Scale Soaring UK

The Dart in action with the 'sustainer'...


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Great Video as usual Chris, I liked the music too. Well done that man.

Fab, as always Chris.

Curious what happens to the motor shaft when you remove the prop?

Also have you run it through a wattmeter to find the max power taken by the motor? Interested in your W/lb.

Rog

Chris,

Superb model, video and music - as usual!

Jolly Roger wrote:Fab, as always Chris.

Curious what happens to the motor shaft when you remove the prop?

Also have you run it through a wattmeter to find the max power taken by the motor? Interested in your W/lb.

Rog

See, I told you they would want to know.

BC

Rog, the shaft protrudes through the centre of the nose, but it was initially cut a bit short. It has been replaced with a longer one by BC, but is still a tad diminished. (I think my hacksaw has a mind of its own) Other than that, I take the fifth amendment

When we test the Bergfalkes, which have the same set up, we will report back on the Watts per pound

chris williams wrote:Rog, the shaft protrudes through the centre of the nose, but it was initially cut a bit short. It has been replaced with a longer one by BC, but is still a tad diminished. (I think my hacksaw has a mind of its own) Other than that, I take the fifth amendment

Thanks Chris. I'd be interested to see details of the prop attachment. Last week I fitted a motor into the nose of a 30% Ka6 and arranged it so that once you've removed the prop, springs retract the prop shaft flush with the nose when you turn 4 bolts. To be honest I just got a thrill from the engineering and can imagine the prop staying on 99% of the time. I'll wait to see if it offends my eye in flight.

Have you noticed how the tide is turning in favour of nose-mounted props on scale sailplanes. Once scale sacrilege, it's drawing fewer comments these days. Aesthetically I prefer the clean-shaven look, but not when it means I can't fly off the flat or in marginal slope conditions. Also my gran had a fab moustache and I loved her to bits, so maybe I'll get over the look of it.

It's all down to Climate Change... Where once we could go sloping 2 or 3 times a week, these days we're lucky if it's 2 times a month. Having a sustainer should at least double the opportunity to fly, assuming that your local rules allow it...

I couldn't agree with you more Chris.Only too often, due to the wind being slightly off the slope or no wind at all have I been fed up with sitting on the grass just talking a good fly. Then like others in the same situation, driven by frustration thrown off only to find the dreaded sink. The Purbeck slopes here are spectacularly beautiful,but are not very high or steep,they therefore need all the aspects of the wind to be right to create our required lift. Also of coarse with a motor up front you have a get me home card should you need it and so are more likely to try out poor air then if you haven't got one.
I decided to fit motors to my gliders some years ago when brush-less electric motors were in their infancy. I now have most of my gliders fitted out with them and can fly any of them whenever the mood takes me irrespective of the wind direction and lift.
Also the venture into the amps,watts and volts makes for a new learning curve which can be embraced and enjoyed.

The purist of our kind who while sitting on their butts watching me fly will say "if you want power why not go to the power flying field and fly power" are missing the whole point. In my world I can switch off the motor and let it soar like a bird once at a height that the lift will sustain it. On a good lifting day I can leave the batteries out pop the prop off and revert back to a pure glider.
I like to fly aerobatic gliders like the Salto and the Fox. If after reaching height I aerobat downwards, I then switch on the motor and climb and aerobat upwards without the disjointed loss of momentum.
The purist might have a point if they fly the old timers which I would agree do not look right with a prop up front,however many of the full size glass ships are being fitted with props just like our scale gliders.There are many vids on YouTube showing this.I have included one to whet your appetite. So lets talk motors. regards Terry.



http://www.google.co.uk/url?sa=t&rct=j& ... ckrW7u8ozg

Re Terrys post, funny how full size is copying us, must be an opening fr somebody to make glider specific folding prop spinners.

This year has been my worst year flying always in the wrong direction when I am free for flying.my local slope is only good in a West wind for larger gliders. So now I am thinking it is time to add a motor to. My be my Vega ? Just so I can get some flying time.I was looking at the new Let gliders with front mounted motor in the full size world not seen anyone model one yet? Their dealer is just near to me in Northamptonshire/ Leicestershire .

Although the whole idea of electrification was to fly slope in light conditions, Mott & I took our E-Bergfalkes to County Model Flying club today for the purposes of experimentation. Geoff's using a 14 x 8 prop giving 43 amps @ 927 Watts on his (Approx 66 Watts per lb), whilst mine has a 14 x 10 giving 52 Amps @ 1105 watts (around 78 Watts per lb)
I timed a 400' climb with my model with a motor run of approx 18 seconds. I was using 2 x 3s 2700 Lipos. I did one climb to 400', then another, getting away to 1200' in a thermal this time. Then we did two more climbs to 400' after which the Lipos showed 50% remaining.
As I say, the model was built predominantly for the slope, but has proved itself pretty useful on the flat, too... (Both models were hand-launched in a flat calm without too much difficulty)

Turnigy G60 Brushless Outrunner 400kv
Turnigy Brushless ESC 85A w/ 5A SBEC
14/10 folding prop
2 x 3s Lipos

Rx powered by 2200 Lipo with 6v regulator