...more than a nice-to-have Subsequent to the issues I'd experienced with the cable-operated water rudder on my Trainstar seaplane, I have retrofitted the float with a direct-acting rudder servo. I chose a 40g gram servo, rather oversized but the smallest waterproof servo that was available. I mounted this directly to the float in a cutout I made, the simplest and easiest method.
Today I had the first opportunity of trying this out at the resident lake, and the result was nothing short of a remarkable improvement. The Trainstar, which previously zigzagged around the lake at will, now tracked remarkably straight and true, the oversized servo making sure that the rudder didn't deviate a millimetre, a far cry from the now-evident lack of control with the cable system rigged off the plane's rudder.
I had originally thought a servo-operated system would be preferable, but hadn't wanted to cut into the floats. Now, having experienced the amazing improvement in stability and likely improved reliability, I would suggest a float-mounted rudder servo to be an absolute necessity...
...not as easy as you'd expect The Canadair 415, whilst claiming to be ARF, does presents some quite challenging issues not clear from the list of required items. Firstly, in order to run two ESC's from a single battery you need a special Y-lead. In fact this lead is so special that it doesn't exist. I decided, in the absence of anything else available, to modify a battery Y-lead, however this requires unsoldering the three connectors and reversing them. However I have discovered, posthumously as it were, that what you really want is an ESC set, which is two ESC's, 30A in this case, already wired together with a single XT60 plug to go to the battery.
This arrangement is actually cheaper than buying two 25A ESC's, a set of XT60 plugs, a battery Y-lead and resoldering. And probably more efficient knowing my soldering. Anyway, as I said, I only discovered this after ordering the above bits, but I think the ESC set is definitely the way to go.
The second challenge is how to mount the motor; I think the 415 was originally set up to have a reduction gearbox, as the motor recess is low in the nacelle. The kit provides sticks but no mounts for the stick. Additionally, these need to be offset mounts, mainly referred to as heat sink type, not those are usually available. Moreover, the diameter of the motor base needs to match the heatsink mount, unfortunately the motors I chose are have are an in-between 9mm. So I am considering installing a plywood firewall for a conventional mounting arrangement, however have still not decided exactly how.
Finally, although I'm yet to get that far, is the kit assumes that bracing wires will be fitted from the wing to the fuselage, to compliment the rather fragile ply spars in the wings. As no one wants to do this, one is then required to somehow brace the wing internally; I have some carbon tubes and rods I plan to use, although exactly how I will install them is still to be decided...
My efforts at converting to water planes has been rather fraught and, in many ways, echoes the tribulations I experienced when starting flying radio control. Firstly trying to find suitable venues has been a challenge in itself; too many people, too close to houses, too far to walk from the car or locations only occasionally accessible. And, with the Trainstar needing a fair bit of headway to get airborne, the size of the lake needs to be quite generous.
The Trainstar seaplane is also not the easiest to take off or fly, in large due to the oversize floats making it marginally powered. Additionally, the Trainstar is skittish on launch which, when combined with its gravid nature as a seaplane, make getting it airborne a bit of a hit and miss affair. Additionally, I've discovered that the cause of the Trainstar stalling and consequently nose-diving into the lake were due to the cable for water rudder sticking, providing no rudder input during left turns. I am in the process of resolving this by adding a waterproof servo directly onto the float, a much better system but which I hadn't adopted initially to avoid having to cut into the floats. Incidentally, the ESC didn't survive it's inebriation, becoming smoking hot to the extent it unsoldered one of the motor leads. This did, however, provided an opportunity to utilise a spare 35A ESC I've had sitting on my spares shelf for ages...
...first retrieval of the floatplane Today the planets finally aligned, with it being calm, the rain remaining in abeyance and access to the lake being open. Things hadn't gone smoothly on the way, however, having to dodge a police roadblock and then having to hunt for the secret access point. Finally, however, with all missions successfully completed, I arrived at the launching point ready for the Trainstar floaplane's second flight. There was just the slightest suggestion of a breeze, the lake calm and reflecting the tranquil palette of the surroundings. The Trainstar was equipped with the new larger battery, which I hoped would provide the extra flying time to avoid awkward situations (plane marooned in the middle of the lake with a flat battery) and also provide a little extra grunt when necessary.
The takeoff runs I'm still finding problematic, with the Trainstarbeing quite skittish at speed and having a tendency to veer. Nevertheless I did manage a few launches and some pleasant flying across the lake. The one issue I have encountered, twice in this session, is turning; sometimes the Trainstarwill get into a tightening turn, whilst other times it won't turn tight enough. It was the latter cases which proved problematic, with the Trainstarending up stalling and flopping nose-first into the lake. In a testament to the unsinkability of the floats, both times the Trainstarsettled back down onto the floats however, by the second occasion, the ESC had a little too much to drink and went for a lie-down. As a consequence I had to break out HMS Rescue for the first retrieval attempt. Due to the inflatable being nicely packaged up I hadn't bothered doing a test run beforehand, however I found that, in conjunction with the electric pump, the boat was ready to go in a few minutes and, once I'd figured how to install the oars into the oarlocks, I was on my way out onto the lake. The inflatable did surprisingly well, although my rowing skills left something to be desired. For the future I think I'll get some sort of tow rope for returning the plane, as trying to shepherd the untethered plane back to shore was rather taxing. So all ended well, except to see whether the ESC can be resuscitated or needs replacing...
...or at least arrived A post office card left yesterday was exchanged for a large cardboard box which I loaded into the car and scooted for home. It was the Canadair 415 water bomber, a bit ahead of schedule having been ordered from the international warehouse which usually takes a little longer, so there must have been a tailwind.
I've yet to unbox it, having just extracated it from its plain cardboard armour, but a brief inspection of the extra goodies I'd ordered came with a sharp pang of disappointment, the ESC's come with no connectors. On either end. That means five wires having to be soldered by mister useless. For each ESC, this being a twin-engined plane. Fortunately I have two spare XT60 plugs, however no bullet connectors for the motor. So that means a trip to one of the local hobby shop for some overpriced parts...
My efforts at getting the Trainstar floatplane in the air again have been unsuccessful, in part due to the weather, as in the case of today, in part due to misinformation, like yesterday, and partially because I want a completed deserted venue as I'm rather shy when I'm learning.
Yesterday I visit a great potential site, however it's bordered by houses but, mainly, had several fisherman whom I'm sure wouldn't be impressed with a buzzy floatplane invading their tranquility. However, on the way home I passed the lake where I'd first flown the Trainstar and was surprised to find the gates open, it being advertised as open only a few days a week. I'm now hopeful that this is the case on most days, so will be taking the Trainstar along in the hope that I will be able to fly it more regularly and with less complication than thus far.
...connector shmonnector The new Zippy compact batteries for the Trainstar were a bit of a surprise, coming with a different connector to what I'm used to. The Turnigy 2700mAh, with a 20C rating, had XT60's whereas the 25C Zippy has HXT's . I guess, therefore, that this is the threshold for the higher-rated HXT connectors. I've been trying to decide what to do, with my ESC having the XT60 connector, thinking that retaining the high-performance connectors would be preferable. However the mating connector has proved difficult to find and, as I recently realised, my charger doesn't have facility to connect to HXT leads.
So I might just change the connectors on the batteries to XT60's and be done with it. That way it'll suit the ESC and the charger, although necessitating changing two connectors, with soldering not being my nemesis...
