Sunday, June 9, 2013

Quadcopter : Crash damage and Plan D...

Well the picture tells the story of a large crash. Completely novice mistake.

I was flying outside my house on a fairly calm day and was getting confident, that was my first mistake. I flew away and too high, so in the process of bring it back I over corrected and landed on the garage roof. The roof is steep so it slid down and flipped over the gutter and onto the concrete below.

The frame had stood up to my novice flying and crashes very well, I can not complain on how strong and sturdy these frames are. Luckily I had purchased another frame kit so I could swap out the broken arm. I replaced both front arms to be red to try and help with orientation.

I have sure learnt a lot over the last couple of months I have not really succeeded in my aim to make a cheap quad, all my fails and lessons learnt have been $$ and I am still not a lot closer to becoming a better quad pilot. It turns out this is much harder that first thought for a complete RC novice.

So what would I do differently from what I have leant to date :

Frames : Starting out I would just by one, as demonstrated above the RCTimer 450 frames are very strong and cheap, get two of them as you WILL crash, it saves the 3 weeks wait on shipping if you have the spares already purchased. Buying a complete frame kit works out cheaper than just one or two arms.

Props : The RCtimer 10x4.5 props that came RTF kit are useless and the hub is waayyy out of balance.   They only last a single crash. The 8x4.5 from Hobbyking have been great, they taken a lot of abuse and crashes and have survived.

Batteries:  I have also leant another hard novice lesson. The low battery warning device I got from HobbyKing works well but kicks in well below the 80% that is recommended, I found this out after I bit the bullet and soldered up the KK2 for battery warning.   It highlighted that I was draining the Turnigy 3S 2200s well below the 80% mark.  I have properly done some serious damage to these two batteries.  This also explains why they were taking so long to charge and I was seemingly getting good long flight times. 

With the KK2 batt warning set to 112 (11.2) I am now only getting about 5minutes flight time before the warnings go off.  And the batteries charge in about 1.5hrs. 

I want to have longer flight times, yes I know that I could order larger batteries or run both in parallel but I have decided to go a different route. 

This RC bug is addictive... So plan D 

From the first plan to build a big DIY wide Quad, to a smaller BlueSkyRC HQuad (Still have plans for this ), to the RCTimer 450 frame .... now comes "Plan D"

What is "Plan D"

Im going small... and light as possible to get longer flight times so more stick time per battery to learn to fly these bloody things.

So what will Plan D be ..

Frame : F330 150g
Motors : SK3 2822 1275kv  31g
ESC : QBrain  112g
FlightController : KK2  55g
Props : 7x3.5 Tri or 8x4.5 
Battery : 185g
Landing gear : HK-500GT   60g Skids and rails (they have held up really well to the abuse on the 450)

Total weight about 690 -700g

Based on the excellent eCalc I should get about 12-13 Hover time, which is all im really doing at this stage.  Waiting for all parts to arrive before i can build this one. In the meantime I will keep flying the 450.