Author Topic: 1867 Otto and Langen Free Piston Engine  (Read 34048 times)

Offline Craig DeShong

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Re: 1867 Otto and Langen Free Piston Engine
« Reply #150 on: October 05, 2018, 01:51:47 AM »
An additional note I'll add.  My engine has a steel piston, pretty heavy because it's nearly solid.  It has two rings.

After the engine runs a few hours ( I take it to shows and I'll start it and it will run nearly all day), it seems to acquire a carbon build-up near the bottom of the cylinder.  The piston will settle on the top of this ring and will not sink to the bottom of the cylinder so the cycle can repeat.

If I open the exhaust, letting the piston settle faster, it will sink through this build-up, but then it runs too fast with the result that the pawl/ratchet starts to stutter.

Time to dis assemble and clean.

Craig

Offline Bjorn_B

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Re: 1867 Otto and Langen Free Piston Engine
« Reply #151 on: January 05, 2019, 06:40:36 PM »
This thread made me interested and I just had to see if I could at least to some degree replicate what Max has done. This is the result, as others I have some issues with the pawl mechanism, the plans are not very clear on the details of this. it runs on acetylene generated with calcium carbide/water into a bag accumulator (no pressure at all). Took me a year to complete..

Offline Dave Otto

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Re: 1867 Otto and Langen Free Piston Engine
« Reply #152 on: January 05, 2019, 07:18:43 PM »
Congratulations Bjorn, you have done a beautiful job on your Otto!

Its interesting that your engine has the same little issue with the pawl dragging on the ratchet wheel. Max has tried many different things to keep this from happening with out much luck.
What works the best is to keep the speed down, when the engine speeds up the dragging gets worse. If the engine is running slow it doesn't drag at all; but as the engine warms up it is hard to keep the speed down, most likely due to leakage by the piston.
If you come up with a solution please let us know.

Nice work!

Dave

Offline fumopuc

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Re: 1867 Otto and Langen Free Piston Engine
« Reply #153 on: January 05, 2019, 08:19:33 PM »
Hi Bjorn, fantastic, a nice runner, congratulations.
Kind Regards
Achim

Offline Craig DeShong

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Re: 1867 Otto and Langen Free Piston Engine
« Reply #154 on: January 06, 2019, 12:10:25 AM »
Nice job with your Otto Langen.  It runs really well.

When I first got mine running, the ratchet and pawl also drug.  After a lot of fooling around I’ve pretty much eliminated this.  Unless the model is running faster that I like to run it, the mechanism usually doesn’t drag.  I’ve attached a video of the mechanism I built onto the “release” lever.  If you observe the video closely you’ll see that the spring loaded mechanism on the slide compresses up against the stop before the ratchet/pawl releases.  Once the release takes place, the spring on the slide mechanism unloads, rocking the pawl free from the ratchet.  This little bit of extra rotation of the pawl helps it clear the ratchet.

Craig