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It won't be new to the old stagers but perhaps worth a documentation for newcomers.
My old sev2 with v3 upgrades was looking sad and it was really vibrating on spool-up and pretty lively on lift-off. I haven't flown it for a while but after loaning it to a plank guy to try..and he never got off the ground I thought it was time for a refurb.
A new mainshaft didn't make much difference. Mainshaft bearings were really good..the old one just looked old but straight so no suprise. With the head off there was still quite a lot of vibe..so decided perhaps it was time to swap out the mended lower frame parts out for new HK clone ones. It looked a lot better but almost as much vibe still. Next was to re-set the pinion mesh..now that realy made a difference!
Most of the vibe gone but still way lively to fly. So TT bearing checks (OK) nowt wrong with the tail..easy-pulled the boom and no reduction in vibe. To my suprise there was a subtle bend to the feathering shaft..so a new one and checked the grip bearings and for slop in upper head parts.
No real difference in fact..so time to re-do set-up from scratch. That was when i spotted a slight movement on aileron servo when slighty loaded. I didn't like the cost of 65mg's to replace the dud..instead I decided on MG90's all round .. same price as one 65mg.
Because the horns are a bit weak on those in comparison I reinforced the horns with epoxy and a layer of fine glass cloth (from the canopy repairing box).
Nice solid horns and set it up. Considerigng they are about the cheapest servos you can get they have zero ccpm interaction!!.
None of this made any difference to vibes of course and actually a pair of rotortech 325's I had new in packet only made a subtle improvement to the old chipped HK3D's..but it was all slowly getting there.
I was just generally fiddling with the model and realising that the 450M motor is so like a scorp that it could be out of the same mould.. so a couple of drops of scorp oil on its bearings..and voila..the last vibes gone!! (the old l and xl's never seemed to benefit)
It now takes off sweetly but isn't quite hands off. I did use a litle trim which I'll get out mechanically later.. probably just a half turn on the pitch link but the rest'll have to wait until I get to the field..the gardens a bit small to chuck it about in and it's raining...when i hope I can now up the tail gain too, now...
My old sev2 with v3 upgrades was looking sad and it was really vibrating on spool-up and pretty lively on lift-off. I haven't flown it for a while but after loaning it to a plank guy to try..and he never got off the ground I thought it was time for a refurb.
A new mainshaft didn't make much difference. Mainshaft bearings were really good..the old one just looked old but straight so no suprise. With the head off there was still quite a lot of vibe..so decided perhaps it was time to swap out the mended lower frame parts out for new HK clone ones. It looked a lot better but almost as much vibe still. Next was to re-set the pinion mesh..now that realy made a difference!
Most of the vibe gone but still way lively to fly. So TT bearing checks (OK) nowt wrong with the tail..easy-pulled the boom and no reduction in vibe. To my suprise there was a subtle bend to the feathering shaft..so a new one and checked the grip bearings and for slop in upper head parts.
No real difference in fact..so time to re-do set-up from scratch. That was when i spotted a slight movement on aileron servo when slighty loaded. I didn't like the cost of 65mg's to replace the dud..instead I decided on MG90's all round .. same price as one 65mg.
Because the horns are a bit weak on those in comparison I reinforced the horns with epoxy and a layer of fine glass cloth (from the canopy repairing box).
Nice solid horns and set it up. Considerigng they are about the cheapest servos you can get they have zero ccpm interaction!!.
None of this made any difference to vibes of course and actually a pair of rotortech 325's I had new in packet only made a subtle improvement to the old chipped HK3D's..but it was all slowly getting there.
I was just generally fiddling with the model and realising that the 450M motor is so like a scorp that it could be out of the same mould.. so a couple of drops of scorp oil on its bearings..and voila..the last vibes gone!! (the old l and xl's never seemed to benefit)
It now takes off sweetly but isn't quite hands off. I did use a litle trim which I'll get out mechanically later.. probably just a half turn on the pitch link but the rest'll have to wait until I get to the field..the gardens a bit small to chuck it about in and it's raining...when i hope I can now up the tail gain too, now...