A Me 263 or is it J 247 from a Cloud Models Me163

[Erfolg]

Although i did vow to leave things until today, I could not help myself, I thought of another check that could indicate the source of the low watts.

That was to use an old Lipo that came recently out of my Delta, which i suspected a cell was going down under load. Connecting up, and then running the motor did indicate that the Lipo was the source of the problem. The now characteristic hunting at full throttle then a fall of watts. I was a little perplexed as the watt meter was showing 9.5v having fallen from over 10v, an inversely (linearly) proportional decline with respect to time. What I mean is the watts were falling! Now the watts were about -200 watts down to 150 watts.

I then thought, lets try a another ESC, although I only have a 30 amp ESC, with the watts down to the extent they were, if the problem is Lipo based, there would not be a amp issue. If on the other hand it was the ESC, then by watching the watt meter i could limit the current drawn via the throttle. There was a strong indicator it was the Lipos that were limiting the watts.

Come today, I was now ready to try another known to be good Lipo and the 60 amp ESC. Although with the wind and rain i had realistically have to work in the kitchen. For safety to the fabric of the kitchen, I placed a barrier of cushions in front of the model if anything went wrong. I think you can guess that the better half is out chauffeuring and cooking for the grandkids.

I now found that my tachometer battery is flat, so no rev readings could be taken. The good news was that on opening the throttle, I now have 500 watts.

So I have placed an order for two 40c 2200 3s Lipos. The duration on full power is not anticipated to be good. Although some of the motor/propeller tests suggest that the thrust could be higher than the models weight. Every thing then depends on the glide ratio and speed on the glide, to decide if the model is viable.

I have a small amount of finishing off whilst awaiting the new lipos, plus the disposal of the performance compromised lipos.

Reasonably happy now.

 

 

Edited By Erfolg on 08/02/2016 20:24:56

Edited By Erfolg on 08/02/2016 20:27:17

[Erfolg]

The model has now flown (above 3m). However the jury is out as to all the flight characteristics of the model.

The model was flown by my test pilot, the model being placed on the field some 10m from the pits with the take off parallel to the flight line.

When the models motor was set to full power the model shot away, as i was making my way back to the pit area (I was well behind the model). From my position I observed the models tracking, which varied from bump to bump. Just before lift of, i did see a rudder input, although there could have been others which i did not see. I was wondering if the model would lift off before running out of mowed area, or stray into the very poor mowed area. Lift of it did, by now I was pretty much behind the flight line. It did strike me that the latest addition to the "A" test, is very demanding, for some models, even with the very best pilot in control. Although I am confident that I could keep the model tracking pretty straight when standing behind or to one side, at 10m (30 feet) this model will test me.

As it climbed out I did wonder would it suddenly pile in, as it had on the very first flight a few weeks back. The answer was no.

For the next 3-4 minutes the model essentially undertook very fast circuits, with a couple of straight up climbs. Although in general the model was flown fast in circuits, either square or figure of "8"s.

My pilot suddenly called landing, the model entered a medium sweeping turn, into the landing approach (for the day). The model flared, touched down, then was airborne again, at the same elevation. As an observer I could it was proceeding from one bump crest to the next. The noncompliant undercarriage absorbing not one bit of the undulations.

When it came to a rest, my pilot said that the CG needs to come forward, as at present the model has to be constantly flown, and that he had been unable to trim it out. The reason being it was so unstable, that any attempt at finding a neutral position was out of the question.

A figure of 1/4" (6mm) was decided upon.

I have now inserted another CG plate @ this position, the Lipo position adjusted to obtain a position.

This method works very well as I can see at a glance that the model hangs perfectly level, or i could adjust to a slight nose down position etc.

Although I am very satisfied that the model does fly and is very fast, I do want to be able to slow down to at least fast.

Another thing which needs to be done is to write down the model weight, wing loading, watts pulled, revs, etc As I have taken some of the values, but have not recorded them it seems.

So here is hoping for a more successful third time in the air.

[Colin Leighfield]

It looks as if you're nearly there Erfolg.