After the build comes the setup. This post is mostly documentation for my own use.
Posts tagged ‘maintenance’
After way to long, I finally found some time/weather combination to fly again. I’m a little embarrassed it took so long…
Of course, all my batteries were fairly dead. The glow heater was completely gone (0V), but was still usable after charging. My starter-battery was dead beyond repair. The LiPo’s of the miniTitan were is fairly good shape after more than a year in the fridge: 3/4th charged.
I got myself a new RC helicopter. It’s an electric one so I can fly indoors.
Here is the partlist and some basic specs:
624mm long, 120mm wide, 210mm heigh, 728mm main rotor diameter, 156mm tail rotor diameter, 750g weight
3500rpm/V, 20A continuous, 30A.60s burst, 12 stator windings, 8 permanent magnets on the (outrunner) rotor
(mine came with the miniTitan kit)
40A continuous, optional governor function
(included in the kit as well)
- 3x Hitec HS 65 MG (more detailed specs)
4.8 – 6V input voltage, 60° in 0.14s (4.8V, no load), 1.8kg.cm stall torque
- Futaba S-9257 (more detailed specs)
digital, 4.8V input voltage, 60° in 0.08s (no load), 2.0kg.cm stall torque
- R319DPS receiver – 35MHz band
1024PCM receiver, 8 proportional channels, 1 digital channel
- Futabe GY401 Gyro
Solid state gyroscope with Heading Hold (AVCS)
- FLIGHTPOWER 3s1p 25C 2500mA 11,1V
Continuous discharge 25C/62.5A, Climbouts 35C/87.5A, Max burst 50C/125.0A
- Flightpower V-balancer
LiPo balancer for up to 6s packs
Tanks flown: 0.3
Time flown: 0h07 (cumulative model timer: 27h10)
Rx battery recharged with: 1665 mAh
Tx battery recharged with: 583 mAh
Glow heater battery recharged with: 561 mAh
Starter battery recharged with: 148 mAh
Same weather as yesterday. I mounted my FlyCamOne2 and wanted to give that a try. Somehow, it managed to record 122 pieces of video instead of the 2 shots I planned. I glued the pieces together, but the result is “jumpy”, the quality is bad, it shakes like hell and is overcompressed, but just in case you still want to watch it: 2m18s, 13.7MB (x264 video, ogg-vorbis audio, matroska container, VLC plays this just fine).
After 2 minutes of flight, I suddenly hear a loud “tack”, but didn’t see or feel anything strange. I landed the heli promptly anyway to do a full check. The sound was fairly loud, since the heli was at least 100m away and was clearly audible. I checked the main and tail-drive gears, but none of them showed any damage. The rotor looked OK as well, until I examined it a bit closer:
The plastic foil at the top-tip of the blade somehow got loose and teared. This tip was traveling at around 430km/h (67cm from the axis, rotating at 1700rpm), which makes a lot of noise when something hits this wind.
Just swapping the blades with the spare (wooden) blades had my bird ready to fly again.
As mentioned before, the cooling fan of my engine needed some attention:
Tanks flown: 0.5
Time flown: 0h17 (cumulative model timer: 24h37)
Rx battery recharged with: <not recharged>
Tx battery recharged with: <not recharged>
Glow heater battery recharged with: <not recharged>
Starter battery recharged with: <not recharged>
Windy day at the field with dark rainclouds at the horizon. I took my chances anyway and practiced flying in windy conditions.
While preparing for the second flight, somehow the cooling-fan came loose (again)…
Tanks flown: 2
Time flown: 1h01 (cumulative model timer: 24h20) (including a lot of setup-time for the governor)
Rx battery recharged with: 268+1472 mAh (same behavior as some weeks ago)
Tx battery recharged with: 554 mAh
Glow heater battery recharged with: 439 mAh
Starter battery recharged with: 141 mAh
I just bought myself a governor and needed to test it out. Besides that, a fairly calm day at the field. Besides testing out the governor, I continued to exercise my figure-8’s and nose-in hoover. After the last flight, I noticed that the rotor wasn’t rotating as freely as it used to.
When investigating this at home, the tail rotor made a slight rubbing sound:
The locking pin to keep the tail rotor shaft in place came out of its place. Pushing it back and re-tightening the set screw solved this problem.
Also, I basically undid the tracking adjustment: “black” was too high, so I decreased its pitch by 1 turn.
A governor is a device that stabilizes the rotor speed using a feedback mechanism. The Hall sensor to detect the magnets attached to the engine-fan. Here is the report about the device itself, its installation and the first test results.uses a
From the 2 flights I did with the governor, I’m fairly happy with it. It does what I want it to do: govern the throttle to keep constant RPM. I must admit that I don’t (yet) do very demanding maneuvers…
Tanks flown: 3
Time flown: 0h51 (cumulative model timer: 21h29)
Rx battery recharged with: 173+1408 mAh
Tx battery recharged with: 672 mAh
Glow heater battery recharged with: 862 mAh
Starter battery recharged with: 62 mAh
Another windy but beautiful day. Verified the tracking with the new balance tape: still good.
Had to replace the glow plug; it completely died after (or during) the first flight.
Tried some (successful) stall turns, mostly on my right side. I didn’t dare to do it as much at my left side due to some unpleasant memories.
At the end of flight 3, the RPM suddenly dropped and the rotor started “flapping” again: the (new) balance-tape wasn’t so good after all…
When recharging my Rx battery, my Graupner Ultramat 12 reported the battery “charged” after pumping in 173mAh. Giving it a second try did fill it up by a total of 1581mAh.
Tanks flown: 2.8
Time flown: 0h58 (cumulative model timer: 18h30)
Rx battery recharged with: not recharged
Tx battery recharged with: not recharged
Glow heater battery recharged with: not recharged
Starter battery recharged with: not recharged
Fairly windy; Engine was a bit boggy on the second start; leaned it 3 more ticks.
The throttle-servo had a bit of play (tightened that) and the “black” blade was tracking a bit below the “white” one (corrected that as well)
Tanks flown: 0.1
Time flown: 0h07 (cumulative model timer: 16h04)
Rx battery recharged with: 870 mAh – 3028 mAh (@-330mA) + 3624 mAh
Tx battery recharged with: 933 mAh – 1615 mAh (@-200mA) + 1957 mAh
Glow heater battery recharged with: 386 mAh – 1651 mAh (@-180mA) + 2569 mAh
Starter battery recharged with: + ??? mAh – 4279 mAh (@-360mA) + 4572 mAh
Not really a flight. Just testing everything after winter maintanance.
Cycled the batteries. The glow heater battery was totally corroded. Mechanically removed the corrosion. Seems to do the job.