For no further reason than that I like engines, I’ve put together an MFA Sport 500 ‘power pack’ from an original MFA Panther 46A engine and a collection of spares. The aim was to make a good educational tool at talks and airshow display stands but overall I just think it looks nice sat on my workbench shelf.
Writing up my PhD has taken most of my time but I’ve finally finished this project. Comprising the best picks from a collection of second hand parts along with a new canopy and wood parts this machine is now like new. The tail surfaces are from a pre-1990 machine and have the ‘high fin’ found on the first batches of the fixed pitch machine. With the introduction of the collective pitch version in 1990 the wood parts were modified to suit both and the fin was reduced in size. The Collective version couldn’t be flown without a gyro and so didn’t really benefit from the additional weather vane affect. I was going to use another ‘period correct’ Guest mechanical gyro but the one I sourced turned out to be at the end of its service life so I will have to keep an eye out for something appropriate. Considering my original MFA Sport 500 didn’t have a gyro installed I suppose it’s more authentic this way!
So that’s that really and I’ve got restored versions of the machines I learnt to fly including hovering/circuits (MFA Sport 500 and Hawk 30 MK1) and early aerobatics (Shuttle Z-ts). I’ve been looking out for a little Raptor 30 V1 with which I started 3D but have so far drawn a blank. Few have survived I guess, or perhaps the vast majority were converted to V2 spec. Raptors went on to become my main 3D machines with a pair of identically set-up Raptor 50 V2’s being those with which I burnt on obscene amount of fuel. Higher education then took over but not long to go now….
I’ve decided to treat my restored MFA Sport 500 fixed pitch to the latest .40 cu. in. engine from the Sanye works. Not heard of Sanye? You will I’m sure have owned at least one of their products in your modelling career as this is the factory that turns out the SC, Magnum and ASP line of engines. In recent years they have come a long way, although having said that I’ve never had a problem with the past variants. The cure to a ‘bad’ engine is usually change to a better fuel; preferably one without castor oil. Why manufacturers continue to plug away at recommending castor I will never know…..
Compared to the SC .40 MK1 in my Sport 500 Collective, this modern SC certainly looks the part with a meaner squarer profile. It’s also considerably more powerful than the previous version but this comes at the expense of slight increase in size. This engine is bigger in width and the carburettor rake is set at a greater angle. All this equaled to some ‘proper’ modelling to get it to fit my heli.
First job was to grind away the inside edge of the engine mount using my trusty mini-drill until the engine fitted This engine has 4 mm bolt mounts. My first instinct was to drill the mount for 4mm but (thankfully) a quick look at my other collective-pitch Sport-500 revealed that 4mm nuts on the other side would either not clear the main frame or seriously reduce available movement for adjustments. Out with the mini-drill again and some copper tubing was quickly cut into some spacers, neatly converting the engine to accept 3 mm.
Next job was the fan blades. Trimming the edges to clear the carb was the easy bit. Ensuring they are all the exactly the same was harder. In the end I jury-rigged the fan onto a drill and sanded down the blades as per a rudimentary lathe; seemed to work rather well. I used the hydraulic locking method to tighten down the drive nut before moving onto the fan shroud. Thankfully this required hardly any trimming to fit. Job done 🙂
Having completed a collective version of the MFA sport 500, the bug had bitten and I decided to keep an eye out for a fixed pitch version to restore. I didn’t have to wait long as parts are plentiful and come up often. First job was to strip it all down and clean everything (I used antifreeze in a pan to do this). From then it was simply a case of choosing the best parts and putting it back together. This is about as far as I can go for now; I will need to keep an eye out for the remaining parts as and when they come up for sale.
(I’ve uploaded the full set of MFA sport 500 manuals, templates, advertisements and magazine reviews here)
Mechanical sympathy was a term coined by Jackie Stewart during his time as a Formula 1 driver. It was his opinion that the best drivers were those who also best understood the machines they drove. I learnt a lot about how my model helicopters worked and how best to handle tools and materials from my luckless battle with an MFA Sport 500. Now before I go any further I want to point out that there wasn’t anything wrong with the Sport 500. It was actually well engineered and designed specifically for the job of teaching its owner to fly. Unfortunately I feel MFA had perhaps forgotten the definition of ‘kitchen top engineering’ and what it is like to be a beginner with no idea how to accomplish the ‘simple’ tasks. For example the instructions did not explain how to tighten the prop nut on an engine that rotates in the same direction when there is nothing to grip onto!
To successfully build and fly the kit as designed really required a number of specialist tools that the average beginner just wouldn’t own. Without these most (me included) would try and substitute tools to get the job done. The result was to scratch, mangle, mash and strip the fragile aluminium and plastic parts and produce a machine that would soon vibrate itself apart before leaving the ground. All too often air did eventually appear under the skids of these poor helicopters; but unfortunately the lift wasn’t provided by the engine as it soared from the pilots outstretched hands into the trash.
On a strict school boy budget I was just about able to purchase the helicopter and radio. Tools however were another matter. My father wasn’t (and still isn’t!) good at DIY and had few tools in the garage. Construction of my Sport 500 therefore took place with nothing more than a junior hacksaw, a set of mole-grips, an old drill and a small assortment of ill-fitting screwdrivers. One weekend during my first GCSE year my technology teacher asked me to bring my ‘project’ into school and work on it as part of the school open day. I jumped at the chance as it would mean I would have access to all the high quality tools the well kitted out technology department had on offer. I did more towards getting my heli working in those few short hours than all the previous months of frustration and learned a valuable lesson that day; the right tools are required for the right job.
Today, 17 years later I’ve amassed a nice collection of hobby related tools and felt like I would like another crack at the Sport 500. I alluded to the purchase of this ‘new’ helicopter on eBay in a previous post. Quite a find in my opinion as it was an unbuilt boxed example. I also managed to track down a period correct Quest gyro and an unused series 1 SC40A engine. Construction went smoothly and the only modification I’ve made is to fit a third canopy mounting bracket to the underside of former F1 using a triangular cross section of ply to offset for the angle of F1. This should stop the canopy rocking back and forth in flight. Finally it wouldn’t look right with a 35MHz aerial extending back to the fin.