The Jekyll or Hyde

25.25 of/sqft, so it is no light weight but I am sure it will fly well, maybe a bit fast for what it looks like.

Have you considered the effect on the ground clearance of say a 'firm' 1 g landing? In other words how much does the U/C 'sink' with another 4 kg resting on top of the plane. In addition in a firm landing it is possible the plane could be approaching the ground in a bit of a nose down attitude as well.

Quorneng wrote: 25.25 of/sqft, so it is no light weight but I am sure it will fly well, maybe a bit fast for what it looks like.

Have you considered the effect on the ground clearance of say a 'firm' 1 g landing? In other words how much does the U/C 'sink' with another 4 kg resting on top of the plane. In addition in a firm landing it is possible the plane could be approaching the ground in a bit of a nose down attitude as well.

I did measure it with the suspension fully compressed but thanks for the heads up. I think I will look into the prop size anyway. As Eric pointed out, it will be on 5s instead of the original 6s.

Don't overlook the fact that as the volts go down, the amps go up!

Crash, it looks like you've got about a 5:1 tail moment advantage, this means you only need to alter the tail weight by about 30gm. Any other solution will only add weight. Can I suggest cutting serious lightening hole in the tail feathers, leave maybe 10% all round, then cover with Solar film or some such. Do the moving surfaces as well, then you can attack the fuselage sides, leaving maybe 20% all round. On the subject of holes, round is OK, rectangular is better with rounded corners and don't elongate beyond 60/40, length to width.

Klippy, first may I wish you & all a happy new year. Thank you for the thought, unfortunately it has come to late as I have already cut the rudder & vertical stab down in size. The whole tail section was salvaged from the Edge, which being designed for 3D had huge surfaces.My original intention was for a STOL & the rational was that I would need large surfaces at slow speeds to maintain control. Due to my inexperience ( or not being that bright) the high wing loading means this is no longer an option, ergo, no need for a huge thick rudder sticking way out the back. This combined with moving the landing gear 15 mm forward & gaining 5 mm in the battery compartment means I now have a CG of 28% with 30 grams at the back of the motor mount. I did cut three air holes in the rear underside of the fuz instead of one. The end result although not so aesthetically pleasing is hopefully more functional ! Pictures to follow.

A few pictures of the modifications. From this; To this; Shame I didn't see Klippy's post first, but it's done now. The battery can't go any further forward than that. I have used Paul's idea & added Pilatus style dummy exhausts. The way it's going it will end up just as ugly too ! :S

crash happy wrote: Shame I didn't see Klippy's post first, but it's done now.

I was very late coming to the party! Too many outside influences!
Surely that servo under the tailplane can be moved way forward? Agreed it may mean an outside snake let in to the fuselage but you'll lose that extra 30gms you're carrying!

Alterations are slowly progressing. The elevator servo has been moved forward by 300 mm & mounted internally under the rudder servo, as suggested by Klippy. Access for adjustment through a cut-out in the bottom of the fuz, once set this will just be taped over. The rudder was originally push - pull with dual servo rods, this is now reduced to one as the rudder is considerably smaller. Servo arms have been changed for lighter nylon ones. The two 60 mm steel screws attaching the back of the wing to the fuz have been changed for nylon. I would have changed the ones at the front, but can't source any long enough. Small details but when added together they have made a difference. 30 grams behind the motor mount has been removed & 40 grams added at the bottom of the nose. The result is, slightly nose heavy with the CG at 28%. I am hoping this will be fine for the test flights & depending on how it behaves I can remove 5 gram segments as necessary. Last job ( when my daughter has borrowed some more tooth picks from work) is to extend the VG's to full span. Then I think it's ready to soar gracefully into the air, or not, as the case may be !:woohoo:

Great lessons in how to lose weight Crash, glad to know you're getting there.

All the mod's are now completed. I managed to source some stronger springs for the landing gear. The struts have been enlarged from 6mm internal & 8mm external to 8mm & 10mm respectively, with the springs internal. Quite a lot of time was spent getting the optimum ground clearance, travel & compression correct. It was worth the time & effort, I'm very happy with final result. The vortex generators have been extended full span of the wing. Lemon Stab Plus RX has been set up, calibrated & checked three times ! All I need now is some really nice weather for the test flight. It could be a bit of a wait ! :whistle:

What a lovely job crash! almost seems a shame to fly it, love the exhaust Stubbs.

Another modification on the Super Tundra. I was lucky to find a set of 4 second hand oil filled shocks. The larger of the two pairs ( with some minor modification) turned out to perfect & have replaced the inner tubes & springs. A much better arrangement, with the suspension close to the wheels. It hasn't flown yet but if the weather forecast can be believed, Thursday could well be the day !

As you may have seen in 'Been Flying', the Super Tundra finally took to the sky last weekend, with hands far more experienced than mine on the TX for most of the two flights. Although it flew, after some teething problems & a bit of adjustment, there is room for improvement.
I started work on this model back in October last year & quite a few compromises were made, mainly due to lack of suitable materials & my lack of knowledge. The plan now is to improve it as much as I can without a major re-build.
The first job was to move the rudder & aileron servos forward into the main body under the wing. They were originally about half way back in the fuselage 430 mm behind the CG. The reason being, at the time I had no tubes long enough for the control rods. Any longer & they were bending. Now I have a source of carbon fibre tube, this was the first issue to address.
With the addition of a 3 mm fillet to the underside of the fuselage, this has reduced the weight by 11 grams. A small saving I know, but from 430 mm behind the CG it should mean I can remove a lot more weight from the nose.
The next job will be to decrease the length of the flaps & increase the ailerons. I would like to increase the chord by 20 mm, but I am not sure that's feasible. Once the the flaps & ailerons are removed, I have considered adding a 20 mm fillet the length of the wing, but I am not sure how that will affect the aerofoil shape, or indeed improve lift ?

Ok, you're unhappy about aileron response, why not use some TX functions to add aileron movement to the flaps? Job done. While you're about it you could add some droop to the ailerons and flaps when you need it for low speed flight.

My own suggestion would be simply to replace the ailerons and flaps but with say 30% more chord. All the mechanical items remain the same and the overall effect on the wing section would be negligible but the surfaces would be significantly more effective. The increase wing area (reduced wing loading) would improve the low speed and as the area is added behind the CofG the nose weight might be reduced a touch.
As you are making new surfaces you could also alter the ratio of the length of the aileron and flap if you want.
In my book a win, win, win.