Possible reason for poor flying Baby Blender. CHECK your WEIGHT.
Hello Anthemius,
I had similar troubles flying my new Baby Blender as well. With the recommended CG of 3.25 in (8.255cm) I found that the plane wanted to climb out to the point of nearly stalling. I had to fly at only half throttle, with FULL DOWN TRIM in order to keep it from trying to climb. I then rebalanced it and moved the CG closer to the original CG shown in the build video (2.5 in or 6.35cm). It still wanted to climb out to the point of nearly stalling. I was fighting to keep it under control and did not really feel it was performing any better. It felt very tail heavy and sluggish and would nose up sharply with the slightest increase in throttle. If I dropped the throttle any lower it would start losing altitude. It was like it only flew at one speed. It rolled and looped ok, but it was not an enjoyable flight at all, as I felt like it was overly sensitive.
I think I found the problem when I purchased some additional foam board. There are numerous different brands and qualities of foam board. The foam board I initially purchased was not the recommended "Dollar Tree" foam board (Adams brand). It was from a craft store and had a glossy finish. I don't know what brand it was as it did not have a label. For comparison I purchased Elmers brand from yet another store. So between the 3 different brands, I found that the glossy finish and flat finish (Elmers) were TWICE the weight of the Dollar Tree (Adams brand). So my plane was exceptionally heavier than the original build done by Josh Bixler. Here are the numbers:
Craft/Hobby Store foam board (glossy finish): 8.7 oz / 600 sq in (246.641g / 3870.97 sq cm)
Elmer's brand from discount store : 8.3 oz / 600 sq in (235.301g / 3870.97 sq cm)
Adam's brand from Dollar Tree : 4.1 oz / 600 sq in (116.233g / 3870.97 sq cm)
After 2 flights I decided to retire the plane as it was not flying any where near comfortably. I took a final weighing of the entire plane at flying weight and found it was 2 lbs 3/4 oz (928.447 g). I then decided to take all the electronics off and bring it down to almost a bare plane (no powerpod and no gear) and the weight was ~ 1 lb 1 5/8 oz (499.668 g) so if I had used the Dollar Tree (Adam's) foam board the plane would have been about HALF the weight before the electronics/ powerpod, and landing gear were added. If your foam board is indeed 8.3 - 8.7 oz (235.3 - 246.6 g) per sheet than that would significantly affect where the CG should be. I had pushed the battery pack (2200 milli amp) all the way up so it was almost touching the back of the PROP, to get the CG further forward, but the performance was still poor at best. It really is kind of a shame as the finished plane looked like this...
I'm now in the process of building a new Baby Blender with the lighter Adam's foam board so we will see if it flies any better. I hope to post again in about a week or so.
Happy flying and more importantly LANDINGS
