Author Topic: By Jupiter  (Read 38153 times)

Offline Roger B

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Re: By Jupiter
« Reply #405 on: July 06, 2019, 05:58:30 PM »
Excellent as ever  :praise2:  :praise2: As a complete aircraft numbskull is the propeller torque transferred by the clamping pressure or by the bolts in shear?  :headscratch:
Best regards

Roger

Online Vixen

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Re: By Jupiter
« Reply #406 on: July 06, 2019, 09:53:30 PM »
Hello Roger,

That's correct, A long thin bolt can always transmit a larger load in tension than it can in sheer. The engine torque is transferred by clamping the two steel discs of the propeller hub tightly to the wooden propeller. Theoretically the bolts should not see any sheer loads. The parallel splines on the front steel disc are there to ensure the engine torque is shared equally to both sides of the propeller.

Mike
It is the journey that matters, not the destination

Offline mike mott

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Re: By Jupiter
« Reply #407 on: July 17, 2019, 03:51:36 PM »
Hello Mike'
I have just finished my early morning read, and chose your build today. I am catching up on a few of the builds that cover the broad spectrum of this wonderful forum. All I can say is that it is very inspiring and humbling at the same time. I will be sharing your adventures with casting the manifolds a good friend who is an award winning silversmith. She has a regular group session at her studio on Wednesday mornings for half a dozed folk who are not beginners anymore. There is an area for wax work that I will look at with a different perspective after your journey with the wax.
Not knowing much about working model aero engines I am blown away by the detail and ingenuity that you have shown to replicate this engine,  I read through Dan's blog first before reading your contribution. A great work by both of you, thanks for sharing.

Mike     
If you can imagine it you can build it

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Re: By Jupiter
« Reply #408 on: July 17, 2019, 09:08:25 PM »
Hello Mike,

I have been quietly following your new workshop topic. You have made me quite envious of your 12 month a year, indoor, heated model building workshop. I have to settle for an  outside garage, which is OK for about nine months of the year.

Thanks for your generous words about the Jupiter. Like your Bristol cutter, the larger scale allows a lot more detail to be added. Yes, Dan set the bar very high and I struggle to achieve his standard of workmanship. We are well on the way to completing the engine.

Regards

MIke
It is the journey that matters, not the destination

Online Vixen

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Re: By Jupiter
« Reply #409 on: July 18, 2019, 05:35:07 PM »
Yes, decision made, it's split pins.

In Dad's old tool box, I found a small cardboard box containing one ounce of small split pins. The box was marked AM (Air Ministry) with the Kings Crown and dated 1944. Dad must have "liberated" them way back then. "You never know when these may come in handy". They had to wait 75 years for their time to arrive.

Mike





It seems that way back in 1944 everything was rationed and in short supply, only enough cardboard available to make a very tiny box, which contained 1 gross (144) split pins 1/32" (0.8mm) diameter by 3/8" (9.5mm) long. They are exactly right for the propeller hub bolts.

Mike
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Offline mike mott

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Re: By Jupiter
« Reply #410 on: July 18, 2019, 06:12:43 PM »
It is great when something finds its time for being used, when it could have so easily have been discarded.

Mike
If you can imagine it you can build it

Offline Ian S C

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Re: By Jupiter
« Reply #411 on: July 19, 2019, 04:12:17 AM »
Much easier having the split pins like that, last time I needed ones that size I had to make my own, clamped a bit of wire in a fretsaw frame and filed it flat to half thickness, then folded them to split pin shape and cut to lenght, a bit tedious.
Ian S C

Offline Jasonb

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Re: By Jupiter
« Reply #412 on: July 19, 2019, 07:30:15 AM »
Don't envy the job of cleaning the rust off all of those pins

Online Vixen

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Re: By Jupiter
« Reply #413 on: July 19, 2019, 08:39:08 AM »
A dip in citric acid pickle would be a whole lot easier than Ian's method of filing down some round wire to a D section

Mike
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Offline Jasonb

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Re: By Jupiter
« Reply #414 on: July 19, 2019, 11:30:49 AM »
I've done the wire and file thing for 0.5mm split pins but bright shiny new 1/32" ones can still be had. Works out quite economic if you buy 1" long ones as you can rebend the two bits you cut off and get 3 for 1 :)

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Re: By Jupiter
« Reply #415 on: July 19, 2019, 12:55:57 PM »
Hello Jason,

I am sure I could buy some shiney new 1/32" split pins, but that would spoil an important family connection.

My 'Old Man' joined the RAF in the 1930's. Like many young lads, he lied about his age. He flew behind the Bristol Jupiter engine in a Westland Wapiti biplane; all over Egypt, Jordan and Palestine (as it was called back then). He was in the back, looking after the Lewis gun and the sandwiches.

I inherited his model making jeans, some of his skill and his tool chest full of little treasures. It seems fitting somehow, to use some of his hoarded collection of split pins on the model Jupiter, after all, they are slightly older than me and almost as old as the Jupiter he flew behind.

Mike :old:

« Last Edit: July 19, 2019, 04:57:30 PM by Vixen »
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Online Captain Jerry

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Re: By Jupiter
« Reply #416 on: July 19, 2019, 01:02:08 PM »
It looks to me like the label reads "Cotter Pins."  That's what I have always called them. When I hear "cotter pin" , I know exactly what we are talking about but "split pin" makes me take a second thought. We older people are set in or ways.


Jerry
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Don't worry about it. try it anyway.

Online Vixen

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Re: By Jupiter
« Reply #417 on: July 19, 2019, 01:17:48 PM »
Hello Jerry,

The Brits have a habit of using more than one name for everything, and 'split pin' is more commonly name for a 'cotter pin' on our side of the pond (at least by my generation).

Mike
« Last Edit: July 19, 2019, 04:58:45 PM by Vixen »
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Offline Ian S C

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Re: By Jupiter
« Reply #418 on: July 19, 2019, 03:05:28 PM »
I'v always called the tapered pin with a flat on one side and a thread and nut on the small end that holds a bike peddal on the crankshaft of a bie, a cotter pin. A splitpin is a splitpin.
The splitpins that I made were I think 1 mm, they were for the governor and throttle link on a Stuart Turner S9 that I was rebuilding. Stainless steel wire.
Ian S C

Offline Jo

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Re: By Jupiter
« Reply #419 on: July 19, 2019, 03:43:58 PM »
BS standard 1574:1994 and ISO standard 1234:1997 calls them split pins.

Edit: in 1943 the SAE standards (USA) called them cotter pins


To go with them the SAE standard uses the term High nut to refer to what we would call a castellated nut.

Jo
« Last Edit: July 19, 2019, 03:52:45 PM by Jo »
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