Friday, 18 November 2011

Further Adventures With The mCPx

Well yesterday was a perfect day for flying - mild, bright cloudless skies and little or no breeze. Just as Murphy would predict though I had a day of appointments and other business to attend to resulting in no opportunity to get out flying. That just made me all the more determined to go out today and would you believe it the weather today was back to cloudy and breezy, with some quite strong gusts easily exceeding 20mph. This is well on the limit for the mCPx and more windy than conditions I have flown it in before.

Seeing as I had to go out anyway to the local post office I thought I would take it with me and go to the flying field - or more precisely the village green (now how quintessentially British is that, a term you wouldn't see used elsewhere in the world I dare say!). It is lined by roads on two sides and garden hedges and trees on the other two, is large enough to have a small children's football (soccer!) pitch in the middle and is covered in short to medium cut grass turf - just ideal for mCPx flying.

The Village Green

I started off flying quite gently, just gauging the wind and the effect it was having on the little mCPx. For such a tiny RC helicopter it handles the wind extraordinarily well. Then something strange happened. During this reserved flying the helicopter just started spinning like it was under full rudder and dropped to the ground. My immediate thoughts were that the main gear had dropped (as it will commonly do on impact but has never done before mid-flight), losing all transmission to the main blades and allowing the body to just spin. Actually it isn't even the likely effect of such an event and on inspection the main gear was still in place and there was no play at all in the main shaft. Further reflection makes me wonder if there was a momentary loss of power to the tail motor - with no counter-acting force to the revolution of the main blades the helicopter would spin as it did.

Having checked the helicopter over thoroughly and found nothing a miss I spooled it up again and as everything was fine with it I gave it another flight. It was performing quite happily so I decided next flight I would try putting it into Flight Mode 1 (which allows negative pitch for inverted flying). At this time the wind was picking up and clearly too strong now to try at getting the mCPx inverted.

The next flight I stayed in Normal Flight Mode and I was pleased with how well this sub-micro class radio controlled helicopter was handling the increasing wind. Then a particularly strong gust lifted it skywards and carried it towards some trees bordering a garden. In danger of going either into a tree or losing it over a hedge into a neighbouring garden I swung it around and pushed the nose down slightly to get it moving forwards and away from the obstacles. However, it was still drifting away from me and the extra lift from facing into the wind just increased its altitude further. My response was to push forward still further on the elevator to try and get some forward momentum into the wind but ended up with it just plummeting from the sky and into the fortunately soft grass.

The damage report:
  • Mud and grass on one of the main rotor blades
  • One missing push rod link from the swash plate to the blade grip (no surprise there then, these come off quite readily and you have to be prepared to lose a fair few)
  • Slight gnarling of a few teeth on the main gear but no tooth had lost its complete width so it is still usable until a replacement arrives (obviously as the main gear was thrown down on impact the motor pinion flat spotted just a part of a few teeth rather than going through the whole tooth had the main gear not thrown) - a quick test has subsequently shown that it still runs smoothly.

 The Derlin Main Gear by Xtreme - harder wearing than the standard main gear.

  Well, with no spare push rod links with me it was time to head home - reflecting on what had happened and what different responses might have been needed.

Time to get some more links ordered (I am down to my last two now) and wait for a slightly less windy day to try again.

In the meantime, here is how it should be done:

1 comment:

  1. Nice post but the mCP-X is infinitely easier to fly. Not only is it more stable to a point, but there is the size factor as well. It's smaller so you are not as intimidated of