Teeny Tiny Micro Model Diesel from Germany

[pirmin]

 

I recently inherited a very very good Set of Drawings from  german Gentleman,i paid 50€ for those 21 pages of excellent Quality and now thought it would be a interesting but also challenging Build .

Please check the Actual size of the Engine beside my thumb.
My idea was to make this engine maybe at 200% scale as a side project beside the Deutz engine .

Would scaling the Drawings work by just double the dimensions ,or would the Engine then become to heavy i wondered.  Maybe on some parts material could be removed more ? For example when i douböe the dimensions of a backplate or certain wall thicknesses ,it wouldnt make a lot sense to just double the numbers. My concerns are about the internals,rod ,crankshaft and liner and Piston,.

Has anyone here already did something like scale up such a model

Here a picture, please look closley to spot the actual size of this beast,it can be overseeen 

[pirmin]

By the way: The Drawings come from the German Fine Mechanic Tradeschool in Furtwangen ( Schwarzwald area if i am not mistaken ) . This area in Germany was a very well known area for Watchmaking and other Mechanical Trades.

The Drawings are very well made, about 15 Pages, signed by a Teacher and Student, with consecutive dates and signed weekly on a new sheet, with very clear material composition and Surface roughnes marks .

it is rare that such good drawings land in the hobby sector.

my suspission is that this was a group project where they made the drawings in the Drafting Class and the engine itself in the Mechanical practice ( thats how a Aprenticeship is done in germany, you work 9 months, and 2 months per yer the school was visited 8-10hrs per day.So it could very well be a School Annual Project )

[pirmin]

Maybe some of the German Members can tell us more about the Berufsschule Furtwangen

[Jo]

SNAP!

We have the crankcase casting for it. (But not the drawings  )

Jo

[pirmin]

jo , how did you come to this casting ?

[Jo]

My supplier found someone in Germany who was doing the Castings for the Kratmo and Kratzsch model engines so he had to have a few sets of each casting  and this little one came along in the purchase as the Guy knew my supplier was (at that time) capable of making it. There was no drawings but its a diesel ... he assumed it must be possible to make something up and then health problems overtook his swarf making.

So when I purchased one of each of the Kratmos and the Kratzsch casting sets from him I got a little one in the set.

Jo

[pirmin]

ahh, ou are talking about Joachim.  I am good friend with him , he made a lot of castings . but those do not look very well, usualy his castings where quite good

[Jo]

Sorry I know nothing of the German supplier. They were initially purchased from Germany about 20 years ago and I picked ours up about 10 years ago.

The drawings for half the model engines were missing and we were going to scale across from the others in the series for the missing ones.

Jo

[pirmin]

could your casting be for the 0,30cc Kratmo ( a very rare engine ) , because to me it looks it has some web cast on the frontside

[Admiral_dk]

Ramon "Tug" has build a number of scaled up Engines here on MEM.
He is not really active (in this field) anymore .... but you can search MEM for some of his great builds - were he in details show how 

Per           

[Jasonb]

As it is so small I don't think scaling it up by 200% will be too much of a problem, you can always compare it with some other engine designs of the new capacity and make any adjustments needed. I'm assuming you mean scale the sizes by 200% not the capacity, if it is capacity then there is not much of a size change so just apply the scaling factor to all parts.

It would not be too costly to get the crankcase 3D metal printed which would save a lot of time cutting from solid.

Yes Jo's looks to be a different engine, her's has the mounting lugs carry around to front and also a web vertically at the front.

[Jo]

could your casting be for the 0,30cc Kratmo ( a very rare engine ) , because to me it looks it has some web cast on the frontside

It could be. My supplier did not know what it was for. He did not have any drawings with it and when I saw yours they are the right sort of dimensions.

Jo

[Jasonb]

Looking a bit more I wonder if this one even used a casting, it is the type of crankcase that just needs the nose piece turning and then the shape of the crankcase can just be milled - top, tapered sides and curved bottom to leave the lugs. Similar style to the 1cc Weaver

I suppose it depends if they were also teaching them pattern making and casting or just machining.

Any clue on the drawing as to whether it mentions a casting or aluminium specification?

Weaver

[pirmin]

yes jason, i also believe they just milled the crankcase,because in the Drawings is no Casting mentioned, and since those are realy good drawings i would assume it would have been mentioned if they worked from Castings. and yes there is a material mentioned , i have toi check the alloy.

btw, the weaver is a Goliath compared to this little fella

[Jo]

Do you have anything on the 0,30cc Kratmo?

A photo would be a good start. 

Jo