MAN Diesel engine from 1907 "DM 2 * 100"

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Oct 5, 2012
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Today, I had a break-trough with casting a center-piece of my scale Diesel engine. For me, that's a milestone. And enough reason to show off!

About the engine:
This is a 200 hp Diesel engine off the "DM"-series. DM stands for Diesel Motor. It was built by MAN. The DM series was the second generation of diesel engines that were sold in volumes and they were the first ones that worked quite reliably. There were different sizes. To my knowledge a DM 8 (8hp), DM 50 (50 hp) DM 75, DM 100 and DM 200. At least the bigger ones (starting from DM 50) were available in 1, 2, 3 and 4 cylinder configurations.
My model is a 2 cylinder version with 200 hp (100 hp per cylinder).
These engines worked with compressed air injection.

How that project started:
January 2005, I got a tip that there is an old Diesel engine at Passau. I found a tiny picture and decided to have a look at it.
Having seen it, I realized that this will be my next project.
I tried to get plans from MAN's archive, but they no longer had them. They lost all of them during a fire.
But I'm stubborn!
I contacted the municipal works (owner of the engine) and asked for permission to take dimensions. They were NOT happy. It took some time, and then they allowed me to take pictures, dimensions and even step on the engine.
Together with a friend, we went there. 'Till noon, we sticked about 1500 dots onto the engine, took pictures from all perspectives (IIRC 200) and removed the dots again.
200 hours of photogrammetry work followed ... even more hours on the CAD. And endless hours hunting for books that showed something of the internals.

The result will be a model in scale 1:10.

Here is a picture of the original engine:
You can see the dots that were sticked onto masking tape to increase contract.

And one that shows a detail of the cylinder head. Just so you can imagine the work involved to re-model all those points. :wall:

It didn't take too long for me to realize, that I will fail with my equipment and my knowledge.
So I bought a used and MAHO MH 700 C mill with a broken controll and replaced that with LinuxCNC.
Bought a Myford cylindrical grinder and completely restored it. Bought X and Y and Z and repaired it.

Then, finally, when I realized that I somehow forgot what I initially wanted to do, started with castings. That was spring of 2011. Built furnaces (2 of them have retiered), built a muller, built a core sand mixer, built ... ahhhh ... tools to make tools to make tools!

Long story short. Here is my A-frame I succeeded in casting today:





These are the cores that go inside. I had to mill channels as gates and a pool that takes the first shot of cold pour.
This casting has a split pattern with two loose inserts and 7 cores. These cores are made out of 10 parts.
Wall thickness is 3 mm in most places!

I'll show more pictures. But now it's time to go to bed. Will have an other casting session tomorrow and take the chance to show more castings I have made.

If you do have questions, feel free to ask!

Well done Nick, I'm impessed with your work and a
nice choice of model.
Castings are Aluminium I assume?
I will follow your build with great interest

Yes, all aluminium castings. Except the flywheel. But I don't get enough temperature yet. I can melt CI, but it is not hot enough for pouring.

I use oil bound sand. OBB-sand (local brand here in Germany), similar to PetroBond.

The cores are PU-bound (cold box). Two components mixed into the sand. Then massaged into the core boxes and the PU activated with amin (SP?) gas (stinks like ammonia and is chemically similar). The cores are very durable and detailed and do have sharp corners that withstand the heat of the pour.
Unfortunately, the cores have to burned out (4 hours at 500 °C) afterwards. Stinks a second time.

Thankfully, I get a lot of the casting chemicals from a friend and generous supporter.

do you have the injectors figured out? and pump assuming it uses them, curious.
Very ambitious project. Will it be a true diesel? What are the bore and stroke of the model?

Very impressive, the patternmaking alone is a major achievement with no proper drawings to go on

Regards Mark
How does the dot photograph method work for making patterns please?

Really great job, well done,

What a wonderfully ambitious project!! From measurement through photogrammetry to multi-cored castings. I am awe-struck and will follow this build.

I have been asked wether I sell the castings. No.
I would have to charge a lot. There are IiIRC 45 different castings per engine. Makes about 150 cast parts for a two cylinder engine.
Making the mold for this cylinder takes over an hour. Making the cores an other hour. Milling the pattern for the cylinder took about 40 hours. Plus the patterns for the cores.
Every part that is a casting in the original, is a casting in the model. No matter now small it is.
And then, there are no plans. If I would draw plans, I would have to spend something like a month for them.

The dots are not used to make patterns. At least not directly. This method is called photogrammetry. Each dot has to be taken at least 3 pictures from different perspectives. Then, you need to know one single dimension. And MAGIC! the dots are all precisely position in space. Import them into CAD and model the shapes, so the do touch the dots. Will drive you nuts!

I do know how the injectors work. I think there is a sectional drawing in Cummin's book. The compressor is two-staged and has something like 70 bar. Won't work in this scale. There are too many losses.

I will try to let it run as a true Diesel, but I have my doubts. I'm thinking about an electronic injection with open jets.

I'll post pictures of all the patterns and cores for the A-frame tonight.

I have about 30 patterns finished. The few remaining aren't complicated.

While I jave my morning coffee (well a bit late), I sized two more pictures of the original:


I have to prepare for the casting session now. No new parts, just "production" work (need spares for machining the model).
And a few castings of a little side project: A Deckel FP1 in scale 10:1, with just 5 castings. Shall I start a new thread about that one? It's not an engine, so would be off-topic.
But I have a teaser:

That's how detailed my casting get. Shows part of a lever of the Deckel.

See you later ..
Just came to my mind:
This specific engine was personally adjusted by Rudolf Diesel. So I was told.
It ran until the '80. Obviously only in rare cases. They used it to heat the water of the municipal pool. It is quite effective at generating heat and capturing it. The exhaust pipes are water cooled. I'll cast them the same way with an inside liner and a water jacket.
Even if you can't see the details, they have to be done right.

Nick -
That is a great project. The range of skills and the level of sheer tenacity that will be needed to complete it is very large. Please keep us all up to date as you go along. I am particularly interested in your methods for photogrammetry and for pattern making, but I'm sure that the machining side will be equally interesting.

Short coffee-break:
Well, re photogrammetry, it's best if you google that. ;)
Takes a bit practice to learn that, but is no black art. The trick is to place the dots at the right spot and make two times more photographs than you think.
The resolution you get is above 1:5000. That means if the object is 5 m big, you can get down to 1 mm. The rails measured exactly 25.6 mm. Must have been the layer of paint.
Needs a software I had access to at that time. Meanwhile, that company I used the software at went TU.

Don't worry, patterns will be shown lathe at night (here).

Hi Nick, this is a great project, I will follow de post.
Pls communicate some technical data.
That's incredible to ear that the municial employees unhappy when somebody is intrested by a unique project like yours!
I start the building of the RR Merlin V12, and I try to get permission to check size of internal component but like in Germany
.........No way!!!

municipal works (owner of the engine) and asked for permission to take dimensions. They were NOT happy.
That's incredible to ear that the municial employees unhappy when somebody is intrested by a unique project like yours!

I do understand them. They would be responsible if something happens, I might fall down from the engine.
I offered them, that they get a written declaration that they are not responsible. Both parties quickly realized, that this would imply that they allowed me to step on that motor. Nogo!
So I shook his hand, gave him a Bavarian promise that he won't be responsible, that he further does NOT allow me to step onto the motor. But in return, he will close his eyes when he sees me on the motor.
The other thing that opened doors was, that I gave away a few posters of my Ellwe 2FB and told them, that I have built it and blablabla.

4 failures and finally the success. Ordered from left to right, first try to last try.

The core box for the inner two cores (they are almost symmetrical. The only difference is filled out with oil bound sand.

Cores and core box for the three pockets (near the top of the A-frame).
Right half pattern of the next picture. Core prints are marked black.

And the splitt pattern itself. The flash made a funny color out of it.
Where my finger points to, there are loose inserts. They are attached from the rear by long screws. After ramming the screws are removed, the pattern pulled and the inserts first pulled inwards and then out of the mould.

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And a few castings of a little side project: A Deckel FP1 in scale 10:1, with just 5 castings. Shall I start a new thread about that one? It's not an engine, so would be off-topic.

Incredible. Yes, please start a dedicated new post... wherever! I think scaled miniature machines are so neat & your casting & mold pictures are fascinating.
I saw you posting regarding your MAN diesel engine project. Your project looked very familiar to me. A few years ago I found a website of an Italian model builder named Emidio Gattafoni who built a working model of an early Sulzer 2D-30 air injection diesel enigne. He also built a Sulzer one cylinder version also driving an alternator. His Sulzer engines look very much like the air injection MAN DM series engine you are working on. I believe he built his Sulzer models as a spark ignition engines due to the complexities of compression ignition in small scale. He has built a solid injection diesel model of an Ellwe 2 stroke marine diesel that runs well. You might want study his website or possibly contact him.

Jeff Conner
I know Emidio personally, have met him a few times at model enginering expositions.
I have seen his Sulzer, but just the castings. It was WIP at that moment. I was very impressed of his castings. He is a son out of a foundry family. So his casting know how was a challenge to me at that time (2005). I think now I'm better than he is.:D
I do know his Ellwe and I have built it (see my introducory thread for a video of mine). I still remember when I displayed my finished Ellwe a year after having bought his castings. When Emidio saw my built, he stared at it in disbeliev. He didn't like his after having seen mine.

His Sulzer is of the same time, so it looks similar.

He has built a solid injection diesel model of an Ellwe 2 stroke marine diesel
His Ellwe runs on Propane gas. I have changed mine to run on gasoline.

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That was not the only casting I have. I'll add more over time.
It looks like you guys want to see the patterns and the cores involved.

Base plate:
Top view.

From the bottom. Nobody will see that, but I know these details are there.
That dark spot in the lower right is not a void, but some speck.

Pattern (simple, not split). Black is the core print. Part is casted in the position as shown.

Core boxes. The center one is symmetrical. So two of them go into one casting.

Cores arranged in as how they go into the mould.

There's even an video.


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