1/4 scale Blackburn 1912d Monoplane - by Webmaster, January 2011

 

I was busy doing nothing in my hangar, when a fellow modeler came around to hassle me. Truth be known he wanted to sell me something he had on his hands. Sure enough after a few hours and all of my beers he mentioned that he may be able to put his hands on a really old, neglected monoplane - ideal for a conversion to electric he said....  My ears pricked up, and I said "Bring it round and I'll take a look".

When it arrived a week later in a transit sized van, the model was a tatty Dave Boddington 1/4 scale Blackburn 1912d Monoplane. The tail fin was warped badly, the structural rigging wires were loose or missing and there was no cowl, undercarriage or wheels.

I put a request out on the BMFA classified ads for drawings and sizes of the undercarriage and cowl...  and almost by return, I had full scale drawings of both. Undercarriage was constructed in 4mm steel rod, with bracing in 2mm wire, all bought from the Scale day at RR Hucknall. All metalwork was bound with wire and soldered in place.

Of course, the model was setup for a smelly 120 four stroke engine. I cleaned all of that mess out, and got to work figuring out how to mount an electric motor. Once loosely in place, I cut out the old fuel tank and made a housing for the 6 cell pack of LiPo batteries.

I wasn't about to spend a lot of time on the refurbishment of this plane, until I knew that would fly. I knew that the fin was warped (which adds to its authenticity) so the plane may well have been condemned to a set of ever decreasing left jand circuits. Also I left the undercarriage in its wire skeleton state to see if would be suitable.  The intention was to clad the wires with timber during the 'up scaling' exercise.

I can just get the fuselage in my car but no other models... so this trip was organised by the Paul Harrington delivery service - cheers. The 'maiden flight', or 'Taxi test' as it was later renamed, wasn't a complete success. The hardwood tail-skid had a steel bolt hanging down to protect the skid whilst on the ground...  but on a slow ground run, it dug into a hole in the tarmac. This pulled the skid backwards which was attached to the rudder. This destroyed all of the hinges, and snapped the closed loop cables. Not a structural failure due to old age, but a design fault.

After replacing the rudder hinges with Robart pin hinges, re-threading new control wires and eventually testing it all again... I turned on the offending bolt in the tailskid. If the skid is pointing in the correct orientation it shouldn't be a problem, so I attached a piece of elastic to the front of the skid and the support post and all looked set again for a flight.
The Blackburn Monoplane strapped into a Ford pickup, alongside the Boeing 777. Both en-route to their own maiden flights.  "Hello, what's your name fella" 'Fossy' seems to have found a friend, or does he think he is talking to Martin ?
The Blackburn comes with a two part main wing, connected by steel dowel pegs, and held in place by the fully working rigging. Without the top rigging wires, the wings stress the fuselage so much that they would eventually drag on the floor. The bottom wires are a little slack when on the airfield, but as soon as the wings take the weight, they are taught again.
Notice the temporary cowl. I was once a Wiko's 6" milk saucepan. Cut in half in its length and again across its diameter, then epoxied to a roll of 1mm ply.... it will do for now, and proves a point. 

The brushless outrummer motor cost a mere £30, and spins a 20" x 10 wooden prop nice and quietly. On this second trip out, the pilot was prepared for the cold, wearing a silk scarf and sitting firmly on his hands.
There was unfortunately a strong crosswind and it was a little chilly on the stick fingers, but the maiden flight was like a dream. The model was lined up with the windsock, and a little power was applied. After about 2 meters the plane was airborne and tracking towards Hucknall town centre. It flew nice and slowly, and pretty true for a re-maiden with new undercarriage, cowl, powerplant and fuel.

Obviously, a turn on rudder only, and such a large dihedral meant that a turn needs to be thought about yesterday, to execute tomorrow.

Landing after a timed five minute flight was on track, but holding an eleven and a half pound model against a side wind proved too much for the 7" wheels. Touchdown was fine, but as the side thrust of the tarmac took grip, it ripped a tyre off.

After a quick check of the model, and that the video had been committed to pixels, I used the same flight pack, and took off into the wind. Once again the model behaved well, with the constant drone of voices in the background giving comment like "it would be a nice place to run a decent four stroke" and that sort of thing.  Of course, I could here them because the model was so beautifully quiet. The battery pack gave out after a further five minutes.... but on such a cold day I was pleased. On a calm warm day (remember those?) it should manage two 20 minute flights without a charge in between.

Maiden flight video  Click on the underlined text to see the video of the Blackburn's maiden flight. It was about 6 Deg, with a strong gusting cross wind right across the runway. The camera can be seen shaking and occasionally the windsock can be seen for proof...   On a nicer day, we will create a better video of a better flight.  Watch this space...

Photos - Kev Tuckley, Video - Mikkel Hansen
Now that the maiden flight has proven the power train and undercarriage, attention was turned to making it look the part again. To buy a set of WW1 - 1/4 scale wheels would cost £40, now the plane is nice, but not that nice (anyone have some second hand ones would be appreciated). So, I have cut a disc of stiff card, and attached it to the 7" wheels... although the ones I have acquired are the right scale, they are not the correct style.

I have already replaced or replaced the structural rigging wires, so I have now re-tensioned the dummy wires to look correct.

Timber strips have now been cut to size, and attached to the wire skeleton of the undercarriage. One job to be completed is to move the motor mount back inside the cowl by about 20mm, and construct a nicer looking cowl from built up timbers. The next task is to find a proper four spoke steering wheel.     More photos and videos to follow...