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 Watter Watter everywhere . . . ruddy things!

by Gordon Walker

Perhaps I should explain, Model Air-Tech Watter to be precise. "A speed 480 sport electric seaplane built primarily from 1/8" x 1/4" strip wood" by Tom Hunt - so it says on the plan (available from Gordon Tarling).

I had always wanted to fly from water and so it had all seemed such an easy idea to knock up a small seaplane for the then forthcoming float fly event in October. My club chairman had bought a built, but uncovered, airframe at the last ‘bring & buy’ and it looked pretty good and straightforward to put together, so a set of plans I procured. One evening to build the fuselage, tailplane, fin and waggly bits. One evening to build the wing, and a Saturday afternoon to finish it all bar gluing on the tailplane. Just as well as it turned out.

On Sunday, Dave (Dave Theunissen, he of electric Optica and 'And Now' fame) flew his Watter, 20 seconds later out came the Cyano and sellotape.

Yes, it flew but was a complete cow! The C of G was moved forward by over an inch from where indicated on the plan before it was half sensible to fly. But every "landing" the nose broke. Dave went home and did some head scratching and declared that the tailplane was way too small as shown.

So my A-Watter (pure stock) was never flown un-modified. A 24% tailplane was built and glued in place.

The next Sunday morning I was the first to arrive at the field. So A-Watter was given a jolly good lob and off it went on full power like a scalded cat, but, as soon as you tried to slow it down it would flick in either direction. Forty seven seconds later, in the rough over the back, the flight ended; luck was with me and nothing was broken.

I went home and put some washout in the tip panels, then went back to the field to try again. This time at least I managed to get the full charge from the battery! Horrible or what - under power, and rather less fun in the glide.

Decided there and then that I would sort the little blighter out, so went home and the Watter-B was born.

The Watter-B is the stock fuselage lengthened by 1 and ½" at the tail. Strategically placed extra diagonals in the nose are fitted to eliminate the turned up nose look after landing. The 24% tailplane is retained. A new wing with straight dihedral was built, with a flat bottomed section more or less copied from my X250, without the carbon spars but with a small amount of washout..

Test flights were reasonably successful, in that I could keep it under control, and the new wing was 1000% better. It was still fairly obnoxious if you took any liberties with it but it did give warning. After a fair amount of flying I was convinced that it was the down wash from the wing interfering with the tailplane that was leading to such problems if you slowed much, so the tailplane was jacked up by a 1/3" and, low and behold, the speed range improved once again and all at the bottom end and the glide now was entirely normal.

By now the rains had come and there was a very decent puddle next to our field on which a couple of other members from the South East Berks RFC had been honing their float skills prior to the float fly. So this was used one Saturday afternoon for my introduction to flying from water. It would have been a great deal easier if the tip floats were big enough to hold the wing tips out of the water. So for Sunday these were enlarged, which helped a bit. With four successful take-offs under my belt I was ready for the following week-ends float fly. No landing could be made on the puddle as I’m not that good as to be able to land on a one-metre wide runway!

The big day arrived and off I went. It was my first public event and my first float fly and my nerves rather messed my flying up.

First flight, good taxi out except where the tip floats were still not enough to hold up the tips when taxing out of wind. Stop the motor, count to ten ( to allow the model to line exactly up with the wind) and start opening up the throttle, twenty feet later and still only at 40% power we’re up on the step, at thirty feet and 55% power it unsticks and we climb away into the drizzle. Excellent, the flying not the drizzle! I must admit I struggled with the circuit and if the landing was like a kiss it would have broken your nose and at least 3 teeth! The slap of it was easily heard at the other end of the lake! Taxi back and drain a little bit of water out and put the batteries on charge.

Flight two, good taxi out, line up and open up, onto the step and phutt - nothing! Prop and plane dead in the water. A short wait to let the wind bring it back in and it is obvious that the ESC is not playing due to it being in the middle of a pint of lake water. Oops.

The rest of the day was spent watching the others drown their models in a variety of ways.

Since then the Mark III tip floats have been and are about to be superceded by the Mark IV. (Yet still more buoyancy with less weight and vertical area) and the C-Watter fuselage has been built which still utilises the B-Watter wing.

The main changes are obvious in the pictures below. Basically, 3" longer in the rear fuselage which has a second step in it. The tail boom is canted up to raise the height of the 24% tailplane above the wing. The fin area has been increased a little. And the effort that has gone into the waterproofing has gone up by at least 100%!!

Initial test flying has shown that the C-Watter is very nearly the plane I was looking for to start with and is incredible at very low speeds. It will climb out at about 60 degrees. I am even thinking of re-motoring it with a 6v Sp400.

The Watter-B is still in commission testing the removable undercarriage. The Mark III undercarriage is going to be brilliant, it’s a shame that I am still on the Mark I . . .M

My fascination with aquatic aeromodelling has grown and I have both a Herr Aquastar and a Pondside kit to be built this winter in preparation for the next float fly.

How on earth did I ever get into this?

Given the advanced state of technical and scientific research, you would have thought, wouldn't you, that the physics and chemistry of  battery charging would, by now, be a matter of scientific fact? Not a bit of it, apparently! Following the publication of Ray Datodi's excellent article on our last issue and my own feature on the Smart Fastchargers beautiful reflex charger, Tony Whiteley kindly drew my attention to an article (which has apparently been around for quite a long time now) on Red Scholefield's 'R/C Battery Clinic' website in which the unidentified author, referring to "burp" or reflex charging, rather sweepingly states, "While many claims have been attributed to this technique, none have ever been substantiated in the laboratory" and then goes even further by making this astonishing declaration, "The reflex chargers are for the customers that cannot separate marketing from sound engineering and feels compelled to perpetuate this hoax while providing a healthy income for its proponents". There are, I feel certain, thousands of us who are not qualified to 'separate marketing from sound engineering' and when we make a purchase it is done in good faith from the information supplied to us; neither do we 'feel compelled' into doing anything more than buying a piece of equipment which we believe is of use and value to us - certainly nothing as sinister in mind as perpetuating a hoax! Tony, by the way, was not necessarily subscribing to the opinions expressed in the article, but brought it to my attention to illustrate the disparity of views that exist on this subject.

Anyway, apart from the hyperbole of which the author is clearly guilty, I found it most interesting and bemusing to find that there is so much uncertainty about the subject as to give rise to such opposing views. Is it really that uncertain and, if so, why? I invited Smart Fastchargers comments on the views expressed in the article, of which they were familiar, and Carmen Horst kindly replied with a fascinating story of the way their product was developed and the warm and enthusiastic reception it has received from its many satisfied users. You can have a copy if you care to ask me, but we're not starting a debate on the subject!

In a very similar vein and on the same topic, every article I can recall reading on battery care and maintenance makes reference to the 'memory effect' of which we are all, therefore, so aware. We are told that it is essential that we should cycle our batteries from time to time in order to minimise the effect of this invidious characteristic of Ni-Cad batteries. It is propounded with absolute certainty by model enthusiasts, battery manufacturers and makers of chargers, etc. - EXCEPT ONE, in my experience! This is what Ripmax's Battery Division currently has to say about it in their Modellers Handbook, "Probably the greatest myth is the legendary MEMORY EFFECT which is supposedly caused by repeated shallow charging/discharging. In practice this is very difficult to produce, even under laboratory conditions. In general it should be TOTALLY DISREGARDED"! How about that?

Oh well, you pays your money and you takes your choice! But surely somebody actually knows!