The next Club meeting at the Rudgleigh Inn, Easton in Gordano, Bristol
Tuesday 31st March 8.00pm
Indoor Flying Sports Hall at Nailsea School
Friday 27 March 2015 20:00-22:00
Just thought members might be interested to know how uncompetitive some E-bay suppliers are, compared to mainstream suppliers. I deal with Hobbyking quite often and was pleased to hear the company has opened a new warehouse in the UK. Now you can buy ready made planes to motors and battery packs direct here. I know the site does not offer the full range of merchandise available from Hongkong, but the range is increasing all the time.
I ordered a warmliner glider called the Speedy. It is a 3 channel fibreglass all balsa sheeted wing. The build quality is very good for a Chineese model. Less can be said about the assembly instructions that were missing. A quick email to HK ande instructions were included for download on their site.
I used these HK 15322 slim digital servos in the wings and also for the elevator. Speed, power and resolution is excellent for the price of £6-37 each. So here is the rub, I checked on ebay and found the same servo for sale on e-bay, probably bought from HK. The E-bay price is £11.95 WHAT A RIPOFF see here HK e-bay servo price
Model: Prop Drive Series 2836 2700
Motor Wind: 6T
Max current: 50A
Max Power: 520W @ 11.1/V (3S) / 595W @ 15v (4S)
Cell count: 3s~4s
Bolt holes: 16mm & 19mm
Bolt thread: M3
Prop Test Data:
4.75x4.75 - 11.1V / 311W / 28A / 0.7kg thrust
4.75x4.75 - 14.8V / 594W /40A / 1.12kg thrust
5x5 - 11.1V / 400W / 36A / 0.85kg thrust
6x4 - 11.1V / 520W / 46.8A / 1.2kg thrust
Initial static tests indicate a current draw and power of just over 600 watt on a 3 cell pack. I am undecided as to use a 3000ma or 2300ma pack.
The balance point suggests a 3000ma pack might be better, but the weight penalty goes up. having said that, this plane will thirve on the extra weight. Having watched a test video on the USA site, I followed their advice and replaced the wing joiner with a combination of Dural and ply, just in case the G force got a little high in the turns. The wing is glued together and fixed to the body by front wood lugs and one rear screw. Experience shows this will be insufficient in heavy use, so I added a front cross ply plate and fixed the front of the wing with another Two nylon bolts. All in all, the plane looks good, there were a couple of issues with fixing the tail plane in that it was slightly out of square with the fin. While gluing the tail plane in I managed to twitst it a little to bring alignment nearer parallel. It was necessary to pack one side of the main wing bearing shoulder with some tape to bring both surfaces properly in line. But this was only a minor problem.
Now the only question is when will the weather play ball for a test fly. I will add more to this story after the first test flight.
At long last I have finally flown this machine. It is certainly a hairy machine at takeoff. With full throttle applied it will hand launch, but climbs in to a very very steep climb curve.reducing power helps, but I found it better to mix some down elevator with the throttle to iron out this tendency. It certainly travels very fast and if this is a warm liner, then I just hate to think what a HOT Liner is like to fly.