Author Topic: By Jupiter  (Read 75240 times)

Offline Vixen

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Re: By Jupiter
« Reply #390 on: June 24, 2019, 02:06:49 PM »
Hello Ian and Andy

I was hoping to make the nuts look as much like the originals as possible. I guess that means I will have to make them.

I have been looking though old photos to try and decide if the nuts were individually split pinned or daisy-chained with locking wire. You cannot trust the details of old engines which have been tarted up for display in museums. There are no flying Jupiter engines out there anymore.

Mike




« Last Edit: June 24, 2019, 02:25:06 PM by Vixen »
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Online Jo

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Re: By Jupiter
« Reply #391 on: June 24, 2019, 05:38:53 PM »

I have been looking though old photos to try and decide if the nuts were individually split pinned or daisy-chained with locking wire. You cannot trust the details of old engines which have been tarted up for display in museums. There are no flying Jupiter engines out there anymore.

Do you not have a copy of the Jupiter's Care and Maintenance Manual? That should tell you  :)

Jo
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Offline Vixen

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Re: By Jupiter
« Reply #392 on: June 24, 2019, 05:58:10 PM »
Do you not have a copy of the Jupiter's Care and Maintenance Manual? That should tell you  :)

Jo

I have copies of the Air Publications for the Jupiter Mk VI, Mk VIII and Mk XI engines. These AP's cover the design, operation and in depth teardown maintenance of the engines. While all the AP's show the castellated nuts and the drilled bolts, there is no mention (or illustration) of the use of split pins or locking wire.

I guess it's a case of doing what looks best. There is nobody, with the knowledge, to tell you that it is incorrect.

Mike :noidea:
« Last Edit: June 24, 2019, 06:09:59 PM by Vixen »
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Online Jo

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Re: By Jupiter
« Reply #393 on: June 24, 2019, 06:23:29 PM »
I would have thought that a wire ring through all would have been safer and easier to fit/remove for maintenance, split pins would worry me as one might come out and could  get lost during servicing  :paranoia:

Jo
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Offline Jasonb

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Re: By Jupiter
« Reply #394 on: June 24, 2019, 06:29:21 PM »
I would have though new pins each time if split pins used.

The nuts in that drawing look a lot nicer than the 2BA that are available that just have square cornered milled slots in  a pressed nut. A quick bit of CNC with a ball ended mill will get the round section and the round bottom slots done quite quickly.

Can you get scale locking wire?

Edit I was looking at this site yesterday for cotton insulated wire, they also seem to have locking wire down to 0.4mm as well as all sorts of other wires

https://www.wires.co.uk/acatalog/index.html
« Last Edit: June 24, 2019, 06:34:26 PM by Jasonb »

Offline Vixen

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Re: By Jupiter
« Reply #395 on: June 24, 2019, 06:50:52 PM »
Hello Jo and Jason,

I agree, castellated nuts to the correct profile will not be difficult to make, and will look much better than the commercial ones, which are are not available in the shape I need. Fuse wire of the correct amperage makes good scale locking wire. I still have my locking wire twisting pliers from my days in the mob.

Jo, In that case, you would be horrified to learn that the RAF approved method for split pins is to cut them short and bend only one leg through 30 degrees, leave the other leg straight. The split pins with a single bend will never fall out and are easier to remove than split pins tied in knots. You never try to reuse a split pin.

You both ready for the Guildford Open Day?

Edit. I cannot get into the Wires. co.uk website

Mike
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Online Jo

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Re: By Jupiter
« Reply #396 on: June 24, 2019, 07:52:23 PM »
Jo, In that case, you would be horrified to learn that the RAF approved method for split pins is to cut them short and bend only one leg through 30 degrees, leave the other leg straight. The split pins with a single bend will never fall out and are easier to remove than split pins tied in knots. You never try to reuse a split pin.

You both ready for the Guildford Open Day?


They normally sign every tool and part out then every tool and part removed back in but the tales of what is found on an aircraft during maintenance  :-X I was thinking also of the pilot being able to walk round and just having to check one wire was securely in place rather than every split pin prior to every take off. You know what fly boys are like if you make them do more than they have to prior to go playing   ::).

I'm ready to go to Guildford  :)

Jo

« Last Edit: June 24, 2019, 07:56:20 PM by Jo »
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Offline Vixen

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Re: By Jupiter
« Reply #397 on: June 24, 2019, 08:08:36 PM »
They normally sign every tool and part out then every tool and part removed back in but the tales of what is found on an aircraft during maintenance  :-X I was thinking also of the pilot being able to walk round and just having to check one wire was securely in place rather than every split pin prior to every take off. You know what fly boys are like if you make them do more than they have to prior to go playing   ::).

Jo

The ground crew account for every item entering and leaving an aircraft and for the aircraft being fit to fly. The flyboys simply swagger about, like "Top Gun" heroes, in their smart flying suits and sunglasses poking and shaking anything they can easily reach, it's all part of the image to make them look good. The aircraft was already signed off as being fit to fly by the maintenance Chief

Mike
« Last Edit: June 24, 2019, 08:58:17 PM by Vixen »
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Offline Jasonb

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Re: By Jupiter
« Reply #398 on: June 24, 2019, 08:09:38 PM »
I'm also ready and the engines I put on the entry form are all finished too.

Offline Vixen

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Re: By Jupiter
« Reply #399 on: June 26, 2019, 09:04:13 PM »

The nuts in that drawing look a lot nicer than the 2BA that are available that just have square cornered milled slots in  a pressed nut. A quick bit of CNC with a ball ended mill will get the round section and the round bottom slots done quite quickly.

Jasonb



Quite right, the 2 BA castle nuts are the correct proportions for a 3/16" bolt. The proportions of a castle nut for a full size aircraft 1/2" bolt, are quite different.The only option was to make my own based on the full size drawing.

I made a batch of scale nuts from mild steel hex bar stock, in three stages. I started on the lathe by drilling and tapping the 2 BA thread before turning the rounded end contour and 30 degree chamfer.




Next, I transfered to the mill to machine the split pin slots. The hex bar was mounted  in my 4th axis unit to quickly index in 120 degree increments. A 1.0 mm slitting saw cut the slots to depth in a single pass. I love the ching ching ching sound of a slitting saw.




The embrio nut was sawn off the bar stock and the rear face finished to length on the lathe. The machine time for each nut was minutes, but the tooling up and setting up took a lot longer.




Not the most exiting day's work, but another job can be ticked of the list

Mike


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Offline Kim

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Re: By Jupiter
« Reply #400 on: June 27, 2019, 06:12:46 AM »
May not have been exciting, but I have to say, those are mighty cool looking!  They're going to really add to the look of your engine!  :popcorn:

Kim

Online Jo

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Re: By Jupiter
« Reply #401 on: June 27, 2019, 07:03:32 AM »
Not the most exiting day's work, but another job can be ticked of the list

All these little jobs add up but it is so nice when you find that all the bits you need to be able to bolt the next bit on are already done  :) which reminds me I have another 30 nuts and 60 studs to do   :-\

Jo
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Offline Vixen

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Re: By Jupiter
« Reply #402 on: June 28, 2019, 06:32:44 PM »
The final parts for the propeller hub were completed today, They are over to the right and include; the shaft centralising cone, center nut (left hand thread), front disc locking ring and the extracter ring. The extractor ring is a simple but clever device, the action of unscrewing the central nut also pulls the hub off the prop shaft taper splines.

All that remains is to cut the eight bolts to length and drill the 1 mm split pin holes. But they will have to wait, it's over 30*C in the workshop today, a welcome change after two weeks of rain.







That's a whole lot of hardware just to hold the propeller onto the propshaft. Must of us simply make do with one washer and one nut.

Stay tuned

Mike
« Last Edit: June 28, 2019, 06:37:48 PM by Vixen »
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Online Jo

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Re: By Jupiter
« Reply #403 on: June 28, 2019, 06:59:33 PM »
Decision made then Mike, you are going for split pins  :)

Looks like she is coming together fast ready for the show  8)

Jo
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Offline Vixen

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Re: By Jupiter
« Reply #404 on: June 28, 2019, 09:16:00 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
« Last Edit: June 28, 2019, 09:39:24 PM by Vixen »
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