BMW R7 Motorcycle Engine

[gbravo]

Crankshaft

 

[gbravo]

More Crankshaft

 

[metalmad]

Thats lovely mate
Pete

 

[gbravo]

Connecting rod

 

[Brass_Machine]

Wow! Nice work.


Sent you PM...

Eric

 

[RManley]

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

 

[gbravo]

Yes, I have almost all parts finished.
I show one part each day.
German

 

[gbravo]

Now Pistons

 

[RManley]

Yes, I have almost all parts finished.
I show one part each day.
German

Ha what a tease. cant wait for the next installment

 

[Brian Thomas]

What a great project and super skills displayed.

 

[gbravo]

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.

 

[narrowgauger]

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

 

[gbravo]

Very interesting information.
I will consider in future proyects.

 

[gbravo]

In my impresion the rockers was the most interesting parts made.
The black color is due to annealing.

 

[gbravo]

More Rockers

 

[BillC]

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

BillC

 

[gbravo]

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)

 

[gbravo]

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.

 

[gbravo]

Cylinders

 

[Brass_Machine]

errr... wow! those rockers are pretty cool!