STOVL Canberra

kitnut617 · August 30, 2009, 03:50:08 PM

Hmm! I thought I posted something about the cockpit earlier today ----- if I didn't I 've missed a step then.

I want to busy up the cockpit so while looking around for some appropriate parts, found something I had bought quite a few years ago. It's a Prowler cockpit tub produced by Golden Dragon Products, I thought I had bought a Prowler too but I don't seemed to be able to find it now, so any way, out with the saw and got it to look somewhat like what I want. It's a bit more roomy than the regular Canberra office but once it's painted up it should look ok, the rear bulkhead here is before I filed it to shape;

Green Dragon · August 30, 2009, 04:38:16 PM

The Prowler cockpit bit was posted in the right place over on Britmodeller earlier today kitnut. Liking this a lot, tried to comment on BM but I keep getting an IPS driver error (whatever that is?). Good luck with the rest of the build!

Paul Harrison

kitnut617 · August 30, 2009, 08:18:52 PM

Cheers Paul --- I knew I had posted on BM but I thought I had done it here too ---oh well

kitnut617 · September 03, 2009, 08:17:15 PM

Got some more done, I've re-developed the transition part to suit the GR.3 fuselage and I've made a decal of it and applied it to a sheet of 1mm card. I've cut the 'fingers' into shape and after giving them a slight curve, made the part into a cylinder. After a trial fit up to the fan front, I decided to leave the pour lug on the back of the fan front as this will assist the line up of the transition. I'm going to concentrate on just one of the new nacelles for the moment and work out all the problems, this should speed things up when I do the second one.

kitnut617 · September 05, 2009, 02:02:40 PM

Looks like all my brain-storming is beginning to pay off, I've glued the transition to the fan front now and to grip all the fingers together equally I squeezed them in with a rubber band, then superglued the finger tips first. Once that dried I flooded all the gaps between the fingers with liquid cement. Once that dried I started chopping the Harrier fuselage good and proper, the transition will start just before where the existing wing root starts but I want to keep part of the nozzle fairing and the hole where the nozzle sticks through. This needed a bit of careful cutting but in the end it has worked out quite well, I'm going to try and make the nozzle rotating mechanism work so I've had to cut a couple of notches in the transition part as well but until I get the insides of the fuselage finished I won't be able to tell if it will.

The wing root will be cut off, as you can see on the starboard side as it just gets in the way when it comes to join it to the new wings.

kitnut617 · September 05, 2009, 02:04:57 PM

Here's what all that work results in, now all I have to do is all that again for the other side.:

Sisko · September 05, 2009, 05:14:23 PM

Wow some great work here!

Watching our for more

John Howling Mouse · September 05, 2009, 06:31:22 PM

Certifiably crazy bashing goin' on, Robert!

kitnut617 · September 07, 2009, 06:17:50 PM

I'm going to be using GR.7 nozzles in these GR.3 fuselages but I have to do some modifications to how they are mounted. I was going to try using the mechanism that allows all the nozzles to rotate at the same time, but that proved to be not possible. So I've had to fill in the large holes that the GR.3 nozzles go in and make them like how they are on the GR.7. I've also cut out the new main u/c bay, the rear fuselage now being just a streamlined fairing for the wheel bay and support for the puffer boom. I'm using some Monogram 1/48 Harrier u/c here, which looks better when it's fitted up to the Canberra fuselage, the 1/72 main u/c looking ridiculously small, the new wheel bay is quite large though and fits perfectly. I think I will slim down the very end of the fuselage though. I had one set of the 1/48 main gear and Barry (JHM) has kindly provided me with another for the other nacelle ---- thanks mate

.

kitnut617 · September 11, 2009, 05:19:34 PM

I've had to re-think how I'm going to do the wing, I found that I had not allowed enough room between the fuselage and the new nacelles. So I've cut them apart and started again but this time making the inner wing a bit further apart. I'm using a large main spar, a piece of .25" x .125" rectangular styrene tube which just happens to fit inside the wing at the thickest point but I've had to taper the ends so they fit inside the outer wings. I've lined up an edge of the spar with a panel line on the underside of the wing which I think is where the real world spar is and so I get the spar in the right place in the outer panel I drilled a small hole which straddles this panel line, this way I can see where the spar is on the inside. The panel line conveniently runs along the rear edge of the wheel well in the inner wing.

kitnut617 · September 11, 2009, 05:40:04 PM

I'm now ready to figure out where the new nacelles will go, my thinking is that the center of the four nozzles in each nacelle should be very close to where the load cg is of the aircraft (in profile) and as the Canberra is a tricycle u/c type the cg should be a bit further forward than the main wheel center, I was thinking maybe as much as 9 to 12 inches in front (real world). So I ask John Adams (Aeroclub) if he could help out with a cg diagram which he kindly did, but I wasn't prepared for what it showed, a full 42" in front. This changes how and where I was going to fit the nacelles because this brings the forward nozzles right up to the leading edge of the wing.

In this photo I've marked the wing with a black line where the load cg is (near the leading edge) and this now positions the nacelle so that the puffer boom doesn't protrude so far out behind the trailing edge and also brings the u/c leg in the nacelle right under the spar I've put in the wing. This will also influence where the load out gets positioned too, and it's not where it's usually carried on a Canberra. Looks like I'll be using some of the Harrier pylons afterall.

Sauragnmon · September 12, 2009, 09:41:43 AM

Seriously, Kit, that is looking seven shades of wicked. Absolutely insane. Keep it up!

Weaver · September 12, 2009, 09:47:57 AM

Awesome project Kit...............

kitnut617 · September 12, 2009, 10:34:59 AM

Thanks guys, I'm doing a parallel build progress on Britmodeler in the Canberra GB over there, and someone has just pointed out something I need to keep in mind. There's a thrust difference between the front nozzles and rear nozzles, he's told me it's roughly 58% rear and 42% front. This would mean I can move the nacelles back a bit, which I want to do anyway. Is there anyone here that can confirm those thrust ratings ? I've had a look on the internet but I can't find anything more than a comment of 'the front and rear nozzles have about the same thrust'. The engines in this project would be the same as what the Harrier GR.7/9 has, or even better, the proposed 25,000 lb thrust engine.

Robert

kitnut617 · September 14, 2009, 07:41:21 AM

The same fellow that told me about the nozzle thrust difference also posted a link to Harrier.org in a later post, I'm afraid he got it a bit wrong, it's actually the other way around but with added info. When reading the 'propulsion' section it says that after the air enters the intake, 58% is diverted into a plenum then out the front nozzles, the remaining 42% goes through the engine and when fuel is added and burnt, it produces about the same thrust as the front nozzles when exiting the rear nozzles. It then says the aircraft cg is center of the nozzles when they are in the lift position. So my original thoughts are on the right track and all that has changed was really locating the actual Canberra cg point. On with the show ------