General Dynamics Canberra PR9

[kitnut617]

There's a product over here called 'Gorilla Glue'. It's a liquid but sets hard. I used it when I realized my unprepared/short field airliner was going to be a tail sitter. I had made a hole for the nose wheel bay and was able to get little clumps of lead into the nose area, I then poured the Gorilla Glue in over the lot. It's set just perfect but I did leave it a few days just to make sure.

[NARSES2]

You can get Gorilla Glue over here as well mate, or could anyway, I've got some and it's very useful.

Re the PVA not setting. Might just be down to the amount you are using Kit. The drying time to amount used relationship is exponential rather than linear. Hope I've got that right, long time since I did anything serious with numbers 

[PR19_Kit]

Yes, it has cooled down quite a bit over this last weekend. Down in the high teens today.

Leaving on the radiator worked OK, and as I was out model railwaying all day today I didn't get baked, and it's dried off enough to glue then nose cone on at last.

[McColm]

Me thinks a Mach2 Group Build will be next

[PR19_Kit]

Having found I've got two Airfix Canberra PR9s  I'm using some parts of one of them to enhance this 'PR9'.

The ECM blister on the fin and the little ECM cone on the tail have been fitted, and it'll have a BOZ 107 pod under one wing too, as well as some of the RAF specific aerials. In addition I found the PR9 kit has TWO bomb bay doors, so one of them has been grafted onto this 'PR9'. It's got lots of camera windows, which the Mach2 kit lacks entirely, but it doesn't fit all that well, but what else is new?

More PSR around the bomb bay will be called for of course, but I used the opportunity of having a girt great hole in the bottom of the aeroplane to top up the nose weight and glue, and now the nose cone is securely in place too and PSR'd as well.

[rickshaw]

I generally find the best place for noseweights in Canberras is just above and behind the forward wheel well.  Plenty of room there and I tend to overload it a bit as I know the recommended weights are usually a bit small compared to what is actually required to make it sit on it's nose and not it's tail.  I have had a few noted tail sitters though.  My "Original PR.9 prototype" for one, which required a massive main spar for the longer wings which I made the mistake of making out of brass, which I just couldn't fit enough weight into the nose to counter!

[PR19_Kit]

Yes, the  Canberra of all types is very difficult to weight properly.

But looking at one from underneath the main wheel wells are a LONG way forward in the wing, and the nose wheel is a long way aft too. The whole thing is very close coupled indeed.

I can only assume that Avons are very heavy indeed and are mounted way forward in those long nacelles. I wonder why Petter designed it just like that sometimes. 

The bomb bay door's I n place now, and I'll post a pre-primer pic later, after I've done 4-5 PSR sessions on the wing roots.... 

[zenrat]

Yes, the  Canberra of all types is very difficult to weight properly.

But looking at one from underneath the main wheel wells are a LONG way forward in the wing, and the nose wheel is a long way aft too. The whole thing is very close coupled indeed.

I can only assume that Avons are very heavy indeed and are mounted way forward in those long nacelles. I wonder why Petter designed it just like that sometimes.  ...

It does, from your description, appear to keep things as close as possible to the centre of gravity.

[PR19_Kit]

Yes, the  Canberra of all types is very difficult to weight properly.

But looking at one from underneath the main wheel wells are a LONG way forward in the wing, and the nose wheel is a long way aft too. The whole thing is very close coupled indeed.

I can only assume that Avons are very heavy indeed and are mounted way forward in those long nacelles. I wonder why Petter designed it just like that sometimes.  ...

It does, from your description, appear to keep things as close as possible to the centre of gravity.

Ah yes, but is that a good thing?

Watching Canberras taxi they look absolute PIGS to keep going in a straight line and they nod like crazy when braking. A longer wheelbase may have made things a lot easier for the pilot, but maybe would need more speed before they could rotate cleanly.

[kitnut617]

This might come in handy then, a real world load cg diagram   

I got this from John Adams when I was working out my STOVL Canberra

[PR19_Kit]

VEEEEERY interesting, thanks, 

That rear fuselage just has to be VERY light, doesn't it? And the Avons look be mounted right on the CG too.

[kitnut617]

0 Feet just happens to be the front of the main gear bay ---- at least on the Matchbox PR.9 I used in my project

[PR19_Kit]

It's in the same position on the Airfix PR9 too, but on the RB-57F there's nothing to compare, the wings are so HUGE, chordwise as well as in span.

[PR19_Kit]

Here's the 'PR9' with the PR9 camera bay added. 

LOTS of PSR was required, Airfix and Mach 2 not really agreeing on the shape of the Canberra's underside.



Lots more PSR tomorrow I suspect.

[rickshaw]

Different aircraft.  Remember, Martin created essentially a whole new lower fuselage when they added the rotating bomb bay to their version of the Canberra, as against English Electric with their original bomb bay.