Sunday 19 December 2010

The rig on the Baby Wingwalker Stearmans

The rig that supports the wingwalkers is quite a complex piece of engineering and has very accurate detail.

The main vertical tube is made from stainless steel tube and is custom made because nothing suitable could be found.  It was made from 20mm tube and flattened it into an aerofoil section.  Aluminium blocks were machined down to make the anchor points for the pivot. The seat is made from 5mm stainless steel round tube which is silver soldered together.

The cushioning on the full size rig is made from plumber's foam tube.  On the models it is made from the foam from hair curlers.  Orange electrical insulation tape (found by chance on the internet) simulates the orange gaffer tape on the full size rig.

The aluminium pulley wheel was machined.  The cables used to rotate the rig go over the pulley wheel to a sail winch servo with a 2:1 ratio.

The 5 point adjustable harness holds the wingwalkers to the rig.  It is an exact copy of the full size one because it is the most effective way of holding the wingwalker (human or model) securely. There are 9 buckles on each harness and each is hand made.  So too is the clasp that holds the harness together.

The rig is turned using a Supertech winch servo. It was important to have the smallest possible servo because it is visible.

It takes a couple of minutes to put the rig onto the aircraft frame.  3 bolts hold it to the wing and 4 rigging wires stop it moving in all directions.

Theres is a battery in the centre section of aricraft wing that powers both the rig and wingwalker.

The receiver for both the rig and the wingwalker is in the wingwalker's body.  2 cables run up inside the rig to take power to the rig and wingwalker. 

After checking the battery usage we have found that the rig/wingwalker batter uses as much power during a flight as the one that powers the rest of the plane.  There is a high load put on the servos as the rig moves and the wingwalkers move their arms and legs.

Monday 6 December 2010

Landing the 30% scale Baby Wingwalker Stearmans

At the end of the flight you have to be on your toes with the Stearmans.  This is because the model wingwalkers are are full of radio gear and weigh more of a proportion of the overall weight of the aircraft than the slender full size wingwalkers!

Because of this you need to be landing into wind or as near to into wind as you can get. There are two ways to land the aircraft.  

One is to settle into a gentle three point landing when there is little or no wind to speak of. This type of landing looks really good on grass strips and you can afford to be a bit out of wind.  The wheels slip more than they do on tarmac and you are much less likely to ground loop. 

The second way is to fly them in faster and land only on the main wheels and use crossed rudder and ailerons to correct any direction changes as you slow down. This is the type of landing that Steve favours in stronger crosswinds especially when flying from tarmac.

Monday 29 November 2010

Construction information about the Baby Wingwalkers

However great the planes look, the model wingwalkers always steal the show.  We are often asked where people can buy them and the answer is "you can't" because they have been individually hand made.

The arms and legs are carved from balsa.  Richard tried making moulds but found they were too heavy if they were moulded.  The bodies are made from a two-piece fibreglass mould, using lightweight cloth,  The bodies are slightly larger than the real wingwalkers because there has to be room for the 2.4 GHz receiver inside which powers 5 mini servos that move the arms, legs and heads.

Each head is individual and based on one of the real wingwalkers from the team, currently we have Sarah and Danielle.  The heads are carved from plastic wood, a two-piece silicone mould is made and filled with fibreglass.  Richard tried a slush mould head but it was too brittle and he couldn't get a consistent thickness.  After all the trials he now has a box full of heads!

 Probably the most time consuming job is stitching the hair into place.  Richard made thousands of 1mm holes in the heads and each hole had 6 strands of hair hooked through. It took 3 long days per head, working 15 hour days.  Danielle's hair took slightly longer because 3 colours were used to match her hair colour.  The hair on the models is slightly longer than the real wingwalkers' hair because it's real hair so it is proportionally thicker and so not as supple.  When it's longer it holds its shape better because of the extra weight.

The costumes are also hand made, using pictures of the real ones to work from.  Because the fabric pieces were so small the patterns were turned into computer drawings and then laser cut to get them as accurate as possible.  Then they were sewed on a standard sewing machine. Lycra is not easy to work with at the best of times because it stretches, but with such small pieces it was very difficult and there was some unpicking and starting again.

The boots and hands are made in the same way as the head, carved and then a silicone mould made. The boots aren't identical to the full size ones because they have to be smaller so they can be taken off to put the clothes on.  Both the boots and hands are slush moulded with expandable foam put in to make them rigid.  The boots and legs need to be kept as light as possible to reduce the load on the arms and legs when they are lifted.  They are attached to the arms and legs with a dowel.

Finally, each model has a watch which is a commercially available 1/4 scale one that has been repainted orange.

Photos copyright of Chris Bowler.

Sunday 21 November 2010

Modifications from the Balsa USA Stearman kit

The Stearmans are built from Balsa USA kits but have had some modifications to make them lighter and more detailed.

Holes have been laser cut in the fuselage formers, the tailplane, fin and wing wherever possible.  This reduces the weight which is especially important in these models because the rig and wingwalker add quite a lot of weight. 

To get the best performance we need to keep the weight as low as we can, whilst not compromising the strength of the structure.

The tailplane was made removable to make the planes easier to transport.  Both planes are transported in one van so they take up less space with the tailplanes off. Carbon fibre tubes are used to join the tailplane.  Elevator servos are in each half of tailplane

The Breitling team use Super Stearmans which have more flying wires than the Stearman so extra mounting points were fitted to attach the additional flying wires.  Hard mounting points also had to be added to attach the wingwalker's rig.

The spar size in the wing was reduced by half and webbing used to make the wing as light and strong as possible. The square aluminium tubes in the kit were replaced with round ones and are not glued in.  That way they are easy to remove so make transportation easier.

To match the full size planes that the models are based on top ailerons have been fitted and the bottom ailerons reduced slightly.  There are several configurations of top ailerons across all 4 planes that are either finished or in construction.  Some top ailerons are nearly the same size as the bottome ones and others are smaller. These reflect the full size configurations.

The nose has been shortened so the prop hub is in the correct line. A completely new cowl was made and starts from the cabane struts. On the full size the cowling was a modified Beech.  New wheel spats were made to the correct shape and a new spinner was made.  The spinner on the Super Stearman is a Harvard.

Tuesday 16 November 2010

A pilot's impression of flying a Stearman as part of the Baby Breitling Wingwalking Team

After a season of flying one of the Stearmans here are some of the impressions from one of the pilots, Steve.

When we fly in formation Richard, who is the first pilot, controls the display and the speed and it's up to me as the second pilot to make the adjustments in position so that we stay in formation.  Each display is different because of the site and the weather conditions so Richard is making adjustments to keep the display within the right area and I make adjustments to stay in formation with him.

I use the rudder a lot to slip the plane into position.  I can't use the ailerons and bank because people will see that the wings are different to the other aircraft and so it spoils the look of the display.

The point at each end of the circuit is the most critical part when you're flying in formation because both pilots may be going into the turn at different speeds which then means we will enter the next manoeuvre at different speeds. If you don't get the formation right at the end then the manouevres in the middle will never be correct.

The Stearman is a simple aircraft compared to some of the planes I fly.  It doesn't have retracts or flaps but it has its own complication in that the wingwalkers make it top heavy so you have to allow for that.  The wheels have a narrow track so, as we have experienced at most shows this year, it is difficult to land in a crosswind.

My favourite part of the display visually is when we put the smoke on - especially when there's a blue sky too.  

My favourite manouevre is the Superman at the end.  It's a straightforward manouevre as it's simply flying inverted but it shows the wingwalker off perfectly.  I've got used to not watching the wingwalker and just watching the plane, but in the Superman I look at the wingwalker as well to help me position the aircraft.

As I come in quite low and slow it's not a place where you want the engine to stop!

Photos copyright Neil Hutchinson & Chris Bowler and may not be used without their permission.

Tuesday 2 November 2010

Baby Breitling Wingwalkers at Gaydon Motor Museum, October 2010

Model aircraft isn't the first thing you would expect to find at a motor museum. But this is the third year that the Large Model Association has put on a static display of models at Gaydon and each year it is popular with both the modellers and visitors.  Just like Yeovilton, there is the chance to look round the museum as well so there is a double attraction.

After the previous day of rain it was nice to be able to put the Stearmans together in the warm and dry and know there was going to be no mad dash for rain covers.  It was a good chance to catch up with the other modellers without the usual rush of a show with one eye on the schedule.

One trick we like to play is to be standing away from the models amongst the rest of the crowd and then gently turn the wingwalkers' heads.  Because it's such a slight movement people aren't sure whether they've seen a movement or whether they imagined it.  Then a little arm waving and leg bending and they can see the wingwalker is moving but they're not quite sure how.  So, if you're at one of our shows you'll know to look out for the person with the transmitter who's standing behind you.

Wandering round the rooms, as well as familiar models you also get a preview of the partly built models that will be on the show scene in all their glory next year or the year after.  One of the modellers, Chris Bates, has put together a slideshow of the models that were there which shows the huge variety.

Monday 25 October 2010

Baby Breitling Wingwalker at Yeovilton 2010

Bringing this blog right up to date, this weekend we flew at the Model Show at the Fleet Air Arm Museum at Yeovilton.

The weather wasn't as bad as the original forecast but we only managed to get in one flight due to the heavy rain showers.

The flying display is only part of the overall show and during the rain we took the opportunity to look round at the variety of models that were on display.  There was everything from Airfix models to carved wagons, spaceships, fantasy figures and Meccano diggers, all packed tightly around the museum's planes.

Outside there was also a good crowd who watched the flying displays that included warbirds, biplanes, jets and a glider as well as our Stearman and wingwalker.  Because there was a short display time we only displayed one plane and wingwalker, which was just as well because the rain showers seemed to give us just enough time to assemble or dismantle one and then the heavens would open.

Friday 15 October 2010

Baby Breitling Wingwalkers at Woodvale Rally 2010

In August we had a busy weekend at the Woodvale Rally near Southport.  The model airshow is organised by the Liverpool Club and is one of the many attractions at the rally.  The Southport Reporter photographed the event and on their site you can see photos of the event, including some silly ones of us.  There is also a report and some photos on the RCMF Forum.

In previous years there has been time to see the military vehicles, motor bikes, cars and wander round the stands.  This year though the team were flying the Breitling Wingwalkers as well as a number of other models so, apart from an hour when we could grab something to eat, one of us was either flying, getting a model ready or waiting in the startup box.  It was a busy weekend, but a very enjoyable one.

The wind wasn't pleasant again for most of the day and there were a few scratches to the underside of the wings on landing because we had to land crosswind on a tarmac runway.  Landing a biplane in a crosswind is always more difficult but a lot of the time it's a fact of life because that's the way the runway is orientated.  On the Sunday afternoon the wind calmed down and we had the best flight of the day.

Every year the Liverpool Club presents a trophy in memory of Arthur Searl to one of the pilots taking part. 

Arthur was one of the members of the Liverpool Club and we used to meet him regularly at Woodvale and the LMA events. 

This year they presented it to the Baby Wingwalker Team which was a lovely surprise.

Tuesday 5 October 2010

Baby Breitling Wingwalkers at Hastings 2010

It was the first time that any of the team had flown at the Hastings Model Show (July 2010) but there were lots of familiar faces there.  The weather was gorgeous sunshine, though there was still the breeze that seems to be constant this year.  It's also a grass runway which is nicer to fly from than tarmac.

At a show the planes are usually parked along the crowdline so that the public can have have a look at them in more detail.  When it's time to fly you push the plane out to the startup box on the display line so you can start the engines safely away from the crowd. It's a long flightline at Hastings so there was a lot of exercise pushing both the Stearmans and the 4 other planes we had taken into place.  We got wise the second day and positioned ourselves closer to the startup box.

After a flight we take the planes back to the crowdline and usually put the wingwalkers through their paces on the ground so that people can see them close up. The Mayor of Hastings was one of the visitors to the show and had her photo taken with one of the planes.

Sunday 19 September 2010

Baby Breitlings at Cosford 2010

Our second show in 2010 was at the Large Model Association's show at Cosford.  This is always a good show to attend as a visitor as there are 2 days of flying displays from the LMA members, the chance to browse and buy in the traders area and also the opportunity to visit the museum.

There wasn't much chance for us to visit the museum as we were flying regularly through the day - both with the Baby Wingwalkers and with our other models.

The weather had been forecast to be wet and windy all weekend which didn't sound good.  We were fortunate that the rain never really materialised and we even saw some blue sky.  But it was definitely windy which meant changes to the flying programme as some people didn't want to risk damaging their models in the wind.

Despite the bad weather, Alex Whittaker and Neil Hutchinson took some great photos of the Baby Breitlings which were published in model magazines RCM&E and RC Model World.

There's a full report of the Cosford Show on the LMA website with some great photos of the Baby Wingwalkers and the other models that were displayed there. 

If you have attended any of the events we have flown at and have photos or video then please share them with us on our Facebook site.

Photo (c) Neil Hutchinson

Saturday 11 September 2010

Baby Breitlings' First Public Display

There has been a lot of activity behind the scenes over the last 2 years, with the conception and building of 2 x 30% scale Stearmans and 2 fully working radio controlled wingwalkers.

It all became public in July when we gave our first display of the year at Woodspring Wings Model Show 2010.

Now most of the season is over, there is time to write about the models and show them in action.

Photograph (c) Chris Armitage

Here is a great video taken at the show which shows the display team in action and also has interviews with Richard  who is the designer/builder and Sarah who is one of the wingwalkers from the full size team that the models are based on.