I first saw this model at Colin Nicol's house (Dunfermline club) and then again at the SAA aerobatics comp in 2004 at East Fortune. The owner of the second model was Gordon Frost (14). Bill Alison took the model up for it's maiden flight and I thought it was just the ticket. As (bad) luck would have it I seriously damaged my Excelsior the following Saturday, so after a suitable period of mourning, I took the opportunity to order the Swallow from Paisly Models, Scotland on the Monday morning.
The main decisions had already been made i.e. YS120 engine, tuned pipe, JR PCM receiver & JR servos. The big question was whether to use the supplied hinges, and whether or not to put the servos at the tail with short / stiff linkages to the elevator.
The following comments were receicved from various sources before building began in ernest:
1) I used the fuel
tank that came with it (nothing particularly special). As the model
expects a YS, I assumed the tank could cope with the pressure. I have
clipped all fueling joints though rather than just relying on push ons.
2) Tank location - I don't think you can tell from the instructions
(which I found to be generally unhelpful anyway) whether they expect
it to be in the nose or in the bay over the wings. As we were using
a heavier than intended engine (120 instead of 91), I opted to put it
in the bay over the wings, as that's much nearer the c of g. Balance
wasn't a problem, but do make sure that your kit comes with the updated
list of control surface throws and c of g ranges - should be on a separate
sheet which supersedes the last page of the instructions.
3) Prop - APC 14x12. This was/is a starting point, still not fully assessed.
Surprisingly, I thought Probuild's prices for all larger APC prop sizes
were good.
4) Elevator/rudder servos - I used the location and linkages they supplied
(rudder closed loop, elevator forked pushrod) ie not in the tail end.
This was probably due to lack of model-building experience, as shorter
rods etc would be more positive. Don't know about fuz strength if you're
going to chop in servos near the tail end (which is why I didn't do
it!).
5) You'll enjoy getting the aileron servos mounted in the wing cutouts,
also having to be at the right depth so the "saucer" fits over the top
of the servo shaft without making contact!
6) Control surface hinges - I discarded the supplied circular thin discs
(told that they won't cope with the vibration) and fitted proper square
flat plate with a hinge pin ones (Kavan), duly double pinned on each
half.
7) Servos - I used F 3001s for all except throttle.
8) Generally - it seems to come with a pretty comprehensive collection
of fittings, including a whole pack of metal fittings from Flair to
replace those that the kit manufacturer had originally included.
There is also some
good infor here: http://www.rcuniverse.com/forum/m_1841818/anchors_2000460/mpage_1/key_/anchor/tm.htm#2000460
and here:
http://www.rcuniverse.com/forum/m_1811048/anchors_1811048/mpage_1/key_swallow/anchor/tm.htm#1811048
The
Build
The
instructions are "interesting", but make sure you read them
all before doing your own thing. Read the rest of this review, and the
others on this web site, then go to http://www.dmac.org.uk and read
the reviews of the Excelsior, Smart Move and CAP232. There are a lot
of good installation photographs to give you help. THEN do your own
thing :)
The only thing to
be sure of is how you want to install the tail wheel, as the instructions
show the tail rod going into the rudder - an operation that needs to
be done BEFORE the rudder is attached to the fuselage.
This model comes with a pre-built fuselage, thereby saving a lot of building time. All the right bits were braced, but there were a few gaps that looked a bit dodgy. I went round as many joints as I could with Aliphatic resin, cyno and epoxy just to give myself more confidence.
From my pre-build investigations, it appeared that the undercarriage mounting plate was the weak point. Hardly surprising gived the amount of moment acting on it. I eventually epoxied a bit of 1/16 ply on the outside and inside and used a 1/4 inch rubber washer between the undercarriade and the mounting plate to give a bit of shock absorbtion. I wimped out and used plastic bolts for the first couple of flights, hoping that removing broken plastic bolts would be less work than rebuilding the front end.
The BOTTOM COWL is secured by 3 or 4 screws on each side. I was not happy with screwing into balsa (even with cyno poured into the screw holes to harden them) so I replaced the supplied wood with hardwood and lived with the extra weight.
I elected to use a John Brown "T" mount from Probuild. Pricey, but I knew it would fit okay, and the 1&1/2 degrees of side thrust could be accomodated. The downthrust was accomodated by my preferred mothod of a tapered wedge rather than the washer as proposed in the instructions.
Give some thought to the WING DOWELS. The ones supplied are aluminium which means that if a hard landing causes the wing to part company with the fuselage, the dowels will not break - but something else definately will. I realised this just after the epoxy had set :(
The other thing to watch is the dimensions for the wing retaining blind nuts. If the holes are too close to the fuze wall, the blind nuts will hit the 1/4 inch balsa used to brace the mounting plate. The good thing here is that the mounting plate is braced on the top and from below.
I decided against using the control horns as supplied in the accessory pack and used the Ripmax type as used on my other models but had to visit the local DIY superstore to get some longer brass self-tapping screws. (No4 x 1 inch) were long enough to go right through and into the backing plate on the other side. Note the mistake - the horn is too far away from the hinge line.
WINGS
I found that my standard servos did not fit the wing properly as the mounting
rails were too low causing the servo the hit the upper surface of the
wing. I epoxied a 1/4 x 1/4 hardwood bearer on to one and a 1/8 x 1/4
onto the other.
The main wing joiner is an aluminium tube. That is, a shiny aluminium tube. It is a sliding fit in the hole so not much room for the epoxy. I eventually took a file and roughed up the outer surface to give some adhesion. The two halves mated perfectly with no additional work on my part.
ELEVATOR
I had a few problems with basic loops with some of my previous models,
so when I came across a dual crank elevator actuator at www.probuild-uk.co.uk
I decided to try it. A bit of surgery gave access to the inside, and a
couple of tapered bits of ply ensured squareness. The plywood seen here
was later covered with white Profilm.
This also let me see inside, and my first concern was whether the closed loop wire would miss one of the vertical braces. As it turned out, it did not. The solution is to move the slot for the wires back approximately 50mm. This did not fix the problem completely, but the route was straighter and gave me a bit more confidence.
As mentioned on the forum, the rudder elevator actuator rod gets a bit too close to the rudder closed loop wires so I raised the elevator servo by 1/4 inch.
Tailplane
When you are about to glue the tailplane in place, cover one half with
clingfilm before pushing it through the slot. That way the glue doesn't
get smeared all over the tailplane. Remember the tailplane goes on BEFORE
the elevators are attached.
FUEL TANK
The big question here is "in the nose" or "above the wing".
"Above the wing" means less change in the centre of gravity
as the engine eats it's way through 15 oz of fuel. The downside is that
if the tank splits, there is fuel all over the servos, receiver and battery.
One advantage of the pumped YS120 is that I did not have to worry about the tank hieght relative to the main needle. In my case the tank was about 2 inched above the needle, normally a recipe for disaster.
THE ENGINE
The kit comes with a transparent plastic cowl to allow you to mark any cut-outs to give access to the main needle jet, to miss the engine, and to miss the exhaust. As you can see here I had to cut away quite a lot to avoid fouling the engine, and my main worry is that I damage the engine if the undercart collapses on landing.
The engine cowl was held on with servo screws, and the holes were strengthened with cyno.
The flexable exhaust pipe is secured using an MK part which came with the exhaust as supplied by Just Engines. The bottom cover needs to be modified to miss the mount (photo to follow). Also once I figure out how to secure the rear of the pipe I'll upload details.
SPINNER
From an engineering or operational reason you can use the spinners
from Just Engines (which you can buy from any model shop) but are about
twice the weight of one from Phil at Probuild. The other problem you might
have is if you use the double jam nut that comes with the engine you will
need to screw the adapter for the cone screw which comes with the spinner
on after it (3 nuts). You will certainly need to shorten the adapter and
sometimes depending on the thickness of the prop hub you may not have
enough thread either on the shaft or left in the adapter to screw it on.
When you get a spinner from Phil you buy a special new double jam nut
on which the front nut is extended and drilled and tapped to take the
cone bolt. Of course you could buy the jam nuts from Phil and the spinner
from Just Engines.... The spinner and adaptor from Probild is about
£50. The spinner and adaptor from Just Engines is about £15.
COVERING
As with most ARTFs the covering is some unknown brand of sticky plastic.
The model did have some bits coming away, but a hot iron solved most
of the problems. For the colour concious, try Audi Laser Red touch-up
paint as it looks a very close match.
The Summary
The model goes together quite well. In this case, my son did all the work so things took a little longer. Althought the instructions are pretty comprehensive, I am not sure how a newcommer to building would get on but, if you are reading this, and you check out the rest of the reviews here and on the Dundee web site, you should not have too many problems. If you have any questions, please do not hesitate to get in touch.