Phil's SCSA Newsletter
14.01.2007 

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DIARY
Indoor Flying, details click here see map Gloucester Model flying club. Saturday 27th January 2007. 6.00pm until 8.00pm

 Jan 19-21st London Model Engineering Exhibition
Alexandra Palace, North London. Contact Avril Spence on 01926 614101 or avril@meridienneexhibitions.co.uk BMFA news

Feb 4th Telford Swapmeet
10 am on. War Memorial Club, Shifnal, Shropshire. Contact Graham Thomas on 01952 583960 or 07967 695384 or thomas_graham@hotmail.com 

Club Meeting Wednesday 17th 8.00PM at the Bear Rodborough, the paper airplane competition

Video clip, indoor flying, not in a hall but in a home. http://uk.video.yahoo.com/video/play 

From The BMFA web site

2.4 GHz AT YOUR CLUB FIELD.

OFCOM have issued the necessary permissions and changes to Government legislation which allow the sale and use of approved equipment transmitting on the 2.4 GHz band at 100mw maximum radiating power in  December 2006.

Equipment on this band is already selling in large numbers and will soon start to appear at the club field or flying event.  At this early stage only one manufacturer is offering equipment on this frequency, however indications are that more will take advantage of this new technology in the near future.   

Below are a few points for your guidance on operation and integration within your normal flying activities, however always remember the final decision on any matter relating to the safety of a flight rests with the pilot.

  • 2.4 GHz is a world-wide band that has many applications and users.
  • The sets currently available are of the “spread spectrum” variety and hence need no frequency control.
  • It can be used to control any type of model either ground based, water or airborne (within the constraints of the law of course).
  • Current sets have the facility to reduce power in order to perform a range check, use this facility in line with the manufacturers instructions.
  • It is suggested that clubs utilising the “peg on” method of frequency control have a separate 2.4 GHz section for members to place a named peg.
  • Club rules governing the number of models airborne at any one time should still reflect the needs and circumstances of the particular flying site.
  • 2.4 GHz transmitter aerials should display a black ribbon.
  • There is no evidence to suggest that 2.4 GHz transmitters will interfere with users of 35 MHz.
  • The use of this band combined with spread spectrum technology will eventually help to alleviate the risk of lone flyers interfering with nearby club operations.
  • This technology has been in regular use in other countries for over a year with few reported problems.
  • Follow manufacturers instructions and guidance on installation into your airframe.
  • At events operating transmitter control 2.4 GHz transmitters should be booked in and accounted for as normal, however there is no requirement to check frequency and the decision on when the pilot flies rests with the CD or Flight Line Director.
  • Follow guidance provided by the manufacturer of your specific set on it’s operation.
  • The effectiveness and safety of any equipment still relies on care and vigilance of the user.

When using 2.4G at the slopes, please place a disc on the ground with 2.4G and your name on it
Phil

Strange fact
The actress Hedy Lamarr invented frequency hopping (spread spectrum) under her married name of Hedy Kiesler Markey along with composer George Antheil they received U.S. patent #2,292,387 for their Secret Communication System on August 11, 1942.

 

Computer nerd bit
One of the files on your computer that needs backing up is the address book from Outlook express. One way is to copy and paste this file to your back up media. To find the file click start, then search, then all files and folders; type in wab and click  search. The file( wab.exe) is in program Files/Outlook Express, right click the file and copy. The file is now on your clip board, you then paste this to your back up files, floppy disc, second hard drive, USB memory stick, camera card or MP3 players may be used. 
The other way is to export the file, open outlook Express and click file, click export and choose address book and follow instructions.


 

Bell Motors
This is one of the cheapest brushless motors and sells for around £6. It draws 12 amps with 8 X 4 prop and has a static thrust of 21oz  on 3 li-poly cells 10.1V.  The motor weighs nearly 2 oz is is suited to heavier park fliers.
Props make a huge difference and come in normal electric, thin electric and slow fly plus the very light GWS props. This motor has a 3mm threaded shaft to take the GWS prop, . It has 12 poles this  gives performance similar to a 3 pole motor with a gear box . If you have a model with a 300 or 400 geared motor this would be a replacement. 
the 2808 has a 12 pole stator that carries the windings and 14 magnets on the outer rotor.

 I do not understand the ratio of magnets to stator poles but I have noticed some combinations have a very notchy feel when turned by hand.
On the left the rotor which is on the outside with an outrunner, this is shaped like a bell giving the motor its name. Right is the stator, there are 3 separate windings  some use 1, 2 or 3 strands of enamel wire. There are 2 ways of connecting Y called star and r called delta 
The 2808-21 has a speed rating  KV: 1750rpm per volt   it's RPM slows to about half of this on load. Brushless motors need a controller to suit, they turn Direct current into 3 phase AC of variable frequency and pulse width; these can be bought for around £12, add a lithium polymer battery from about at about £15 and you have a complete power system. 
Mike the Web made his own motor from a kit see http://www.brinkwmj.f2s.com/scsa/tips/brushlessmotor.htm for further reading. These motors come in several sizes, type brushless into a search engine and you get more results than you can shake a stick at. http://robotbirds.co.uk/ have a good selection.  Also Clive at C.J. Models Barton Street, Gloucester sells and flies electric models and parts, give him a ring or visit the shop tel. 01452 308007

Friday at Frocester, a good blow straight onto the slope.

Andy's Zagi bending in the strong breeze this went backwards.


Saturday 13th, the 4th indoor session at Chosen Hill school.
five of Club members turned up for what was another excellent evening. Steve flew his 3mm depron Extra but not after it hit the wall, the damage is quick and cheap to repair with these models.
I took 4 models, the long delta flew round Ok but was not much fun, my smaller Delta was under powered by a 100 sized brushed motor only just managing to stay in the air for a few minutes. I broke my IFO again, which was  powered by the 2408 I did the brief revue of, this was over powered for indoors. The Yak went well surviving 4 midairs all with Chris Bishop and one direct hit with Chris.
 The picture shows Clive poking it from the curtain that leap out at it

I flew Chris Bishop's Home brew mini IFO , fitted with a rudder and tiny brushless, it was delight to fly, this is almost unbreakable, an ideal indoor model. Clive has one of these and also stocks the carbon to make them. Chris will do a write up later on http://www.glos-mfc.co.uk/  next meeting 27th January 2007

My Yak's low pass

 Ken's BMFA Dart, not a great performer


 

Sunday morning at Frocester, sunny and warm for January. A good turnout 5 scale models flown. Dave had a buddy lead fitted helping his son to fly their Eppi-soar. Peter helped our newcomer with his Multiplex

Mike The web launching Brian's Wanabee and his own ASW27b

Andy flying his ASW15

 A  Multiplex Easy glider on its first outing, expanded polystyrene with style

Caerphilly Trip
After endless weekend gales or mist, Sunday was at last a clear bright day with a decent SW wind. Med and I traveled to a fine slope near Caerphilly about 45 mins from Bristol for some slope action. However by the time we arrived the forecast 10 mph was closer to 20, the glass was happy enough and the breeze kept the paragliders down but the windchill was more of a problem for us. Here are a few pictures, we had several good flights with easy landing on the huge unobstructed field behind the slope. Only 9 weeks until spring. 
Phil W