Pacific Vapor Engine from Morrison & Marvin Castings

[Dave Otto]

Hi Everyone

Here is the continuation of the intake valve construction.
The valve body was removed from the frame using the band saw; I’m sorry I got carried away and didn’t take many machining pictures. It was all pretty straight forward; I decided instead of reaching down through the 1/16” pipe openings to cut the ports that I would make an insert that would have the ports, valve seat and threads for the cap. My buddy gave me a bad time about it but it all worked out well.


After some machine work and fettling here is the valve body ready to have the insert installed.


Here is a shot of the insert; you can see the ports and the valve seat on the edge of the flat land.


And a different view.


The insert was Loctited in place with high strength cylindrical bonder (609) also I always use the primer.


After the Loctite set the top of the insert was faced off flush with the bronze body.


Here is a shot of the valve; the original had the tapered top like this one does (at least the one I saw a photo of did).


The two remaining parts were the cap and the bob weight. The cap was designed to look like the one on the exhaust chest only smaller.


Here is a shot of the cap installed on the body.


And finally a couple shot of the completed valve assembly installed on the engine.



I’m very pleased with how it turned out; hopefully it will perform ok as well. I still need to make the copper sealing washers for both valve caps.

Now on to the gas and air hand cocks.


Thanks again for checking in and all the kind words.
Dave

[steamer]

Wow that is Gorgeous Dave!

Dave

[swilliams]

That's really turned out beautifully Dave

Steve

[Don1966]

That's really turned out beautifully Dave

Steve

What Steve said, I ilke..........

Don

[Jo]

  It does look rather nice. There is nothing wrong with having an insert for your ports and seats  .

Jo

[vcutajar]

What a beauty!!

Vince

[Kim]

Wow Dave!  That looks really nice! 

Kim

[smfr]

Very nice! That looks almost too good    The insert is a neat trick, too. 

Simon

[Tennessee Whiskey]

Magazine and museum quality stuff. I just dream of being able to replicate this level of craftsmanship.

Whiskey

[Dave Otto]

Wow thanks for all the kind words everyone; that means a lot to me.

Simon, the bronze oxidizes pretty fast so hopefully it wont look too nice for very long. No polish on this one; I want it to develop a nice patina; it will be painted though.


Dave

[Dave Otto]

Hi everyone,

The Pacific doesn’t have any type of mixer or carburetor just 3 hand cocks; one for air one for gas and the third acts as a throttle. Primitive I know but after all it was 1890.

Morrison and Marvin supply these beautiful bronze investment cast hand cocks. These are scaled directly from originals of the same period.

To properly make these valves there really is no getting around having to make some fixtures. I thought about this a lot (procrastinated) about how I was going to do it. Having access to rapid prototyping equipment at work I decided that I would like to try making some machining fixtures on the 3D printers.
So maybe part of this segment should be titled adventures in 3d printing.


Here are the valve castings from Morrison and Marvin. I did just a little fettling to remove the mold lines and then a trip through the bead blaster which restored the original finish.


Starting with the body castings; they were held in a hex collet and indicated in. Carefully the end was faced and center drilled. The main diameter was turned and a notch cut as a reference to where they would be cut off.


Here are the bodies ready for the next operation.


Flipped around and held in a collet the bore for the ID thread is opened up with a boring bar to maintain concentricity with the opposite end.


The 1/16” NPT or 5/16”MTP is taped using a guide in the tailstock.


After the bodies have been cut and faced to length the taper for the pipe thread is machined using a boring bar. Also the hole through the center will be drilled.


Here are the three bodies ready to have the threads milled. A couple of reasons for wanting to mill the threads; this something I have never done and will (hopefully) result in better threads than with using a die.


Here is my first printed fixture; this one done on a FDM machine (Fused Deposition Modeling) the most common 3d printer you see these days.


The assembled fixture in the mill ready to mill the threads. This type of fixture could also easily be used in a 4 jaw chuck.


I indicated each one in but surprisingly they were all within a couple thou of each other.


Here is an action shot of the thread milling operation.


With just a little tweaking I was getting an acceptable thread; I did run a couple of aluminum dummy parts to get it dialed in.


The three valve bodies ready for the next operation.

I kind of went overboard on the pictures so I will post more later.

Thanks for checking in,
Dave

[Don1966]

That's some awesome work Dave. I am getting more and more interested in those 3D printers.

Don

[swilliams]

Love it Dave. Great to see a bit about what some of this new technology can do

Steve

[Jo]

Those are rather nice lost wax castings 

Jo

[steamer]

I like that a lot Dave! ....you know, it's the first time I've seen NC thread milling in a home shop....plenty in industry mind you....and why not!....it does a great job!

Dave