Author Topic: Bristol Mercury revisited  (Read 11847 times)

Online Vixen

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Re: Bristol Mercury revisited
« Reply #30 on: September 12, 2019, 04:44:40 PM »
Thanks everyone for calling in and for your generous comments.

Dave,

The bevels are standard straight cut bevel gears, nothing special. They are arranged to form a very compact epicyclic gear reduction set. If you study the layout closely, you will be able to see the input bevel is the sun, the three pinion bevels are the planets and the fixed bevel in the front is the annulus. You may need a bit of imagination, as the epicyclic function  is folded in upon itself; but it's there and it works.

This form of bevel gear reduction was used on all the Bristol radial engines from the Jupiter through to the mighty Centaurus. It was light, very compact and very reliable. The 2:1 reduction was the most common, but other reduction ratios were available to match different aircraft performance requirements, by changing the tooth count.

Cheers

Mike
It is the journey that matters, not the destination

Offline steamer

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Re: Bristol Mercury revisited
« Reply #31 on: September 12, 2019, 07:45:12 PM »
Ahh    not tooth form but gear arrangement.    I think I understand now

Dave
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Offline Roger B

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Re: Bristol Mercury revisited
« Reply #32 on: September 20, 2019, 11:36:37 AM »
Mike, excellent work as ever  :praise2:  :praise2: This type of folded epycyclic (like a differential gear set) was used in the Automotive Products automatic transmission. Some details are given here:

http://www.austinmemories.com/styled-105/index.html
Best regards

Roger

Online Vixen

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Re: Bristol Mercury revisited
« Reply #33 on: October 05, 2019, 12:50:24 PM »
Sonia and I celebrated our 50th wedding anniversary with a ten day tour around the old Imperial capitals of central and eastern Europe. We visited Prague in the Czech Republic<, Vienna in Austria, Budapest in Hungary and Nuremberg in Germany. The old Imperial splendour was still there, it had survived the ravages of the the 20th century, world wars and in some cases, the Communist regime. Budapest was by far the most impressive of all the cities we visited. Today the splendours of yesterday are slowly being submerged by modern concrete and hi-rise development. But, I guess it's the same everywhere.

I have been able to put the finishing touches to my revised display stand for the 'exploded' Bristol Mercury Mk VIII radial engine.

I used a new sheet of smoke tinted Perspex to form the base of the display. I layed a copy of an original blueprint under the Perspex base to add interest.

I attached full size copies of the three data plates to the wooden surround. These data plates can also be seen, in their miniature form, mounted on top of the Thrust Bearing Housing, immediately behind the Reduction Gearbox Casing.




Here you can see the main engine data plate. I built my replica engine as a model of engine serial number M 40614 which was originally completed in May of 1937 (82 years ago). You can read the engines vital statistics for yourself.



Here is the completed display stand, all dolled up but with nowhere to go.

Model Engineering Exhibitions may be disappearing, a thing of the past, but fortunately, we still have MEM, where we can still enjoy a virtual model show.












I am pleased with how the revised display stand has turned out. The single display is much more compact and tells the story much better than before. It is also so much easier to transport, display and store one item than two. Some of the intricate gear mechanisms are not so clearly visible as before but overall I think it does a better job of displaying the engineering genius of Roy Fedden, the Bristol Aircraft Company and a bygone era of aviation history.



Now, it's back to the Bristol Jupiter

Mike

It is the journey that matters, not the destination

Online Jo

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Re: Bristol Mercury revisited
« Reply #34 on: October 05, 2019, 02:18:35 PM »
 8) Nice.

I must come and visit so I can see your new display in person Mike  :embarassed:

Your "blue print" I hope it is LaserJet printed so it won't fade over time  :ThumbsUp:

Jo
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Offline Jasonb

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Re: Bristol Mercury revisited
« Reply #35 on: October 05, 2019, 02:36:12 PM »
Looks impressive Mike, will you be displaying it at the Midlands show in a couple of weeks?

Online Vixen

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Re: Bristol Mercury revisited
« Reply #36 on: October 05, 2019, 02:53:19 PM »
Looks impressive Mike, will you be displaying it at the Midlands show in a couple of weeks?

Hello Jason,

No, I don't think so.
Ask Jo about the welcome I received from the organisers at last year's Midlands show

Mike
« Last Edit: October 05, 2019, 06:03:15 PM by Vixen »
It is the journey that matters, not the destination

Online Vixen

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Re: Bristol Mercury revisited
« Reply #37 on: October 05, 2019, 02:55:02 PM »
8) Nice.

I must come and visit so I can see your new display in person Mike  :embarassed:

Your "blue print" I hope it is LaserJet printed so it won't fade over time  :ThumbsUp:

Jo

Your always welcome Jo.

And yes it is a laser print, not a real blue print smelling of cat's pee.

Mike
It is the journey that matters, not the destination

Offline steamer

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Re: Bristol Mercury revisited
« Reply #38 on: October 05, 2019, 03:14:43 PM »

Yes...the pea smell is from a Diazo copy, which is special sensitive paper that develops with ammonia.    Used one of those for a few years.   The prints are made by laying a vellum original on top of the paper and running it through the machine which then spitted out the pair, you put the original away and take your copy....it's more like a blueish background....not like a blue print.   You could also get the special paper in pink.   We would use that paper for parts that were going through the shop the first time.   If you saw a "Pink print" you knew that the manufacturing process and the design was new and subject to change.

Dave

« Last Edit: October 05, 2019, 03:24:26 PM by steamer »
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: Bristol Mercury revisited
« Reply #39 on: October 05, 2019, 03:24:00 PM »
Mike

That's one of the most beautiful things I've ever seen.       Wow!

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

Online sco

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Re: Bristol Mercury revisited
« Reply #40 on: October 05, 2019, 04:39:24 PM »
Incredible piece of artwork Mike - as Dave said, Wow!

Simon.
Ars longa, vita brevis.

Offline AVTUR

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Re: Bristol Mercury revisited
« Reply #41 on: October 05, 2019, 06:19:59 PM »
Mike

Magnificent! Does Fedden proud.

I will copy the pictures and show the lads at work, Bristol RRHT, in the next couple of weeks.

Budapest is a good, fine city. I went there for a long weekend in 1991.

AVTUR
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Offline Johnmcc69

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Re: Bristol Mercury revisited
« Reply #42 on: October 05, 2019, 07:53:20 PM »
Museum quality! I like the "old" blueprint in the base.
 :NotWorthy:
 John

Offline Admiral_dk

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Re: Bristol Mercury revisited
« Reply #43 on: October 05, 2019, 08:28:57 PM »
Fabolous exhibit - absolute museum quality  :praise2:

Considering how much time you apply to the engines you build - I think that you and the missus did a somewhat superficial tour of those nice cities - or perhaps better said this way :

Both those cities and you both deserved a longer stay  ;)  - congratulations  :cheers:  and best wishes

Per

Offline fumopuc

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Re: Bristol Mercury revisited
« Reply #44 on: October 05, 2019, 08:46:41 PM »
Yes Mike, it is a masterpiece.
The engine and the 50th wedding anniversary.
« Last Edit: October 05, 2019, 08:50:14 PM by fumopuc »
Kind Regards
Achim