large vacuum engine

[Michael S.]

Hello,

I started building a vacuum engine. There is a construction plan and the motor has a bore of 50mm and a stroke of 90mm. I've never built an engine like this before.
I discovered on the Internet that there is a dealer in Luxembourg, rc -machines, that offers a few castings that fit the engine well. They aren't that expensive either.
I bought the flywheels at an exhibition. One of them is already painted red and the other is still rusty. But already edited. As a cylinder I use a pipe from the plumbing store. In 2 inches.

I'll start with the crankshaft bearings.
All castings have already been partially milled by the dealer. The cast iron is easy to work with.
The bearings are split and I would like to use these finished bronze bearing bushes.
Oilers with lids are placed on top of the bearings. I think that fits quite well.

The crankshaft has a diameter of 14 mm and is adapted to the bore of the flywheels (12 mm).

The beginning has been made

Michael

[bent]

That is a nice looking set of castings.  And an interesting (to me) pipe nipple - it looks as if it has been continuously cast in a bronze alloy before having the threads machined?  My wife did some research and modelling of continuous castings for the Olin Corporation before upping her game and becoming a stay-home mom.  Looks like a fun project, Michael! 

[Michael S.]

The crankshaft is made of 14 mm silver steel.
For the crank webs, I glued two pieces of steel together with Loctite and machined them together on the milling machine.
For safety, the shaft is also secured with small pins.
Since the crank has a large stroke, I thought it would be positive to install counterweights there for smooth running.
I'm quite happy with the result.

Greetings Michael

[Michael S.]

Hello Bent,

yes, the pipe nipple is made of bronze/gunmetal.
Inside it's pretty well rounded. But has an inner diameter of about 50.50 mm.
After processing it will definitely be 51 to 52 mm.
The challenge is clamping on the lathe. I have similar problems to Chris with his cylinders.

Greetings Michael

[Roger B]

Looks to be a fun project  RC sometimes has some interesting castings 

I find my Keats angle plate good for holding slightly strange shapes.

[crueby]

Looks like a fun build - following along here!
 

[Michael S.]

The last casting part is the holder for the cylinder.
There is already a hole of 50.00 mm but I need 60.00 mm.
The milling machine was used to drill out and all the other holes were made straight away.
All other work must be done without castings. I will now prime the castings with paint and then paint them red. That's fitting for a flame eater.

Michael


<a href="https://www.youtube.com/watch?v=F8ikEPygi-A" target="_blank">http://www.youtube.com/watch?v=F8ikEPygi-A</a>

[crueby]

Great start on the parts. Those flywheels are perfect for this engine.   

[Kim]

That's a pretty good sized engine, Michael!  Looking forward to watching you work on this one 

Kim

[cnr6400]

 

[Davyboy]

Great work so far on some good looking castings.  I love the photos, keep them coming.  This engine has some interesting design features, such as the head and valve arrangement.  I would like to see more details on that. 
Davyboy

[Michael S.]

I started with the cylinder barrel. This 2 inch piece of pipe with the threads on the ends doesn't make it easy to work with. But still better than drilling out a piece of bronze or cast iron.
A threaded part from the scrap box forms the flange. And it was first turned to size on the lathe. Then clamped around and turned a small section round. For a second flange.
Drilling out the inside was very adventurous and stressful. But since the material is very soft and I only had to remove a few tenths of a millimeter, the rest could be done with sandpaper.
I now have a bore of 52.35 mm in the front and rear of the cylinder. I think the surface is sufficiently smooth.

Michael

[Michael S.]

A brass ring was made with screws. And a connection piece for the oiler for the piston.
Then everything was softly soldered.
So that the 2 inch thread disappears at the front end, I turned a 2 inch sleeve as a ring and this now forms the end. With a connection for excess oil from the cylinder. There is a circumferential groove at the front end.

Michael

[crueby]

Impressive set of parts!  Following along, great build!
 

[Michael S.]

The cylinder head is finished. It is written in the building plan that it should be made of cast iron. I would have had to order such a large piece first. But I had a piece made of aluminum.
I hope that will work too.
(If the thing doesn't run, it becomes a steam engine.)
Milled the slot for the flame and opposite a hole for the outlet valve.
There is also a cast iron plate on the intake slot.

Michael