If this is to be your first entry into the world of scale models, the first thing to do is to get all of the catalogs and brochures you can and peruse them at length. You need to decide whether to make a 30-size model or go for something bigger. If you have just mastered the art of flying your 30 size trainer around then sticking with a 30 size machine is probably best for you, but if you are happy with a 60, then go for the bigger machine if that’s what you would like to do. The 30 size will not be able to carry so much detail and it may have odd holes in it for mufflers and other appendages which can't be squeezed into the fuselage.

One thing to seriously consider for a first model is the excellent range of Funkey pre painted fuselages into which you can just slot your Hirobo Shuttle or other mechanics and go fly a scale model in a couple of days. It will introduce you to the art of flying a scale helicopter and making it look like a real one, without a vast amount of work.

Ok, so you are bit past the Funkey fuse stage and have seen pictures of a scale helicopter or there is a helicopter local to you which would make a superb scale project. Ask yourself, is this a machine for showing and competing with, or is it a machine to go out and have fun with and fly every day? If you go the full detail route, in time you may find all the antennas and other little bits get knocked off as the model is transported to and from the field. So maybe if you are making an every day flying model, you may want to consider one with less detail on it.

My very favorite flying model at the moment is a Giant Hughes 300C from Robbe with a Super Tigre 90 motor in it. The model flies very slowly and has very little scale detail because the way the mechanics go into it. But, watching it lumbering down the field, flying very slowly at 4 or 5 feet off the ground and then swooping round into a graceful chandelle and coming back for another low pass is just magic. I fly it every opportunity I get and I love it.

If this is one of your first scale models, you might consider the 300C, Lama and Bell 47G type of model. The tailboom is easy to paint and a lot of nice detail can be put inside the cockpit when it should be protected from handling damage. Vario makes a Petrol version and a glow version of the 47G and my glow one is another favorite of mine, which goes out to fly most days. The disadvantage of the petrol one is the mechanics are quite expensive. One of these machines can be built in about 2 weeks including building the mechanics.

If you favor a fuselage rather than a lattice boom model, consider the tail drive system you will be employing. If you opt for a Jet Ranger type model or a 222 or 230 then the tail rotor will be in the same plane as the tail boom. The Huey and Seaking type models have the tail rotor cranked up to the same height as the rotor blades and this will add a measure of complexity. Both Robbe and Vario make 145 degree tail rotor gearboxes for this type of application.

You could go for an even more complex model like the EC135 or Dauphin/ Dolphin machines with a multi blade fenestron tail rotor system such as is produced by Hirobo and Vario. Just remember that the more complex it is, the more complex it will be to set it up to fly nicely and the more impressive it will be when it does fly.

One thing to consider when selecting your model is the color scheme it will end up with. You need to research color schemes of full size machines to help you make your decision as to how your model will end up looking. There are a number of books on full size helicopters, which have many color pictures in them to give you some ideas. You can also search for them on the Internet. www.helispot.com is a very useful source of pictures.

Ok, we are getting close to having made our decision now. The next thing to consider is the mechanics. Are you going to buy a kit from one manufacturer and assemble the whole thing, or buy mechanics from one source and a fuselage from another? Hirobo makes a very nice range of scale machines which include the mechanics, you just ad a radio and motor. However, they are designed for everyday flying and the fittings are a little bulky for a true scale machine. For everyday flying, they are just right as the extra strength in the fittings means they will last and not suffer from hanger rash quite so easily. I saw a beautiful Hirobo Cobra at Phoenix funfly in 2000 and was quite impressed with it flying around. However, when I saw it on the ground the guns and rockets all looked a bit plasticky . The other side of this coin is that the kit comes with these parts already made. I have spent hours making them for my Len Mount Cobra and they will probably get damaged in short order when I start taking the model to the flying field.

Vario has an enormous range of fuselages and most of them can be flown with their Skyfox mechanics or their Benzine Petrol mechanics. More are becoming available for use with their Xtreme mechanics, but that seems to me to be a contradiction in terms, fitting a set of highly aerobatic mechanics in a scale fuselage. Vario also has an enormous range of fittings for both the inside and outside of a scale model and I consider the Vario catalog an essential part of scale model building. Their scale cockpits and external fitting kits make light work of what can be a quite difficult part of finishing a model off. One thing they don’t do too well is the instrumentation, which is generally a printed sheet to be glued onto the dashboard.

Robbe make some very nice scale machines but their range is somewhat limited. I am fond of the 300C and the BK117, but they lack detail and if you want a detailed model you will need to add a lot of it yourself. The giant models are designed to use the Futura mechanics and I have to admit they do fly beautifully. The big problem with them is in the gearing for the main rotor speed. They are designed around the pod and boom machines and when you fit them into a large-scale fuselage; you really want to fit long blades. The motors can't be geared down enough to fly nicely with 800+mm blades so you have the choice of a motor straining to produce high power at low rpm, or using shorter blades and turning them fast, which doesn’t look so good on a scale machine. Robbe have produced an adapter kit to allow the use of the Super Tigre 90 motor but again it is geared up to turn the head at 1500+ rpm and the motor struggles if you run the head slower. They also have a gas conversion kit, which allows the use of the ubiquitous G23 motor, still geared for 1500+rpm though. Robbe also makes a number of smaller scale models based on their 46-size machine, the Mosquito. The Robinson R22 is a nice example.

A number of manufacturers have made scale kits available based on their 30 size trainers. These include the Century Hawk, the Ergo 30 and of course the Hirobo Shuttle. The kits are of machines like the Hughes/Schweitzer 300C but Hirobo have even made a twin rotor Vertol machine for the very ambitious builder.

If you fancy making your own mix of mechanics and fuselage then there are a number of sources of fuselage to choose from. Funkey is the obvious choice as they have a nice range of pre painted fiberglass models in the 30 and 60 size range. They are not very scale but they do look nice. Century make a wide range of fuselage kits as well. Their quality was very poor some years ago, but the last 3 fuselages I have bought from them have been of a very high standard, so quality control is definitely improving. Of course you could always buy a Vario fuselage and fit your own mechanics.

There are a number of specialists fuselage makers who have a limited range of very high quality models to choose from. Len Mount in England has specialized in giant scale models and produces a Cobra AH-1S over 6 feet long, a Lynx of similar dimension, and has just announced a Dolphin at the same scale. Jerry Hicks sells his 212 and 412 super scale fuselages with an impressive amount of detailing built in. The instructions, which come with his kits, are most impressive as well. Unique Aircraft have a very nice UH-1B Huey fuselage.

Now we have decided which one to make, all we have to do is to decide what mechanics we are going to put in it. The first decision is gas or glow (or electric). Gas makes less smoke and looks better; glow is lighter but will leave a trail of smoke behind. This will be less if you use one of the European motors such as Webra or Rossi and run them on 0% nitro fuels as they are designed to be run. A scale helicopter with an OS61 or YS61 on 30% nitro looks pretty stupid wreathed in a thick cloud of white smoke when it is the hover. Electric’s are possible particularly using the Mikado Logo or Vario Silence 60 size electric mechanics, but the fuses have to be built very light as the power/duration tradeoff is quite steep. A friend of mine has a Mikado logo in an Augusta 109 fuse and it is very impressive spooling up with a turbine like whine and then cruising quietly around the field looking and sounding great.

If you are using 30 size mechanics, it may be necessary to use 30% nitro fuels to get the needed power to lug the extra weight around. If you don’t already have a set of mechanics, look at the built up weight of the finished pod and boom models and pick a light one.

One thing to think about when selecting mechanics is the head speed and blade size you want to run. Another friend of mine has a Vario Airwolf with Skyfox mechanics and 10:1 gearing. He runs the head at 1500 rpm and thus the motor is turning at 15,000 rpm. It all sounds pretty fast, but the Airwolf is a fast flying helicopter so the scale model hurtling round the sky doesn't look that much out of place. The Huey, on the other hand, runs a very low head speed and if he was to use the same combination in that, it wouldn’t look right.

If you build a large model, you need large blades, and most 60-size machines won’t fly well with big blades and a low head speed. The motor is simply in the wrong area of its power curve to develop consistent power. It becomes necessary to change the gearing to get the motor to run faster and put it back in its power curve. For example, if you select an Xcell SE as the mechanics, with an OS61WC motor, geared at 9:1. The peak power developed by the motor happens at 16,000 rpm. This means that the peak lifting power will happen at a head speed of 1777 rpm. This is perfect for an aerobatic 3D pod and boom machine, but for a scale Seaking it is hopeless. So if you slow the head speed down by increasing pitch and reducing the throttle, you can run the head at a more scale like 1250-1300 rpm but the motor is now so down on its power curve that it only develops a fraction of its maximum horsepower.

Its time for a brief look at power and motors. As a general rule, the power that the motor develops, is the same power that appears at the head. So if you have a 2HP motor, the head will be able to develop 2HP. I have discounted any losses and of course the tail rotor power requirements at the moment. To get the best performance from your helicopter, it needs to have the motor developing its peak HP. Check with the manufacturers figures and see at what RPM this happens. Now you have a choice. Either run the head speed at the level the mechanics gear ratio dictates, or find some mechanics which will allow you to gear the engine down so the head speed runs where you want it.

Most gasser mechanics are designed to run with a head speed in the 1500-1600 rpm range. Fortunately, the gasser engine has a fairly flat power curve so reducing the rpm of the motor is not a big sacrifice in power terms. Glow motors are a different story, particularly the highly tuned European motors. These are designed to run at high rpm on a tuned pipe with no nitro in their fuel. When run at lower rpm, they don’t run so sweetly and their power is well down. Tuning them is not so easy either. More about motors in the engines chapter.

Now that we have decided which motor we want to use, we can make a decision on the mechanics to put it in. There are one or two things to consider here that you may not have thought of. The first is the heights of the mechanics in the fuse and of course its width. I have a Blackhawk fuse, which is so low, and squat, almost no mechanics will fit without sticking out of the top. However, there is plenty of width for mufflers etc. The second thing is the height of the tail rotor drive shaft. If the mechanics are as low as possible, will the drive shaft go down the tail boom or is it still too high? On the Xcell mechanics, the drive can be taken from the bottom of the main gear rather than the top and this will lower the drive by about 1". The problem is that the extra support bearings needed to ensure accurate tail rotor drive train integrity cannot be used and there is an increased danger of stripping main gears, especially if a fast gyro/servo combination is used and some rapid start/stop pirouettes are performed. Just go easy on the rudder stick and you should be ok.

The last consideration is that of the servo tray. On many mechanics, it sticks out the front, just where you want your nicely detailed cockpit to go. On some mechanics it can be shortened and the linkages adapted to make it work, but others are impossible to change. If this is a problem, consider an ECCPM mechanic set where the servos are all set around the swashplate and push up from directly underneath it thus occupying none of the cockpit area. More about CCPM in the electronics chapter.

Well that’s it then. Now we know exactly which model/mechanics/motor combination we want and there are only three problems left to overcome.

1. Convincing the wife you need another helicopter
2. Paying for it all
3. Building the model and getting it flying.

One items 1 and 2 you are on your own; I’ll help with item 3

Chapter 2