RPM (thrust) Test --- PART 7

I did test 4, 5 and 6 again with a 7 x 4 inch folding prop. With this prop I got less thrust, but a higher RPM. This means that the accelartion of the aircraft will be slower due to less thrust. But eventualy the max airspeed will be the same due to the higher rpm. The 7x4 folding prop also draws less amps compared to the 8x4.5 folding prop. So if I would just make some training flights, nothing special. Then acceleration is no must and I could choose this 7x4 prop and extend my flight time.

I hope I can test my modified setup as soon as possible and upload a video. First in air test flight will be the modified setup with the 8x4.5 prop and the 2cell Lipo. Second thest will be the modified setup with 8x4.5prop and two Nimh batteries

RPM (thrust) Test --- PART 6

And now the test with dual Nimh batteries. I connected 2 x 7.2v nimh 700 mAh batteries in parallel. So I should get the equivalent of 1 x 7.2 nimh 1400mAh. This setup will give my plane the same weigth as the original setup with 1 battery. We got 7000rpm that is almost the same as with the 2cell Lipo. 270 grams of thrust. Compared to the 2 cell lipo 800mAh, we have a little less thrust, have more weight, but have more battery (energie) capacity. So at normal cruising speed this setup would have longer flight time.

RPM (thrust) Test --- PART 5

Now see what thrust we can achieve with this modified setup, but with the old crapy 7.2v Nimh 700mAh battery. This type off battery isn't a good performer but due to the efficiency of the 1700kv brushless motor we got more thrust then on the original setup. As you can see 6000rpm ~ 190 gram thrust. Because this rebuild is 70 grams lighter than the orignal setup I could even place a second Nimh battery. to be continued ...

Rebuilding the Goose

As we saw in our previous test, we can increase the power of this little cheap rcplane just by changing the battery.  But we know that the original brushed motors are not efficient and make this plane heavy. To get more performance or increase efficienty and flighttime I will rebuild this Tin Goose.

I'll replace the 3 original brushed motors by 1 brushless motor. After looking arround I found the Turnigy 2730 Brushless Motor 1700kv. This motor should fit in to the nose of the Tin Goose and would give me enough thrust on a 2cell Lipo combined with a 7 or 8 inch folding prop.



This modification reduces the weigth of the plane with 70 grams. In the next blogs I will test this rebuild with several types of battery and with a 7" and 8" folding prop.