which is better: 550 kit or 425 to 550 conversion?

[stark]

Hi,

I'm toying with the idea of building a hurricane 550 heli.

Should I buy the 550 Kit (http://www.aircraft-world.com/prod_d.../GA-HUR550.htm) or should I buy the 425 kit and convert it to 550?

I have 3000maH, 6S battery packs with me and want to use them on the 550. Is it possible with the 550 canopy? If not what must be done?

cheers,
-roger

[PTcaflyer]

I use a 3000mah batt on my 550 under the chin (no angle adapt. and the stock can fits O.K.
I would think if you choose either one, it will work out to be the same cost( shipping, Etc.)
(...hint...At that price, I would get a spare kit for parts...)
PT

[stark]

looks like 550 frame comes pre-assembled unlike the 425 kit which comes entirely disassembled. Is this true? In that case it would be fun to work on the 425 kit.

[PTcaflyer]

I believe they are both un-assembled...I have only purchased the 425 kit...It took one Saturday to build, ready for zeroing the servos...
PT

[Mikej]

When I bought mine (4 years ago) the 550 was assembled - I stripped it down to add lotite / CA as appropriate.

The 425 is basically a shrunken 550 - they changed the boom, belt, rudder rod, gearing, flybar paddles and tail blades - everything else is the same.

[stark]

I'll go the 425 to 550 route if I decide to build.

Flylbar & paddles

Do I need to order 550 flybar paddles for the conversion? gaui # 204544
or the 425 flybar paddles are sufficient for 550 heli? gaui # 204756

what about the flybar? is it the same for both? gaui # 204042

Main gear
What main gear comes with the 425 kit, is it 50T or 42T?

One-way Bearing (OWB)
Have they improved the OWB in the newer kits? the vendor says "New designed 8mm One Way Gear Shaft provides high-efficiency power transfer."
http://www.heli-shop.com/shop/produc...ee9ab77b0afd2a

Motor
is 850kv/1300W motor sufficient for 550 mm blades. (Turnigy 3025 850kv) http://www.hobbyking.com/hobbyking/s...dProduct=17230
It would give me 2000~2100 rpm with 42T main gear, 19T one-way gear and 16Tpinion. (90-95 % efficiency)

[Mikej]

Originally Posted by stark

I'll go the 425 to 550 route if I decide to build.

Flylbar & paddles

Do I need to order 550 flybar paddles for the conversion? gaui # 204544
or the 425 flybar paddles are sufficient for 550 heli? gaui # 204756

what about the flybar? is it the same for both? gaui # 204042

I would get the 550 paddles - they are bigger and heavier. The flybar is the same

Originally Posted by stark

Main gear
What main gear comes with the 425 kit, is it 50T or 42T?

It seems to vary - personally I use a 50T one on of mine and a 60T on the other - it depends on the kV of your motor. It shoudl come with the later OWB shaft now - but the 20T OWB gear is stronger.

Originally Posted by stark

Motor
is 850kv/1300W motor sufficient for 550 mm blades. (Turnigy 3025 850kv) http://www.hobbyking.com/hobbyking/s...dProduct=17230
It would give me 2000~2100 rpm with 42T main gear, 19T one-way gear and 16Tpinion. (90-95 % efficiency)

I used the Gaui 850kV motor for a long time - it was fine, I don't know the Turnigy one, sorry

[Jerrymac]

My 550 kit bought about 3 years ago came with a 42T main gear. Both of my 425 kits, one IRCHA kit and one I got last year came with a 50T main gear.

I prefer the Light weight flybar paddles as they give a slightly better cyclic response. G-204734
I would recommend adding the CNC swash plate guide. G-204677 I just don't trust the plastic elevator arm to hold the swash plate in place.

The 550 also uses longer tail blades. The 425 comes with 70mm tail blades. The 550 comes with 79mm tail blades. With 553mm main blades, I use 84.5mm tail blades to give the tail a little more authority.

I am still using the stock Gaui 850kv motor in mine. Like Mike, I have no experience with the Turnigy motors either.

[stark]

Thanks for your replies.

Jerrymac, could you please provide part number for 84.5mm tail blades?

[Jerrymac]

Originally Posted by stark

Thanks for your replies.

Jerrymac, could you please provide part number for 84.5mm tail blades?

Sorry, I guess I should have been a little more clear. Gaui doesn't make 84.5mm tail blades. I use KBDD tail blades.

These ones;


http://helidirect.com/kbdd-extreme-e...mm-p-25135.hdx

[wakeup]

Hi everybody from Russia,
Try to understand the same issue, what is better and still not solve it
It is funny but I am looking for the same website to buy 550. Stark what was you final solution 425 or 550 and if it is 550 how was the experience with that shop?
I have 70$ shipping with 90$ for model is good deal?
Thanks for the answers


Stas

[stark]

Hi Stas,

I went ahead with the 425 because

• 425 comes fully unassembled, v/s 550 which comes pre built, hence the huge package and high shipping. I can buy it from http://shop.rc-now.com/ or www.conrad.de
  
• I'm a beginner and 425 has lower crash cost than 550.
  
• I will upgrade to 550 later when I'm more comfortable flying.

cheers,

[wakeup]

Hi Stark,

Thanks a lot for the quick and detailed response.
I am beginner too. I agree with your points especially for assembling the heli from the beginning.

Did you try already that shops? Cause I can not find for that moment the 425 basic kit.

[stark]

i bought from shop.rc-now.com. Quick shipping and good service. But now the 425 is out of stock there.

conrad.de is a renowned shop. the kit is still in stock there.

http://www.conrad.de/ce/de/product/2...archDetail=005

[wakeup]

Hi Stark,

I've just ordered it. I am really happy
Now it is a long waiting time to Russia, as always
I am really believe that they will pack it as stronge as possible, cause only this way parcels can go through the ... russian posts.

Thanks for help

[PTcaflyer]

...I take it everyone knows that Air Craft in Japan has the 550 kit on sale for $89.00...
Shipping might be a little high though.
PT

[R/C Mayhem]

Shipping to Florida for that kit is $61.00...Yikes

[volens31]

Air Craft also have the 425/550 FES head with GU-365 FOR $79....over here that same kit is 200GBP!! Although I'm not sure about the 365 unit...:what:

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[dunkonu23]

From what I've heard, you need to avoid the 365 like the plague. I hate to say it about a Gaui product but it's just not as good as other FBL units out there, now. Suffice it to say, Gaui does not offer it on later kits opting instead (depending on location) for microbeasts or mini vBars.

Scott

[volens31]

+1 on the above....365:what::eek:

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