Winter Scale Project

[shades]

As the UK non flying weather aproaches I am planning a scale build to keep me occupied during the winter gloom.

Looking at a 50 size fuselage and am planning to use a 600esp as the main mechanics. What other elec mechanics could I use as an option?

I want to have a four bladed head and tail but am confused when it comes to specifying an ESC and motor.
Will be using a spare 3G unit that I already have with DS610's cyclic DS650 tail.
I already have a few 6s 5000 mAh packs that i use in my 550e so really want to be able to utilise these if possible and dont really think i need a 10s / 12s setup.

With the four bladed system I am assuming that a slower head speed is the norm but have little idea as to what the head speed should be.

So what do you guys recommend for the following...
Mechanics
ESC
Motor KV etc ???
BEC / regulator
Main Rotor
Tail Rotor
Blades

What else have i forgot that I need to consider to build a list of parts ???

[Steve]

Is this your first scale project?

If so, why not try something that doesn't need a 4 blade head and tail? Like maybe a Bell Jetranger or something? Two main and tail blades, no retracts, no angled tail output, would look good flybarless etc. It would get you into the build and finishing nicely without presenting too many mechanical and electrical challenges.

[shades]

Have previously done a md500 on a 450.
I am really set on a 4 bladed system. More than happy to have a few challenges along the way !

[trillian]

I have a 500 size BO105 fuselage in RedBull colours I was going to build up and eventually put a 4 blade head on it but I am
starting to think about selling it as I just have too many other heli projects going. It looks fantastic. Align also now make a 4
blade head for the 500. I have the beginnings of the 500 mechanics, basic frame,
motor, ESC, blades etc. Anyway, 'just thought I'd mention it as I have not yet listed it for sale anywhere.

[antsis]

Have previously done a md500 on a 450.
I am really set on a 4 bladed system. More than happy to have a few challenges along the way !

1. Do you want to build any model and use the 4 blade head or do you actually want to copy a full size heli that has a 4 blade head? Some examples for the 600 size are Agusta A109, BO105, EC135, EC145, AH-64.
2. The 3G unit will help with the flying characteristics, but not phasing. You can buy heads for the 450/500 size models which do not need phasing, but to my knowledge, there are not any available for the 600 yet.
3. As for mechanics, most fuselages are designed around the Trex 600, but can be adapted for other mechanics. Does it have to be an ESP with shaft drive? Otherwise look at the Phoenixtech Flasher 600.
4. If you are going 10-12S, then your choice of fuselage must be able to accomodate the batteries. Perhaps you might consider going 8S instead?
5. I found the headspeed for my 5 blade head to be 1650rpm, but tested it at speeds from 1200rpm. You need to experiment to find the right "feel".

[shades]

Quite like the EC and the augusta and would like to have a 4 bladed head setup.

Have been trying to investigate the motor specs that I would need for a suitable 6s system.

((Motor KV * Battery Volts) / (Main Gear / Pinion)) = Headspeed
((1000 KV * 22.2 Volts) / (170t / 11t)) = 1437

How do you work out what head speed you actually need ??

[antsis]

((Motor KV * Battery Volts) / (Main Gear / Pinion)) = Headspeed
((1000 KV * 22.2 Volts) / (170t / 11t)) = 1437
How do you work out what head speed you actually need ??

You need to factor in motor efficiency. This is usually 0.8 and including this into the calculation would give you a HS of 1149 rpm. The lower KV motors are generally designed to take a higher number of cells, so if you used an 8S lipo instead of a 6S, the HS = 1532 rpm.

I used the original 1220 kV Align motor and with a 13T pinion got just over 1650 rpm. I then changed to a Scorpion 1100kV motor and, with the same pinion, the HS dropped to 1494rpm. I was flying the model with no electronic stabilisation and sorted the phasing with the Tx. I did not find a great deal of difference between the various headspeeds, but some of that could have been down to the way my tx was set. I basically got to a stage where the model did not feel too spongy or too snappy.

One thing to note is that the mechanics behaved a lot differently when fitted into the fus due to the extra weight/drag.

I'm a fan of the A109, so that would be my choice. It is also simpler as there is no need for a cranked tail, although nowadays, most fuselage kits would come with the conversion bits.