Rudy Kouhoupt's Open Column Steam Engine - Cast & Double Size

[vederstein]

Today I poured another cylinder head and bearing block. The casting quality continues to improve.

Now that I've done a few pours, I've been noticing a few things:

1. I need to add water to the green sand much more often that I was expecting. I new the moisture would evaporate over time, but not to this extent. It's not a big deal though. Just add a little water and mix with a drill.

2. Draft is important. In areas where I didn't have draft (usually areas that don't matter or get cut off during machining) the sand breaks every time. I need to remember this as I create more patterns on the 3D printer.

3. Sand gets everywhere! I'm trying to improve my practices, but a sand dust is coating my garage.

Today's pour completes the smaller cast parts. Now I have three large ones left:

The Cylinder
The Base
The Flywheel

Doing these larger castings I anticipate will be a challenge in itself.

Happy modeling...

...Ved.

 

[vederstein]

Today I machined the bearing blocks.

From machining cast bearing blocks on other engines, I've learned to machine the blocks at the same time wherever possible. This results in more consistent critical dimensions.

First I clamped the two block in the milling vise and eyeballed them parallel with the vise.

After indexing from the crown of the blocks (bottom surface) I milled both block to the proper height at the same time. Then I milled around them to get four square faces on each block. I should have drill/tapped the mounting holes at the time, but forgot to. Therefore I'll transfer punch when assembling to the base.





I re-positioned the blocks for drilling/reaming the shaft journal. I did need to find the center line of each block, but the height from the block bottom to the center of the hole is consistent.







After drilling/tapping a 10-32 hole in the crown for an oil cup, I put each block in the lathe to face off a surface. This operation is strictly for aesthetics.

 

[bmac2]

Hi Ved green sand works great for straight round cores it just needs a little help with support. This core if I remember right is 12”(304mm) long 3”(76mm) in diameter with 3 or 4 pieces of stiff wire running the full length (think rebar in concrete).
Oh and ram the crap out of it! *club*

Green Sand is the nemeses of the hobby caster but once you get it dialed in its great stuff. For the surface finish it’s never going to be smoother than your sand. I think my sand if about 25% my original sifted play sand from Homer Depot, 50% 50-100 blasting media and 25% 100-200 blasting media. The 100-200 is mostly from facing sand I but directly against the pattern. It’s just the Myfordboy green sand recipe with the 100-200 media.

 

[vederstein]

... 3 or 4 pieces of stiff wire running the full length (think rebar in concrete).
Oh and ram the crap out of it!

...25% my original sifted play sand from Homer Depot, 50% 50-100 blasting media and 25% 100-200 blasting media....

Thanks for the good info.

I have some water glass on order. Depending on what gets delivered will dictate my next casting core try.

As for the sand, I realized that my sand is too coarse after a few pours. But I'll keep soldiering on partly because I want to see where this goes, but mostly because I don't have any desire to spend another long afternoon pulverizing clay kitty litter.

Necessity is the mother of invention. Laziness is the mother of "It's good enough."

...Ved.

 

[bmac2]

I hear ya on the kitty litter. When I got started I spent an entire Saturday morning grinding up litter in a small flea market blender only to find a pottery supply place less than a half hour from my house that sold bentonite clay for couple bucks a pound.
And I do agree that a casting should look like a casting.

 

[vederstein]

Three pours today.

First one was the base. It was salvageable, but not good enough, so I tried again. The second attempt was much improved and good enough for me.



The third pour was the cylinder. It's total failure. The static pressure from the molten aluminum separated the molds and molten aluminum poured out between them.



Lesson learned.

To be continued...

...Ved.

 

[vederstein]

Also today, I tried to mold up the flywheel. The six spokes were too close to each other and on every try of removing the pattern the mold would break apart.



So I gave up on that design and redesigned to flywheel with three, but thicker diameter spokes.



Time to waste more plastic on a 3D print...

 

[vederstein]

Successful day today.

First I had a successful pour of the steam engine cylinder. It took three tries pouring and four tries making a core, but I finally got there.

[ame]http://www.youtube.com/watch?v=Y74ngR8Phk4[/ame]

Second (on my second try) I had a successful flywheel pour.





I have a decent amount of flash to grind off, but this flywheel, made of zinc, I can definitely work with.

Thirdly, I started machining the base. There's some porosity, but It's nothing I can manage.





That's it for the casting. From here on out it's machining for this project (I hope).

...Ved.

 

[vederstein]

Today was a big step: Machining the cylinder.

This is what it looked like after removing the gates, sprue and sand core:



First I fixtured it into the four jaw and machined the top of the cylinder.







Then I switched to the three jaw chuck and flipped the cylinder. Upon I faced off the bottom end and bored out the cylinder.





That was it for lathe work...

 

[vederstein]

Next up was mill work.

First I clamped the cylinder into the vise with the valve port face up. There was not good way to indicate this, so I eyeballed it. Then I roughed of the valve face.



Then I used a flycutter for a better surface then faced off the inlet and outlet face. It's important to face them off at this time because it allows the cylinder to be rotated 90 degrees with 123 blocks.





Next was drilling out the valve, inlet and exit ports.







I neglected to take photos, but then I drilled out the bottom for the posts. I couldn't resist at this point, I had to do a dry fit.



That's it for this week.

...Ved.

 

[Herbiev]

Coming along nicely

 

[deverett]

I admire your tenacity.

Dave
The Emerald Isle

 

[vederstein]

Today was dedicated to machining the flywheel. This is really the first time I've machined zinc. It was quite enjoyable. The chips were small and not stringy. I've added a short video of an OD pass to show. It cut easily and it shiny. Good stuff.

[ame]http://www.youtube.com/watch?v=LniYlGs9z24[/ame]

No need for a bunch of descriptions here. The photographs should be self-explanatory.

...Ved.

 

[vederstein]

It took four tries at making the valve, but I finally got the engine to somewhat run.

Being single acting engine with the rotating face valve that Rudy K. designed, this engine will never make real power.

But hell.. IT RUNS!!!!!!!!!!!!!!

I hope that as it breaks in it will improve. Though the biggest issue is for such a large diameter piston, the porting is small. Therefore the 180-190 degrees of non-powered movement is restricted by the exhaust valve ports making the engine far less efficient. The small porting also contributes to the jerky motion.

[ame]http://www.youtube.com/watch?v=_hNspgr1xwk[/ame]

 

[vederstein]

After my successful test run it's time to disassemble the engine for painting.

My wife wasn't too keen on painting it because she wanted the raw cast surface to show people that I was one who make the castings.

But alas, this is my hobby. Not hers. So we have paint. This time I went for blue.

Instead of a rattle can, I went with a brush this time. With a brush I hope I can control the edges a bit better and fill in the rough casting surface a bit.



That's it for this week.

...Ved.

 

[vederstein]

Being that's it's exhibition time of the year I broke out my boiler and did a test run to see if it survived the winter. Everything was good so I told myself what the hell, it's worth a try to see if this engine (which was never meant to) would run on live steam.

Amazingly it did. As expected it leaked profusely and my steam is quite wet. It didn't run well, but it did run. I'm calling that a win.

For all you haters out there. If you're going to b][tch, please don't. It's not helpful. I'm well aware of it's issues.
For the rest of you, enjoy...

 

[bmac2]

I love it! No question that it's running is steam. Reminds me of the old Hollywood movies where engines belched steam from every seam.
All due respect to your wife but I like the blue.
You have inspired me to get back into the shop and make some chips . . . Well as soon as I get caught up on the spring "honey do" lest

 

[Cogsy]

Isn't that how steam engines are supposed to run - slow and billowing steam? I think it looks great. Be proud!

 

[ShopShoe]

That turned out well. It does look good running on steam. No complaints here about the color.

--ShopShoe

 

[JohnBDownunder]

Looks like a seam driven engine, sounds like a steam engine (old paddle steamer comes to mind). I do prefer the sound it made on air but that may just be the position of the microphone and where it was recorded.
Either way is is a jolly good effort, so congrats.