Sunday, 30 June 2013

Fuselage now shaping up..

This weekend I managed to find a few spare hours to assembly about 80% of the Sapphire's fuselage.  I wasn't too difficult to build.  The kit required splicing two pieces of 2.5mm square strip balsa to make each of the bottom fuselage longerons - instead I hand cut full length ones from some 2.5mm thick sheet balsa which I hope will be slightly stronger.


The fuselage formers F2 and F3 that give the initial rigidity to the body were a little too flimsy for my liking.  The 1.5 mm thick front former split on the grain, so in retrospect I think I should have cut my own formers from 2.5mm balsa for added strength.  As it was, I added some balsa strip along the top and bottom of the formers to add some extra strength.

I just now need to finish adding the width-wise balsa strip to complete the main body and then I need to knuckle down to shaping he nose block.

Craft Saw Set

On my last visit to The Hobby Box I splashed out on a Expo 735-44 razor saw set. 

This comes with a handle and number 234 and 239 razor saw blades.   I've been using these to accurately cut balsa fuselage longerons and stingers to size.  I'm still unsure if they provide a better result than using a very sharp craft knife, but I guess it is good to have a range of sharp cutting tools handy to help with any balsa kit build.




Thursday, 27 June 2013

Sapphire Wing Construction, Part 3

The bulk of the wing construction work is now complete on my West Wings Sapphire.  All I need to do now is to hand carve the wing tips out of some block balsa and then the surfaces are ready for covering with tissue.  Next step, the fuselage!


Tuesday, 25 June 2013

Sapphire Wing Construction, Part 2

I've now completed the initial construction of the wing tips and main wing section to my West Wings Sapphire.   I need to now shape some 12 mm square balsa for the ends of the wing tips and glue the wing sections together at the correct dihedral.


Shaping up quite well.  I hope to move into the tail and tail plane later this week if I get free time.

Monday, 24 June 2013

Sapphire Wing Construction

Last week I was given a West Wings Sapphire 32.5" wingspan rubber powered model aeroplane kit for Father's Day, however, due to a really busy week I only managed to some free time on Sunday to start it.

With most models I normally construct the wings first. This model has two large wing tips and a main wing.  It was a relatively easy build. First, I pinned the plans down to a board, wax the paper to prevent glue sticking to it.

The ribs were pre-cut, so it was a case of popping them out of the cut sheet and tidying them up. The leading edge required cutting the 3 mm x 6 mm down to 3 mm x 5 mm and sanding down the front two corners to make a leading edge profile.  The trailing edge required notches to be cut about 1.8mm deep to accommodate the end of the wing ribs.  There is some under-camber to the ribs that required the front underside of the trailing edge to be wedged up by 1.5mm before pinning it down and gluing in the ribs and then the spars.


I took an enjoyably slow paced two hours to finish the build.  I'll try to find time this week to build the wing tips and finish the wing.

Sunday, 23 June 2013

Webcam Bird Watching

My son has been begging me to rig up a camera to record the birds on the back garden bird feeder.

I lashed up arrangement of a small HP netbook running Ubuntu 12.04,  an old webcam and my camera tripod on some old bricks.  My first attempt was to use the "webcam" tool from the xawtv package, but the camera kept on falling offline and closing prematurely when the light levels dropped too low.   So, I just ran the "cheese" webcam tool and set it to video record mode and this worked reliably.

We left the rig to record about 40 minutes worth of video and then copied the video over to a more powerful laptop to edit the video using mplayer to allow me to skip to the interesting frames and ffmpeg select and re-code the webcam feed into mpeg video.  The quality of the webcam is not great as it was an old second hand one I picked up for free several years ago.  We've ordered a cheap webcam with higher resolution, hopefully we will get better results next weekend.

Here are the edited bird feeding high-lights:




video
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Monday, 17 June 2013

Restart Parties

The BBC has an excellent report about Restart Parties occurring in London.  A venue is chosen and advertised and encourages people to bring along either their fixing skills or gadgets that need fixing.

The outcome is that gadgets get fixed rather than being condemned to being recycled or ending up as landfill, and hopefully some education on fixing skills is imparted too.


Sunday, 16 June 2013

West Wings Sapphire

This year my kids gave me a West Wings Sapphire for Father's day.  This is a 32.5" (825mm) wingspan rubber powered sports aeroplane that apparently has high lift and good stability as well as promising some long duration flights.


Inside the box:



The quality of the wood looks good, the plans are clear and the instructions are well thought out and easy to follow.  It looks like it will be an enjoyable build.  The West Wings website does mention that one can finish this model with heat-shrink covering, but I will stick to the traditional tissue and dope finish.

Not a bad kit at all.  I've never built a West Wings kit before, so I look forward to seeing how well it builds and performs in the air.  My only quibble is that it came with a rather chunky yellow propeller rather than the more aesthetically pleasing blue one as shown on the box.

Saturday, 15 June 2013

Making an indoor balsa wood chuck glider

I've been meaning to teach my 10 year old son how to build balsa wood indoor chuck gliders for some time, so today we visited The Hobby Box, an excellent model shop in Uckfield, East Sussex, to purchase some balsa.


Materials list:
  • 1/16 x 3 x 36 inch balsa sheet for the wings (1.6 x 75 x 915 mm)
  • 3/32 x 3/32 x 36 inch square balsa strip for the fuselage (5 x 5 x 915 mm)
  • PVA wood glue
  • Metal ruler
  • Modelling knife
  • Fine sand paper
I created a design in metric because that's easier for the modern metric thinking child to deal with.

Components:
  • Fuselage: 25 cm of the 5 x 5 mm balsa strip.
  • Tail plane: 2 cm x  9 cm from the 1.6 mm balsa sheet.
  • Tail: 4 cm high x 2.5 cm base x 2 cm top trapezoid from the 1.6 mm balsa sheet.
  • Two main wings (left, right): 3 cm x 18 cm rectangles of the 1.6 mm balsa sheet.

Construction:

Cut the fuselage from the 5 x 5 mm balsa strip.  Cut out the tail plane and tail.  Glue the tail plane to the end of the fuselage. Gently sand to smooth the edges. We used tiny pins to hold it in place while drying.

When dry, glue the tail on top of the tail plane.  We used some Lego bricks to hold it vertical while drying:


Cut out two of the 3 cm x 18 cm main wings from the balsa sheet and glue these half way along the fuselage.  I decided to have about 3cm of dihedral so 3 Lego bricks to hold the wings into position while drying seem to do the trick:


We also glued a small slice of 1.6mm sheeting on top of the wings to add a little more strength on the join.

Finally, add a small blob of Blu-Tack or plasticine to the nose to balance the chuck glider.  Ensure the chuck glider balances when one holds the plane with a finger under each wing tip.  Add more weight if it stalls, remove weight if it nose dives.

My son built the chuck glider in the pictures under my instruction.  It was the first time he had used a metal ruler and a modelling knife for cutting, so some help was required to get him to cut straight and confidently.   After he was happy with the tailplane he measured and cut the tail and wings all by himself.  I explained the way to trim the glider and in no time he had it flying perfectly.

By our reckoning these cost about 50 pence per glider to build.  Not bad at all.

Wednesday, 12 June 2013

Fixing the volume control on a radio.

The volume dial on my relatively inexpensive digital radio has recently been crackling and working eratically.   The fix for this relatively easy by just applying some electrical contact cleaner.


First, one has to open up the radio.  There were two screws on the top back of the case, one inside the battery compartment and two sneaking away under the rubber feet on the bottom of the case:

Screws indicated by the helpful arrows on the case
Screw hiding under a rubber foot pad
Opening the case required a little bit of wiggling to pop the headphone socket out of position.  One has to be careful not to snap the socket off the mounting, but apart from that it isn't too hard to do.

Next, a small plastic cover over the volume control had to be removed to reveal the potentiometer.  A small spray of electrical contact cleaner followed by exercising the potentiometer back and forth to work the cleaner over the dirty metal contact surface is enough to do the job.

Cleaning the contacts of the potentiometer does the trick
After re-assembly the radio works as good as new.


Sunday, 9 June 2013

Foam Plane Repairs

My son and I went out this afternoon to fly some of our model planes in the nearby playing field.  After quite a few successful flights the tail on my son's foam jet snapped off.


This is a simple repair using a thin spread of glue and some tape to hold it together while it dries.  This has worked well with previous breakages and we hope to be flying again next weekend.


Saturday, 8 June 2013

Fixing my Veron Domino glider

Quite a few years ago my brother kindly purchased me a Veron Domino glider kit for my birthday.  This was the same glider I built many years ago when I was a teenager, so it was a delight to be able to re-live the building experience all over again.

The Domino is an A1 free flight glider, all-balsa (Jedelsky) construction sporting a decent 1190mm wingspan.   I took the liberty to give it a all-white gloss finish which turned out to be a rather winning look.   Unfortunately the glider was temporarily moved to the garage while our house underwent a rather radical loft conversion and got slightly damaged when a board fell on it.  I waited a year before looking at the damage as I really didn't want to face up to seeing how damaged the glider was.

Fortunately, the solid balsa wing lends itself to fixing fairly easily.  There were two breaks, one across the main left leading edge and the right wing tip had snapped off just above the join to the main wing. I administered suitable amounts of wood adhesive and used some stretchy insulating tape to hold the join while drying.  A few books were used to set the wing tip dihedral while the glue set.

Wing tip wedged between books while drying

Linux device drivers books come in quite handy
The main fuselage was broken in the same place my original snapped, so I guess this is a fundamental design flaw.  The fuselage is solid balsa, so it was a simple case of drilling two holes in each part and inserting a 4 inch dowel to reinforce the joint.

After gluing. I need to find some paint to finish it off.
Fuselage and tailplane need some cleaning.
Hopefully when I get some calm evening weather I will take it out for a quick flight to see if my fixes are adequate.  I will report back. 

Creating order out of chaos

I'm an engineer at heart.  I enjoy turning messy disordered broken objects back into a working state.   It seems that burnt deep into my DNA is the need to fix stuff, to functionally improve it and make it fully fit for purpose.  Most things just fall apart, break, end up in disrepair.  I fight the decay of entropy and try to turn chaos back into order.

Conquering Entropy is not just a battle to fix things before they end up in land fill. It is more than that.  It is the desire to turn materials into a higher ordered state through creative work.  For example, turning sheets of balsa and tissue into a decent flying model or globs of acrylic paint into a rendering that is aesthetically pleasing.

So, join me in my adventure as I attempt to create order out of chaos and in a small way try to conquer entropy's universal reign.