Concept-EP helicopter.
I wanted an electric heli so I could practice
hovering man oeuvres on my lawn. Unfortunately, the
Concept EP is far from easy to fly, and looks very fragile
to boot, so I've put it to one side till I'm totally
happy hovering on the LMH-110 and the Raptor.


Concept Rotor Head Mods.
I had found the Concept EP-SR VERY
difficult to hover - it would lurch one way, I would correct, and it would then lurch the other way! I thought
it was down to my inexperience, but now, after looking at it again after
flying the lighter LMH, I'm sure that it was a problem with the ARTF
version that I bought.
If you have the ARTF version, then you need to dismantle the head
assembly and do the following:-
1) Scrape/sand the molding flashes from the control balls on the flybar
teeter unit.
2) Scrape/sand the molding flashes from the pivot points of the teeter
unit where they go into the pivot bushes - make sure that these are a
smooth easy rotating fit in the bushes.
3) In my case I also had to reduce the thickness of the teeter bronze
bushes to get rid of excess friction caused by preload of these bearings
in the main head molding.
4) Carefully use a pair of pliers (I've just ordered a
JR ball-link resizer) until EVERY balllink that moves on the entire head/mixers/swash
plate assembly moves smoothly and without any binding or friction.
I haven't yet finished reassembling the EP yet, as I'm awaiting the
mini-servo mount kit so I can save some weight with smaller servos, but
I have absolutely no doubt that the work detailed above will transform
the performance of this model.
This page was last updated on September 06, 2006