WELCOME TO SMALL ROTORS
KYOSHO HEAD RAISE
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Lower Head |
Raised Head |
Test Flight |
Finished |
If every-one who has an R.C Helicopter gathering dust in their attic's gave them to me I would in all probability have to hire an aircraft hanger to keep them in.
Why are these machines so difficult to keep in operation, is it;
1....Money (the larger the heli the more expense)
2....Time (They don't fly themselves you have to practise)
3....Mechanical Knowledge (they are not toys they function like the real thing)
4.... Expectation (I thought I would be flying in a week but its been 6 months and I can only hover for 2 mins)
I think all 4 points are valid but for me number 3 is make or break. To illustrate this lets take a look at a project that involved 1 of these "gathering dust in the attic heli's".
Kyosho Head Raise
We were given an old type Kyosho Concept EP that had been bought secondhand and was prone to boomstrikes. The owner had given up on it and relegated it to the attic.
It had very short flight times (about 2 minutes) and was in a sorry state with its boom in 2 pieces (amazingly the belt was in one piece) and no blades.
A new set of blades for £22 and a tailboom £10 and it was ready for a trial flight to see exactly how it behaved.
This first test flight was a dissapointment as the battery it came with was not good enough to effect a lift off, this could have been partly due to its age or the fact it was a 7 cell, 1400 mAh battery as opposed to the usual 8 cell, 2400-3600 mAh. Luckily we have quite a few different types and sizes of battery for our heli's so there was no need to buy a new one.
The second test flight was again dissapointing as although the Kyosho took off it had a boomstrike on landing.
Basically we were back at the start again. We did not consider it worth buying another set of blades so a pair of Eco 8 blades were cut down and balanced and the boom was straightened. We were ready to fly again.
Since I have a Kyosho it seemed a good idea to compare the two; one big difference was the height of the head. The lower head on the older heli made boomstrikes almost a certainty if the landing was a little hard as the standard blades flexed down and impacted with the boom. we were hoping the less flexible Eco 8 blades and a higher head would solve the problem or at least improve it.
So how to raise the head, well one way would be to buy a new longer shaft and links but instead we decided to see if we could find a doner heli cheap at auction with the higher head so all we would need to do would be change the shaft and links over with extra spares if needed. This is a good idea if dealing with an older model where parts can be a problem.
We bought the doner heli for £60 and it came in good condition with a set of blades but no electrics.
It was not difficule to change the shaft although it was fiddly, in the end we changed the whole head instead of just the links as there was a little play in the old one.
So now the old Kyosho was sporting a newer design of head, a cut down set of Eco 8 blades and a higher powered battery; it was ready for test flight 3.
This time it flew for 5 minutes plus and landed safely but the tail was very sloppy.
Back to the drawing board again. On looking at the tail closely there was excessive lateral movement in the tail shaft. This was taken up with a small washer.
A tiny adjustment to the REVO mix as it was not using a heading hold gyro and we were back in business.The Kyosho now flies for 5 minutes plus and has a positive tail which coupled with the higher head should make for safer flying with less chance of boomstrikes
It is not a novice heli and it has to be flown positively; so was all the effort worth it.
To be honest probably not as it's age is against it but although it will not be in our 1st string at least it is "not gathering dust in the attic".
