Author Topic: 3rd Generation Otto Langen  (Read 4745 times)

Offline Craig DeShong

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Re: 3rd Generation Otto Langen
« Reply #60 on: October 20, 2020, 08:20:07 PM »
Thanks for the replies Don and MJM.  Thanks also for those just stopping by to see the latest update.

Iíve been so lackadaisical this last week with my posts, I thought Iíd be a ďgood boyĒ and be a bit more prompt with the updates; at least for a while. 8)

Today was spent working on the tubing to get fuel and air into the engine, and exhaust gasses out.  In the below photo you see the air and acetylene intake tubing.  The acetylene tubing is, in reality, a solid cylinder that Iíve drilled out.  It has a restrictor at one end that is drilled to .025 thousandths of an inch.  Iím thinking this might be a bit too narrow, but Iíll start there and go up if needed.



Things get more interesting on the exhaust side.  The exhaust needs a one way check valve in order for the engine to operate correctly.  This is because the slide valve returns to the ďneutralĒ position, where the exhaust port is opened to the cylinder, before the piston has been driven down toward the bottom of the cylinder by atmospheric pressure.  Without the check valve, air would just rush into the cylinder and the engine wouldnít get all the power out of the atmospheric pressure it would otherwise. 

The full size Otto Langen engines use a ball valve and Iíve designed this little valve to function likewise.  The full size has an oval casting with internal passages; something I really canít duplicate by machining.   



Hereís a photo of the completed valve and tubing, ready for application of the flexible acetylene delivery tubing. 



I just couldnít resist making some kind of builders plate for the model.  I just made up a patent number.  Itíll be interesting to see if someone notices.

Craig

Offline Craig DeShong

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Re: 3rd Generation Otto Langen
« Reply #61 on: October 23, 2020, 11:58:50 PM »
Thanks for stopping by to see the latest.

Lots of odds and ends consumed the day yesterday, getting ready to try the first run of this model.  I was ready for an attempt by late in the day; but I decided to wait till the morning today so I would have time to work out any lingering problems; lucky I did because there were a few.

This morning I turned on the acetylene and switched on the ignition.  After pulling the flywheel through a few ďdeadĒ cycles to allow the gas to reach the engine I was rewarded with a rather robust, first fire, a bit larger than I expected.  Everything worked as it should on this first cycle; the ratchet and pawl cycled the valve, the upward motion of the piston was arrested by atmospheric pressure and was driven back down where the clutch engaged and spun up then flywheel.   I was surprised at how quickly the flywheel spun up; I would have thought itís mass would have required several cycles.

Things didnít go so well on the next cycle.  The ratchet and pawl engaged enough to lift the piston a bit and open the slide valve, thus pumping fuel into the engine cylinder; but the pawl and ratchet slipped and the valve motion stalled there.  As the ratchet and pawl stuttered and the slide valve remained open it began to dawn on me that all that fuel being emitted into the cylinder wasnít the best :o situation.  About the time that I realized that I needed to cut the ignition before the engine fired, the pawl and ratchet finally engaged, carried the mechanism around and closed the ignition circuit.  ÖBAM!... :o

You might remember me stating that while at a show a few years ago I inadvertently did something to overcharge the cylinder of my first generation Otto Langen model.  The resulting explosion damaged the model.  While effecting repairs I decided to install a heavy spring at the top of the cylinder to gently arrest the piston motion were this to re-occur.  I installed a spring in the Crossley and I did so in this model.  So even though I had a serious over-charge situation this morning, the spring did its job and no damage to the model occurred.

I spent the morning changing the attack angles on the pawl and ratchet; thus ensuring a more positive latch-up when the engine is at speed, and I made a new restrictor pipe for the fuel intake; thus further limiting the amount of fuel available to the engine during a normal cycle.

With these adjustments and a few more I have the ungoverned engine running fairly well.  This engine hits harder than my 1st generation model, but I want it to do so, because I want it to rapidly get up to speed where the governor will allow it to coast a while, so a power cycle needs to provide the energy to do so.

At this point, the engine is firing well.  It just runs away if I let it.  Once I get the governor fully installed Iím expecting that it will regulate the speed.

The below video isnít the first run, but itís the first Iím willing to show you.
Craig

Offline crueby

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Re: 3rd Generation Otto Langen
« Reply #62 on: October 24, 2020, 12:09:27 AM »
That is fascinating to watch!

When the governor is in place, does it work sort of like a hit/miss where it keeps it from firing only, or can it prevent fuel being drawn in too? 

EDIT: hmmm, never thought about it on hit/miss engines either, do they still draw in fuel on the miss cycles?
« Last Edit: October 24, 2020, 12:19:57 AM by crueby »

Offline awake

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Re: 3rd Generation Otto Langen
« Reply #63 on: October 24, 2020, 12:18:58 AM »
Looking good, Craig! Glad you didn't blow up the model ... or the shop!
Andy

Offline Dave Otto

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Re: 3rd Generation Otto Langen
« Reply #64 on: October 24, 2020, 01:28:18 AM »
Congratulations on the first pops Craig.

Dave

Online Kim

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Re: 3rd Generation Otto Langen
« Reply #65 on: October 24, 2020, 06:32:44 AM »
That's really cool, Craig!  :cartwheel:

Kim

Online Jo

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Re: 3rd Generation Otto Langen
« Reply #66 on: October 24, 2020, 08:26:51 AM »
 :whoohoo:

Well done Craig

Jo &  :pinkelephant:
Enjoyment is more important than achievement.

Offline scc

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Re: 3rd Generation Otto Langen
« Reply #67 on: October 24, 2020, 10:32:48 AM »
Very impressive Craig, Well Done. :ThumbsUp:         Terry

Offline Ramon

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Re: 3rd Generation Otto Langen
« Reply #68 on: October 24, 2020, 10:38:48 AM »
I confess I haven't followed your build Craig but you are to be congratulated on a superb model and a fine runner to boot - bet you've got a good grin on  :ThumbsUp: :ThumbsUp:

Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline kvom

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Re: 3rd Generation Otto Langen
« Reply #69 on: October 24, 2020, 12:30:27 PM »
If there's no 4th generation, what are you going to do next?   :cheers: :stir:

Great action on the engine.  Mesmerizing to look at.   :ThumbsUp:

Offline MJM460

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Re: 3rd Generation Otto Langen
« Reply #70 on: October 24, 2020, 12:47:15 PM »
Well done on another runner Craig.  Great to see it in action.

Having achieved that must really be encouraging as you continue getting the governor running.

MJM460

The more I learn, the more I find that I still have to learn!

Offline ShopShoe

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Re: 3rd Generation Otto Langen
« Reply #71 on: October 24, 2020, 01:27:16 PM »
Fantastic.

You must have been holding your mouth right for that to work so well so early.

I am intrigued by this build and can't wait for the updates.

ShopShoe

Online propforward

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Re: 3rd Generation Otto Langen
« Reply #72 on: October 24, 2020, 02:25:39 PM »
Superb - a mesmerizing engine to watch! Thoroughly enjoyed that.

 :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp:
Stuart

Offline Craig DeShong

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Re: 3rd Generation Otto Langen
« Reply #73 on: October 24, 2020, 09:16:04 PM »
Chris, Andy, Dave, Kim, Jo, Terry, Ramon, Kirk, MJM, Stuart, and Shopshoe; thanks ever so much for the comments and compliments.  Thanks also to those silently stopping by to see the progress.

Chris: Iím not THE authority on hit-and-miss though Iíll take a good stab at your question.  Hit-and-miss engines are named such, because their speed is controlled by denying them every possible power stroke.  A governing mechanism forces them to coast through one or more cycles until their speed is reduced to the degree where the governor allows them to take enough power strokes to where the governor will again limit the power strokes taken.  Once these engines are ďhittingĒ on every power cycle; further loading them will just result in them being overloaded and eventually stopping. There is no throttle.

The method usually used to deny the engine power strokes is to hold the exhaust valve open.  Most of these engines have an ďatmosphericĒ intake valve not controlled by a pushrod, just the vacuum created in the cylinder during the intake stroke opens the intake valve to allow air and fuel to be drawn into the cylinder.  With the exhaust valve open, it is doubtful any appreciable amount of fuel or air can be drawn in through the intake valve.

There appears to be more mechanical ways devised for a governor to hold the exhaust valve open than you can imagine.  Every manufacturer seems to have had their individual method.  I was told some time ago that this was due to patents and the fear of patent infringements. 

Not all hit-and-miss engines have their speed regulated by holding the exhaust valve open.   The 15 HP Witte I just modeled has its speed controlled by eliminating fuel from the input when the engine speed is to be reduced. With this method the engine goes through all the cycles it normally would; there just isnít any fuel in the cylinder to combust.

Even the two cycle Maytag washing machine engines of the 1930ís and 40ís are, technically, hit-and miss engines.  Their speed is regulated by shorting out the ignition circuit to limit the engine speed. 

This treatise could go on and on; but Iíve probably bored everyone enough and  hope Iíve answered your question.

To answer your question regarding the Otto Langen; when at speed and governor controlled, the engine coasts with the mainshaft turning my inertia of the flywheel.  All other mechanisms are at rest.  The fly ball governor keeps the pawl and ratchet from engaging, thus the piston is not lifted and the valve does not cycle to emit fuel into the cylinder. 
What I fail to discuss in the following video is this governor control (I havenít built it yet) but with a governor installed, another lever prevents the pawl and ratchet from engaging.  Thus with a governor two conditions must be met for the engine to take a power cycle.
First: the piston must be at the bottom of the cylinder (this prevents overcharging of the cylinder)
Second: the governor must be running slow enough to allow the pawl to engage the ratchet and cause an other cycle to be taken.

Craig

Offline crueby

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Re: 3rd Generation Otto Langen
« Reply #74 on: October 24, 2020, 09:34:15 PM »
Great descriptions, thanks!!!