Messages

46

Wanted / Re: Multiplex Flamingo / Flamingo Contest

« on: October 30, 2019, 21:38:44 PM »

Fred,
Firstly  no, you can't have my Flamingo Contest.
However you are right that they are a really good machine - the best layout - Rudder, elevator, ailerons and airbrakes. I have been lucky to have had two. I bought the first from Willie Owens in Bray about 1989 and I flew it for 27 or 28 years.  I flew it regularly - maybe 20 saturdays a year for at least half an hour. So at least 10 hours a year at about 30 to 40 kph for 28 years - the best part of 10,000 kilometres! No wonder I liked it. It had suffered a fair few thumps and bumps over the years but was never seriously damaged until a couple of years ago. I launched it and it flew out perfectly - ignored the radio control (new 2.4gHz stuff), slowly banked to the left, and gained just enough height to do serious damage before it piled in. Total flight time 30 seconds. Goodbye to my favourite plane.
Luckily, 15 years ago David Mayrs had given me his damaged model as a source of spares for mine - a donor of vital organs as it were. My son had looked at Davids model for a month or so before he announced that he reckoned he could rebuild it. He flew it for a few years before being distracted by life and I am flying it now.....

JIM

47

Slope Soaring / Re: Is there life on the Glider Ireland forum???

« on: September 30, 2019, 16:49:36 PM »

Hi Fred,
Yeah ok.... I admit I normally rely on others to put something up for me to read. I will try to do better.... How did Mt Leinster go or was the weather uncooperative?

Jim

48

Slope Soaring / Re: Is there life on the Glider Ireland forum???

« on: September 29, 2019, 09:48:36 AM »

Thanks Keith,
Hopefully there will be some other replies. You may have started a roll call and we can see how many say 'here'. Has everyone migrated to Facebook or some such of which we are unaware.

Have you noticed and can you explain the counter at the bottom of the main page that seems to suggest that there were way over 700 people on line this morning?

JIM

49

Slope Soaring / Re: Is there life on the Glider Ireland forum???

« on: September 29, 2019, 09:25:35 AM »

Hi Keith,
Yes it has been kind of quiet - almost tumbleweed like.
I am still here occasionally but I cannot make it to Mt Leinster this weekend. Hopefully this is not another golden age that is coming to an end - I have come to realise that I am so old I have seen a couple of eras start and end. Is there anyone else out there?

JIM

50

Events / Re: ISR 2019 Gliding events

« on: September 20, 2019, 09:13:24 AM »

Hi Everyone,
Regrettably I can't make it to Mt Leinster this September. I hope the weather behaves and you all get some good flying and that almost every model goes home intact - (it would be asking too much for good weather and no damaged models).
On another matter I presume most of you got the invitation from the MACI Chairman to a meeting shortly. This has been re-scheduled (for which I offer my thanks to the Chairman) in order to avoid a clash with our event at Mt Leinster so that no-one has to chose between flying and attending the meeting. Can I encourage as many as possible to attend? Particularly as to my great embarrassment, having requested the change of date, I am unable to attend........

Pretty please??

JIM

51

Club talk / Re: 2019 Fees

« on: March 02, 2019, 11:42:32 AM »

Hi Ralph,
It is my intention to pay you at Mt Leinster at St Patrick's weekend.

JIM

52

Road trips / Re: Killakee let's get together thread!

« on: January 11, 2019, 19:28:08 PM »

Hi Fred,
Westerly yes - but maybe too much wind. In any case, yes, seeing you are asking, I will be there from 14:15 or thereabouts. I better charge the batteries.............

JIM

53

Slope Soaring / Re: Happy new year

« on: January 01, 2019, 08:22:46 AM »

Thanks Gerry and many happy returns.
And to repeat Gerry's good wishes - happy new year everyone!

Jim

54

Club Talk / Re: Bon Noelle, Happy Christmas everybody

« on: December 24, 2018, 12:28:51 PM »

Happy Christmas everyone and fair play to you Peter - I thought it too damp / cold / grey for Kilakee on Saturday!
Anyway the darkest day has passed and we can look forward to 2019 - could it possibly bring as good weather as last year ...... once we got past that snow for the first trip to Mt. Leinster that is.
Jim

55

Events / Re: 2018 ISR events

« on: September 27, 2018, 10:32:35 AM »

Thanks Bill, Fred,  I will see you there.

Bill,
I see you have been championing a mass PSS build. I haven't built anything for a long time - years if the truth be told but maybe...... I'm not sure how this works but I can use CAD so if you need a plan drawn up let me know.

Fred,
How about a mass build wooden F3fun style glider? I never got around to building that one I drew up a few years ago.

JIM

56

Events / Re: 2018 ISR events

« on: September 26, 2018, 21:06:55 PM »

Hello everyone,
Great summer   but it's September and traditionally we have rain / no wind / too much wind or clouds all the way down to the ground by next weekend.
Anyway I hope to be at Mt Leinster - probably Saturday. Is there a plan? Will there be a crowd?

JIM

57

Events / Re: 2018 ISR events

« on: April 08, 2018, 20:23:28 PM »

Hey Fred,
Where are all the photos………………………..

Saturday was one of the best all round glider events it has ever been my pleasure to attend and if you had as much fun today you can certainly take a bow. Yes there have been days when I have flown longer – and there have been days when I was warmer.
But Saturday had it all – the chance to fly, to watch really good pilots fly, to watch really good models fly (particularly the Cortina!) was great and the chance to socialise over a splendid lunch with so many friendly souls was a joy. 

And it all happened just because you organised it!

Chapeau!


Thanks also to the French contingent who made us feel part of an international community rather than a few lonely souls standing on a hillside - it was great! Your presence (and your most excellent catering!) made the event. It was a pleasure to meet you all.
JIM

58

PSS / Re: MIG 29

« on: April 01, 2018, 10:51:27 AM »

Great explanation John,

That all makes perfect sense to me. I love it when I understand (or at least I can convince myself I understand) what’s going on.  Yes my initial response was from a technical standpoint but I like that approach. I am an extremely slow builder (so slow I have been stationary for a few years) so I like to know how things are going to work out before I start. I suppose that I sort of hoped that my initial reply would spark off a discussion of the technicalities of our models – mainly because I would enjoy it.

Maybe I will start a new post on the technical side – I could start it off with some aspect of the subject I think I understand and see if anyone joins in.

Thanks again,
JIM

59

PSS / Re: MIG 29

« on: March 29, 2018, 19:53:11 PM »

Hi Bill – so the plot thickens.
I wonder what weight John’s model was. Had he also started light (no batteries for the motor etc.)?  Did he feel it needed to fly faster in order to get the wing working or was it just lacking in response at the lower speeds? Would it slow down for landing? Was it difficult to throw it fast enough at the launch? Hopefully John will log again on soon………………
Or, just maybe, it’s only a pensioner like me that thinks that fast flying models are a pain to land and the thing will be fine for everyone else at 2.7kg!

JIM

60

PSS / Re: MIG 29

« on: March 29, 2018, 11:32:50 AM »

When I read John’s reply I must admit I was sceptical. How could a change of wing section make much of a difference to this model? Surely the low aspect ratio, short and enormous fuselage, double fins, huge tailplane and all the other lumps and bumps guarantee that the parasitic drag on this model is going to be so great that the comparatively little differences between one aerofoil and another would be insignificant. Surely this one would fly with any wing section. However I was curious and had a look at the RG14 drag curves. Sure enough the low drag range at low Reynolds numbers only extends from a CL of 1.0  to minus 0.2 so it’s not a thermal soaring section. It won’t fly slowly but it will fly inverted at high speed!  Maybe it was time to do some sums………….

The wingspan is 1.145m and the wing area is .226sqm giving a mean wing chord of near enough 200mm. The weight is given at 2.7kg. Doing the maths …..  at a cl of 1.0 (ie slow flight!) the model would fly at near enough 50kph. This will be exciting to land – too fast to land on a rough slope. The Reynolds number is over 180,000 so we can forget about the 50k and 100k plots. 2.7kg is far too heavy and a wing section that would fly slower (ie at a higher cl) would be an advantage.

Redoing the maths with a weight of 2kg and using a wing section that would still be in low drag at a CL of 1.2 the model would fly efficiently at 39kph and would still fly (with high drag) even slower so landings without damage might become more frequent. At 2kg the Reynolds numbers would still be respectable so the weight could be reduced even more.

SO:
John has a point. An aerofoil that works more efficiently than RG14 at higher coefficients of lift would reduce the landing speed and that would be good. However reducing the weight is even more important. I still think that in the range of cl’s from 0.8 to 0.3 (where most of the flying would take place) the differences between RG 14 and a more glider friendly section wouldn’t amount to much compared with the parasitic drag.

JIM

PS to John – I cannot find any drag curves for SD3020 – have you got any?
PS to Fred - Would you be tempted - as I would - just to reduce the weight and fly it at it is....... the difference between flying at a cl of 1.2 against a cl of 1.0 is less than 4kph and the high drag at slow speed might help in getting it down!!