My first thread - I'll start with a video

[Mark Kettle]

When it's your first thread its hard to know what to write, well I'll start with a video of a slope we use near to where I live, Its called Burrough Hill, its a small hill, we call it our pimple compared to other hills around the UK.

This glider i've been working on for nearly a year, and now its flying really nice, once I gave it to my relative to fly he didn't want to give the transmitter back.

I'm planning to do another version with power on whether puller prop up front or pusher from behind so I can fly it elsewhere. Some have said use a electric ducted fan this would mean I wouldn't have to alter the tail, can anyone recommend a good power set up?

The models 58.5" span about 3.75 sq ft wing area and presently flying at 27oz unballasted.

Enjoy the video, and I look foward to your replies.

rc slope soaring Gazelle 

[David Ashby - Moderator]

I'm no slope soarer I'm afraid but it looked very good to me Mark, it's something I must try one of there days. The turns seem very flat - is that what you tend to aim for on the slope, presumably as a flat turn looses less height?   

[Mark Kettle]

Thanks Graham to the reply.

Well as for the flat turns, these I suppose its a response for sometimes from being a little off wind and a bit of wind on the side of the body and its going around that way and steady as it goes on the stick for that direction and its turning out of wind, (sometimes you use a little-very little) opposite stick just to control the position or bank, yes your right as regards flat turns you will loss less height, however you have to be cautious that you dont loss position and drift and end up say behind the slope line/ flight line or out of the main lift.

As you can see from the video you can turn it tighter when needed and on the right slope its just like flying with a power model, you know the wings are banked over less wing opposed against gravity and gravity says come close to me, however level the wings after the turn and you can adjust the height afterwards, to be honest some slopes around and like those up Derbyshire give you the ability to gain height do stunts and within seconds be regaining any height lost, whilst at the slope I say to others at the side of me, 'its like have a 0.40 i.c engine up front' this is say on the 60" competition slope racers we fly often being able to do multiple rolls whilst climbing at 30 degess.

Cheers Mark

[Tim Mackey]

hi Mark...nice one !

If you want a cheapie EDF power set then add about 30% of current airframe weight to get total AUW of around 2lb. Assuming you only real want reasonable rather than ballistic performance then work on about 100watts per pound, therefore a 200watt EDF set should suffice. I asssume you will use a Lipo battery, and therefore you can lose the onboard Nimh pack and use the BEC on the ESC. How this one ??here

Just ad a cheapie 3s LiPo of around 1800 mahr 20C and away you go. 

[Mark Kettle]

Sorry David for starting off and naming you Graham, its because I fly sometimes with a Graham Ashby.

I had one good tip from Timbo, so and a link to some good equipment can't wait to get started.

[Former Member]

[This posting has been removed]

[David Ashby - Moderator]

No problem Mark, I sometimes fly with a Graham Ashby too

[Mark Kettle]

Eric - Yes your right at the particular hill its marginal sometimes, its only got 150ft above the closest surrounding ground, and thats a bit scrubby and it absorbs the wind, however the Gazelle will just float around in no wind at all. Now when we take it to coastal sites, Whitesheet or the slopes up Derbyshire like the Gate, or Curbar Edge well its a different plane, needing all its ballast, 14oz and great fun. 

[Alistair Taylor]

Hiya Mark

Nice looking delta. Seems to fly very well judging by the video - I like the colour scheme.

It looks like you've got quite a narrow fuselage and a thin wing section, with elevons that stop at the change in sweepback angle outboard of the fuselage. I'd be tempted to try a twin motor installation - with either two cheapy outrunner motors on carbon tubes epoxied into the wing, or two inrunners buried in the wing at the end of the elevons, fed by one common lipo in the fus. You could then achieve over 200 watts relatively cheaply, and (if you use a pusher prop on one motor, and a tractor prop on the other) without any torque reaction - thus retaining the stable flying characteristics of the slope soarer. The extra weight of the lipo in the nose, would also be neatly balanced by the motors at the back, and you wouldn't have to worry about losing fingers while launching as with a single motor pusher installation.

See;

Cheapy inrunner

Cheapy outrunner

AlistairT

[Mark Kettle]

Hi Alistair -

 Thanks for the ideas, your comments have really got me thinking, I'm reaching for the drawing board now. I will be posting any developments when they happen.

Cheers Wibberley.

[Mark Kettle]

Comments - Messages

The sound track sounds superb on quality speakers -or- on headphones-

The Band is -A Flock of Seagulls -the song -'I ran'

[Rob]

Nice model ,are you thinking of making it available at some time ? looks great and well worth the time you spent on it .Well done

[Mark Kettle]

Irony - Timing
According to a telecall received, The music (-'I Ran' - by the band - A Flock of Seagulls -) to this video appeared on a advert for a compilation CD avaiable from Tesco stores it called 'The Edge on the Eighties'. Within minutes a fellow flyer had rang me up to tell me.

I had just got out of Wilkinson's hardware, I was picking up some carpet spray for the next build, and another viewer to the u tube vid had stopped me to say -'what a good track to use on a flying video', she actually lives local to Burrough Hill and relatives she had passed the link to said 'you must take us for Burrough to see the flying. 

[Mark Kettle]

Its a scratch built at present, I designed it and I've working on a i.c. setup and a ducted electric fan version. When I'm happy with the results of these I'll put another video together.

The look like a Vulcan is no co-incidence, at our power flying site, this must only be 7 miles from where the only surviving and now airworthy Avro Vulcan is kept at Buntingthrope Leicestershire -(an old US air force base in the 50's - 60's).

However on the slope side there’s been so much interest in it -when I let fellow flyers have a go its about twenty minutes before I get the tranny back, so for the last three months there’s been a lot of others I have raked in to helping with tooling towards producing a kit.

Some have commented that the Gazelle is like 'a high aspect ratio Vulcan', which I would agree with, its a bit like how the the Starfighter turned into - U2 adaptation.

The models stretched wing span does give it good flying characteristics, and a low wing loading which lend it to alteration with the addition of different power sources.

I would love to be able to give you a date when this Gazelle kit will be available, the good news is we've a start and someone’s busy at the moment writing the assembly notes with a rough hand cut kit, then we will take some photo's of the jig cut version and insert them into the text.

Getting the epp is the problem, and we are trying to get details of a source of good foam from Germany. Watch this space.

The beauty of using epp, is it very crash resistant and with the Gazelle such a stable flyer it would make a good trainer, with the help of an instructor in the early flights a student would come on in leaps and bounds, plus not have the worry of a bump or crash destroying there plane.

Thats why I'm confident when we go to different slopes, to let total strangers (flyers of cause) have the transmitter for a fly and have an experience with the Gazelle.

Thanks for the comments Wibberley.

[harry]

hi Mark     nice plane and video, Burrough Hill is my nearest slope at 40 miles and its a great place to fly the guys there are great company.I look forward to catching you there one day and hope to have a fly with the Gazelle,cheers      Harry