Mystic 40

This is Hanno Prettner's 1993 World Championship model - scaled down for a piped 40 or possibly a 60 sized 4 stroke,

It results in a model of about 56" span and hopefully quite light.

 The design was actually pulled together using DevFus for the Fuselage and Profili for the wing. This enabled me to get the shape of the formers exactly right without needing to guess or manually interpolate.

A very slender fuselage and surprisingly deep. Its not really obvious from the until the size of the fin and wing is considered.

A detailed build blog exists on the Model Flying Forum  which covers many of the constructional aspects of this model and will not be repeat here

The output from Profili and DevFus were combined into a single file and edited using DraftSight. The parts were transferred to DXF and sent Dylan at LaserCraft for laser cutting - Liteply and Birch Ply wing ribs and fuselage formers

So rather than repeat the build blog, just a few progress photos here:

Tailplane construction is quite simple, the trick is to select good quality light wood. Elevator hinges using Kevlar cloth which is what I tend to do nowadays

The fuel tank area and Firewall are assembled as a crutch and the fuselage built up around it

Fuselage construction is quite straightforward

Upper decking is 1/16" balsa sheet

Wing construction is traditional. Building tabs used to make sure the wing stays flat

Retracts are HK copies of e-Flite and a cheap MG996 servo used as the retract servo.

And a video of them working

Leading edge sheeting added and a dry fit of the model - looking OK :)

Next bits were the tuned pipe tunnel, ailerons wing tips and rudder

 Wing tips hollowed using a dremel and sanding drum after the external shaped had been roughly carved and sanded to shape. A lot more wood than that came out.

The lower fuselage was crafted using lite ply formers and soft balsa sides

 Rudder laminated from 3mm balsa. The fin cap has a 3mm lite ply base to help keep it nice and straight and importantly, add a lot of strength. Balsa on its own is just too fragile

Ailerons laminated from 5mm balsa sheet over the Kevlar hinge. The ends are capped with 3mm lite ply to maintain nice crisp edges

 The Canopy came from an old defunct model that lost its life when an aileron linkage broke..

And so far, it looks like this.

Sloping Off - a wonderful afternoon flying

It started with the customary email from Ian Jones. Weather forecast nice with a decent breeze from the East. My opportunity to try out slope soaring on Bosley Minn, a N-S ridge at the western edge of the peak district.

The weather was superb, bright sunshine with a 20-30kt Easterly wind.

I arrived first and helped the farmer fit a new gate - always a good sign if the landowner is friendly.  Ian arrived about 10 minutes later with a few slope slopers and we assembled and headed onto the field about 100 yards away

Ian went first

After a few moments of trepidation I flew my own design Glass Slipper - Ian now on the camera and then me back on the camera while Ian had a fly of her.

After a long and fun flight or three, I decided to try the Bubble Dancer on the Slope. By now, the wind had started to drop although it was still quite  gusty, so waiting for a lull and the model went up vertically by about 20 feet and with a little down elevator I manager to get her away from the slope.

Unfortunately the glider was over elevated for some reason and due to the amount of lift was a nightmare to try and land. However, I did get her down in one piece and breathed a huge sigh of relief.

Great Fun.

Another couple of flights with the Glass Slipper and I was away home at 1630. Absolutely wonderful afternoon :)

Bellerina 115

The RCM&E Mass build this year (2016) is Peter Millers Ballerina - published in the December 2015 RCM&E magazine as a free plan.

The full build blog is here on Model Flying website and I am not going to repeat it here

http://www.modelflying.co.uk/forums/postings.asp?th=112868

I was quite pleased that this model was selected as it is reminiscent of the Fred Dunn Astro Hog from 1958, the  first Aerobatic World Champion.

This is Peter's original

It is designed for a 40 Four Stroke or 32 Two stroke. Having neither but I did a have a preference for a larger model I chose to scale it up by a factor of 1.15 to suit the spare clapped out OS70FS that I have.

This gives a model with a span of about 62 inches and 12.5" root chord.

 A couple of my build shots - I elected for a built up tailplane around a flat plate, a flat plate fin with built up rudder.

The Fuselage

Tailplane and Fin and Rear Fuselage

I'll post a few more photos as the build progresses

It's a very pretty looking aeroplane. Quite pleased with it so far

The wing was quite straightforward - the only real deviation from the plan was the laminated wing tips that I chose to use

The undercarriage is designed to be removable. Held in place with M3 cap head bolts through a 3mm ply plate to star nuts behind.

Just about ready for covering

Fit out was very straightforward - 2 mini servos fitted for the ailerons with mechanical differential built in.

The cowl is bent from 0.5mm aluminium sheet - hand formed then reinforced on the inside with 150g glass cloth.

And then covered in Solartex

Underneath

Just waiting for a Canopy and Pilot to show up

The model was maidened on the 29th January 2016.  It flew beautifully although just a little nose heavy. Much more agile and responsive than I imagined that it would be.

Great fun. A superb Peter Miller design