The Home Machinist!

We haven't done much machining of any of our parts yet, that may open our eyes to the mixture we use.

Thanks for the wishes on the wife. She saw the doc today and got real good feedback, she is happy! My nursing skills aren't to bad I guess.

Tom C.

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tom_at_srclry_com
Lost somewhere in Michigan!

If that becomes an issue, you can be selective and use alloys that are able to be artificially aged. It does wonders to the machineability of cast aluminum, which is notoriously lousy to machine.

I recall running a large order of castings that were made from 6061 (not a casting alloy, and not recommended for casting). This was before I started my own shop, when I was working in a job shop. The foundry that ran the material managed to get decent castings, so they were solution annealed then heat treated to a T6 condition. Really helps.

Harold

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Wise people talk because they have something to say. Fools talk because they have to say something.

Here is a shot of some of the finished stake pockets. I see that I didn't center the core in the center of the pattern. Have to work on that in the next batch.

Tom C.

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tom_at_srclry_com
Lost somewhere in Michigan!

Um, cores should be pocketed into the master mold. That way they will always index correctly for your parts. It is simple to do, and only extends the corebox a bit. I suppose you are using Sodium Silicate mix for your cores. If you are running a lot of stuff over a few days, you can store coremold mix in a plastic bag, to hold out the air, as the CO2 is what sets it up. it will grab the CO2 from whatever it can, like natural gas and air, albeit slowly. I have sucessfully stored cormix for weeks with a Nitrogen cover. (from my AC purge tank) Conversely, cores can be set on a cookie sheet and 'baked' in a warm oven, but it is theCO2 generated by the flame that does the work, not the heat.

As far as extrusions, they are gummy to work sith and dont machine well in my experience, piling up material on the cutting bit and makeing a rough finish. Casting material can be a bit brittle, The strongest material I have worked with are Pistons. They are very hard to beat, but many are forgings, not cast.

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Big Dave

Be Alert! The world needs more Lerts.

Our crack pattern maker has been at it again. He didn't like the profile of our queen posts so made a new pattern to try, didn't like the pattern for our bolster center casting so made new and we needed a shoe for the swing motion passenger trucks we are building so made a pattern for them. We warmed the foundry up and made a few molds to see how they turned out. Not bad we think.

Tom C.

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tom_at_srclry_com
Lost somewhere in Michigan!

Our parts have machined really well and have the Pedistals and Journal boxes nearly complete. Here was our test one to see what need to be done and test set up.

Tom C.

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tom_at_srclry_com
Lost somewhere in Michigan!

We roused the foundry from slumber and made a few parts we needed. Some brake wheels and a new pattern for turnbuckles. They came out nice as we cut back on the water in the mix as it is real easy to get it too wet!

Tom C.

PS Pockets, if you see this, a wheel is yours.

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tom_at_srclry_com
Lost somewhere in Michigan!