mrbones121 said:
After getting a DJI Phantom 2 setup wth a FPV setup and gimbal at my work, I am now hooked on AUVs and I am looking to build my own now.
I am thinking about basing it around a DJI NAZA Lite and an E300 propulsion system and then buying the frame off of Ebay and I have no idea what type of controller to buy (a DT7 seemed to expensive for what you get). I don't want to spend an excessive amount on this AUV but I would like something that is reliable and that I have the option to modify and add onto in the future.
What type of controller should I buy? What do you think of this current setup? The E300 seems kinda pricey, is their a better buy out their? Are $30 Ebay frames reliable? Does the NAZA Lite preform well?
Thanks for the help!
OK - if you are serious about building your own multi from scratch then I would suggest you start by looking at some of the calculations needed to get yourself a viable aircraft.
Personally, I always start off with the AUW (after deciding whether I'm buliding a Quad or Hex etc and size). I include in that EVERYTHING but the kitchen sink. That means, frame, hardware (nuts and bolts), props, esc, cables, connectors, motors, FC, RX, GCU, Gimbal, Lipo's Telemetry modules etc, etc, etc. From your AUW you would need to divide that by the number of rotors which will give you grams of thrust per axis to get airborne. This WILL ONLY give you figures to get you airborne. You want to be hovering at around mid stick so you need to double these figures and give yourself some overhead (say 10-15%). This will give you an idea of what motors you should be looking at to give you the required thrust, length of flight wanted (depending on your choice of props and cells per pack).
Prop size and pitch are a HUGE governing factor in your design and not only have an influence on thrust/efficiency but also will affect how hard your motors work and therefore the temperature your motors will get to under hovering, flying and full throttle climb-out.
You also need to consider very carefully the maximum current that your propulsion system will draw. This will determine not only the Lipo pack(s) size you will use but also the guage of the interconnecting cables, power distribution system and of course your esc choice...... and all these decision go back to affecting the weight of course !
There are a plethora of variables to take into account when you are designing and building your own craft.
Once you have a basic knowledge of the things I mention above (and their interaction) I would strongly suggest you head over to eCalc
http://www.ecalc.ch/xcoptercalc.php?ecalc&lang=en and play around with some parameters to work out whether your decisions are viable.
Unfortunately it is not as straightforward as simply selecting a propulsion system (like the E300) and thinking that it will suffice.
When you work out your AUW (including what camera/gimbal combination) you want to carry it may just not be up to the task.
Alternatively if you design something that is way too overpowered you are missing the 'sweet spot' of efficiency again and you may well find the multi is very difficult to control.
Start with the basics..... What do you want to build...Quad, Hex, Octo etc, Frame size, what do you want to lift, AUW, target flight time and so on....