Definitely connect with the Sacramento Live Steamers.
You will fine immense knowledge there, and hopefully people interested in sharing that info.
Have fun building that shay. They are beautiful machines.
~RN
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Harold_V
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Location: Onalaska, WA USA

Re: castings, start to use them

Post by Harold_V »

Think smart and don't machine until you are very familiar with what you intend to do. That will help save you from scrapping your castings.

While you're likely to get some help at the club, one thing for you to understand is that there are features of castings that don't get machined. Those features should end up in positions related to machined surfaces, so depths of cuts will be determined by that relationship.

Castings don't necessarily reflect the exact size or shape of the piece desired. For that reason, you should evaluate the casting well, trying to determine if some faces will require more or less material to be removed in order for all features to end up within desired parameters. For that reason, it's not wise to jump in and start machining until you've explored all possibilities. You may have to compromise a little to achieve an acceptable result.

Once you "get it", it's not all that difficult to make the proper decisions. Any time you spend studying the casting(s) against the print will be time well spent.

If you have at your disposal a surface plate and height gauge, it's often possible to set up a piece and scribe lines that represent finished surfaces. The lines would be established by making reference to unfinished surfaces, and how they should relate to the finish machined casting. Things don't work out well by scribing, simply make the necessary changes, as no material will have been removed.

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
Kerrywil
Posts: 3
Joined: Sat May 23, 2015 12:19 pm

Re: castings, start to use them

Post by Kerrywil »

Thanks Harold, Your description is exactly my situation. I am not sure what is a "surface" and should that "surface" kept at the same angle. I am cautious. Part of the build is the journey and the other a working machine. I'll study the parts and the plans. You I have a surface plate and a height gauge.
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steamin10
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Location: NW Indiana. Close to Lake Michigan S. tip

Re: castings, start to use them

Post by steamin10 »

Kerrywil: There are some thoughts in the build section, " Alternate ways. Getting it done', that may help organize your thoughts. it is a work in progress.

Castings can be a puzzle, but it is not so bad once you decide what is important for critical function, and carve those measurements into the shapes you have.

I dont have a fancy gauge stone, or plate. I have settled on a 1/2 inch glass table top, (x2) that I also use to make hand shaped waxes for casting. Formerly I had a large 16 inch Italian slate tile for marking and getting things flat. (I dropped it).

I cannot spend freely on my hobbies anymore, and have to weigh against real life. Take heart and make it happen.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.
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NP317
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Location: Northern Oregon, USA

Re: castings, start to use them

Post by NP317 »

If the castings are iron, remember to make the first cuts deep enough to get below the "crusty" surface. Otherwise the cutting tools can get damaged. After that first cut, it should cut like butter. ... and dusty. I use a face mask to keep from breathing powdered iron!
~RN
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littleevan99
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Location: Northern California
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Re: castings, start to use them

Post by littleevan99 »

Were you there yesterday for the run day? I brought my CliShay and ran it for a few hours. You could tell it was me from the aroma that burning coal creates. If you join there is a lot of help from all the members there, and they helped me a lot.
1.5" scale CliShay
1.5" scale 2-10-2T
2.5" 36 Ton Shay under construction
YouTube: http://www.youtube.com/user/littleevan99
Kerrywil
Posts: 3
Joined: Sat May 23, 2015 12:19 pm

Re: castings, start to use them

Post by Kerrywil »

No, I had cataract surgery Friday and I am on restricted duty until
Next Friday.
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Fender
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Location: Chattanooga TN

Re: castings, start to use them

Post by Fender »

If they are sand castings, as opposed to investment castings, there may be undesirable roughness or parting lines from the mold on the castings. These should be removed or smoothed down by using a belt sander, die grinder or other method, before beginning the machining operations. The British would call this "fettling". This will make the layout easier, and provide a smoother surface for holding the casting in the lathe chuck or milling table.
Dan Watson
Chattanooga, TN
joneg
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Joined: Sun Feb 17, 2008 11:36 am
Location: pa

Re: castings, start to use them

Post by joneg »

Hello Kerrywil

I am also building a shay based of Kens 3 truck shay castings. Proceed with caution, i had two major problems with a lot of the smaller castings.
1. stock up on carbide end mills, the truck castings were full of very hard spots.

2. measure carefully and make notes, several castings had no extra material on them. i had to machine undersize to clean up. one example was the overall length of the crosshead guides. had to cut them undersize to clean up and add the missing material to the bottom cylinder head.

3. check the dimensions on the hole spacing of all the upper and lower truck bars, my drawings had a 1/16 inch error and i had to remake the lowers when nothing fit together

4. the design of the drive shafts is incorrect from how lima built them. a centerline thru the u joint pins should be 45 degrees from the flats of the telescoping shaft, not parallel as Kens drawings show it

hope this helps
jon
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kenrinc
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Location: SF Bay Area

Re: castings, start to use them

Post by kenrinc »

Kerry,

I thought you were going to build an A3? LOL

A great resource for that particular engine is Nelson Riedel's website:

http://www.nelsonslocomotive.com/Shay/shay.htm

Ken-
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