Spektrum Telemetry – Altitude and Flight Voltage in a Glider

I have recently been exploring the Spektrum telemetry system a bit.  I have fairly full house Telemetry install in my 50cc size Mustang but it has limited flight time at this point and getting it out in the snow wasn’t feasible so I started with a smaller testbed to do a little experimentation.

I installed a TM1000 Telemetry receiver into my Parkzone Radian glider.  I had recently replaced the original receiver in that bird with one of the new, low cost 4 channel DSMx receivers which just so happens to be telemetry compatible so by just running the standard wiring from the data/bind port on the receiver to the TM1000 I had a working system.  I then added the Altimeter sensor and created a little wiring harness to tap into the balance plug on the 11.1V, 1300mah LiPo flight pack and I had access to a fair amount of information.  I could see fades, frame loss and hold on each antenna as well as receiver voltage and the pack voltage plus the altitude.  I went out to my test area (known as the side yard) and made a short glider flight.  Here is what the display on my iPad looked like when I downloaded the data afterwords.  The red line is the battery voltage (note the drop in voltage when I was climbing/running the motor).  Green is altitude.

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While examining the data after the fact on the iPad was interesting and informative the best part was what the system allowed me to accomplish while I was flying.  During the flight I had the display up on my DX8 showing altitude and while having the motor shut down was able to get into some lift that I believe was coming off a neighbors roof heated by the sun.  I noticed a bobble that I thought might indicate some lift but couldn’t tell whether I was getting into a lift area or not… the bird was already at 500+ feet altitude and a couple hundred yards away at the time and I just couldn’t tell visually whether I was gaining altitude or not.  By peeking at the display from time to time and circling around the suspect area I was able to figure out when and where I was gaining altitude and was able to verify where to position the Radian to gain some altitude.  I spent about a minute continually peeking at the altimeter readout and circling back to the lift area and gained about 150′.  While I’m sure others could do much better and probably do so without any need for instrumentation, for me this was ground breaking stuff.  It was the first truly useful example of what these tools can add to the game that I’ve seen and it convinced me that adding telemetry could give me more than just some cool factor!  I’m already thinking about other ways to make use of some of the other available Spektrum Telemetry sensors.

Next time I’ll talk about my first experiment with the GPS sensor at our New Years day “freeze fly”.

Parkzone UMS Sbach 342 3D

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My Sbach – A fast but stable aerobat thanks to AS3X

I’ve had the little E-flight AS3X equipped Sbach for a couple months now and the first thing I’ll say is it isn’t what I’d consider a great indoor plane. It seems to fly better fast and I personally don’t enjoy spending all my time just “missing the walls”! However the stabilization system really makes it fly more like a larger model… Maybe akin to what you’d expect from a 40-60 power model. It’s quite impressive. Though I’m not much of a 3D enthusiast I have been trying out hovering a bit with it and it seems to be doable as power is not a problem.

As an outdoor airplane it flys very well with sustained knife edge, (use the side force generators from the beginning) crisp feeling 4 point rolls, loops small or large, stall turns, snaps and more within its repertoire. Landing takes a bit of work as it needs to carry a bit of speed for anything resembling a normal landing. The best thing is it can do all that in 10 to perhaps 15 mph winds if you remember to correct your flight line with judicious use of rudder! That’s impressive for a sub 3 ounce aircraft.

All in all, I enjoy the little Sbach. While the AS3X system does make for some seeming “resistance” to smaller control inputs, it also makes the plane track great even in high winds that other micros can’t handle. Flights don’t seem to be to short so the little 180 mah battery seems to be about right. It’s unfortunate it has a different connector than anything else I’ve owned before, there is a little adapter cable from horizon that adapts it to most balancing chargers so if you don’t get the model with the charger or want another option there is a fix out there.