Opening the box
I have bought a few kits from new and they have all been a joy to build. It seems to give you a sense of achievement and, more importantly, a greater knowledge of the finer points associated with the helicopter. This new found knowledge will be imperative whenever the helicopter is required to be striped down for maintenance, for the addition of upgrades, or after that ill fated accident.
Most new helicopters come in a rather large cardboard box which weighs very little but always seems to cost a lot! The main reason for the size of the box is protection. Most kits these days come from the far east, therefore kits must be well packed to survive the journey. When the magical time comes to open the box, you are greeted with a load of plastic bags containing even more plastic bags. At this point, please do not be tempted to open any of these bags, but instead, find the instruction manual and read the instructions carefully. I am not trying to be a kill joy but the reason will become clearer later.
These seem to come in two forms.
The verbose method , used by Miniature Aircraft for example, uses an A4 book of around 90 pages or more and is sometimes backed up with a large 3D drawing sectioned off into rotor head, tail assembly etc and the manual will refer to this drawing during each step leaving little room for misunderstanding. This book is very descriptive and each section starts with a list of parts, together with their part numbers, the quantity and which bag number you will find them in. Next you will find a 3D sketch of the current assembly stage followed by anything up to 3 pages of written text backed up by further sketches to make the assembly process very clear. With this method, it is virtually impossible to make a mistake or leave out a construction step especially if you tick off each step once they are completed. As an example of this type of manual, here is an extract from the Miniature Aircraft's Fury Extreme manual explaining about installing the mainshaft and main gear:-
“Select two #0875-1 “Split” type mainshaft collars. Examine the collars. One end of each collar has a flat surface with a .03mm raised step near the bore. This end is always to face a ball bearing. Using this criteria, slide two split collars onto the mainshaft exposed below the upper bearing block. The upper collar should have it's flat surface (with step) facing up to the underside of the upper bearing block and the lower collar should “face” the bearing in the lower block. Slide the mainshaft further downward into and through the lower bearing block until about 6.0 - 7.0mm is exposed.”
The above is only step three in a sequence of 8 steps covering two full pages of text, and this is not including the 3D sketch! The manual is a work of art and a great reference source for later perusal, but each section must be read through twice before committing to assemble this stage of the model.
The pictorial version is the most common as less work is required by the manufacturers in translation for different countries. These instructions rely on pictures to show you how to construct the model, using symbols where necessary to inform you where to use grease, retaining compound (locktite) or glue (cyano). These are backed up with pigeon English sentences if further information is required.
E.G. “Attach the linkage rod to the parallel elevator linkage balls.”
Since the drawing did not point out the names of the parts mentioned above, I did not bother to try to understand what it referring to, but in all fairness, looking at the excellent picture, an explanation was not required.
Although this method works well, it can be very easy to miss a screw fixing or even leave out a part as it is up to you, not only to spot the part in the picture, but follow all the lines on the 3D picture to find out how the part is fixed, this problem is compounded if the part is fixed on the other side of the model not clearly shown on the 3D drawing. This is why it is best not to open all the plastic bags when opening the box.
The majority of kits use a method of each step in the construction having a set number that corresponds to a numbered bag. By emptying all these parts from that bag into a suitable container, you will know when the current step is finished as no parts are left over in the container. You can then proceed to the following step.
How manuals are split up
The pictorial types of manuals seem to follow a similar format. The first part informs the buyer hazards associated with radio controlled models. The second part informs you of which tools you will require together with the equipment you need to start the helicopter.
The next section takes you through the building sequences which are normally broken down into the following sections:-
- Fuel tank assembly
- Main Frame assembly
- Main gear assembly
- Washout assembly
- Pitch control assembly
- Main rotor head assembly
- Tail rotor and boom assembly
- Final fitment of all sub assemblies
- Electrical installation
- Canopy assembly
The forth section is helicopter setup and normally after that, there's a section on how to change certain parts without doing a total strip down. Kyosho cover this aspect very well and this often reduces downtime. The final section of the manual is often dedicated to a pictorial parts list and an upgrade section, which only goes to prove my comment in the first article about producing kits to a price sensitive market, upgrades are available for your new kit if the need arises.
quality of parts supplied
The kit contents for the smaller 30 size helicopters mainly contain plastic components which are manufactured by injection moulding. These parts will have the tell tail signs as 'flash' marks can be seen. This is where plastic enters the mould and is usually cleanly broken off these days, but in the past, these flash marks required to be trimmed back. This process is very reliable, but it is still worth trial fitting the parts together before securing them together.
Choosing a place to build
Choosing a place to build to your helicopter very much depends on the type of kit it is, if it is a plastic framed helicopter then you can construct the helicopter in the lounge on a tray (Partner permitting!), if the helicopter frames are aluminium or carbon, then you will require a flat surface, preferably with a piece of glass on top. This will aid in obtaining an accurate set of frames using a set square. Whatever surface you choose, make sure you have plenty of room and that you can continue the construction over several evenings without parts being disturbed.
Special equipment needed
I have already covered the tools required to construct and maintain your model, but here I will be covering tools specific to the model you have just purchased. These tools are sometimes supplied in the box and you only find them when you have finished constructing the model. This is why it is always best to read through the manual completely before starting construction. Miniature Aircraft supply Allen keys, clutch alignment tools and other special tools required to construct their kit. They don't however supply the Dial Test Indicator to align the parts up!
Now that you have the helicopter kit, it is worth having all the extra items that you will need before to start building, such as:-
- Engine and Mufflers
- Radio receiver
- Receiver battery
- Switch harness
There are many brands of engines; some are very good, easy to setup and give trouble free running, some are less fortunate! The rule of thumb is the more you pay, the better the engine. The most common brands are:-
- OS engines
- Irvine engines
- Webra engines
- Thunder Tiger engines
One thing to be aware of when purchasing an engine is that it must be a helicopter specific engine. These engines have a larger head heat sink and a dedicated carburettor giving a very linear throttle response across the whole RPM range. The engines are also designed to run on a higher nitro methane content that boosts the engines output.
You will also require a suitable exhaust. These exhausts come generally in two formats:-
- Tuned Pipes
As the name suggests, mufflers just quieten down the engine, some do have mild performance enhancements, but if the muffler is supplied with the kit, then it is only designed to quieten the model which leads to a degree of degradation of the engines performance. This is not a concern when learning to hover, but when starting out in circuits, power can be handy!
Relatively new to the market are the Zimmermann mufflers, they are made of stainless steel as opposed to the other brands that are aluminium. Stainless steel is far easier to clean as most oven cleaners will remove the brown exhaust residue that sticks to them caused by the caster oil present in the fuel.
Tuned pipes on the other hand, can add a great deal to the engines performance by balancing the back pressure to the two stroke engine. Although this method sounds great, many factors have to be taken into account from length of tuned pipe, type of fuel used, the type of glow plug, engine speed required etc. In fact, it is very much a black art and there are very few articles covering this subject. Therefore, for a beginner, it is best to use a muffler.
The next items on the list cover such things as servo's, receiver, and receiver battery and switch harness; this can all be supplied together with the transmitter. Choosing a transmitter is very much a personal choice which comes down to price, what other people use down your local flying site and how comfortable it feels in the hand. The leading brands are:-
- Sanwa (Airtronics in America).
Note: Most sets can be linked together, known as “buddying up”, via a cable and this allows an experienced pilot to take control of your model if you get into difficulty. This function is best used between like makes of transmitter i.e. Futaba to Futaba.
Gyros are last on the list. The purpose of the gyro is to help keep the tail of the helicopter under control stopping it swinging due to wind or counteracting torque generated from increased pitch and engine speed. A few years ago, you could only purchase mechanical gyros, today, piezo gyros have taken over the market. These piezo gyros come in two forms:-
- Heading lock.
- Yaw rate demand (Non heading lock).
Heading lock gyros are very good as they will keep the tail pointing in one direction, but if you move the tail stick on the transmitter, then the tail will obey. In yaw rate demand, if you move the tail stick on the transmitter, the gyro will detect this as an unwanted movement and the gyro will try to counteract your command.
Heading hold is very good but does require great understanding when setting up, which I will cover in a later article.
So there you have it, it is always best to have all the parts you require to assemble the helicopter before you start as this will keep the building continuous. Having to wait for, say, the engine before the next step can be completed is very frustrating.
In the next article, I will be giving tips on each assembly stage. Until then, have a look for your preferred radio equipment.