RE: LR-1 Pylon racer
Greg,
the CG seems really good at 2 5/8" from LE at fuse, just a touch of down elev when inverted. Stall was very mild (AUW 3 lb - 5 oz)
I'm going to try something that I've seen the Quarter 40 guys use, and thats a nose skeg/skid. They just touch down with the prop stopped and nose it over onto the skid. It seems to work well for them so I'm hoping it should work for the LR-1. I have no problem touching down softly, the problem is that it is still above stall speed and wants to lift off again if you try to get the tail down. With a skid, I'll just bump the plane onto the nose/skid and it should stop pretty quick.
What I need some suggestions is on the power system. According to P-calc, the Aveox 36/24/1.5 should be pulling around 65+/- amps with an APC 7x7 prop.
I ran a 3S2P of the Maxamps 2250 cells and measured 97.5 amps max static at 19700 RPM with the 7x7 apc. This is what worries me. I know the P-calc is just an estimation, but it is pretty far off. The motor seems happy at about 65 to 70 amps (approx 2/3 to 3/4 throttle) so I suppose I can do most of the flights at that setting and only burst to full throttle occasionally. I don't know if electric motors "unload" like IC engines do in the air, and if so, does the amp draw go up or down? Also, I keep reading about it not being a good idea to run the ESC's at partial power because it heats it up too much. But I'm not sure if this is for the really high powered guys or what.
I also checked the amp draw with the 3S3P TP 2100 cells and got about the same 96 amps max static, but the voltage dropped faster on the TP cells.
I picked up a 7x6 prop to use if the 7x7 is too much for the setup. But I liked the speed with the 7x7. I suppose a 7x8 or 7x9 would start melting and puffing things so I'm looking for suggestions.
Ciressarg said it right when he said that we need a 3s2P 100 amp continuous pack for this plane.
I'm not sure if I can go higher voltage and try to drop the amps a little. All my packs are 3S so I don't think a 6S1P would work.
Open to suggestions..