Hi guys
I haven't flown for months after selling a few of my planes and decluttering. Other hobbies have taken over recently.
However, I still miss fpv and have kept the bare minimum gear to get in the air and have some fun. I also have some damaged kit which I can't really sell which I intend to use to build a cheap expendable fpv plane.
My wing of choice is a tbs cap. I loved my old one and it was so compact, I ran it with the standard electronics package but with a 3s battery and it was great.
As this is a budget build, I want to use what components I have lying around. This includes
3x 2700 4s batteries
2x MFD autopilot. One is smashed up and missing the peripherals the other water damaged. Goodness knows whether either will work
Water damaged EzUHF rx
I want this to be an all purpose wing. If I give it the beans a solid 50-60mph would be nice- but I'm primarily aiming at medium range efficiency. To get this from a 4s setup (I don't want to buy new 3s batteries) I feel I need to aim for a low kv motor.
I was pleasantly surprised to find a fair few of HKs light motors happy with 4s power.
Can anyone suggest any suitable motors? And what do you think to the following two?
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=25081 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=25081)
http://www.hobbyking.com/hobbyking/store/__25080__NTM_Prop_Drive_28_30S_800KV_300W_Brushless_Motor_short_shaft_version_.html (http://www.hobbyking.com/hobbyking/store/__25080__NTM_Prop_Drive_28_30S_800KV_300W_Brushless_Motor_short_shaft_version_.html)
As a guideline- the tbs 3s package is about 250W and 59g so I'm aiming for similar figures- just a much lower kv motor for greater distance.
I'm leaning towards the 900kv motor above as I think a 9" prop isn't a ludicrous size for the cap to be dragging around (it uses 8" in 2s form anyway). I may experiment with a 8x6 perhaps to gain greater cruising thrust provided launching isn't too tricky.
Anyway- I don't even have an airframe atm- but I figure I may as well spec her up :)
Any advice would be great thanks.
My advice would be to avoid NTM motors if possible. I've had one which the bearings failed on after 2 flights, and I've heard nothing but bad things about them.
Why not go for a sunnysky -
http://www.banggood.com/Wholesale-SunnySky-X2212-KV980-Brushless-Motor-p-60600.html (http://www.banggood.com/Wholesale-SunnySky-X2212-KV980-Brushless-Motor-p-60600.html)
980kv, nice and light and copes easily with 9x5 props on 4S. I've never had one go wrong on me.
Also consider the flyingwings falcon EVO airframe. Much cheaper than a Caipi and just as capable.
Just to argue the other side of the NTM motors, I know a few people on here have had them burn out. I've used (And still do!) NTM motors on almost all of my fixed wing and multirotor aircraft and have never had one fail. The 800KV ones you've got listed I use on my Discovery Quad on 4S with 1045 props, and on a Hex with 1238 Props 4S with no issues.
With regards to your specific build, the 900KV could be good, the 800KV would be too low (I wouldn't run it on any less than a 10 inch prop on 4S)
Everyone I've ever known with a TBS Caipirinha has been really specific about how finicky it is when its loaded up. The CoG has to be spot on as well.
I think you're gonna struggle with 4s batteries, plus an autopilot etc. It certainly will have altered flight characteristics from what is optimal.
interesting thoughts guys thanks
this will be my second tbs cap. You're right Steve it's super cg sensitive. and loading with an autopilot will be pushing it. but I think it will be ok. mine still flew well even when loaded up. in fact the super light spec was so affected by wind I preferred it a little heavier. the tbs 3s setup runs a 4000mah 3s- so a 2700 4s + autopilot won't be drastically heavier I reckon.
iwan- thanks i have had a Falcon too. tbs was smaller, WAY more crash resistant and looks cooler. I had a very efficient setup on my Falcon. with hindsight it was perhaps slightly underpowered- i didn't have the confidence that it had the power to get out of real trouble. it is an option though given how cheap the airframe is. a slightly more powerful motor and it's a good second option. it would probably have taken on a different personality with a slightly more powerful motor. perhaps I should look out for a used Falcon on here.
interesting on the ntm controversy. sunny sky def seems like less of a risk.