Building the Fury Tempest FAI
Simon Lockington

Click on each picture to enlarge

The big box wasn't as big as I expected, but I was glad to see it when it finally arrived!

The head with the flybar carrier and flybar installed. Note the length of the carrier. Prime candidate for replacement in a crash.

The spindle shaft assembled with radial and thrust bearings. The blade grips bolt into the retainer, you can see two of the holes in this picture. The O-rings are pushed up into the head and are not lubricated. I have gone with the 50/60 durometer combination.

The blade grips mounted with the pitch arms fitted. The grips can be mounted in either a leading or lagging position. I have chosen leading. The nearest grip shows the bolt that goes into the back of the retainer.

Flybar assembled with paddle. You are given a length of lead from which you make your own weights. I've decided to go with no weights, the paddles weight about 35 grams empty.

The heli is assembled left frame first, the right frame is attached later. Note the three mast bearing blocks and the threaded steel inserts all over the frames.

Right frame attachedwith autorotation unit and radio tray in place. Note you can move the tray forward and back to obtain the best CG.

Landing gear attached to main frames.

A couple of months ago I made the decision to try one of the new Fury Tempest models that Miniature Aircraft in the USA have just released to the market. There were a few reasons for this. I wanted another 91 powered machine for 3D use and I had a feeling the new Vigor would be some time away. Therefore I decided to use my existing CS for 3D and get another machine for FAI work. I liked the flexibility of the Tempest FAI model in terms of being able to adjust dampening, paddle weight, flybar ratio, delta, gear ratios and various other settings quite easily.

I'm travelling to Australia in November to compete in the Victorian F3C Championships and this was the machine I was planning on using for this event so I was on a pretty tight schedule. Time to build the machine, set it up and get used to it before the event meant that I really couldn't afford to lose weekends of flying time.

I placed the order with the local distributor for a Tempest FAI with the 7.75:1 gear ratio and waited for the machine to arrive. I waited and waited then finally asked the distributor to find out what was going on. He found out that MA had shipped the kit on the 29th of July but as of August 21st it still hadn't arrived. Cyndi at MA tried to track it down from their end but to no avail and I was starting to get anxious as I needed to get the machine ready for upcoming competitions. However luckily at the eleventh hour, the kit turned up in one piece.

This is my first non-JR kit and I expected a few differences and anticipated quite a steep learning curve to get used to the design ideas of the Tempest. I'd also heard many stories of the complexity of Xcell machines in the past and was preparing myself for a bit of slog at building the thing up.

First impressions were that the box was a lot smaller than I expected, however opening the box revealed a large gel-coated canopy and many bags of bits which where fairly clearly marked. I was a little disappointed to find that the instructions were separated into a book of text and a book of diagrams. What was nice though was the supplied parts listing book.
There were a few other guys present at 'the opening' and soon there were many hands fetching plastic bags out and examining the parts (they weren't allowed to open the little bags just yet J). The general consensus amongst us all was that the quality of the parts was very high quality and the fact that just about everything was metal was impressive.

Sunday night the building began on the rotorhead.

Rotorhead
The rotorhead is the main reason I brought the Tempest, it's highly adjustable which can be both a good and bad thing, but I was looking forward to it. I had canvassed a few F3C pilots in the US who have been flying the Tempest for a while to get a general setup to begin with.
The first steps are to assemble the flybar and rocker assembly which was very straight forward. One nice touch is the Xcell ball links have small hex holes in the top so you can drive them down tight. The JR units are normally a small bolt going through the middle of the ball.

As per the initial recommended setup, I used the 0.9:1 (out of the available 0.65:1, 0.75:1, 0.8:1 and 0.9:1). The mixing arms are mounted on the very long flybar carrier which is very free. I suspect however that should a crash happen, the carrier will be stuffed given it's length.

The dampening system uses O-rings which seems to have become the defacto standard with new model helicopters now allowing pilots to customise their dampening with different O-rings pretty easily. The Tempest kit provides different combinations of O-rings (hard and soft ones) as well as different sized shims to futher adjust dampening. I chose a combination of 60 durometer O-rings inboard with 50's outside followed by a 0.25mm shim. This has yielded a similar dampening feel to my Vigors which have the Ron Lund O-ring system installed.

The assembly of the blade mounts and feathering spindle is quite different from what I'm used to. In this case you assemble the dampening, shims and bearings on the spindle while it's in the head. You then bolt it all up without putting the blade grips on. You then SLIDE the blade grips over the assembled shaft and press the pitch arms into the blade grips and bolt it down to the retainer sleeve. Not necessarily better or worse than the JR system I'm used to, just different, which in reality sums up the construction of this helicopter.

Following this, you setup the amount of delta you want on the pitch arms. You can have Positive 3.3 or 5.3 degrees, or Negative 3.3 or 5.5 degrees. I chose to use negative 3.3 degrees.

The paddles are supplied with a long strip of lead with which you can customise the weight of each paddle. At this point I have left all the weights out of the paddles to see how it goes, if it's too twitchy, I'll add some more weight.

I have to take the opportunity here and praise the extremely high quality of all the parts in this kit. All parts are just beautifully machined and designed. However is creating these has really got a handle on what's going on.

Frame Assembly
A nice touch with this heli is that you assemble just about everything on the left frame first then bolt the right frame on. There are three bearing blocks with four bearings supporting the main shaft.

One of the first things you install is the tail drive shaft through the rear frame rail into the middle bearing block. This is one area where the Tempest has the CS over a barrel. The front of the Tempest's tail bevel gear is supported by the middle mainshaft bearing block whereas the CS's bevel gear is not supported at the front at all.

However having said that the CS takes the Tempest for simplicity of it's autorotation unit. This took me a couple of hours to get my head around and I have to say that at first I felt it was unnecessarily complicated considering other autorotation systems around. The Tempest system uses an assortment of O-rings and various combinations of shims in order to get it right. Not being the most mechanically minded, this took a little thinking for me, but once I understood what they were trying to achieve it all came together. Still, it's not the plug and play setup of the Vigor systems. Having said that, the unit does look very strong and durable.

Instead of using a bolt to secure the auto assembly to the main shaft Miniature Aircraft are using dowel pins secured by grub screws. At first I was a little concerned at how easy this would be to use, but if everything is lined up correctly the pin just slides in and can be easily pushed out again via a small hole on the other side of the hub.

What DID piss me off was the fact that the instructions call for the contents of bag '2B' which I spent about two hours looking (read 'stressing') for, even ringing up my mate's place where we had opened the kit to see if the bag had fallen out there. It turns out that the contents of bag '2B' are actually in bag '2A'...

Radio Tray
The adjustability of this machine even extends to positioning the radio tray to where ever suits the center of gravity. Move the tray forward to get more weight forward etc. Velcro straps are supplied to secure the tray contents to the tray.

Right Frame Assembly
As you would expect, attaching the right frame assembly is a straight forward task. Another nice feature of this machine is that the frame rails have threaded sections which you bolt into, so in many cases you do not have to worry about getting in behind with a cresent to tighten up lock nuts. Just a small thing, but very nice.

Attaching the servo bell cranks is a non-event as you would expect.

Rudder control is passed back from the rudder servo to the tail via a bell crank mounted at the rear of the right frame and the gyro sensor sits atop a purpose built platform above and behind the radio tray.

Landing Gear/Bottom Frame
The landing gear is very nicely made with titanium skids (no shit) and what seem to be very durable black struts which attach to the carbon bottom frame in straight forward fashion. A minor gripe was that the holes for the grub screws that secure the skids into the struts are not pre-drilled, you do that yourself. As I said, it's a minor thing, but I've not had to do it on JR machines at all.

The assembled landing gear is then attached to the main frames.

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