4 Blade Main Head: Shorter blades ok? - HeliFreak
Fun, Learning, Friendship and Mutual Respect START  HERE

Go Back   HeliFreak > R/C Helicopter Support > Scale Helicopters > Mechanics

Mechanics Mechanics Discussion

LinkBack Thread Tools Display Modes
Old 01-21-2014, 04:48 PM   #1 (permalink)
Registered Users
Posts: 1,157
My HF Map location
Join Date: Oct 2010
Location: Beavercreek, OH
Default 4 Blade Main Head: Shorter blades ok?

Hey, Freaks,

I am setting up a 500 with an Align 4 blade multiblade rotor head. I have setup mutliblades on 450s, using scale blades (the shorter chord blades).

I was wondering if it is better loading on the motor to use 4 x 450 blades on this heli instead of 4 x 500 blades? I fly it 6S.

Pretorian435 is offline        Reply With Quote Quick reply to this message
Sponsored Links
Old 01-21-2014, 08:48 PM   #2 (permalink)
HF Scale Support
Posts: 2,458

Join Date: Jan 2010
Location: Mississauga, Ontario, Canada

You are missing some information to help us help you but let's go with what you have and then you can add as needed. A 450 helicopter uses, on average, 325mm blades and a 500 size uses 425mm blades. There is too much of a loss to use that short of a blade. You might be able to use 400mm blades but certainly no shorter than that or you will be beating the air with the blades and getting nowhere. You should spend some time reading build threads here to see what the fellows have done to make their helicopters more scale-like in appearance and operation. Head speed should be reduced quite a bit for a 500 size four blade head to something below 2000rpm. Align does not do anyone building their Blackhawk a favour by selling them the head and not informing them that they need to rework the gear ratio and motor KV. Once you get into larger scale helicopters, high rotor speeds are detrimental to the smooth operation and in some cases, 3D speeds can result in damage to the heads and a serious crash. Good luck with your build and take your time.

Keyrigger is offline        Reply With Quote Quick reply to this message
Old 01-21-2014, 10:28 PM   #3 (permalink)
Registered Users
Posts: 281

Join Date: Nov 2011
Location: Chatsworth, Calif.

I am flying 2 T500s both scale builds using 425mm blades and low head speed approx. 1600 and the fly great I drop them to 1500 once in a while
DJI 550 extended / Y6 custom build / X8 custom build / Quad custom build, Trex 500-MD500E / Trex 500-EC135. All using NAZA controllers, Walkera 450/Bell 222, Walkera 400 5 blade.
jim treg is offline        Reply With Quote Quick reply to this message
Old 01-22-2014, 02:50 AM   #4 (permalink)
Registered Users
Posts: 4,193

Join Date: Apr 2008
Location: Brisbane, Australia

As above. I would suggest at least 4x 425mm standard chord blades, or perhaps a set of Spin 425mm scale (narrow chord) blades.

I use 2x 465mm wide chord Spin asymmetrical blades on my 500 sized UH-1N and fly it at 1700rpm. The wide chord asymmetrical blades provide more lift and allow for a slower headspeed usually. One thing to watch is loss of tail authority - I run 2x 95mm tail blades to counter this.

Not a great idea to use the ESC to reduce headspeed. Better to get a slower motor and small pinion.

Your OP refers to shorter chord blades which would usually mean narrow chord (skinny) blades, but then you talk about 450 sized blades. Chord refers to the width, not length. Are you talking about shorter length or narrower blades ?

Vario Long Ranger 700e
Seahawk 600
UH-1N 500
Baumann EC-145 800+ (coming soon )
Andy01 is offline        Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1