Author Topic: Ohrndorf V12, new challange  (Read 21066 times)

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #165 on: July 19, 2024, 08:37:52 PM »
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.
Kind Regards
Achim

Online crueby

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Re: Ohrndorf V12, new challange
« Reply #166 on: July 19, 2024, 08:42:16 PM »
Impressive parts!   :popcorn: :popcorn:

Offline Admiral_dk

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Re: Ohrndorf V12, new challange
« Reply #167 on: July 20, 2024, 08:58:03 AM »
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)  :ThumbsUp:

Thank you for showing another useful trick  :ThumbsUp:

Per           :cheers:                         :popcorn:

Offline RReid

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Re: Ohrndorf V12, new challange
« Reply #168 on: July 20, 2024, 03:00:48 PM »
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!
Regards,
Ron

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #169 on: July 22, 2024, 11:57:07 AM »
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>

Kind Regards
Achim

Offline Roger B

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Re: Ohrndorf V12, new challange
« Reply #170 on: July 23, 2024, 07:59:43 PM »
That's some complicated stuff   ::) Still following along  :)
Best regards

Roger

Offline Michael S.

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Re: Ohrndorf V12, new challange
« Reply #171 on: July 24, 2024, 07:37:37 AM »
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

Offline Niels Abildgaard

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Re: Ohrndorf V12, new challange
« Reply #172 on: July 24, 2024, 10:03:17 AM »
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.

« Last Edit: July 24, 2024, 03:53:06 PM by Niels Abildgaard »

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #173 on: July 25, 2024, 07:55:11 AM »
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.
Kind Regards
Achim

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #174 on: July 25, 2024, 07:57:38 AM »
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.

Kind Regards
Achim

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #175 on: July 25, 2024, 07:58:56 AM »
That's some complicated stuff   ::) Still following along  :)


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

Offline Niels Abildgaard

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Re: Ohrndorf V12, new challange
« Reply #176 on: July 25, 2024, 12:09:59 PM »

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.

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #177 on: July 25, 2024, 03:38:07 PM »
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.
Kind Regards
Achim

Online Kim

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Re: Ohrndorf V12, new challange
« Reply #178 on: July 25, 2024, 08:12:47 PM »
Great progress, Achim!   :popcorn:  :ThumbsUp:

Kim

Offline fumopuc

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Re: Ohrndorf V12, new challange
« Reply #179 on: July 28, 2024, 05:53:30 PM »
Great progress, Achim!   :popcorn: :ThumbsUp:

Kim


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

Kind Regards
Achim

 

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