SAPAC BLUE ARROWS HAWK

The Sapac composite models are some of the best available in the 70mm size, superb levels of detail and finish in the glass fuselage along with beautifully built wings and stabs, all built up construction and fully sheeted.

I have started with the wing and thought I would document the progress of the build. The wings are very thin on the Hawk and it requires a very small servo the size of an HS65.

Sapac have come to the plate with servos and their MSD65M Digital servos feature metal gear train, 2kg of torque @ 5v and are extremely fast and accurate. The holding power of the digital servo is very useful for the flaps where you want no deflection during flight, a cheap analogue servo just doesnt work as well, I tried it!

Picture shows the Aileron servo mounted, this is a bluebird 373MG servo, again same size as the HS65 but metal gears. Once my Sapac servos arrived I swapped out the bluebirds with the MSD65M's and fitted the Sapac servos to the flaps as well.

NExt up is the retract cutout and mount. The mounts are already in place inside the wing and the cutout above the mounts is already there. This means you can leave the film on for bungee/hand launch, cut the small square of film away for mounting fixed undercarriage, or cut the square away then use the supplied template to cut out the retract bays.

I have elected to fit the Sapac alloy air retracts and matching CNC Alloy Oleo struts, these struts have to be seen to be believed! The finish is superb, you would think they had been made in OZ or the US, not China!

Cutting the hole is easy enough, first trim the template to suit either wire legs or Oleos (its marked on the plastic) then lay it in place on the wing, hold it firmly and score around it with a brand new exacto. Keep cutting around until you go through the wood, remove the piece and clean out the bay of the rib, then sand the edges of the hole and iron the edges of the film down. I also wick thin CA into the wood edges to seal it then clean the film with acetone to remove any CA white dusty stuff

I have also wicked CA around the retract mounts and will also add some epoxy around the joins of the mounts to help strengthen the bond of all the interlocking wood.

more please

Ok wing is pretty much finished, I decided to tape my ailerons and flaps on like I did with the original Ver1. I use regular scotch tape, high quality clear and trim the end, lay it onto the LE of the aileron first, top side, half the width on the aileron, half hanging off. trim the excess off the end then lift the tape up a little and position it where you want the aileron, hold it lined up and drop the tap down and smooth from centre out either end.

Once this is done fold the aileron over the top of the wing and tape the underneath across the TE of the wing and LE of aileron. This gives you a strong gap free almost invisible hinge line that worked brilliantly on the old Hawk.

Flaps are the same but being hinged from the bottom you lay your first tape layer on the bottom surface then fold the flap down over the bottom of the wing and repeat as with the ailerons.

Picture showing retracts installed, servos installed, all wiring routed through the wing panels and hidden from view in the wheel wells. All thats needed are the struts fitted to the retracts.

Some photos of the fuselage, and insides. Very nice workmanship on the V2 and V2.1 kits, about the only thing I can complain about with the Hawk is the fan end of the intakes are roughly joined on my one and need some cleaning up with sandpaper/dremel. Not a huge deal but thought I would point it out.

Sory guys I have been a bit preoccupied lately, holiday time and lots of other work to get done, will get back onto the Hawk later this week, I want to see it in the air too!

I finished the Hawk a few weeks ago and have been flying it every weekend, very cool plane just like the original and seems to carry its full house 1950 grams of weight very well.

I will add some final build notes in here next week along with some pics of the inside where I modded the batt tray etc.

Very nice!

I'm thinking about picking one of these up myself. But, my local club has a rather short landing strip. How well does the hawk slow down with the flaps?

TIA

hk

Some photos of the internal layout and the battery tray mod. I removed the centre section of the bulkhead at the back the tray area and slid the tray back as far as it can go until it nestles up between the ducts.

The tray is on an angle so as to keep it as low as possible, the Battery sits across the wing centre line at an angle and is roughly balanced along the line which is nice.

Velcro on the tray and a strap to hold the pack down, with the tray well epoxied at the front, rear, and underneath to the lower part of the bullkhead, just above the wing retaining slot.

Must apologise for the delay in gettting some video edited, been very snowed under the last few months and with my HDD dying a few weeks ago I have only just reloaded all the software into the pc. So anyway here is the Blue Arrows Hawk with its harrier style cricket pitch takeoff! Works great

SAPAC 70mm Composite Hawk from Extreme RC AUSTRALIA (2 min 29 sec)