Quorneng
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So far I have described what I had built. This is my latest and as yet un flown.
At the same time North american was building the amazing mach 3 bomber the XB70 Valkyrie they also designed a long range mach 3 interceptor the XF108 Rapier.
I had already built a foam XB70
So I though it would make a good partner for it however unlike the XB70 the XF108 was never actually built being cancelled once it was realised that bombers were no longer the main threat as the nuclear deterrent had shifted to ICBMs.
This is an artist impressions of what the XF108 would have looked like.
Interestingly North American did build a full scale mock up.
but it was highly secrete at the time so there are few pictures of it.
To make matters worse the design was not fully finalised when it was cancelled so there is no "actual" final configuration so whatever I select will be wrong!
I do have a 3 view.
It seems to be fairly representative of the main XF108 features so I will use it but those cut off "under fins" might be a problem for a belly lander!
As this will be a lightweight I intend to use two 12 blade 40mm EDFs. With a span of 32" (965mm) the inlet ducts will be plenty big enough to feed the EDFs.
The main part of the fuselage is basically a box so will be built first and then everything including the wings added to it
The ducts are printed in LW-PLA. The EDFs are buried inside the printed exhaust nozzles. with the EDFS right at the back the batteries should need to go in the nose forward of the inlets. Note the solid magnet wire EDF wires led through the foam formers. Such wires only weigh about 1/2 that of convention silicon insulated multi strand wire.
Next the wings
Although a thin symmetrical section with just top and bottom skins in 3mm foam they are stiff enough without any reinforcement and are simply glued onto the side of the fuselage box!
The fin and top skin are added once the elevon servos are in the wings and the servo wires run forward. The negative dihedral wing tips are similarly ust glued on.
Finally the nose is built as a 'stand alone item' and simply glued onto the front of the fuse;age box between the intakes.
When the nose hatches are complete it is given a brushed coat of acrylic silver as an undercoat and finally an acrylic spray to achieve a more metallic finish. Finally the cockpit glass detail is painted on.
With a 1500mAh 3s on board it weighs 368g (16.5 oz).
A nose down thrust test onto a set of scale showed a thrust of 458g giving a 1.2:1 thrust to weight ratio. Some true "vertical" should be possible.
About 5 weeks work compressed into a single post. I can only hope it flies as well as my XB70.
I will let you know.
At the same time North american was building the amazing mach 3 bomber the XB70 Valkyrie they also designed a long range mach 3 interceptor the XF108 Rapier.
I had already built a foam XB70
So I though it would make a good partner for it however unlike the XB70 the XF108 was never actually built being cancelled once it was realised that bombers were no longer the main threat as the nuclear deterrent had shifted to ICBMs.
This is an artist impressions of what the XF108 would have looked like.
Interestingly North American did build a full scale mock up.
but it was highly secrete at the time so there are few pictures of it.
To make matters worse the design was not fully finalised when it was cancelled so there is no "actual" final configuration so whatever I select will be wrong!
I do have a 3 view.
It seems to be fairly representative of the main XF108 features so I will use it but those cut off "under fins" might be a problem for a belly lander!
As this will be a lightweight I intend to use two 12 blade 40mm EDFs. With a span of 32" (965mm) the inlet ducts will be plenty big enough to feed the EDFs.
The main part of the fuselage is basically a box so will be built first and then everything including the wings added to it
The ducts are printed in LW-PLA. The EDFs are buried inside the printed exhaust nozzles. with the EDFS right at the back the batteries should need to go in the nose forward of the inlets. Note the solid magnet wire EDF wires led through the foam formers. Such wires only weigh about 1/2 that of convention silicon insulated multi strand wire.
Next the wings
Although a thin symmetrical section with just top and bottom skins in 3mm foam they are stiff enough without any reinforcement and are simply glued onto the side of the fuselage box!
The fin and top skin are added once the elevon servos are in the wings and the servo wires run forward. The negative dihedral wing tips are similarly ust glued on.
Finally the nose is built as a 'stand alone item' and simply glued onto the front of the fuse;age box between the intakes.
When the nose hatches are complete it is given a brushed coat of acrylic silver as an undercoat and finally an acrylic spray to achieve a more metallic finish. Finally the cockpit glass detail is painted on.
With a 1500mAh 3s on board it weighs 368g (16.5 oz).
A nose down thrust test onto a set of scale showed a thrust of 458g giving a 1.2:1 thrust to weight ratio. Some true "vertical" should be possible.
About 5 weeks work compressed into a single post. I can only hope it flies as well as my XB70.
I will let you know.
