Our Recommendations - Model Tech Sukhoi SU-31 Assembly Instructions Manual

This section describes our recommendations to help you in deciding which types of accessories to purchase for your new airplane.
Please read through this entire section very carefully. We have provided you with recommendations that,
if followed, will result in a great flying airplane. Failure to follow our recommendations may result in a poor
flying airplane.
The Sukhoi SU-31 Profile 3D ARF can be flown using either a two-stroke or a four-stroke engine. We suggest
using a .40 - .52 size two-stroke engine or a .70 size four-stroke engine. The airplane will fly great using
any engine within the recommended size range, although for the best aerobatic performance we suggest
using an engine at the upper end of the size range. For 3D flying, you'll get the best performance using a
lightweight yet powerful engine, such as the Magnum XLS .52A two-stroke engine
matched with a large diameter, low pitch propeller, such as the APC 12.25 x 3.75
composite propeller.
For the best flight performance, we suggest trying to keep the ready-to-fly weight
of the airplane as light as possible. Using an engine that's bigger than recommended will only add extra
weight to the airplane, negating any of the extra power from the larger engine. In most cases, you'll get
better flight performance from a lightweight, but powerful engine than from simply a higher displacement
engine. Also, remember that the heavier the airplane the more stress that is applied to it during extreme aerobatic flight,
which could result in failure of the airframe.
What radio Control SYSteM and SerVoS Should i uSe?
Standard servos can be used on the flight-control surfaces, although we do recommend using the ball bearing type. For throttle
control, a standard non-ball bearing standard servo can be used. We recommend using Cirrus CS601 Standard Ball Bearing servos.
These servos have a ball-bearing-supported output shaft and produce 75oz/in of torque.
Although you would lose mixing capabilities, the airplane can be flown using a basic four-channel radio control system. If you do this,
you will need to use a servo Y-Harness to join the two aileron servos together.
There really isn't much else that you'll need to finish the airplane. Most of the hardware is included, so about the only thing else you'll
need is a spinner, servo extension leads and typical modeling supplies, such as foam rubber to protect your receiver and battery,
and fuel tubing.
heRe'S A liST oF WhAT USeD To FiniSh The AiRPlAne ShoWn in TheSe inSTRUcTionS
QTY. 1 Hitec Eclipse 7 FM Radio System
QTY. 1 210760 Magnum XLS .52A Two-Stroke Engine
QTY. 1 237153 Magnum 2-1/4" Diameter Chrome Spinner
QTY. 1 608684 APC 12.25 x 3.75 Composite Propeller
QTY. 5 440601 Cirrus CS601 Standard Ball Bearing Servos
QTY. 2 444713 Cirrus 12" Servo Extension Leads
QTY. 2 444718 Cirrus 24" Servo Extension Leads
IMPORTANT
The Cirrus servos are compatible with all receiver types. The Cirrus servo extensions are compatible with Hitec and JR radio
control systems. These servo extensions are also available with connectors that are compatible with Futaba and Airtronics radio control systems.
The Magnum spinner includes a 1/4 - 28 adapter nut.

our reCoMMendationS

What enGine Should i uSe?
To get the most out of the airplane, we suggest using a four or more channel
computer radio system with mixing capabilities. Since the ailerons use separate
servos, they can be plugged separately into the receiver, allowing you the
capability of flaperon and spoileron mixing, differential mixing and flaperon/spoileron
to elevator mixing. The transmitter should also feature dual rates and exponential
adjustments. Most computer radio systems will include all these features, plus
many more. We really like the Hitec Eclipse 7 FM system.
What other iteMS do i need?
QTY. 1 115559 Thunderbolt # 3 Performance Glow Plug
QTY. 1 115923 Global XX Silicone Fuel Tubing
QTY. 1 868638 Dubro 1/4" Protective Foam Rubber
QTY. 1 534867 Monokote White Covering Material
Page 
(for Sealing Hinge Gaps)