1867 Otto Langen Engine

[raveney]

Hello All,

Wanted to share some pictures and videos of a very interesting and unique internal combustion engine that I built several years ago. There are several members that have built this engine already and their information was extremely helpful.

A lot of information exists on the web, but I recall that it is credited as the first "commercially successful" internal combustion engine. Mr. Otto is the same as Thermodynamics uses in the Otto cycle. The engine has a distinctive Victorian beauty and steam punk vibe to it as it runs. I built mine to be run off self generating acetylene and battery operated spark ignition.

All parts were fabricated individually from bar stock except for the ignition, gearing and clutch. It was extremely challenging to make the cylinder consistent as it is an approximately 9-1/2" bore and I have cheap imported benchtop equipment. I line bored it and added the top and bottom parts afterwards.

 

[kvom]

A beauty and a great runner

 

[minh-thanh]

A great project, Runs great !!

 

[Sprocket]

Carbide for the acetylene generator? I used to have a carbide lamp for caving. didn't burn as clean as your motor.
Doug

 

[GreenTwin]

That does have a fantastic look and vibe to it as it runs.
Most impressive !

Edit:
Now if I could just figure out exactly what it is doing.

.

 

[wce4]

Never seen or heard of such engine. Very impressive, thank you for posting.

 

[raveney]

A beauty and a great runner

thank you,
it is speed regulated by adjusting the small exhaust valve at the bottom where fuel is connected. Also need to control the water drip rate on the acetylene generator

 

[raveney]

A great project, Runs great !!

thank you,
it took around a year to build and I really enjoyed it. Largest flywheel I ever made and the taper flutes were also a first time evolution.

 

[raveney]

Carbide for the acetylene generator? I used to have a carbide lamp for caving. didn't burn as clean as your motor.
Doug

I found a 1 lb. can of calcium carbide pellets online. I was told about this by two old timers at work who remembered using it for racoon hunting lights and when helping their dads do oxy/acetylene welding. Doing it this way added a cool feature and also eliminated the regulator. I still have a bunch of pictures that I will post showing some of the construction. Below is an image of the flame testing while I sorted out the flow rates. The test tubes are used as a flashback feature, sediment/moisture trap (SS wool) and also visually indicate flow (bubbling in the water filled one)

Thank you for your interest

 

[raveney]

That does have a fantastic look and vibe to it as it runs.
Most impressive !

Edit:
Now if I could just figure out exactly what it is doing.

.

Thank you
It is one of my favorite engines. The power stroke occurs as the piston and rack descend downwards with gravity and the cooling of the exploded gases providing the motive force. I will post more pictures of the build and some explanation of how I interpret the functionality

 

[raveney]

Never seen or heard of such engine. Very impressive, thank you for posting.

Thank you,

Cool Springs museum has an impressive collection of restored engines and their members have built full size versions as well as scale replicas

 

[GreenTwin]

I purchased several carbide lamps back when I use to go caving.
They work extremely well in caves due to the very wide angle of light, and the even illumination across that angle.

The LED headlamps at that time generally provided a much more narrow beam of light that was too bright at the center, and required you to turn your head a lot to see what was around you.

The residue can be neutralized I think with baking soda (I think it is caustic).

They used these lamps on bicycles, motorcycles, and I think early automobiles too.

Not my photos.
They work really well in a cave, and are very controllable.
Gives off a natural golden light color like sunlight, unlike some of the LED's which don't have a very good color temperature.
I still have mine.

.

 

[raveney]

Cylinder Core

Boring the cylinder pushed the limits of my benchtop lathe. I started by making a pair of fixtures similar to traveling steadies that would bolt to the t-slots on the cross slide and hold the round bar to enable drilling and line boring. I didn't own a welder or have large part brazing capabilities at the time. Best I could come up with was several cast iron butterfly valve bodies at the scrap yard which served the purpose nicely. 1/4-20 bolts and jam nuts hold the cylinder blank solidly and semi-accurately.

Start by center drilling each end, align to a dead center in the headstock and tailstock.

Drill each end up to 7/8". Accuracy isn't super critical at this point. Both inner and outer diameters will be refined to be concentric and colinear later.

I chose to use a 2-1/2" 1214L free machining steel round bar and add the aluminum capital and pedestal later. This minimized material waste/time and also reduced the possibility of scrapping a perfectly bored cylinder because of an error making the pedestal.

Make a boring bar with enough travel to traverse twice the boring length. I started with a 7/8" bar and swapped to a 1" bar as I got closer to the final dimension to reduce chatter and improve finish. The bars use a 3/16 HSS round blank held in place with a 6-32 set screw and adjusted outward by an 8-32 screw. I drilled at a 45 degree angle to keep the cross-sectional material best possible. Unfortunately the cutting action takes place midspan where the bending stress and deflection is highest. Slow speed, lots of oil and blowing air while cutting. Used diving weights, lead shot inside mesh bags, to deaden the vibration. Line bored up to 1.125" and made an aluminum internal lapping bar to finish to size 1.126"

Then make centering mandrels so the part can be turned to make the outer profile. I offset the tailstock to turn the (long to me) taper.

The final operation on the cylinder core assembly is to add the fluting. The column is tapered and the depth needs to be consistent so set up using an adjustable tailstock and rotary table. After having so much effort invested in a part, this difficult operation seems frivolous but it is extremely worth it when completed. I did a lot of maths to come up with the number of flutes and the depth of the ball end mill. Also use the x-travel stops so the start/stopping is consistent. I believe the cylinder was the hardest part of the build by far but really gives the engine that Victorian appearance. The original would have been a casting and probably cosmetics were over the top because of the Paris Exposition where the engine debuted. Later versions eliminated the fancy fluting to save costs and make the product more commercially viable.

 

[a41capt]

Cylinder Core

Boring the cylinder pushed the limits of my benchtop lathe. I started by making a pair of fixtures similar to traveling steadies that would bolt to the t-slots on the cross slide and hold the round bar to enable drilling and line boring. I didn't own a welder or have large part brazing capabilities at the time. Best I could come up with was several cast iron butterfly valve bodies at the scrap yard which served the purpose nicely. 1/4-20 bolts and jam nuts hold the cylinder blank solidly and semi-accurately.

Start by center drilling each end, align to a dead center in the headstock and tailstock.

Drill each end up to 7/8". Accuracy isn't super critical at this point. Both inner and outer diameters will be refined to be concentric and colinear later.
View attachment 152232
I chose to use a 2-1/2" 1214L free machining steel round bar and add the aluminum capital and pedestal later. This minimized material waste/time and also reduced the possibility of scrapping a perfectly bored cylinder because of an error making the pedestal.
View attachment 152230
Make a boring bar with enough travel to traverse twice the boring length. I started with a 7/8" bar and swapped to a 1" bar as I got closer to the final dimension to reduce chatter and improve finish. The bars use a 3/16 HSS round blank held in place with a 6-32 set screw and adjusted outward by an 8-32 screw. I drilled at a 45 degree angle to keep the cross-sectional material best possible. Unfortunately the cutting action takes place midspan where the bending stress and deflection is highest. Slow speed, lots of oil and blowing air while cutting. Used diving weights, lead shot inside mesh bags, to deaden the vibration. Line bored up to 1.125" and made an aluminum internal lapping bar to finish to size 1.126"
View attachment 152233

Then make centering mandrels so the part can be turned to make the outer profile. I offset the tailstock to turn the (long to me) taper.

View attachment 152234View attachment 152235
The final operation on the cylinder core assembly is to add the fluting. The column is tapered and the depth needs to be consistent so set up using an adjustable tailstock and rotary table. After having so much effort invested in a part, this difficult operation seems frivolous but it is extremely worth it when completed. I did a lot of maths to come up with the number of flutes and the depth of the ball end mill. Also use the x-travel stops so the start/stopping is consistent. I believe the cylinder was the hardest part of the build by far but really gives the engine that Victorian appearance. The original would have been a casting and probably cosmetics were over the top because of the Paris Exposition where the engine debuted. Later versions eliminated the fancy fluting to save costs and make the product more commercially viable.
View attachment 152236

Very nice piece of work. Quite a big investment in time and energy not only performing the work, but also building the setups. I look forward to following your progress and seeing its first “pop”!

John W

 

[DKGrimm]

I love this engine. Here's some construction pictures from my build in 2006. Cylinder is cast iron, drilled and reamed and lapped to size. Still take it to every engine show.

 

[raveney]

That looks great DKGrimm,

Looks like you had a bigger lathe and a very rigid reamer for the cylinder bore. Also see that you cut the rack yourself. I couldn't figure out the setup for that so I had purchased it and all the other gearing. I needed to make my own centers and hubs. Some tweaks were made to the shaft support centers to keep the piston on center.

What fuel and ignition do you use?

 

[raveney]

Cylinder

Ordered some large 6061 aluminum blanks for the separate pedestal and capital. Seemed like it was taking forever with my small benchtop WEN bandsaw to cut the parts so I tried making a lazy man's self cutting feature. Bungee cord and wood clamp on the trigger.

Seemed to work but blades break a lot faster using this method. I imagine the "K" spring rate changes force as the cut progresses. Good reason why real bandsaws don't do it this way. Wish I had more room for a bigger bandsaw, but this tool works okay and blades are plentiful and inexpensive online. I use a waxing compound in a stick instead of oil or kerosene.



The rough blanks were then bored for a sliding fit onto the cylinder core and epoxied in place. Then we profiled the capital on the lathe using a round nosed HSS blank tool and radius gauges. Purely cosmetic feature, but very visible when the model is completed. While it was held in the lathe, we rough turned the pedestal to take advantage of auto feed and speedy material removal.



Then set the part on the mill table between centers and faced the octagon shape. This was only the second time I ever needed to angle the head of the mill. I used a shop-made fly-cutter as shown.



I remember thinking and planning an awful lot about the next feature before going ahead and doing the raised panels. So much time and effort invested and a very small endmill used to trace these panels eight times. I indicated each face level each rotation to be sure I didn't BOZO it up. This is why I came up with the idea of Y-axis table stops for this mill. See the post under tool modifications (G0704 table stops) for them. They come in very handy for accurate repeatability.

It all went smoothly though and all traces of machining erased with a gray abrasive pad and some elbow "grease."

 

[DKGrimm]

That looks great DKGrimm,

Looks like you had a bigger lathe and a very rigid reamer for the cylinder bore. Also see that you cut the rack yourself. I couldn't figure out the setup for that so I had purchased it and all the other gearing. I needed to make my own centers and hubs. Some tweaks were made to the shaft support centers to keep the piston on center.

What fuel and ignition do you use?

Thanks for your comments, raveney. The story of the reamer is that I originally set up with a double-length boring bar between centers in the lathe to bore the cylinder, but I just could not get it to quit chattering, so I mad and ordered the reamer. Then I lapped the cylinder to make it absolutely round with no taper, and to get a good surface finish. The piston was sized to fit.

The rack was made using the lathe as a horizontal mill (as shown in the picture). I did not have DRO on the lathe, but I rigged up a digital caliper on the X-axis for tooth spacing. I set up the fixture in the picture to only cut a few teeth at a time (for rigidity) so had to re-indicate the setup every time I moved the rack in the fixture. I got lucky and made a good rack the first try.

One of the biggest problems I had was to align the upper rack guide with the cylinder center line. The slightest offset would cock and bind the piston in the bore, and it would not free-fall on exhaust. I finally lightly sanded the ends of the piston to make it slightly barrel-shaped so it could tolerate a bit of misalignment. Works great.

I use acetylene for fuel. I run a regular welding regulator on the gas cylinder, set to about 0.5 psi, and a demand regulator between that and the engine. That works the best of anything else I tried. I've head of someone running one on propane, and I certainly tried, but I never got it to fire even once.

There were a bunch of other lessons learned getting it to run. When I get time, I'll try to make a list of the problems and solutions and post it here.

 

[DKGrimm]

That looks great DKGrimm,

Looks like you had a bigger lathe and a very rigid reamer for the cylinder bore. Also see that you cut the rack yourself. I couldn't figure out the setup for that so I had purchased it and all the other gearing. I needed to make my own centers and hubs. Some tweaks were made to the shaft support centers to keep the piston on center.

What fuel and ignition do you use?

Oh, yes; ignition. I had no end of problems with conventional points and coil. I kept getting sparks from contact bounce at bad times and got very erratic firing. I ended up with an extension of the slide valve underneath the base with a hall sensor and a "buzz coil" CDI. It fires while the slide valve it near the top of its travel.

 

[weir-smith]

It has been an interesting read of the engine build. I finished mine two years ago and adopted a some what different approach to the build. The problem for me was always going to be the cylinder bore. I did purchase a suitable reamer and after a trial run put it to one side. My lathe just wasn't ridged enough to give a good finish. A friend of mine was building the Henry Ford Sink Engine and was using a length of Molly Tube as used in building racing cars and similar. The internal finish of the tube was mirror smooth and accurate. So while expensive compared to other material types, it would do the job nicely.

I made the base, the column and the top as seperate sections bored out to fit the Molly tube. I then used Loctite to put the pieces together and then finish the column off using a suitable mandrel. I have included a photo of the brass work which I had lazer cut which worked out well. The slide valve I ground on my surface grinder to give it a good finish and I machined all of the gears on the mill which worked out well.

I have attached some photos for any one interested. The build took me two months as we were down sizing and I had pre sold my workshop so I was on a short time schedule to when we moved.

Your build looks great and I am sure that it will run and be exceptional.

Bruce Weir-Smith
Western Australia