Endurance - again!

Fitted the tiny 4ch 35 meg Corona radio. No problem getting it in as it is slightly smaller than the case-less 6ch Orange 2.4 but soldering the two aileron servo leads onto a single socket to create a Y lead was a bit fiddly.
Unfortunately the aileron servos ended up off centre and a bit 'drooped'. Of course with the servo arms being glued directly to each aileron it is non adjustable!

I did fly it this evening but with no washout, no dihedral and limited longitudinal stability it had 'interesting' flight characteristics.
A bit of surgery should fix it!

Cutting the servo arms from the end of each aileron is a bit brutal.

But it has all gone back OK. Not completely made good yet but a short (15 minute) test flight this evening showed the handling was fully restored. Not an accurate timed flight (no timer!) but it certainly looks like the 35meg radio has reduced the total current draw.

That would seem to confirm my finding that 2.4 uses quite a bit of power and is probably made worse as the rx's get ever more miniaturized!

Out early this morning.
Launch 6:58 am, Landed 8:02. Used 1040 mAh giving an average of 0.975A.
Will try again as the weather remains very calm to see if this result is repeatable.

Second endurance flight this morning did no go so well or rather it went too well!
Much more thermal activity and the Endurance climbs like a home sick angel in any lift. Actually kept up with the buzzards power off!
Puffy clouds, strong sunlight and blue sky makes it hard to see at 1000'(ish) so no great surprise I managed to 'loose it' and only found it again by entering a spiral dive so the sun reflected its bright white wings. This happened twice so I came down much lower - 400'(ish) and made sure I kept the sun well behind me. I just glanced at my watch but blow me down it happened again it was simply 'not there' when I looked back. Spiral again but no luck this time and being much lower I knew it would be 'down' in just a few seconds.
A friendly dog walker pointed and said just behind those trees. As the trees in the copse are about 100' high I could only hope he was right!
Fortunately he was!
It had come down right on the edge of a crop field which made retrieval easy but the ground was heavily ridged and baked rock hard.

A yard either way and it would have had a lovely soft landing although it probably would have been much harder to see!.
At least I got it back and the damage to the V tail means I no longer have any excuse not to fit a more conventional one!

With the weather as it is I had rather hoped to get the Endurance II back in the air by tonight but the gamage proved just a bit too severe.
Anyway got this far.

Wing spar repaired with top and bottom fish plates under the wing skin, the motor glued back in place and the battery compartment rebuilt. It must have hit the ground with quite a wallop as the solid Depron nose block was badly indented.

In fact it is quite hard to imagine how ploughed soil could do that to Depron! :woohoo
Still should get it flying with its new tail tomorrow.

More or less structurally finished.

Some filling and paint but it will be test flown like this first.
The elevator servo is built into the lower fin

In fact the servo provides much of the support for the entire tail assembly!

Did re- maiden the Endurance this evening.
No problem with no dramatic trim changes.
The new tail has about the same horizontal area as the V tail but rather more vertical. It is lighter but rather more flexible!
For 'endurance' flying it appears to be quite satisfactory but it may require some stiffening to ensure it could recover is it got seriously 'out of position'.

Another 1 hour endurance this morning with the cruciform tail.
With such long flights you do get to fully understand the finer points of its handling.
Interestingly the cruciform tail has reduced the roll stability such that it now slowly 'tightens' in a prolonged gentle turn (it behaves the same circling left of right) whereas with the V tail in needed the odd dab of pro turn aileron to keep it turning at a constant rate.
I was not aware that a V tail added to the roll stability!

It flew for exactly 1 hour and used 1090mAh so that is a 1.09A average.
I think I might go back to a V tail!

So I suppose the first test is to reduce the area of the fin to near that of the V tail.
I am still not sure it is not stability related as before it tended to fly straight now it tends to circle with no input required.

Yes but dihedral tips cost wing efficiency.