Ohrndorf V12, new challange

[fumopuc]

And here we are at the end of this day.
3 of 7 possible sets are made already another 4 to go.
All three con rod pairs assembled at the dummy plate with 4 bearing blocks and surprise, it is still possible to move by hand.

[crueby]

Impressive parts!   

[Admiral_dk]

When I saw the first picture of the assembly Spacer / Jig - I thought - Smart but you are never getting it off again (not thinking about a removeable Pin) 

Thank you for showing another useful trick 

Per                                    

[RReid]

Hello Achim. Having just had time to read through and look more closely at the pictures of the crankshaft assembly process and associated parts, I'm even more impressed. Clever stuff!

[fumopuc]

Chris, Per, Ron, thanks for watching.


Some progress with the crankshaft assembly.
6 from 7 available web pairs are together now and still alive.
5 pairs left hand side at their position where they should work in the engine also.
The set very right is also fine, made from my remaining set up parts, but can not stay there.
The set in front, not fit together, is the one which should work in this position, close to the prop or better fly wheel in my case.
The designer has given the connection between the last web and the shaft two 2 mm pins as an additional carrier.
If this should fit in a proper way, I think it can be drilled together only.
But unfortunately the shaft is not made yet and so the very last web can used for drilling alone only.
The hole unit, fixed in the external dummy set up is easy movable by hand still.


<a href="https://www.youtube.com/watch?v=ghGjMQkMQpI" target="_blank">http://www.youtube.com/watch?v=ghGjMQkMQpI</a>

[Roger B]

That's some complicated stuff    Still following along 

[Michael S.]

Hello Achim,
brilliant structure and very interesting! I wonder: did they cry at BMW when you retired from there? You have lost a good man.

Greetings Michael

[Niels Abildgaard]

A mr Westbury used another clamping method for some  homebuilt single cylinder two stroke engine called Bumblebee .
 Bristol aircraft engines also built 60000 Hercules two row radial engines with clamped crankshafts.
It would be interesting to compare the Westbury/Bumblebee method with Your Ohrndorf method  for max torque capacity and ease of manufacture.



Your stubs are 6 and 9mm diameter 10.5mm apart  and discs are 7mm wide and clamping bolt M4.

I only need to find distance over 2 conrods side by side.
11.5mm?

I can then sketch and make a model and torque it until it slips or break.

[fumopuc]

A mr Westbury used another clamping method for some  homebuilt single cylinder two stroke engine called Bumblebee .
 Bristol aircraft engines also built 60000 Hercules two row radial engines with clamped crankshafts.
It would be interesting to compare the Westbury/Bumblebee method with Your Ohrndorf method  for max torque capacity and ease of manufacture.



Your stubs are 6 and 9mm diameter 10.5mm apart  and discs are 7mm wide and clamping bolt M4.

I only need to find distance over 2 conrods side by side.
11.5mm?

I can then sketch and make a model and torque it until it slips or break.

Hi Niles, an interesting idea.
You are right, 11,5 mm is the dimension.
Earlier I have made a mistake, the bolt is M3 not M4, sorry about this confusion.
I have purchased some M3 hex bolts with a strength of 12.9 class.
But I have to find out what should be the reasonable torque to tighten it.

[fumopuc]

Hello Achim,
brilliant structure and very interesting! I wonder: did they cry at BMW when you retired from there? You have lost a good man.

Greetings Michael

Hi Michael thanks for watching and the friendly words.
This crankshaft with 7 bearings at the end in this scale is something total new for me.

[fumopuc]

That's some complicated stuff    Still following along 

Hi Roger, not as complicated as a "Diesel Injection", in my eyes.

[Niels Abildgaard]

Hi Niles, an interesting idea.
You are right, 11,5 mm is the dimension.
Earlier I have made a mistake, the bolt is M3 not M4, sorry about this confusion.
I have purchased some M3 hex bolts with a strength of 12.9 class.
But I have to find out what should be the reasonable torque to tighten it.

Why not use M4  Unbrakos?

Reserve five of these screws for a once only  and torque them to destruction in a test block with M4 threads and write down the torque?
For assembly of Your crank, torque to say two thirds of mean value.

[fumopuc]

Hi Niels,
I think there is no difference between an Umbrako 12.9 or a 12.9 bolt from another supplier.
Concerning the dimension M3 or M4, here a screen shot of a CAD model.
Left hand M3, right hand M4.
The M4 head could be 0,22 m wider than the web.
7,22 mm in the 7 mm web is not the best.
The recess for the bolt head would be much bigger than the width of the web.
The original design is made with M3.

[Kim]

Great progress, Achim!    

Kim

[fumopuc]

Great progress, Achim!   

Kim

Hi Kim,  thanks, it is time to catch up agian with the build report.