Servos for 1/4 Scale Sig Cub - RCCanada - Canada Radio Controlled Hobby Forum
RCCanada - Canada's Radio Control Hobby Forum
Giant Scale Aircraft Discuss Giant RC Scale Aircraft.

Closed Thread
Thread Tools Display Modes
Old 11-24-2008, 07:24 AM   #1
RCC Noob
Join Date: Oct 2008
Location: Brandon, MB

Feedback: 0 / 0%
Posts: 4
Total Props: 0
Servos for 1/4 Scale Sig Cub

       Remove this ad - become a site supporter!
I'm currently building a Sig 1/4 Scale J3 Cub and it states in the instructions that I need servos for the rudder and elevator that have 35 oz's or more torque to operate them. I have Futaba 3004's which have 43 oz's of torque. I'm using a CRRC 26 gas engine in the plane. Do the experienced builders out there feel that these servos will do the job or should I be looking for something with more torque?

Bustedprop1 is offline   Quick reply to this message.

Sponsored Links - Subscribe to remove this ad.
Old 11-24-2008, 08:34 AM   #2
RCC Master Contributor
DO335's Avatar
I am: Cheshire C
Join Date: Jan 2004
Location: Newmarket Ontario

Feedback: 13 / 100%
Posts: 1,320
Total Props: 1
Re: Servos for 1/4 Scale Sig Cub

Based on running a 1/4 size Sig clipped wing Cub for some 20 years on both wheels and floats, I'd recommend that you use a servo suitable for giant scale.

Something like a Futaba 3010 will do it if you are on a tight budget. If there is a bit more wiggle room with the finances, the Futaba 3050 would be better.

You would not be permitted to fly that plane with the standard 3004 servos at an IMAA event, since it does not meet the minimum criteria. You would also need to address the issue of your battery capacity. The standard 600 mAh or 500 mAh battery which comes with those of the shelf radios do not qualify.

In my 1/4 size Sig clipped wing Cub, I ran servos in the 90 torque range, one per aileron, one on elevator, one on rudder and a 3004 type on throttle. Battery was 1500 mAh and power was a fully cowled OS 1.08 running inverted swinging a 15-8 wood prop. Never had any problems with those mechanical components. I flew it successfully at many giant scale IMAA events with never a question as to the set up and never a failure.

There's a lot more to the servo than just the torque. You need be concerned with the strength of the gear train, support of the output shaft, reliability of centering and achieving the same outpuit for the same control input repeatedly over its long life and a bunch of other things. Using a standard servo in a giant scale application is not the answer to those requirements. It may work for a while but not in the long run. There are reasons why there are minimum equipment requirments for the IMAA evnents.
DO335 is offline   Quick reply to this message.
Old 11-25-2008, 07:00 AM   #3
RCC Noob
Join Date: Oct 2008
Location: Brandon, MB

Feedback: 0 / 0%
Posts: 4
Total Props: 0
Re: Servos for 1/4 Scale Sig Cub

Thanks DO355. I'm going to start looking for servos that will do the job. I haven't been in the hobby for nearly 10 years and things have changed a lot. This is the first large plane I've built as well.
Bustedprop1 is offline   Quick reply to this message.
Old 12-02-2008, 09:33 AM   #4
RCC Senior Contributor
Flybaby's Avatar
I am: Ron B
Join Date: Jan 2004
Location: Cranbrook B.C.
Radio of choice:
# of RCs: 6

Feedback: 0 / 0%
Posts: 563
Total Props: 4
Re: Servos for 1/4 Scale Sig Cub

Use 1/4 scale servos for the tail surfaces. Got Hiteks in mine.
I also made a 6 volt flight pak up of 5-1500ma "C" nicads. Check first to make sure you can use 6V with the equipment you do use.
MAAC # 77858
Ever since I learned to fly better, I've had a lot less radio problems!
Flybaby is offline   Quick reply to this message.
Old 12-02-2008, 01:06 PM   #5
Gary Maker
RCC Supreme Contributor
I am: Gary M.
Join Date: Jul 2003
Location: Stoney Creek, Ontario
Radio of choice:
Spektrum DX8
# of RCs: 7

Feedback: 25 / 100%
Posts: 7,331
Total Props: 9
Re: Servos for 1/4 Scale Sig Cub

The origional 1/4 scale Balsa USA Cub that I flew had standard 43 in/oz torque servos all around. I had an OS 1.20 flat twin and the plane flew absolutely perfect with no issues for many seasons. As a previous post in another thread said, its a Cub and to fly it scale like is not going to over stress any of the control surfaces with standard servos. You don't want a scale cub flying at 300 mph scale speed, its not meant to do stringent aerobatics but just to fly like a cub flies!

Perhaps the cirteria has changed today but standard servos were what the origional plans/instructions called for, what the plane was designed for, and thats what people used. Thats what I used.

NOW that being said, it has always been my philosophy to use the best servos you can afford. Todays servos are a lot stronger and very reasonably priced compared to just a few years ago. For example, Hitec 625MG servos are high torque with metal gears and are only about $28 each. More than enough servo for a 1/4 scale cub if you plan on flying it like a cub!!
Stoney Creek Hawks RC
MAAC No. 43659

Radios used: Spektrum DX6i
Current builds: 1/4 scale J3 Cub & Neiuport 17 and KMP B-25.
Currently flying: Scratched Tele 40, Parkzone Stryker & 60" SPAD Debonaire


"Time flies like an arrow - fruit flys like a banana." Groucho Marks
Gary Maker is offline   Quick reply to this message.
Old 12-02-2008, 07:19 PM   #6
RCC Pro Contributor
Wayne22's Avatar
I am: wayne b
Join Date: Nov 2006
Location: Sh. Park, Ab

Feedback: 0 / 0%
Posts: 1,955
Total Props: 5
Re: Servos for 1/4 Scale Sig Cub

At Cub speeds the control surfaces are not very highly loaded. As Gary mentioned, it was designed for standard servos, and many, many of them flew that way for years and years. I had standard JR's in mine with a 20cc gasser, except for the rudder, I put a coreless 4721 in cuz I use the rudder a lot...
Zero issues in all the years I flew it.

Now on the other end of the scale I have a very heavy Balsa USA cub with twice the engine up front....intended for towing gliders. The weight and severe useage dictated stronger servos, so it has the big quarter scalers all round.

Do whatever you are comfortable with. Hitec six and a quarters would be a good compromise.......
There aren't enough days in the weekend. -- Steven Wright
Wayne22 is offline   Quick reply to this message.
Old 12-10-2008, 10:28 AM   #7
RCC Contributor
I am: Robert S
Join Date: Jul 2007
Location: Zephyr Ontario

Feedback: 1 / 100%
Posts: 422
Total Props: 0
Re: Servos for 1/4 Scale Sig Cub

keep in mind good gear is transferable so if you get rid of the airframe or have an accident the gear will go in your next plane so it is always worth the investment. but to get flying on a budget like the others have said you don't have to break the bank.

truman is offline   Quick reply to this message.
Closed Thread

Quick Reply

Register Now

In order to be able to post messages on the RCCanada - Canada Radio Controlled Hobby Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Member names may only be composed of alpha-numeric characters. (A-Z and 0-9)

!!ATTENTION ADVERTISERS!! If you intend on advertising anything on this forum, whatsoever, you are required to first contact us here . Additionally, we do NOT allow BUSINESS NAMES unless you are an Authorized Vendor. If you own a business, and want to do sales on this site via posting or private message, you will need to follow the rules. Shops, Stores, Distributors, Group Buys without being authorized will see your account terminated.
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.
Email Address:
Your Name
Your first name and last initial is required if you plan on using the forum.
Which city & province you live in. This is mandatory for classified listings.
Radio of choice?
Which radio is your current favorite to use?
Number of RC Vehicles?
How many boats, cars, planes do you own?


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.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
vBulletin Message

Thread Tools
Display Modes

Forum Jump

All times are GMT -5. The time now is 06:33 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.