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luftluuver
04-18-2006, 09:28 AM
fantastic workmanship of 1/4 and 1/5 scale a/c engines displayed at the 2005 Barcelona Model Engine Exhibit

http://www.enginehistory.org/ModelEngines/barcelona_exhibit.htm

Some of the engines: DB601E, DB603, Merlin, Bristol

Airmail109
04-18-2006, 09:56 AM
Those guys should build the real things http://forums.ubi.com/images/smilies/sadeyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

Low_Flyer_MkVb
04-18-2006, 10:05 AM
Wot? No Peregrines?!! http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

VF-17_Jolly
04-18-2006, 01:16 PM
Originally posted by Aimail101:
Those guys should build the real things http://forums.ubi.com/images/smilies/sadeyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif
never a truer word http://forums.ubi.com/images/smilies/25.gif

luftluuver
04-18-2006, 05:14 PM
Originally posted by Aimail101:
Those guys should build the real things http://forums.ubi.com/images/smilies/sadeyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif But then they would need a 50,000sqft building (and the mega bucks) instead of a small garage workshop.

Sergio_101
04-19-2006, 02:59 AM
Truth is building full sized copy's is
not any harder than those 1/5 scale models.
it may be easier.

But it is not the 50,000 sq feet of building
you will need, nope, it's the team of lawyers
to keep RR, P&W, CW and others off your back.

With todays CAD and CNC machines it's not
as big a deal to copy the original.

Sergio

luftluuver
04-19-2006, 07:17 AM
Originally posted by Sergio_101:
Truth is building full sized copy's is
not any harder than those 1/5 scale models.
it may be easier.

But it is not the 50,000 sq feet of building
you will need, nope, it's the team of lawyers
to keep RR, P&W, CW and others off your back.

With todays CAD and CNC machines it's not
as big a deal to copy the original.

Sergio If you have the money to buy the converter software.

SATAN_23rd
04-19-2006, 08:09 AM
Do they run, or are they just static models?

x6BL_Brando
04-19-2006, 08:17 AM
I think the idea that full-size construction would be easier is pretty wide of the mark - purely because we're looking at a hobby that primarily is about the joy of making small things single-handedly. The tooling necessary for 1:1 is a lot larger (obviously) and would involve things like heavy hoists and expert help - unless the idea of assembling a full-sized 12-cylinder engine alone is appealing.

Much of the appeal of modelling is in the name. Scaling-down is an integral part of the experience to most, and is part of the buzz of the hobby. True, it might be the talk of the exhibition - but a 1:1 scale Merlin would look very strange on the sideboard.

Creating full-size replicas of vehicles, winged or otherwise, is not to be confused with model-making.

B.

Airmail109
04-19-2006, 04:24 PM
I dont think the engine manufacturers would mind to much as long as you kept it low key and didnt tell many people.

Sergio_101
04-20-2006, 02:50 AM
Originally posted by Aimail101:
I dont think the engine manufacturers would mind to much as long as you kept it low key and didnt tell many people.

They mind in a big way, My company was sued for
making Wright R-1820 pistons. We lost our ***.
They won't care if you make one and don't sell it.

Yes, those models run.

Sergio

Sordid_Sinister
04-20-2006, 03:52 AM
Page no works.

luftluuver
04-20-2006, 05:19 AM
Do you want your own 1/4 scale Merlin?

http://dynamotive.netfirms.com/merlin/

Did any look at the main link? http://www.enginehistory.org/model_engines.htm

Here you can here a 1/5 scale Merlin running,

http://www.enginehistory.org/merlin_xx.htm


Sergio, I think there is more to your P&W problem than meets the eye, for one can get automotive after market pistons, as well as other engine parts.

Airmail109
04-20-2006, 09:58 AM
Ive heard those 1/5 and 1/4 scale engines can be used in models is this true?

Sergio_101
04-20-2006, 05:27 PM
Aircraft engines in full size are huge with
monsterous bores and strokes.

The CW R-1820 pistons aere 6.125" in diameter
as I remember. (6.875 stroke, over 200cid per cylinder!).

The largest commercially available "Automotive"
piston I have seen is 4.625".

Aircraft pistons typicaly are full skirt
designs with three or more compression "keystone"
rings. Some with double oil control rings.

While I don't have the alloy number handy
I can tell you that you can't make reliable
pistons from 6061-T6 or 7075.
Special alloys are used. We machined forgings
provided by the US Navy.

To copy an existing design is a daunting task.
But at least you might find critical parts
and/or forgings commercially.

Automotive parts generally are not designed to
run for thousands of hours at 75% power.

BUT, to build a 1/2 or 3/4 scale engine
or an inexpensive airplane motor it's ok
to toy with automotive based engines.
Engine life will be short, but it seems
many are willing to make the effort.

It would be very cool to build a 3/4 scale
Merlin using as many Chevy parts as possible.
It would turn heads if it were installed in a street rod!

Harley Davidson connecting rods are the blade and fork
type, but have no rod caps and require a built up crank.
For a scale radial the Harley male rods would
require little or no modification to be
used as slave rods.
Three cylinder Harley based radials have been built and
run very well.
It seems to me it would be simple to build a
7 cylinder HD based 7 cylinder radial at 350CID.
Having worked at manufacturing HD based engines
I would say the "Twin cam" based design would
be easily adapted to a 7 cylinder radial
with 7 cam shafts.

Sergiohttp://www.gsbmwr.org/photogallery/DSC00091.JPG