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Re: Semi scale Slingsby Skylark 1**

Let us all watch your new project progress.
B Sharp

Re: Semi scale Slingsby Skylark 1**

Post by B Sharp »

Hi Karolis.
You are doing just fine there.
You do however need to start thinking about your radio, especially the servos as you will need to plan exactly where they are going in the airframe well before you get to the point of covering. I am not going to lecture you on what radio to buy as most types are good and it is down to personal preference. You will need mini or sub-mini servos for this airframe but there are tons of them available and most are pretty reliable.
Get your servos, work out where they will fit, work out how you will install them and go on from there.
Brian. :)
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Ian Davis
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Location: Bishopstoke UK

Re: Semi scale Slingsby Skylark 1**

Post by Ian Davis »

Hello Karolis

Brian is absolutely correct regarding servos, you need to get them soon so that you can plan control runs and servo positions. It's good to future proof your purchases to avoid getting cheap, low end gear only to find it's no good for the next model. Your idea of FRsky is a good one, the Taranis complete with 8 channel Rx and charger is about as good as it gets.

I'm not sure of the size of your model but on the basis of using batteries to provide power and aid balance, rather than lead weight, then a 2 cell LiFe battery from Puffin models would fit the bill. The charger of choice for this and anything else you ever need to charge would be the Bantam BC6. This unit allows for 240 and 12 volt operation and has every function needed.

Aileron servos might be a bit difficult to conceal in such a thin wing, but at semi-scale sub miniature servos mounted so that they face vertically downwards from the wing with the working parts exposed would not go amiss.

Ian
Barry_Cole

Re: Semi scale Slingsby Skylark 1**

Post by Barry_Cole »

If this is the Westwings one, you will never going to get a 2 cell LIFE battery in there.

I will be building one after Christmas (I hope). I think a small 2 cell Lipo and a BEC unit may be best.

BC
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Peter Balcombe
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Location: Clevedon, North Somerset, U.K.

Re: Semi scale Slingsby Skylark 1**

Post by Peter Balcombe »

Karolis,
Just posted a response on this one but seems to have disappeared!
No servos do not need to be the same make as the radio gear as they all use the same electrical interface - except for the connectors which can be slightly different, but all tend to fit any receiver.

A word of warning though about servos, as not all can withstand being powered by more than a 4 cell Nicad pack.
This is why Barry just referred to using an ESC with a 2 cell Lipo pack - to reduce the nominal 7.4v battery voltage down to 4.8v.
I would advise the same route with a LiFe pack unless you use what they call 'high voltage' servos and receiver.
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Peter Balcombe
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Location: Clevedon, North Somerset, U.K.

Re: Semi scale Slingsby Skylark 1**

Post by Peter Balcombe »

Karolis,
I would think that Ian means the Dual Power version of the BC6 as he mentions both 240v and 12v operation.

As far as servo ratings go, I would think that for a model of that relatively small size and if flown in a scale type fashion, you would be ok with around 2Kg/cm for the ailerons (if servos are in the wing then you will need small ones anyway), and perhaps slightly larger ones, like mini servos such as Hitec HS81/82 (2.6Kg/cm) for the rudder & elevator.
This means that any good micro would be ok for each aileron as these tend to be ok for between 1.8 & 2Kg/cm at 4.8v.
If you have a single servo mounted in the fuselage for both ailerons ( I am not sure of your model construction) then it is probably better to use the larger servos for everything.
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Peter Balcombe
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Re: Semi scale Slingsby Skylark 1**

Post by Peter Balcombe »

Karolis,
If you are building the West Wings Skylark kit, this model does appear to need 2 aileron servos & the advert I read stated that JP Energ 6g servos were ideal for ailerons. These are even smaller than I was suggesting & only produce 0.9Kg/cm torque, so anything similar to this in size & torque should be fine. On this basis, you could probably get away with 2 standard micro servos, each with about 1.8/2Kg/cm torque for the rudder & elevator.
Nigel Argall
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Location: Cornwall

Re: Semi scale Slingsby Skylark 1**

Post by Nigel Argall »

I don't want to contradict Ian above about transmitter choice but my understanding of the FRsky kit is that it is very capable BUT you have to do a lot of 'programming' yourself. If you like computer related stuff, go ahead, if this is not your thing and/or it is your first radio, I think you'd be better off with a basic (say) six channel piece of kit from Spektrum or suchlike.
spike spencer

Re: Semi scale Slingsby Skylark 1**

Post by spike spencer »

If you are using Lithium batteries, an 'economy' charger is not a good choice and may be a false economy. I have been using a Bantam BC6 charger for a couple of years now and it is a rugged and reliable bit of kit. There are many alternatives at much higher prices.

The BC6 dual power (mains and DC) saves messing about with other DC power sources on the bench but can also be used in the field. As well as LiPo, It has settings for Lithium Iron (LiFe) cells that many others do not. Following Ian's advice some years ago, I obtained mine specifically to look after some LiFe receiver batteries but now use it for all my other LiPos as well.

Ultimately it is a personal choice.
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Peter Balcombe
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Re: Semi scale Slingsby Skylark 1**

Post by Peter Balcombe »

Karolis,
I use an iMax BC6 AC/DC charger which is similar to the Bantam & I am perfectly happy with this for glider batteries and eflight power batteries.
There are other similar chargers out there from Hyperion, Sigma etc and some have extra features or power levels.
I would have thought you just need a standard charger capable of up to 6S, 50/60W output and capable of charging LiPo, LiFe and Li-ion battery technologies for the foreseeable future.
Some chargers have extra features such as data download to a PC but it depends whether you want/need this as you may well pay extra for the capability.
Just watch that you do not get a Chinese copy of what you want as these are likely to be less reliable in the longer term.
Unless you move into very large batteries the 6S, 50/60w charger is likely to meet your current & future needs.
john greenfield
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Re: Semi scale Slingsby Skylark 1**

Post by john greenfield »

Karolis
The slot in the elevator looks like the slot where the control horn should fit. If this is properly glued in it will be ok for a model of the size you are building.

AEB
AEB = Aeronautical Energiser Bunny (with thanks to CW)
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