PMR 7 Twin Cylinder Steam Engine

[zeeprogrammer]

Started on the cylinders.
Has not gone so well but it's too early to say whether one of the cylinders ends up on the wall of learning.
The biggest boo-boo was getting one of the valve holes off-center.

1st pic shows the cylinder ready to work on. The 'x' tells me that's the end that mounts to the base.
2nd pic shows that end faced. The power cross slide gives an amazing finish.
3rd pic shows the cylinder bored for the piston. Again, the power X drive was helpful.
4th pic shows the valve hole drilled and reamed. The rod in the piston hole was used to center but I messed up centering the valve hole on one cylinder.
5th pic shows the hidden steam passages drilled. Then drilled/tapped for a set screw that will plug the passages.

Later, I'll use the same bit used to drill the hidden passages to center the part for drilling the angle passages from the piston bore to the hidden passage.
I'll use a bit of wire or wood so I can see/feel when I get to the hidden passage.
I also still have to drill/tap the steam inlet and the holes for mounting the cylinder to the base and the holes for the head covers.

This is the 2nd time I'm posting this. The 1st time I'd forgotten to resize the pictures and the post didn't take. Odd? I wish the text had at least posted.
Also, I've noticed once in a while that a reply to a post ends up with a 403 error. Retries sometimes work. If they don't, I back arrow to my post, copy the text, get out, get back in, and paste the text in a new reply.
I think it happens if I happen to be posting a reply at the same time as someone else.

[Gas_mantle]

Looks fine to me Carl 

I've made a couple of spool valve engines and find they work quite well. When I made my Potty Mill I had fairly crude tools and didn't have a mill so I drilled the ports very slightly off. To correct things I just made 3 or 4 valve spools all very similar but not the same and picked the one that worked the best .

I guess I cheated a bit but it worked 

[b.lindsey]

Nice work on the cylinders Zee. The slightly off center hole shouldn't be a problem. The articulation between the valve itself and the cam follower arm should take care of it unless its way off.

Bill

[zeeprogrammer]

Thanks guys.

Well I can't say I'm ecstatic with the results but I'm pretty satisfied the cylinders should work.
The biggest issue was finding square. Not a lot to go on with these shapes, not to mention the sparse experience.

As people have mentioned on the forum...castings are for the experienced although my first model was a casting.
A lot depends on how simple the model is and how much help is available. In my case, my first model came with a how-to video.

Things are a bit 'off' but should be okay. Biggest boo-boos were getting the valve bore off center on one cylinder and crushing the cylinder in the vise that caused dimples on the faces.

I most feared the steam passages but they found each other.

1st pic just shows what I did to find the center line.
2nd pic shows the steam passage into the piston bore. I had used a piece of wire in the passage I was trying to meet up with to be sure I got deep enough.
3rd pic shows the cylinders thus far. I still need to drill/tap the holes for the covers.

So far, so 

Been slow the last few days. Once again I found myself passing a gallstone. I should probably go ahead and have that little lobe of liver lopped off. 

[crueby]

Nice! Any forward progress, even if a little off center, is progress. This is one of those hobbies that you can learn some by reading , but it needs doing to really get it.

 

[b.lindsey]

Zee, things like good in the pictures. If you think the dimples will be a problem, the heads will cover them most likely, but if you worry about sealing the heads for ait leaks, you can always add a thin paper gasket for insurance.

Bill

[zeeprogrammer]

This is one of those hobbies that you can learn some by reading , but it needs doing to really get it.

True for most anything in life. People often ask me about learning to program. "Start programming" is where the answer usually ends up. Pick a small project and do it.
Change 'programming' to machining, wood working, writing, dancing,...pretty much anything.

Zee, things like good in the pictures. If you think the dimples will be a problem, the heads will cover them most likely, but if you worry about sealing the heads for ait leaks, you can always add a thin paper gasket for insurance.

Thanks Bill. I figure a little sanding and the gaskets will do it. Since I won't be running on steam but on a 'limitless' air supply...I'm hoping it'll run. Looks very promising so far.

Gotta say...I'm really enjoying this.

[bent]

True for most anything in life. People often ask me about learning to program. "Start programming" is where the answer usually ends up. Pick a small project and do it.
Change 'programming' to machining, wood working, writing, dancing,...pretty much anything.

Yup, gotta agree ... except dancing.   

[zeeprogrammer]

Not a lot to show.

Drilled and tapped for the cylinder covers.
Pic shows one 'installed'.
I tried to square everything up...then set the covers on then used a little bit of eyeball and a square and then a drill bit to 'spot' where I wanted to drill/tap.

You can see a nice boo-boo on the left cylinder to the right of the valve hole.

  When I flipped the lever to engage the cross slide power feed...I'd forgotten the carriage slide was the one engaged.

Ugly but won't affect performance.

[b.lindsey]

Just do the other to match Zee and all it a personalized feature

Bill

[ddmckee54]

Zee:

Let's just call it an "Undocumented Feature" and charge extra for it.

Don

[crueby]

Or do the same to the other so they match, then its per design.

[zeeprogrammer]

Nah. I'll just place a mini-tutu on the other cylinder. That should serve to distract. 

[Tennessee Whiskey]

Artistic freedom is what I’d call it: hey, it’s “handmade” .  Great job Zee. Once you get to going, man, you’re on a roll

Cletus

[Craig DeShong]

American Indians intentionally place a,fault in their jewelry so that the piece is never perfect.  Sounds like a good explication to me.  I've used it myself.