GAUI EP 100 ''spare parts management''

Summary:

Buy EP 100 SE as first heli?
Shopping list
List of recommended spares to buy at the same time

Introduction

The EP 100 SE can be an attractive helicopter for beginners, because it is comparatively cheap.

EP 100 as first heli?

Depends. It is not as easy to fly as a bigger heli, and requires more careful work and more time to fix.
But: parts are cheap. Batteries are even cheaper. One can fly continuously with 10 batteries and 8 chargers, it costs around 200 dollars. The same investment for a T-Rex 600 would be far beyond 2000 dollars for the batteries and chargers alone.

Quite a number of people have learnt to fly on this heli, and quite a number of others have failed miserably.
In my opinion, it depends on the type of person:
Somebody who is focused (and patient) enough to treat this little toy with the same respect as a motorcycle should have no problems.
Others, who will bump their heli around like a 15-year old treats his skateboard, will have more (and longer lasting) fun with a HoneyBee Fixed Pitch instead.

Shopping list

Here is a list of parts that I would buy, if starting from scratch. Some comments below.
Sorry, some links are to Finnish shops. But I hope the parts are clear.

(X) Heli, motor controller, motor. About once a month, the same webshop offers the same without case for a much lower price, but only for 24 hours.
either 3x (X)(Fi) Servo: BMS 306 BB (Sabe)
or: 3x (X) HS-45, recommended servo, 20..25 euro each. Note: DON'T buy cheaper servos.
(X) Gyro and rudder servo
(X) "stretch kit" (longer boom and blades) this is the difference between my two helis in the last picture
(X)extended boom support rods
(X) plastic blades: tough as nails!
(X) CNC tail blade grips, recommended, the stock plastic parts have too much slop
(X)(UK)Batteries
(X)(Fi)chargers: one or two will do, 8 are needed to keep flying without break
(X)(Fi)12 V supply for up to 12 chargers
lightweight 6+ channel receiver, and computer transmitter with heli CCPM program. Futaba or Spektrum 2.4 GHz system recommended. 7 channel is €100 more expensive, but easier to set up (I use 6ch Futaba => the cheapest)
(X)Carbon fiber landing gear. Not required, slightly heavier, but easier to fix when it breaks. For example, glue some cotton shoelace to the inner side, then soak with CA glue.
(X)(Fi)A better motor. If the kit includes a motor, it is the GAUI kV 4800, which is powerful enough. This motor (Z-power kV5150) has much more “punch”, BUT it requires batteries that can deliver high enough current. I use 15 tooth pinion for both (on 7.4 V LiPos).
(X)Alternatively, for a setup with 11.1 V LiPos, this motor is a good choice.

Spare parts

After the decision to start the hobby and buy the equipment, the 2nd question is usually “what spare parts should I buy”.
Those who have a well-equipped local hobby shop can stop reading now. But for the others it is a good idea to consider advance ordering the essential spares at the same time because

Shipping from Hong Kong is expensive
It may take one week plus a couple of days in customs
Sometimes, parts (example: belt) are sold out “everywhere” at the same time
The smallest screws disappear frequently, and are hard to find from hobby shops

One gets a lot of motivation from starting a new hobby, and in my opinion it is not good to waste it on waiting for spare parts.
On the other hand, simulator training is a good idea while waiting for spares (and costs nothing). FMS will do just fine.

Spare parts 'strategy'

Unfortunately, this hobby is expensive. By acknowledging the fact, one can possibly save some money in shipping costs, and time.

2nd kit

Buying a 2nd barebones heli is IMO the best option. Spares are available immediately, and obtained at a “discount”.
If the original heli is wrecked badly, one can change whole modules (tail, rotor head).
A long term perspective is the option to re-build the 2nd kit to a full second heli, possibly as long-tailed version, or ultra-light.

complete 2nd heli

It's a bit more expensive, but with two helis chances are good that one of them is always operational.
In a flying session that lasts several hours, it is quite likely that some part will fail. Simply switch to the other heli, and do the repairs at home on the bench.
Or: why should my collection of spare parts lie unused on the shelf, when I could just as well have some fun with them?

spare parts collection in bags

Possibly more convenient but more expensive.

What's best?

IMO a 2nd kit, and some extra spares.

Essential spares

Blades:The symmetric plastic blades are the cheapest option for beginners. They break with the least damage to the rotorhead and can be used a 2nd time.
Blade holder screws M2x10: Every time the blades touch the ground, those should be replaced. Cheap, buy several bags.
Spare servos: Small servos break easily when binding occurs, or by careless handling. Buy at least two, or even more
Belt: Any tail rotor contact takes its toll on the belt. After a while it starts to flip or even breaks. Buy several.
Tail blades: On a gym floor, they last forever. But they break after a number of contacts with rough asphalt or gravel.
Main shaft: After a “proper” crash (blades break), this is bent. It can be bent back, but that's a lot of work and the parts are cheap. Buy several.
Screw kit

Those below are covered by a 2nd kit:

Swashplate holder (anti-rotation) here on flying-hobby.com, other shops don't sell them individually
rotor head linkage set
a whole tail assembly possibly CF upgrade (not CNC, it's IMO too heavy) including
Tail rotor bearings Those can break, if the tail rotor gets stuck on carpet.
tail rotor grip / hub Screws break easily
A tail boom or CF upgrade
Tail servo mount (not CNC, too heavy). The screws come loose after a while because the plastic wears out.

Wear parts:
Those below may need replacement after 30 or so hours of flight time

tail rotor bearings
Tail shaft (chrome plating wears off)
Tail pitch slider (bearings, but replace the whole slider because it's crimped)
Tail blade hooks When worn, they jump off the ball towards the inside.
Tail 90-degree lever The ball wears down (oil frequently)
3x6x2.5mm bearing (? I had to replace one inside a GAUI motor ?)
Linkage setOiling the ball links in the rotor head may be a good idea, otherwise they wear out.

Note, the bearings above were on board in my first flight attempts and may have taken some damage there.
It is likely that the bearings can last longer.

© Markus Nentwig 2007-2008
The content of this page is provided without any warranty and may not be reproduced without permission.

Comments? Questions?

Please send me a mail! mnentwig@elisanet.fi