Post Bronze ARTF'ery

Thought I would show the build of the Blackhorse Twister. This model according to the box it’s for advanced to intermediate flyer's. If you want the basics of ARTF building have a look at Basic ARTF Assembly

So the box:

 

And inside it:

And the bits to kit it out. I've transfered the small parts into a plastic tray to stop them getting lost:

First things first I did read the instructions but did not follow them entirely. Starting point is the wings and the fitting of the servos;

Just marking then drill the pilot holes for the servo screws.

Unfortunately the servo leads didn’t quite make it to the exit holes cut on the underside of the wing . So had to add a couple of extensions with lead locks (Note: not the ones that bend the leads) :

That done its time to join the wing, but firstly remove the film that’s on the face of the root rib and slight sand:

And the servo leads taped out the way of the epoxy:

 And the wings joined and left to dry:

Next the engine mount comes in two halves and can be adjusted to the width of the engine crankcase:

Now first deviation from the design. The instructions tell you to mount the engine inverted at an angle of 45 degrees. I didn’t fancy the problems of starting an inverted 2 stroke so opted to mount the engine 45 degrees off the centre line, but upright. This was no bother as the mounting holes in the firewall are evenly pitched.

A big problem with mounting the mount as the captive/blind nuts that are on the inside of the firewall kept popping out and getting them back in was a real pain …wasted about 45 minutes.

Marking the holes for the engine. Kit gives you self tapers, but I prefer bolts and I would have to drill the holes anyway…so no real hassle:

This moving the engine around meant that a further exit hole for the throttle pushrod had to be drilled… no real hassle and this change was purely my preference.

Next onto the tail feathers. Just a matter of marking where the film needs to come off, ensuring the fin is square to the tail and the tips are equidistant and parallel to the tailplane…lots of dry fits and re-measures and wee nudges until happy:

     

Note all the surfaces clamped up during this process and everything left to dry:

I had also put the servos in the fuselage before this, but that’s straight forward so no photos. However, the biggest pain to date was the tank. Take a look at this:

Yep the bolts protrude about 6mm beyond the inside of the firewall and the tank rests right up against the firewall. If left in this state any heavy landing would puncture the tank. I could protect the front by putting a balsa block in front of the tank but the tank would be in the wrong place. So the only solution is to use shorter bolts or cut the 6mm off. If doing this make sure you have the nuts on the bolt first. Must say this was pretty poor. As it meant taking the engine and mount back off and these had been thread locked in .

Anyway, the shorter bolts:

That solved back to putting the tank in:

Just some old snake inners fed through from the front and attached to the tubing. Then ease the tank into place pulling the snake inners as you go. This can be done with the engine in place as was my intention hence using the snake inners as they’re pliable.

Next the control rods. The instructions ask that swing keepers be used, but they also ask that you screw the clevis on first and connect up to the control surface horns (sorry I didn’t take any photos of a horn being put in place…what’s the point) However, through choice decided to not use this in the fuselage anyway as its too much hassle trying to mark and bend the wire to the correct length, particularly as the rods are about 10cm too long . So instead used collets as the set up is much easier, but fitted them not as per the instructions for the throttle one provided… two nuts below the servo arm and not either side as per the instructions. Also thread locked on:

 

The throttle linkage is fine but its wire against wire! Some say this can cause interference so I modified this to take a plastic clevis.

As shown in instructions :

And as modified :

Now the cowl. Pretty easy mark where you need to cut away and start with cuts well inside the lines and cut away. Finally finish of with a Dremmel or similar tool with a sanding drum and a final light sand. Just make sure you mark it up with the spinner in place:

Undercarriage: Firstly the tail wheel:

Just mark the position of the screws and drill pilot holes.

And the main gear, already has the bolts in situ, but again blind/captive nuts kept falling out…not so bad as these are accessible unlike the firewall ones. Two piece undercarriage… not so sure about but gave it a try:

The plane comes with spats, but I felt they are more hassle than they are worth off grass so decided not to use them. Also the bolts for mounting the main wheels didn’t fit through the hole in the metal. So I just replaced them with stuff I had.

Wing push rods:

Again swing keepers and clevis:

Now the wing bolts. When putting the wing on I felt that the bolts were turning, but they were not tightening up. On investigation the captive nuts were again just popped in and there are no teeth to bind them to the brace:

Epoxied these in situ.

Where does the radio gear go? C of G about 90mm back from the leading edge of wing so tried in the space provided and it worked:

And final just about ready to go:

Just about, the more I looked at it the more I thought what a pathetic wee canopy. So last mod was to remove it and wee bit of Solartrim put on the fuselage itself:

Those old timers will say it’s a Precedent Fun-fly…I reckon if you are one you wouldn’t be far wrong. Only difference is this is a wee bit bigger, cheaper, has a built up wing and is ARTF. Though I reckon the designer of this must have had one...just a pity Precedent aren’t around any more as they never produced a bad kit. And even though not ARTF they went together very quickly.

So all in all told about 10 hours from start to finish.

Likes
Gluing bit not a problem
Fairly quick, but could have been quicker

Dislikes

The fittings caused lots of frustration and wasted about 2 hours of my time

Some bits of instructions unclear
Had to remove a good bit of glue to get the elevator to move freely.

Unsure
Main undercarriage.

Flying

How did the plane fly…great …very slippery and lots of control movement if you want it.

Picture courtesy of Colin for the above.

Word of warning… this plane is not for a beginner learning to fly!

Nothing Is Ever Perfect

However, there is a lesson learned by myself here, and this is if you are unsure about something, as I was with the undercarriage, then maybe you should change it... Find out more HERE