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Early Aviation
Discuss World War I and the early years of aviation thru 1934.
Roden Merc engine head scratcher query
Kornbeef
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England - South East, United Kingdom
Joined: November 06, 2005
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Posted: Monday, July 27, 2009 - 09:13 PM UTC
Okay.....on my second attempt at building and detailing the cylinders for my OAW DIII. I seem to have hit a snag.
I'm wondering if its me or has anyone else noticed that the Engine dimensions are wrong?

All my measurements are approx but when fitting the cylinders which I had cut from the block there seemed not enough distance beween the last cylinder and the cockpit coaming to alter the upper deck to suit the Windsock plans.

I know you might think quite rightly this seems pedantic as it will be covered by the top wing but I have put an awful lot of work into her so far to have something like this mar the build.

So I measured approx the plans against the kit parts the block length seems fine but when I measured the cylinders from front of front to back of back there is a glaring difference which puts everything out of line

The plans :-
length approx just under 21mm equating to around 1000mm at 1:48 which = 31.5 at 1:32

The kit :-
34.5 at 1:32

Now this might not sound much but it throws everything out , the manifold exhaust, cowlings guns and decking. All quite easy to mod I agree but when the cowls are fixed to the kit already and I spent 3 days changing the rocker assembly to the correct style and adding all those PE rocker arms, guitar string springs and making plugs it kinda P's you off and makes you wonder why I bother.

Any imput guys and girls would be gretly appreciated even if its just to slap me about a bit and tell me to get on with it.

JackFlash
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Colorado, United States
Joined: January 25, 2004
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Posted: Tuesday, July 28, 2009 - 06:10 AM UTC

Quoted Text

Okay.....on my second attempt at building and detailing the cylinders for my OAW DIII. I seem to have hit a snag.
I'm wondering if its me or has anyone else noticed that the Engine dimensions are wrong?

All my measurements are approx but when fitting the cylinders which I had cut from the block there seemed not enough distance beween the last cylinder and the cockpit coaming to alter the upper deck to suit the Windsock plans. . .All quite easy to mod I agree but when the cowls are fixed to the kit already and I spent 3 days changing the rocker assembly to the correct style and adding all those PE rocker arms, guitar string springs and making plugs it kinda P's you off and makes you wonder why I bother.

Any imput guys and girls would be greatly appreciated even if its just to slap me about a bit and tell me to get on with it.



It sounds like you have three options

A. Alter the cowling openings then relocate the engine forward 04.0. and extend the cowling ring 04.0.

2. Slap! Get on with it!

Z. Detach the cowlings and leave on the base for a maintenance look.

You bother because you are a steely eye modeler. Model On!
Kornbeef
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England - South East, United Kingdom
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Posted: Tuesday, July 28, 2009 - 08:16 AM UTC
I went for option X.... I carefully removed all the etch and then chopped the blessed cylinder block into 6 individual cylinders... Now I have to try and thin each and not make it too obvious...... the darkness has lifted and I can see some light again.

On inspection I realised I would have to shorten the rocker boxes assy's and chopped the thing into bits realising after I had chopped them at the wrong end.... payment for being a grumpipants.

I must have looked at the plans and differences a hundred times and only now did it catch my eye as the panel over the fuel tank filler is different, it was realising it wouldnt fit that made the penny drop.

Ho Hum..."Model on" as you say Stephen
JackFlash
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Colorado, United States
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Posted: Tuesday, July 28, 2009 - 11:29 AM UTC
Ouch!. Keith please don't quarter the cylinders you will hate yourself for it. 6 cylinders each cut 4 ways. No don't do it stop oh the humanity of it all.
Kornbeef
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England - South East, United Kingdom
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Posted: Tuesday, July 28, 2009 - 12:12 PM UTC
No....god forbid that, it would be easier to carve new Cylinders from stock, what I have done is shave and sand the front and back of each so they are ovalled in section. I have had to sacrifice the gap between each, had I not done the plugs and valves already I might have remade them but once all the manifold and exhaust, the rockers etc are on not that much of them show.

I got them to where the windsock plan shows them and I'm happier about that.
thegirl
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Alberta, Canada
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Posted: Tuesday, July 28, 2009 - 02:03 PM UTC
Gee Keith are we feeling a little ambishus of late ?!

What happened to the rigging on the SE5a ? ( runs and hides )

Model on Keith , mmodel on ...............just don't forget to share some pic's here with the rest of us kinder folks here ..................we like pictures you know !

PS , I would have move the engine forward in Stephens options
Kornbeef
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England - South East, United Kingdom
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Posted: Tuesday, July 28, 2009 - 08:50 PM UTC
Terri, I know moving the engine might have seemed the easier option BUT..... I spent a lot of time getting the front right to give that little gap tween spinner and cowl that is so SO distinctive and Roden seemed to miss and to add 4Mm eep it would have ended up looking like a Pfalz
JackFlash
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Colorado, United States
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Posted: Wednesday, July 29, 2009 - 08:07 AM UTC
I wonder if the Datafile drawing for a 1/32 Albie are accurate?,. . . (Runs and hides in a wardrobe.)
Kornbeef
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England - South East, United Kingdom
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Posted: Wednesday, July 29, 2009 - 08:16 PM UTC
Datafile is 1:48th, it matches the Eduard DIII nicely sizewise, and this also explains why on my DI I had to tear out all the fuelpipe plumbing I had added to the tank etc. So all I have to do now is the rocker assemblies....has to think the best way to go about it, chopping about might leave alignment issues NVM I'm sure it will come soon

(Locks the wardrobe door, turns it to face the wall and leaves you there till you know better)

LOL
JackFlash
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Colorado, United States
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Posted: Thursday, July 30, 2009 - 06:51 AM UTC
Good grief I am in Narnia. . .
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