Jumping about like a mad thing

[Mikej]

Hi guys,

Hoping for some help please

Just got my Shogun V2 together and about to try my first flight (I also have a Honey Bee FP and I'm having lessons on a Raptor so wanted something in between :D ). I have a fairly basic set-up - still got the Brushed motor (with a brushless one ready for when it burns out), HS-55 servo's, Align Rx, PG 03 gyro, 2100 16C 3S lipos.

The thing that is concerning me is that when I spool up (the brushed esc kicks in pretty hard :( ) and then gently raise the revs the heli is jumping about a lot more than I would like. I'm wondering about relative blade heights (is this adjustable ?), or anything else that I should check to make sure that it is set-up OK - I'm pretty confident that the basic head balance is about right as it is only when it is about to lift off that it starts jumping - I understand about ground effect etc. - but this is not just that - the heli just doesn't seem to want to respond to the cyclic properly etc.

Any suggestions or pointers towards other things to check on my set-up gratefully received.

Cheers,
Mike.

[futura]

I've seen this jumping when there was slop in the connections from servo arm to pitch lever or at the ball links on the blade holders. Also check to make sure there is no "jittering" of the pitch servo. This was also made worse by having blades out of track. It all smoothed out as pitch went positive and the head loaded up pulling the linkages tight (outer most extreme of the slop).

That said, the slop was significant to make this happen. When holding the trailing edge of both blades and lightly twisting in/out pitch (with the electronics off/unpluged) the stock guns have a couple mm of play that should not translate into the jumpy result.

Make sure there is no play in the zbends at the servo arm/pitch lever. Check for slop at the blade grip ball links. Make sure your servo isn't jittering and track your blades....(fix slop before tracking blades).

I'm not sure if the two were truly related but I also had a jumpy gun when the spendle was slightly bent....again it smoothed out under load but the main blade disk did the "toilet bowl" move when slowing down from forward flight...tipping me off to the spendle. I'm not saying a bent spendle will cause it to jump but in the process of replacing the spendle, the result was that the jumping went away as well. There are a number of setup steps to do in replacing a spendle. One is making sure the blade grips are tight to the spendle, replacing the O rings, seting proper tightness of the blades in the grips and making the tightness equal.