Cliffwhacker

[Dane Crosby]

Hi BP. The PP motor already arrives with the mount at the front.

I had rearranged the nose formers so that the prop spinner was where the original nose was. I rear mounted the previous two motors so had to re-engineer the PP to be rear mounted too. It is slightly longer so a new cowling was needed; about 5mm longer.

If in a hurry I band the prop. I use a spare switch on my tranny to use the Specky Throttle Cut option. Whatever I do with the throttle stick the motor won't run. I use this on all my leccy models to make wrestling with battery connection safer.

There are hundreds of ways to make cowlings and nose cones. I make a solid version out of block balsa. Sand, sanding seal then polyurethane varnish. When dry fix it in the bottom of a plastic cup, yogurt tub, margarine tub etc.

I fix it down with melted wax but vaseline will do. Wax the solid all over. Then fill the tub with plaster of Paris. After a cuppa the plaster is pulled out and you then have a mold which, when dry, I cover in release agent and use glass tissue and resin to make the very thin, but strong nose cone. I fix it with small self tappers.

Good fun.

[Richard Haynes 1]

Thought 1... the plan and parts available from Sarik seem to have abandoned Whittaker's original semi-semi-symetrical wing form; ergo the build instructions for the wing in the magazine needs approaching with caution because the wing does NOT have any flat bottomed section and if you try it the lower ribs will settle proud of the wing ribs... I fell into this trap: loads of work to fix with a Dremel router and NOT for the fainthearted. Packing up the lower wing ribs may be the best solution.

 

Thought 2... the sharp angles of the fuselage sides, even with a Slec fuselage jig, may be problematic. If you try to bend them you will run into trouble if the sides are of different stiffnesses, as mine were, tending to distort the fuselage even if forced into line by the jig. I had to saw the sides off my fuselage and start again. A better solution is to the cut through the fuselage at the bend lines to ease the bend AND possibly to use water to loosen the wood. The kerf line, and my preference is for interior ones are then flooded with thin CA. Ideally you want the fuselage to sit at the fuselage-side-angles dry and with no force or guidance. I'll be trying for that on my next fuselage which I'll start when the wood comes from Sarik.

[buster prop]

I decided to fly my Cliffwhacker again after it has been gathering dust for about two years. There was a moderate south east wind forecast and Ivinghoe has a slope facing in that direction. When I got there the wind had moved round to due east and was quite strong so I had to fly from the bowl, off the path which goes from the car park to the top of the hill and the west facing slope. That isn’t the best slope at Ivinghoe, gently sloping down towards the big field. Anyway I launched off and the Cliffwhacker flew away, gaining height and just needing some down trim in the strong wind. Much smoother flying once I got it above the turbulence. I’d forgotten how well it flies, good penetration and can move a bit too. The last time the Cliffwhacker flew was in much lighter conditions and I’d taken some nose weight out. With the CG on the wing spar it always seemed a bit nose heavy and I think mine flies better with it a few mm back. Anyway I really enjoyed flying the Cliffwhacker again and must give it some more air time.