View Single Post
Old Dec 09, 2012, 12:16 PM
WhalleyB0Y is offline
Find More Posts by WhalleyB0Y
Registered User
WhalleyB0Y's Avatar
Canada, BC, Surrey
Joined Jul 2011
960 Posts
I finally had a chance to maiden my FJU with the suggested 3600kv motor and 6x4 prop. I started out with a 3s 3500mAh 30C lipo pack and did an easy overhand handtoss. It got airborne without any issues and once the trim was adjusted it flew quite well. I noticed how quiet it was on 3s when compared to the other FJU's at this field. While I had no way of measuring speed and I was at the field by myself I cannot say how fast I was going. A few seconds into a high speed pass and it was already getting to the edge of my sights. I brought it in for a landing after 5 mins and it slid along the frosted grass for about 40 ft coming to a stop on the sidewalk. The paint on the belly had rubbed off. The motor and mounting plate was both cool to the touch.
Now I put a 4s 3500 30C pack in and did another overhand toss. The plane was noticeably torque'n with the prop as it lifted up and flew away. Now it was louder and screamed like a banshee going past which seemes more familiar to me. It was also alot faster as expected but still not as loud as the other fJU's I had seen. It seems a quieter plane can create the illusion of also being slower. I didn't have the courage to hold on full throttle for very long so it must have been pretty fast.
My next trip out I would like to try smaller lipo packs, maybe 4s 2200's because the FJU felt heavy coming in for landings. I also was expecting this setup to be mind blowing fast but it seems to fall short in this aspect. Maybe because it was so quiet or maybe because the packs were large. After two back to back flights the motor was still very cool so at least the heat-sink and cnc motor plate with the heat paste was working well. The half spoon air intake over the back of the motor and esc was also doing its job well.
I got back home and got it plugged into the laptop to see what the CC logger had to say. The currents was within range and the rpm's were as expected. The temps never went higher than 60*C and the graphs showed how quickly it cooled down after a high speed pass. The packs did sag and there also seems to be a ripple even despite the cap pack I have in there. I will post the graphs next.
WhalleyB0Y is offline Find More Posts by WhalleyB0Y
Reply With Quote