Author Topic: 1/4 scale Porsche 917 180 degree V12 Build  (Read 57524 times)

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #150 on: November 15, 2021, 01:25:08 AM »
Good progress today!   First of three gears went great.   I'll cut some more this week .   I need 3 of this tooth count.

Dave

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Offline crueby

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #151 on: November 15, 2021, 01:56:18 AM »
Looking great!  What is the black coating in the gear teeth?


 :popcorn: :popcorn: :popcorn:

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #152 on: November 15, 2021, 02:13:26 AM »
Just a shadow.no coating

Dave
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Online Kim

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #153 on: November 15, 2021, 05:29:57 AM »
Nice looking gear!  Is it going to stay this wide? Or get narrower before actual use?

Kim

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #154 on: November 15, 2021, 11:13:05 AM »
Nice looking gear!  Is it going to stay this wide? Or get narrower before actual use?

Kim

Hi Kim.   Thanks for looking in!    No actually it will finish off looking like the picture below.   To physically cut the part, the blank needs to be 1" away from the face of the DH spindle...so at the moment it's a gear on a stick...
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Offline Vixen

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #155 on: November 15, 2021, 12:37:16 PM »
Good progress today!   First of three gears went great.   I'll cut some more this week .   I need 3 of this tooth count.

Dave

Another small step foreward

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #156 on: November 15, 2021, 12:51:07 PM »
Good progress today!   First of three gears went great.   I'll cut some more this week .   I need 3 of this tooth count.

Dave

Another small step foreward

Mike

YUP   And with what's going on in my life.   well small steps is all I can do.  i'll endeavor to take them every week.

Dave

 
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Damned ijjit!

Offline Admiral_dk

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #157 on: November 15, 2021, 09:53:08 PM »
Great to see progress Dave and a nice result  :ThumbsUp:

I would have said that only one of them ends up as a part of the crankshaft  :headscratch:

Are the two others idlers or for the Oil Pumps ?

Per

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #158 on: November 15, 2021, 10:09:26 PM »
Per


Power comes from the center of the crank
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Offline Admiral_dk

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #159 on: November 15, 2021, 10:14:55 PM »
So this time my memory wasn't half bad  ;D  thank you Dave.

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #160 on: November 15, 2021, 10:19:01 PM »
So this time my memory wasn't half bad  ;D  thank you Dave.


 :headscratch:

No the output shaft is below the crank shaft...so that's the primary, and the output way shafts

The other gear is for the fan and the distributors.
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Offline crueby

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #161 on: November 15, 2021, 10:34:31 PM »
Very interesting arrangement on the output shaft!

Offline Admiral_dk

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #162 on: November 16, 2021, 11:54:40 AM »
OK, I wasn't clear.

I understand it as, two of the gears you made, are for the Crank and the Output shaft (the red line) - they certainly appear to be same size ...?

I admit that I guess that the third will be slimmed down and placed on the last shaft in the picture .... so, all three mess with each other .... I know it's a dangerous assumption ....

Offline Hugh Currin

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #163 on: November 16, 2021, 02:44:25 PM »
Dave:

Great progress. Thanks for dragging us along.

For the "gear on a stick", did you consider making a "pinion shaft"? What I mean is cutting the gear section long enough to get all three gears from. More overhang but only cutting one long gear. Just curious.

The center take off on the crank makes sense to me. The torque is half on each side rather than pulling power from one end. The crank will see more cyclic loading than the final output shaft after the gear. Might explain why the final output isn't larger than the crank? Makes sense for a racing motor, but would probably be more expensive for production vehicles.

Thanks again.

No actually it will finish off looking like the picture below.   To physically cut the part, the blank needs to be 1" away from the face of the DH spindle...so at the moment it's a gear on a stick...
Hugh

Offline steamer

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Re: 1/4 scale Porsche 917 180 degree V12 Build
« Reply #164 on: November 17, 2021, 01:12:38 AM »
Hi Hugh,

The problem I have is that with the dividing head on my table, I lose some travel...to complicate it, I need to have the HS side of the gear at least 1" away from the spindle of the dividing head.   I run out of room to put the footstock/tailstock on the table...so I can't make the gear blank too long....so you end up with a gear on a stick ......Im going to build a sub table that lets me hang the HS way to the left over the table drive, that will let me get a footstock/tailstock on

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

 

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