Oscillator Cylinder Pattern

[vtsteam]

Broke up a small rotor and got 8 pounds from it, so that's what I'll use as a melt size. Molding sand is hydrated. Facing sand has coal dust in it. 13 grams ferrosilicon measured out. I found two wooden flasks about the right size. Outside temp is 36F. Setting up the furnace and tools now.

[CI]

 

[vtsteam]

Exciting day, not all the fun type! I was under the gun because I was requested to go get a Christmas tree at a farm about a half hour away, and you know, that's one of those priority jobs you can't weasel out of! 

Thought I'd cast first, the place closes at 4, so plenty of time, right? Uh, no. First problem was just setting everything up -- it's been about a year since I cast anything, and I'd moved a lot of equipment around, plus had to find leathers -- welding cape, apron, spats yeah, I believe in being well dressed for iron. Nothing was where I remembered it.

Anyway finally got everything (I thought) in place and ready. Even gave a short test blast in the furnace to make sure it worked, which it did. And wisely, as it turns out, I did not try to mold while it was melting metal. I decided doing two things at once, probably not a good idea when a little out of practice.

First molding attempt, I didn't pack hard enough and a flask slipped its contents on one of the rolls. Darn! Okay remake the mold, second try. Opened it up to pull the pattern, and it broke out rough from the cope. Okay settle down. Get down to your alpha level. Concentrate. Take it slow. Third time's the charm. Well almost. A little sand broke away but not much, it's okay.

Here's the drag and you can see the small amount of breakaway. Also notice the pointless boss on the valve face, since that's where the ingate is going anyway. I opened that up after this photo. Also notice the crack in the sand upper left on the flange. Risky, but I decided to go with this mold, because time was moving at an alarming pace. Had I been molding for an hour and a half already?

[vtsteam]

Well I got the mold back together successfully. Powdered the sprue hole so I wouldn't mistakenly pour down the riser. (I would never do that.....) Piled weights on top of the mold. At last ready to fire up the furnace. Went to get my gloves on the molding bench and noticed a cylindrical object there. Turns out it was the core I'd made!

Uhhhh, okay, take off the weights again, bring the mold back to the bench separate the cope, place the core, close it back up, carry back to the furnace, set it down, replace the weights.

What time is it? Oh.......

Okay we can do this. Cardboard on plinth, not that it makes a difference often, set a brand new A6 crucible on it. Add the iron. Close the top. Start the compressor, set to 30 pounds, connect the line to the burner. Grab my torch, crack the fuel line. Ignition. Turn on the blower, adjust flame. We have heat!!!!

[vtsteam]

Thirty five minutes later, according to my watch, I had fluid molten iron. That was fast, but I was using pure diesel, and the crucible wasn't full. The melt went smoothly compared to the molding. The pour was just right. I'd like to say I did everything perfectly here, but for one more flub. There was no place to pour the metal left in the crucible after the mold was filled -- I'd forgotten  to set up the ingot mold! 

So I had to put the crucible back in the furnace, start that up again so the iron wouldn't freeze in place, and hunt up the ingot mold. Finally found it, heated it for a minute over the exhaust to make sure it was dry, powdered it, and finally poured the ingots and shut down the furnace. Whew, done.

And it was 3:00 time to go get that Christmas tree!

[Sanjay F]

Looking forward to seeing what comes out 

[vtsteam]

Breaking out shortly. I do have a question, I hope somebody can answer. Never had one before.... is this a shop elf?

[vtsteam]

The casting, well surprisingly good despite all the difficulties. The core just poured out -- It was a little damaged to begin with so the inside is a little uneven, but I don't see any obvious flaws or holes. But only boring will tell. I think the core worked perfectly, and I will definitely use one to my recipe again, though this time oiling the aluminum tube mold to release it easier.

Also the valve face doesn't seem to have any shrink issues where the gate fed in. Of course the original boss there was cut out of the sand so now it's just a rough clump. I was able to saw through it with a hand hacksaw to release the casting. This means it wasn't chilled there. I have enough extra thickness in the valve block to machine a short trunnion boss there anyway.

There's a little flash at one end of the cylinder. The only obvious flaw is the thinning of one of the end flanges. Not sure why that happened, but I'm suspecting a gas bubble. The flanges are pretty thick and deep. There's probably enough to machine back to even them up. But otherwise it looks like a good casting. Unless there is a problem in the bore, this could actually make an engine!

Well, there we have it, some hole saws, scrap wood, some bondo, molasses and corn starch form the kitchen, and a scrap brake rotor and we get a steam cylinder out of it. No wood lathe needed to make a pattern, and if we had a better foundryman, it might have been perfect.

Oh, cylinder weighs 3 pounds exactly, btw.

I did get the christmas tree!

[crueby]

Breaking out shortly. I do have a question, I hope somebody can answer. Never had one before.... is this a shop elf?

Run!  Thats a rabid shop tweazle!!   

[vtsteam]

Uh oh.....

[CI]

Great casting !
What a casting effort.
It is great when things come together like that.
Surface finish is very nice.
Too cool.
Winter casting too.
Awesome.
.

[vtsteam]

Thanks CI! 

[Jasonb]

That looks to have come out nicely, hopefully all is good under the skin too.

[PaulR]

That looks great! Looking forward to seeing some of it machined.

[vtsteam]

Thanks guys, very much appreciated! 

I took some test cuts today. It machines very nicely, no hard spots, no holes, fine grain, Really nice material 

I bored it to 1.422" and had cleared the bore. It was pretty rough from the damaged core to start with, but no sand inclusions. It was clean all the way through.

I'll continue to 1.500" finished bore tomorrow. Casting barrel O.D. is 2.005"

Happy with that!