Kalt Baron 60 α (Alpha) (1989)
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Specification:
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| Documents: | |||||||||||||||||||||||||||
 Manual Alpha/Excalibur |
 decal |
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 Manual AlphaII |
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Based on the 60_Baron but with upgraded in many areas the most significant of which being the engine repositioned to face forward thus allowing the tank to be located under the main mast. As a result, the machines CG stayed the same as the tank emptied and thus did not significantly affect the machines flight characteristics. Modification made to the swashplate and scissor arms reduces backlash for more precise control and it also featured a high specification clutch and drive train with autorotation made by the Omega products subdivision.
1989 F3C Japan championship winner Kazuyuki Sensui with Epsilon 60_Baron α
The Kazuyuki Sensui designed 'Epsilon' contest fuselage had the unique option of no landing legs only 'fins' which reduced drag for a higher top speed.
Kalt 60_Baron αII (Alpha) (1991)
Second generation Alpha 60 with aluminium tail boom, back slanting landing gear with uprated pinion gear and bevel pinion gear plus slight changes in frame and fuel tank with the Omegae tail assembly and Black-10 SII rotor head as standard fitment.
Kalt 60_Baron αII (Alpha) USA (1991)
Upgraded by demand from the USA and Europe to include a top start cone system and the higher specification PE fin and tail.
Kalt Baron GS α (Alpha) (1991)
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Specification:
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 GS Alpha Manual |
 KG-22 addendum |
 decal GS-Alpha |
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Various small upgrades including the PE fin of the 60_Baron Alpha 2 USA.
Later version used the same plastic gear assembly for tail drive as the 30 barons....!!!! Petrol engine initially caused ignition interference problems and Tim Count who traded as TC Heliservices developed additional suppression which was incorporated in later Kalt kits.
Kalt Baron α (Alpha) 30/53
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Specification:
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 Manual Baron Alpha 30 with 4-stroke supplement |
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This is a rather different kind of review to that which we normally present and the result is one man's (probably jaundiced) view of something which is certainly different to the current trend. Read on and decide...
The story so far
It is no great secret that the Kalt company is in the process of producing a new '30' size helicopter of metal, rather than plastic, construction. Some prototypes of the machine have been seen in this country, in the hands of various demo flyers, and it has become known as the 'Alpha 30'. This is the Kalt name for the machine, although the potential UK importers would prefer to call it the 'Genesis'.
When the machine arrived superbly packed in a large cardboard box an even bigger surprise was that it was already built, with engine and servos fitted. A mixed blessing since I was now faced with talking about a machine which I had not built and for which I had no instructions! With no knowledge of - and a pronounced dislike for - four-stroke engines, I was clearly about to embark on a steep learning curve.
What else do we know?
A little research has established that Kalt intend to market the machine in three forms:
1) A 30 powered basic machine with a belt start that can also take an engine fitted with a pull-start.
2) An up-dated '46' powered machine with a top-start system.
3) A '53' four-stroke powered machine with a top-start.
The top-start system will be available as an up-grade for the '30' size version. Prototypes of all of the above are actually being advertised for sale in Japan, but are not available elsewhere. The reasons for this are that the people who might import them into the rest of the world are waiting for a fully developed version and are not convinced that the world at large wants to go back to metal-based helicopters. As to the interest in a four-stroke powered machine...
The model
In some ways, this could be described as a metal 'Space Baron S'. The undercarriage and the complete boom, tail drive, tail gearbox, tail rotor and tail feathers are, in fact, identical to that machine. Two metal sideframes clamp the boom between them in a manner very familiar to those who have owned earlier Kalt models. These frames appear to be one stamping which is bent into left and right hand versions. The undercarriage is bolted onto the outside of the frames just as it is on the 'Space Baron' with metal spacers between the frames. A complex machined aluminium mount accommodates the motor and fits between the sideframes. The motors crankshaft points upwards and the cylinder head faces forwards. The clutch/maingear/tail drive set-up looks almost identical to the old 'Baron 2OMX', although closer examination reveals that everything is actually different. The clutch is a one-piece metal item, which is almost unique on a Kalt model. Pitch input is accomplished by means of a 'Space Baron' pitch yoke pushing a wire up and down the centre of the mainshaft. The shaft itself is a new item, but with a very familiar-looking autorotation unit. All of the swashplate controls are again identical to the 'Space Baron', with the same mixer being driven up and down by the same system. The difference is that the top bearing holder is of aluminium, with a spigot to accommodate the clamp-around 'SB' unit.
As supplied, the tail rotor pitch linkage consisted of a length of thin piano wire, encased in a plastic tube, which extended all the way from the tafl gearbox to the front-mounted tail servo. Despite having two supports on the tail boom, the front half of the wire was unsupported and there was a lot of lost motion in the system. To make things worse, the supported section took a very winding course along the boom. More anon.
A metal gyro plate bolts between the rear of the frames and has offset holes which allow it to bolted in two positions. There are also two sets of holes in the frames at different heights so that you actually have a choice of four positions. An identical plate at the extreme front of the model serves as a receiver/battery mount. A standard 'SB' tank is clamped between the sideframes. These frames are rather further apart than the 'SB' plastic frames and the tank is free to move something like a quarter of an inch sideways. A Kalt three-way filter is used which allows the tank to be filled via the feed line.
Two vertical metal frames separated by spacers serve to mount the servos in a very similar manner to the 'SB' and are attached to the front of the side frames.
The canopy is of similar design to the 'Alpha 60' and is attached to two side stand-offs (similar again to the 'Space Baron'), with a clip which attaches to the front undercarriage crossmember. This is quite a convement system as you can unclip the front attachment and hinge the canopy upwards for glow-plug and switch access.
Supplied with the model was a set of K&S blades, very similar to those recently supplied for the 'Enforcer', but without the angled tips and weighing 125 grams each. These were quite well matched, the spanwise CG's being a 'mere' 2.5 mm different.
So what's really new?
We made brief mention last month of the new rotor head. Apart from the use of the bladeholders and flybar paddles from the 'Space Baron S', this is completely new. It also features what I believe is the first underslung flybar from Kalt. A complex centre moulding incorporates guides for the top end of the wires which drive the mixer unit up and down (unlike the 'SB', where the guides are incorporated in the main shaft) and this is supported by an aluminium collar which also accommodates the two fixing screws whieb screw into the mainshaft from each side (ala 'SB').
The flybar has two operating cranks which look remarkably like Baron 20' items, apart from which the whole system of inputting pitch commands is identical to the 'Space Baron'. The bladeholders are connected by a 'through axle' which floats in two rubber 'O' rings. An interesting difference here is that the blade holders are retained by nylock nuts on the end of the axle, rather than the familiar capscrews going into the axle. A metal collar inside each bladeholder butts up against the 'O' ring and serves to hold the axle central, but there is a big. big difference between the diameter of the axle and the size of the holes in the 'O' rings!
This means that the entire blade/bladeholder/through axle assembly can be raised and lowered by some 3 to 4 mm without any resistance being met. The assembly can also be rotated by some 5 to 10 degrees in each direction relative to the main shaft. Perhaps it should be pointed out right now that it feels perfectly normal in the air!
So far, much mention has been made of the 'Space Baron' and other previous Kalt machines. I feel that I should apologise for this, although I really cannot see any other way of making the comparison. It is difficult to decide whether the machine is to be regarded as a 'metal Space Baron', or as a throwback to earlier designs. Fortunately, I have a 'let-out', because it has a four-stroke engine fitted!
The engine
As mentioned earlier, this is an Enya '53' four-stroke engine. On this engine, the valve gear and pushrods are mounted at the rear, with the carburettor attached to the backplate. Examination reveals the rather surprising fact that the carb appears to be a two-needle unit which has been modified to an air-bleed type.
The relative disposition of the tank and carburettor means that the carb is about one inch below the bottom of the tank. It is no surprise, therefore, to find that fuel literally pours from the carb when the tank is filled. What is, perhaps, surprising is that the model came complete with a pressure line from the silencer/pipe to the tank vent!
Another surprise is that the silencer (in itself an item which is frequently omitted from a four-stroke) appears to be a tuned pipe (apparently, a turned-from-solid K&S unit). This is on the end of a very long header and it seems very unlikely indeed that it can operate in the conventional sense. After some experience of running the motor and flying the model, I believe that the purpose of this exhaust system is to act as a rev limiter, rather like those currently employed on state-of-the-art (?) control-line aerobatic models (FAI F2B). Although so far unexploited, I believe that this technique could be used to advantage in '3D' flying - though this cannot be the purpose here.
It was very soon established that the pressure pipe served no useful purpose and made the engine go very rich in certain circumstances. It also gave a very large 'flat spot' when the throttle was opened. It also became full of brown 'gunge' making its way from the silencer to the tank. Removing the pressure line gave a great improvement, but the real secret was to increase the nitro content of the fuel. I started off on 'Duraglo 5', but as I was already using 'Superglo 16' on the OS 615X in the XI-pro', it was convenient to try this on the Enya. This was a real breaktrough and the motor now runs very consistently. On a subjective note, I find the persistent flat drone to very boring!
One characteristic which still persists is that, if the model is landed and the motor allowed to tick-over for several seconds, on opening up and lifting off again the motor will hesitate momentarily before continuing. I suspect that this is caused by the plug cooling off. Incidentally, the plug does not resemble the usual Enya type and I have no idea what it is
Four stoke Baron Alpha 53 and Alpha 30 Kit
Kalt Alpha 30 4 stroke Upgrade kit
Baron Alpha 30 - electric version
