Author Topic: Otto Langen internal combustion atmospheric engine  (Read 3718 times)

Offline Bjorn_B

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Re: Otto Langen internal combustion atmospheric engine
« Reply #15 on: October 31, 2017, 06:49:57 PM »
Wow, someday.. I have to try build one :) That is a very nice and strong engine it seems!

Offline Mcgyver

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Re: Otto Langen internal combustion atmospheric engine
« Reply #16 on: November 01, 2017, 12:02:56 AM »
that is a great looking project.  Whats with the black sidebars in the video?  I see them occasionally and was wondering

Offline Craig DeShong

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Re: Otto Langen internal combustion atmospheric engine
« Reply #17 on: November 01, 2017, 02:30:16 AM »
Thanks.  I took the video with my phone camera, thus the tall narrow profile.  I'm thinking the video players just fill their "normal" size frame with those black bars ?
Craig

Offline Craig DeShong

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Re: Otto Langen internal combustion atmospheric engine
« Reply #18 on: July 15, 2019, 06:42:16 PM »
I thought I might make this post to show some additional “tweaking” I’ve done on my Otto Langen model recently.

I’ve noticed while reviewing various threads folks have posted that some of the models have an annoying problem where the pawl taps the ratchet as the engine coasts. This results in an annoying chatter and probably introduces unneeded wear on the tips of the ratchet wheel and pawl. I’ve stated that my model hasn’t experienced this but, low and behold, at the shows where I took it this summer, it started exhibiting this phenomenon.  I got my thinking cap on and have devised a solution to this problem that works, at least on my model.

Fist, a little nomenclature; I’ll use a photo of the “idler shaft” on my engine.



In this photo you can see the idler gear and shaft, the two eccentrics and eccentric straps, the ratchet and pawl.  The two eccentrics and the ratchet and pawl fit on a hollow cylinder that rides on the idler shaft and I’m calling this the “yoke” for lack of a better name.  The flat piece of steel that attaches to the end of the yoke and carries the pawl around with it I’m calling the “pawl carrier”.

When my pawl started tapping on the ratchet I performed a very close inspection to see why this started occurring.  I noticed that the ratchet was releasing cleanly from the pawl, but then shortly afterward, the yoke was rotating slightly BACKWARDS on the idler shaft thus allowing the pawl to rotate back into the ratchet’s teeth.  Why this was happening I couldn’t determine.  I would have thought that the drag on the eccentric that controls the slide valve would prevent this backward rotation of the yoke, but it wasn’t. Maybe the parts were FINALLY worn in to where friction had minimized to the point where this could happen? Who knows?

I decided I needed a mechanism to prevent this backward rotation and I realized that if I captured the pawl carrier at its most forward position, not allowing it to rotate backward, I could accomplish this.


What I’ve done is change the shape of the end of the pawl carrier and I have added a spring loaded “lock” to the table.  These two parts work together to prevent the reverse rotation of the yoke.  The above photo shows this mechanism.  Mounted to the table on the far left is the lever that raises the piston, connected to its eccentric.  Immediately to the right is the other eccentric that controls movement of the slide valve.  To the right of that, mounted to the table, is the new spring loaded “lock” that denies the yoke reverse rotation at the point of pawl/ratchet release.  This is a lever hinged at the far end of the picture with a spring underneath that lifts the lever.  The recessed flat head screw you see in the foreground limits the distance the lever can be raised by the spring and is a height adjustment.    Again, to the left, mounted to the table is the release lever for the pawl.


Above you get a good view of the pawl and immediately behind it, the pawl carrier.  Notice the stop attached to the end of the pawl carrier that engages with the spring loaded lock shown above.


Above I’m showing the pawl and ratchet at release time.



Above, really hard to show the motion, but the yoke has made nearly a full rotation from the previous picture and the pawl carrier has depressed the lock bar and is about trip so it can’t rotate backwards.  The pawl and ratchet are still fully engaged.


Above, very hard to get a photo but the lock lever has moved up, stopping the yoke from reverse rotation and the pawl and ratchet are still engaged.


Another view


Above, the pawl and ratchet have dis-engaged and the engine is in its coasting cycle.

I got to tryout the “slow motion” feature of my phone camera and after numerous “tries” got this video of the action.  I think it shows the pawl and ratchet engaging and disengaging fairly well.  At speed, the mechanism has a very positive sounding “click” when the pawl carrier is arrested by its lock and the pawl disengages from ratchet.


While I was fiddling with the Otto Langen I though I’d address another issue.  I run my engine on acetylene and I was using a single standard torch regulator.  On the initial build I had included a fine needle adjustment to regulate the acetylene provided to the engine but I found this superfluous. 

Wayne Grenning (Wayne is THE authority on these non-compression engines) some-time back had suggested that I double regulate my fuel supply to get a more consistent fuel pressure and thus, more consistent fuel/air ratio.  I found myself diddling and diddling with the torch regulator through the day as the pressure fluctuated up and down by a half pound or so.  With this fluctuation, the engine is either hitting VERY hard or not firing at all. 
I had purchased a 6 to 9 inch water column regulator a while back so I decided to add that regulator between the torch regulator and the engine.  I also replaced the needle adjustment with (what I’ll call) a baffle: really just the delivery tube to the slide valve on the engine.  I’ve found I need to have several sizes of these, depending on- well I really don’t know.  I keep several of these tubes, drilled with a variety of diameter holes, and swap them out as required.  The hole diameter is stepped from .020 inches to .031 inches.  The most popular size I seem to use is .026 inches.  With the torch regulator set to around 5 PSI and the secondary regulator stepping the pressure down to around a 1/4 PSI I find the engine runs much more consistently over longer periods of time.  It will fire every cycle with very few misses but yet, fires hard enough so it can coast some, yet not so hard that it carbons up quickly.

Well, this is the latest with this engine.  I’m hoping those of you with Otto Langen engines facing some of these problems will find some value in what I’ve stated.
« Last Edit: July 15, 2019, 09:41:21 PM by Craig DeShong »
Craig