GliderIreland - Ireland RC Forum - Flying Model forum in Ireland
Gliders => Thermal / Flat field => Topic started by: DennisZ on December 25, 2009, 21:07:21 PM
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Seasonal Greetings to Everyone!
The Holy Trinity (my Wife, Birthday Angel and Santa) have decided to make me a present - ARTF sailplane :-)
(ARTF - because same guys aren't happy to have 'construction site' on the attic).
So, I am looking for 2.5+m ARTF bird that will be good for flat field.
Here is my current list:
Spirit 100
http://www.sussex-model-centre.co.uk/shopexd.asp?id=21210
Spirit Elite
http://www.sussex-model-centre.co.uk/shopexd.asp?id=2187
Bird of Time
http://www.sussex-model-centre.co.uk/shopexd.asp?id=18920
I would also consider a 'moldy' like
Super Rieti
http://www.sussex-model-centre.co.uk/shopexd.asp?id=353
CMPro DX Ventus Glider
http://www.sussex-model-centre.co.uk/shopexd.asp?id=25468
ASW-28
http://www.sussex-model-centre.co.uk/shopexd.asp?id=22312
Any advise from the gurus will be appreciated.
Thanks,
Dennis
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Of those you've listed Denis, I would go Bird of time or Spirit Elite.
If you check RCGroups (sorry Fred :oops:), there is some info on strengthening the BoT wing a bit.
For the Spirit Elite, Paul Naton used it as the demo model in his Perofrmance Tuning DVD. I have a copy if you'd lilke to see it.
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Hey Dennis,
From your list, I'll go for the Spirit Elite !
For the BoT, the guys in the West have much more experience than me to talk about that one, but the Spirit, is pretty much ful options, and will gives you a bit more vesatility I think.
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Did you decide what model you're going for Denis?
As I said I have copy of a good dvd that will help with set up if you go for the Spirit Elite.
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Did you decide what model you're going for Denis?
As I said I have copy of a good dvd that will help with set up if you go for the Spirit Elite.
Thanks Bill, looks like Elite is a favorite now.
Actual purchase is planned for the end of January (that is when my birthday and first paycheck after Xmas are ) ...
so I still have a time to make up my minds.
And thanks for the tip on Paul Naton's website - I will definitely buy more than one dvd from him.
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hi denis, 'the guys in the west' have been flying bot's for a few years now, both built up and arf and they all fly very well. the arf's are a little heavier so penetrate better in a decent breeze. the b/u's will float forever in very light air. the arf fuse is fiberglass and is quiet weak around the wing seat, b/u fuse is a very solid affair. arf's have a 3-piece wing, good for storage, b/u's 2-piece wing is a fairly complex build. i put airbrakes in both types, simple operation in the b/u's, a bit of a headache in the arf's. flying both types is very enjoyable especially with that distinctive wing plan. in light lift on a sunny day.....magic! hope this helps denis and iv'e not been too long winded, best of luck. ps, all of the above is my own opinion on the bot
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Thanks for your comments lads.
Now - servos:
I do not really know which to choose :oops:
one thing I learned - plastic gears break, regardless whether they were cheap or branded (Futaba).
I'm currently looking at these http://www.brchobbies.co.uk/?page=shop&action=additem&item=154
... any advice here (keeping cost for six within 150 pounds) ?
Thanks.
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Dennis,
You only really need 4 metal geared servo's. The rudder and elevator should be fine without metal gears, as they don't get the impact loads the flaps and ailerons can. (MUST remember to put Crow brakes away BEFORE landing! :!: )
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Yes, I’ve also found out the hard way that plastic gears shear, Dennis. Although some plastic gears are stronger than others.
Although metal gears are stronger, I’ve found they also wear more quickly, so you get slack in the gears allowing the control surface to flutter. :!:
I’ve not found a perfect answer yet. It’ll be interested to see what ideas anyone else has on this matter. :?:
Keith
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Hi,
My last plastic gears servos on a glider was for my DG1000, 10 years ago ! :P
First flight, all the servos were GWS I can't remember what, but good ones, all plastic gears.
First flight, first landing (slightly rough, first flight!...That's my excuse anyway!) and I had to change the gears for 4 servos ! Never had issues with planes etc, but gliders, they just kill plastic gears much more easily!
All that to say, if possible, put metal gears all around, you can find really cheap and good ones these days. Don't know the TP90 though, but as Keith said, the problem with metal gear, is that they tend to be less precise, or become less precise on the neutral with time (steel on steel friction, wear quicker), but I don't think it's a real worry unless you do F3F contest, DS and all that sort of silly things. I have some MG servos for 13~14 years for the oldest ones (GWS 2BB MG), and no real issues.
A bit more expensive, are the Hitec with Carbonite gears, supposed to be as strong as the MG ones, but stay precise with time...
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Just to add... My comment was on mini servos !
For standard size servos, for exemple, I use C5077 everywhere on my Lo100 ! Several hard landings etc etc, and never broke a gear ! Best standard servos ever in my opinion :D
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Buggy steering servos.
Brian
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Hi Dennis
I use various servos in all my models from £100 to £10.00 cost per servo. I had a very interesting talk with some of the display pilots at this years British nationals on the subject of what servos to use in models, The pilots where of the opinion that in high performance jets and Imac models (50% and up models) the use of top brand servos where used.(JR, Furtaba HiTec etc) due to the high loads on the control surfaces.we all agreed,
One pilot commented on the fact that many model suppliers push the point that you need digi servos in all models 10kg etc, however he said that before the age of digi servo he flew many models at displays on standard servos, e.g. JR 591's and never had any problems,he said that in many cases, the cause of a crash was due to the load on the batterys from big powerful servos and not failure of the servo, digi servos are power hungry!!
I buy servos to handle the loads from the control surfaces e.g is the control surface large, is the model fast, is there large amounts of movement on the control surface, etc all elements add to the load on the servo. A slow flying model with a small elevator does not need a super strong expensive digi servo.
The small B52 uses standard servos JR 591's and on the elevators i used two 16g MG servos which cost £12.00 each, great little servos and very strong and light.The big b52 will use a selection of standard servos(JR 591's) and 10kg Hitec's on the very large main control surfaces. Ali's hobbies has a good sale, at the moment,on HiTec servos e.g. 10kg digi MG servo £32.00, that's cheap!!
I also got some servo's last year from Richard at Expressfly, they where from a USA company, MG 19g servos, one the the best servos I ever used, perfect for gliders I think!!
A few ideas hope this helps
johnp
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Hi John,
This little chat is not about servos v's flying loads.
It's about servos that can take crashing oops I mean landing impacts.
There is no relationship between the two.
It's about the rough terrain we land these things on and the skinny fuz's that offer no protection by way of clearance.
Brian
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Sorry Brian, when you mentioned Buggy steering servos, I was under the impression that power servos where the topic of the chat. Yes the MG servo is the way to go, never had one fail in flight or in a crash, I mean 'controlled hard landing'.
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No prob,,s John.
Brian
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So Dennis, ……… the forum is awaiting your decision! :)
Which model are you going for, and what type of servos are you gonna fit in it? :?:
Keith
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- Spirit Elite
- MG servos for flaps only
(http://www.gliderireland.net/forum/images/uploads/DennisZ/elite.JPG)
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Well done Dennis! :clap:
I had an Elite. Built it from a kit. Flew on no more lift than a rabbits fart. It would float around for hours. :D
How will you launch it, bungee? It would probably be a good model to tow, if you wanted to give that a try again in the summer.
K.
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Thanks Keith,
thats is ARF, they tend to be bit heavier that built ones.
Bungee, yes ... if our Club will allow me :?
I do have a plan to install proper tow release ... at some stage .
Dennis
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So, my bird has arrived !
Actually, it arrived week ago, it took some time to get replacement servo http://www.leinster-model-flyer.org/wordpress/?p=275 .
Now, my 6ch radio does not have CROW braking mixing so idea is to configure ailerons as flaperons (channels 1 and 6) and have flaps on channel 5.
This will allow me to use throttle stick to move both ailerons up or down and have on-off flaps.
I may have to buy servo reverser for one of flaps or simply mount one servo "in reverse" .
Ok, back to the bird ...
there are couple of disappointing moments :(
- steel wing joiner is about 5 mm longer than it should be
- servo hatch covers are either completely of wrong size or the opening for servo arm was cut on a wrong side ... turned 90 degrees
Also my choice of servos was not very good - looks like aileron servos are about 2mm too thick.
Hopefully I'll manage to fix all that.
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Hey Dennis Glad your plane has arrived. Allow me to tell you a little tale about using flaperons. :!:
The picture at the end of this posting is the fuse’ of a little mouldy I have. There are a total of 5 breakages’ along it’s length. :(
I couldn’t understand why this little Filip 400 would often come into land nicely, then suddenly drop one wing and cartwheel along the landing area, breaking the fuse with the inertia. :cry:
Then I was then told about the effects of “Wash-in” and “Wash-out” at the wing tips. :?:
The end result was that instead of using the ailerons as flaperons when landing (Which increases Wash-In) I was told to make both ailerons move UP to become Spoilerons. This increases Wash-out which tends to stop the wing from tip stalling. :D
Result: Perfect landing every time! (Well………nearly perfect. Well,………..landings without damage, lets say that! :oops: )
You might want to bear this little story in mind
(http://www.gliderireland.net/forum/images/uploads/Happy%20Days/filip%20400.jpg)
Oh, by the way. The Filip still flys, although not quite as well as it used to !!
Keith
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Thanks Keith.
I was told to make both ailerons move UP to become Spoilerons. This increases Wash-out which tends to stop the wing from tip stalling.
That is exactly what I was going to do: flaps down, ailerons up = crow braking.
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OK, it took me only 7 month to "build" ARTF model :)
have not flown yet
(http://farm5.static.flickr.com/4137/4854473779_2cffee6659.jpg)
(http://farm5.static.flickr.com/4080/4854478117_73f5de43a9.jpg)
(http://farm5.static.flickr.com/4095/4855101772_02d7b2d777.jpg)
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Looks good Denis :clap:
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Looking at the picture of the Elite on your floor Denis, it looks to me as though the wing is a polyhedral. Is that right? :?:
You’re going to enjoy flying this one, :D if only because you’ll know in the back of your mind that you can slow her down for landing. :wink:
Hopefully we’ll see her up on the Big L soon, or at the September Glide-In?
K.
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Looking at the picture of the Elite on your floor Denis, it looks to me as though the wing is a polyhedral. Is that right? :?:
Well, the spec says it is polyhedral . For me, the middle part of that wing is rather flat.
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Well, she made the first flight at Killakee north slope this Saturday.
Flew fantastic :) need more practicing on landing skills .
(no footage of that).
Next day, with camera ready, we went to the Phoenix park.
With proper bungee - big thank to Peter.
Managed only few flights when guys with big motors arrived ...
[youtube]http://www.youtube.com/v/Kok-lnLyq8o[/youtube]
[youtube]http://www.youtube.com/v/3lOzND-Z0Uk[/youtube]
[youtube]http://www.youtube.com/v/24GjWmLw1R8[/youtube]
[youtube]http://www.youtube.com/v/BO_-_ICCUSA[/youtube]
[youtube]http://www.youtube.com/v/axTzPBvPM5A[/youtube]
[youtube]http://www.youtube.com/v/XZ4azfYvn0U[/youtube]
[youtube]http://www.youtube.com/v/YkUd-rKWh5c[/youtube]
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The first launch was a bit of a surprise!!!. :lol:
Don’t know if this is any use to you Dennis but when I had a bungee the instructions told me that the shock chord would extend to four times its contracted length. From what I saw on the vids I would have thought you could have stretched yours rather more, and so got greater height.
K.
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The bird had lived short, but beautiful, life ...
reduced to pieces this weekend - nose dive to tarmac :cry: :cry: :cry:
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Sorry to hear you have lost your Bird !!!!!
Maybe time to get new bird and have plenty more fun on slopes and flat field.
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Thank you Richard.
Already got antique WildFlecken from Fred.
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Hi Dennis it is good you have new plane :clap:
ENJOY
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How about 1 of these ;)