Otto-Langen Atmospheric Engine

The first internal combustion engine.
Used atmospheric pressure to perform the work.

Otto-Langen Atmospheric engine

Nikolaus August Otto is the father of the "Otto Cycle" of almost all modern internal combustion engines.  In the Otto cycle 4 strokes of the piston occur to complete the cycle.
- Intake
    As the piston goes down, the intake valve opens and allows fuel and air to be drawn into the cylinder.
- Compression
    Once the piston is at the bottom of the stroke, the intake valve closes and the piston begins to move up, compressing the mixture.
- Power
    When the piston reaches the top of the cylinder, an ignition source is introduced to the mixture.  This ignition source can be spark, flame, hot tube, etc.  This ignites the mixture and it begins to rapidly expand driving the piston back down.
- Exhaust
    Once the piston is at the bottom of the stroke it begins back up pushing the now spend mixture out the exhaust valve.


There are several great articles about Nikolas Otto on the internet but suffice to say, he defended his patent on this cycle very vigorously.

This engine was the first internal combustion that he built.  While partnered with Eugen Langen in 1867, he devised the "Atmospheric Engine".  This engine used the power of combustion to drive the piston that is connected to a rack, up.  The cooling, condensing combustion gasses pull the piston back down.  While the piston is descending, a one way bearing engages inside the gear to the rear of the piston rack, this is what powers the flywheel.


I didn't get too many shots while I was building this engine.  However, most people are more intrigued by the column and I did get shots of that.  I started with a 4" X 11" bar of leadloy.  I did all of the turning and boring, then went to the mill.  Boring a hole that deep was a challenge without having the bar chatter.



I mounted the column into the index head for the milling part.  Notice the aluminum plug in the center end of the column in the top.  That has a tapped hole in the bottom and I have a piece of all thread running down through the chuck and out the back.  This is helping to keep the whole package together since the chuck jaws are only about a 1/2" deep.  It worked out great.  The panels on the bottom were pretty straight forward.  The flutes on the column however, were tedious.  The column is tapered so I had to kick the tailstock up a bit then cut those flutes.  A couple passes with a 1/16" carbide ball mill then switch to the 3/32" carbide ball mill.  The bottom shot is the column almost done.  While I think of it, leadloy rusts very easily.  I've been wiping those parts down with "Breakfree CLP".  It really seems to help keep the rust down.



Cutting the gears, then a shot of what was completed by this point.



Cutting the exhaust valve cover was another challenge.  I don't have a ball turner so I had to improvise a bit.  The cover is 7/16" radius so I found a piece of 7/8" round stock and used that as a pattern.  Using an indicator on the bar I traced it while feeding the cutter.



The flywheel wasn't too much of a challenge except it was the same size as my rotary table.  That made clamping a challenge.


I have one video so far.  The engine is running for the first time.  There are some leaks causing it to run fast.  I just wanted to get it to run.