Author Topic: Crossley Otto Langen  (Read 8640 times)

Offline awake

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Re: Crossley Otto Langen
« Reply #150 on: January 29, 2020, 11:08:20 PM »
First start - that is surely going to be a tremendous feeling of accomplishment, after so much work!
Andy

Offline Craig DeShong

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Re: Crossley Otto Langen
« Reply #151 on: February 03, 2020, 10:41:07 PM »
Thanks for commenting Andy.  Thanks also for those of you that take the time to drop by.

Progress is moving along nicely with the model.  I have the governor installed with the bevel gears spinning it nicely.
Also, all the levers and what not required for the governor to operate the pawl/ratchet lock out/release have been made and installed.

Below is a short video of the governor locking out the pawl/ratchet from cycling and letting the engine take a power stroke.  When the flywheel RPM gets low enough, the mechanism is released. 
I’m holding “out” the “safety” that normally would be “out” were the piston at the bottom of the cylinder.  I have temporarily held the piston up because It is difficult to get the engine up to sufficient speed for the governor to lockout the mechanism when the piston is at the bottom of the stroke and the mechanism is cycling; repeatedly lifting the piston, trying to get the engine to fire.  Without fuel and spark that won’t happen. 

With all this progress you would think that the model were complete but there are still a few a few odds and ends to address; still an attempted “first run” should not be too far distant.
Craig

Offline Craig DeShong

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Re: Crossley Otto Langen
« Reply #152 on: February 06, 2020, 07:36:23 PM »

I thought I had some 7mm pattern wire to use to connect the sparkplug to the coil but apparently I don’t.  I sent an order off to Starbolt and it should be coming along in a week or two.

I also have decided that I want to attach a short, heavy coil spring to the bottom of the platform at the top of the cylinder to prevent an overcharge from driving the piston hard against the platform and possibly damaging the engine.  This engine has a much shorter stroke than my other Otto Langen, and it has occasionally suffered that problem. (I thought I’d get a spring for it too while I’m at it).

While waiting for delivery of these purchases I’ve turned my attention to adding some of the details this scale model needs.  I’ve been keen to do this because, quite frankly, as I’ve been building this model and looking at it; it appeared to have a touch of the “ugly duckling” syndrome.  I wouldn’t call the full size an attractive engine (as compared to other types) so you might expect the model to suffer the same condition.
A week or so ago I painted the engine and that has helped it aesthetic appeal a lot.  Now I’ve been adding some details and replacing the hardware store nuts with brass model nuts; a little bright work always helps.  I’m quite pleased with the results.  I won’t say the “ugly duckling” has turned into the “swan”, but I believe the model has gained quite a bit aesthetically.




Craig

Offline Johnmcc69

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Re: Crossley Otto Langen
« Reply #153 on: February 06, 2020, 08:26:28 PM »
 :ThumbsUp:
 Looks great Craig! I like the black with the brass hardware.
 Nice job!

 John

Offline awake

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Re: Crossley Otto Langen
« Reply #154 on: February 06, 2020, 09:11:39 PM »
Urgh - I can't see the latest pictures. :( I'm not sure why, but sometimes they show up fine, and sometimes not.

On edit - the pictures show up fine on Tapatalk - and it looks great!
« Last Edit: February 06, 2020, 09:48:55 PM by awake »
Andy

Offline zeeprogrammer

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Re: Crossley Otto Langen
« Reply #155 on: February 06, 2020, 10:52:12 PM »
Very good looking! The changes are good.  :ThumbsUp:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Craig DeShong

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Re: Crossley Otto Langen
« Reply #156 on: February 13, 2020, 11:47:54 PM »
John, Andy, and Zee; thanks for commenting.  Thanks also for those of you who stop by to see the latest.

It’s time to think about the electricals.  The full size uses flame ignition, but at this models size flame ignition isn’t possible so I’m using spark ignition.  With acetylene the fuel, I prefer a longer spark that a simple pulse magneto would give so, as I did on my first Otto Langen, I’m using a “buzz box”.

Rather than buy one, they are relatively inexpensive and easy to make.  The design I’m using has been floating around on the Internet for a while.  Below is the schematic.



The heart of the electrics is a 5-pin, 12 volt relay as you’d find in auto applications.  You can pick these up (along with the socket) on eBay for under ten dollars.  The thigh-tension coil (on eBay) will run another ten to twenty, depending on how lucky you are; so the “buzz box” is pretty cheap to make.  I was worried about burning out the relay points so I bought a handful of them back when I built my first Otto Langen.  It’s run many hours and I’m still on the original relay so burning up the relay appears to be a non-issue.
Here is a photo of a 5-pin relay.



And following is a photo of the “buzz box” in action.  As you can see, you get a good strong, continuous spark.
Craig

Offline Craig DeShong

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Re: Crossley Otto Langen
« Reply #157 on: February 17, 2020, 10:05:34 PM »
Thanks for stopping by to see the progress and I have some great progress to report: :pinkelephant: It’s running…. well, sort of.

I tried starting the model for the first time a few days ago and, unlike my first Otto Langen (which showed no signs of life for about a year), this one was firing immediately.  Mechanically, everything seems to be working as designed; all the mechanics cycle admirably.  Unfortunately at first it’s operation was so lethargic it couldn’t sustain running.

I’m using a “restrictor pipe” to control the amount of fuel the engine can draw and I immediately assumed it needed more fuel so I commenced drilling out the “restrictor pipe” and running the engine, hoping to see improvement.  It didn’t show any improvement so I continued to do this till the thing was blowing black soot out the exhaust, obviously I was going the wrong way.

I made a few new restrictor pipes since then, going from .025 inch diameter down to .020 inch diameter with marginal improvement.  I also removed one of the rings from the piston (with carbon in the cylinder, the piston was having a hard time settling to the bottom of the cylinder); and I’ve also increased the lift distance of the piston; increasing the amount of fuel/air the engine uses per stroke.

At this point the engine is sustaining running fairly well, but it still doesn’t “hit” hard enough to get up to speed where the governor will kick in and limit the power cycles.  Sporadically something funky is also going on with the valve cycle because it occasionally blows a bit of flame out the air inlet (kind-of exciting when that happens)

The engine is still running too rich: after several hours of fooling with it the cylinder is carboned-up where it really won’t run anymore, so cleaning is in order.  This is a clear indication the fuel/air mixture is too rich.  I’m using 1/4 PSI of acetylene pressure and a .020 diameter restrictor pipe; these things really sip fuel, probably leaking away more than they use.  I have a .015 inch diameter drill on order and when it comes I’ll make a new restrictor pipe and see if I can lean it out enough to get it to fire with enough power to get the speed up where the governor will kick in.  That could easily “fix” the flaming valve situation, when I get the engine to take a good long stroke so everything has time to cycle before the piston is at the bottom of the cylinder and tripping the pawl/ratchet for a new cycle before it even has a chance to come fully around yet.

All in all, I’m pretty pleased with the progress.  I didn’t expect this thing to run well right off and I’m delighted it’s doing as well as it is already.  Some “tinkering” and adjusting is to be expected.

With my first Otto Langen I made at least a half dozen videos of it, a new one every time I got it running a bit better.  With this model I’m thinking I’d like to get it running at least near right before I make a video of it for you to see so stay tuned and maybe success is just around the corner.
Craig

Online MJM460

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Re: Crossley Otto Langen
« Reply #158 on: February 17, 2020, 10:23:47 PM »
Hi Craig, that all sounds most encouraging.  Testament to your care and excellent workmanship in getting to this stage.  It has been a fascinating journey to follow. 

I hope that remaining little step or steps are not too far away.

MJM460
The more I learn, the more I find that I still have to learn!

Offline awake

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Re: Crossley Otto Langen
« Reply #159 on: February 17, 2020, 11:03:18 PM »
Exciting! I'm eager to see it run!

Sent from my Lenovo TB-8504F using Tapatalk

Andy

Offline Johnmcc69

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Re: Crossley Otto Langen
« Reply #160 on: February 18, 2020, 01:10:10 AM »
 :ThumbsUp:
 :popcorn:
 John

Offline Alyn Foundry

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Re: Crossley Otto Langen
« Reply #161 on: February 18, 2020, 11:19:18 AM »
Hi Craig.

Your description of the " lethargic " combustion and soot definitely point to an overly rich mixture.

After a thorough clean may I suggest trying to use Propane? You might find that this particular model takes more kindly to it.

Another thought would be passing the incoming air through a Petrol/Gasoline " bubbler " and ignighting the vapour. This is something I did many years ago to run my little Leek atmospheric engine on. I used a trembler coil and plug in the same fashion.

Whatever the outcome, I'm eagerly awaiting the video.

Cheers Graham.