BMW R7 Motorcycle Engine

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Crankshaft

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Crankshaft1.JPG


Crankshaft2.JPG
 
Thats lovely mate
Pete
 
Its only when you see a photograph that it makes you realise how small 1/4 scale can be. Are there more parts already made or are you working like a mad man :)

really nice :)
 
Yes, I have almost all parts finished.
I show one part each day.
German
 
gbravo said:
Yes, I have almost all parts finished.
I show one part each day.
German

Ha what a tease. cant wait for the next installment :)
 
Today Camshaft.
This is one of main differences, in the original motor the movement of camshaft is with chain and in my engine is with gears, for this reason the cams are in opposite way.
I don't know any small chain.


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gbravo

I am in awe of your BMW engine. will be looing forward to the next episode.

noticed that you were looking for small roller chain. Perhaps this may help:

- 0.1475 inch pitch roller chain (3.75mm pitch) is available from Precision Scale Model Engineering [[email protected]]
- material stainless steel.
- sprockets available, although I normally cut my own.

Larry DeMilo is a great guy and will be happy to help if you need smaller pitch roller chain.

have fun
Bernard
 
Very interesting information.
I will consider in future proyects.
 
In my impresion the rockers was the most interesting parts made.
The black color is due to annealing.

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Rockers 1.jpg


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Now, you're going to need to expose how you made those rockers....They're pretty darned accurate and nicely shaped - beautiful.

BillC
 
I don’t have pictures of the machining, but I will try to explain how I made rockers.
1. First I turn a stock cylinder of SAE 1045 steel to diameter 19 mm and long 38 mm.

2. Turn one of ends to dia. 17 mm with 24.5 mm long, this diameter is the center cylinder of the rocker with length increased in 20 mm for clamping.
(See rocker1 picture)

3. I place the stock in the CNC mill and I milling in Z axis (0 degrees) with horizontal milling in 3 axes
(See rocker2 picture)

4. Rotate in 90 degrees and mill
(See rocker3 picture)

5. Rotate to 180 degrees and mill
(See rocker4 picture)


Rocker1.jpg


Rocker 2.jpg


Rocker 3.jpg


Rocker 4.jpg
 
6. Rotate to 270 degrees and mill
(See rocker5 picture)

7. I milling finishing in 4 axis with continuous rotation in axis A (around X axis)
(See rocker6 picture)

8. Finally I turn the inside hole (4 mm) and cut the center cylinder of the rocker to the finish length.



Rocker 5.jpg


Rocker 6.jpg
 

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