Sebart Angel S EVO 50E

[Bruce Collinson]

Hello all,

struggling with c of g with this plane which I bought secondhand but unflown.

Manual has c of g at 145mm behind LE.   With a 6s LiPo pushed right up to the bulkhead/firewall it’s tail heavy.   LiPo weighs 654 gm and is far forward of the battery tray (not insurmountable per se) and will still need ballast on the motor box, which is anathema to me.

 

What am I doing wrong?   The tail servos are in the tail and having spent some time and effort to get them in and tidy I’m reluctant to take them out again although lighter servos would help.   Won’t get the LiPo where it was designed to go though.

 

Wondering if anyone has experience of this plane?

Bruce.

[Philip Lewis 3]

This just doesn't sound right. I have one of these planes, am using a quite a light motor up front and have trouble getting the batteries far enough back which is more the opposite of what you are saying.

Edited December 9, 2023 by Philip Lewis 3
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[Denis Watkins]

Bruce, have rung a flying buddy who has the Angel, and his rudder servo is not in the tail, but behind the wing tube up front on a closed loop system.

The elevator servo is in the tail, as is yours you say.

He balanced 145mm as recommended using the battery position.

[Robert Welford]

I have an Angel 50S with Hacker A50 V3 motor and Hacker ESC with elevator servo (JR8231) in the tail and rudder servo (closed loop) behind the wing tube.

With the battery (6s 5000mAH) I can balance at 145mm, but I believe the CofG is further aft than this to give me the handling I want.

 

I would test fly at 145mm using lead on the firewall and then see how it handles.

[Philip Lewis 3]

My rudder servo is mounted in the tray behind the wing tube which is as it comes from the factory as shown on page 13 of the manual atached, I think having the rudder servo in the tail is your problem.

Assembly-AngelS Evo 50E.pdf

[Colin Carpenter]

I fly a Miss Wind 50 on 5s (small field ) and the lipo is as far back as I can get it ! Both servos at rear. No lead. Perfectly happy with it like that. Colin

[Bruce Collinson]

Thank you all.   Probably, the fact that it was assembled (not but me) with three servos at the back is most of the problem.   Have subsequently worked out that it will need c. 250 g of ballast so we might be turning it back to closed loop rudder.   I notice that the horn on rudder is double sided so there’s a clue.

 

There seem to be discrepancies in the replies thus far.   Odd.

BTC

[Philip Lewis 3]

Three servo's at the back would be very strange, mine has one servo controlling both elevators (as page 12 of the manual I uploaded shows), never seen anything other than this on these planes.

 

I think the only discrepancy in relies is that one forum member is describing a Wind 50 which is a different plane entirely.

Edited December 9, 2023 by Philip Lewis 3
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[MattyB]

Sebart factory CGs are notoriously nose heavy; every modeller I’ve seen with a Sebart (including me on my Miss Wind) end up flying them with a CG well behind where the manual recommends. I would not worry too much if you can’t achieve their position if it looks reasonable n a TLAR check.

[Bruce Collinson]

10 hours ago, MattyB said:

Sebart factory CGs are notoriously nose heavy; every modeller I’ve seen with a Sebart (including me on my Miss Wind) end up flying them with a CG well behind where the manual recommends. I would not worry too much if you can’t achieve their position if it looks reasonable n a TLAR check.

Isn't the mantra, c of g forward, flies badly; c of g rearward, flies once?   Nevertheless I take your point but am keen to hear where the c of g sweet spot is.

 

16 hours ago, Philip Lewis 3 said:

My rudder servo is mounted in the tray behind the wing tube which is as it comes from the factory as shown on page 13 of the manual atached, I think having the rudder servo in the tail is your problem.

Assembly-AngelS Evo 50E.pdf 1.53 MB · 8 downloads

Grateful for this.

 

What I conclude is that mine was built off piste, with two elevator servos, within the tailplane, hidden by what does look like original film.   The plan elevator servo location is occupied by the rudder servo, so three servos in the rear and I cannot access the elevator servos to check weight etc.   I think it needs to be ballasted to 145mm, flown, trimmed then put on a diet, probably starting by reverting to closed loop rudder, maybe with the servo a bit further forward as the LiPo will still be well forward.   I'll move the Rx forward too, not that it will make a huge difference, but "Tesco" (every little etc.).   Hopefully the ballast can then be removed incrementally.

 

Bit frustrating.   In the confines of a back-of-van seller at Weston, four of us scrutinised it carefully, one a lifetime F3A competitor, and we didn't twig any of this.   Never stop learning.

 

Any empirical evidence of flyable c of g location, as opposed to what might be a very defensive 145mm, will be welcome.   Thanks for your input thus far.

 

Bruce.

[Philip Lewis 3]

I just wonder if this has been put together with the tailplane from maybe a Wind S 50E which does have the two servo's in the tailplane as it would be very difficult to build in servo mounts to an Angel tailplane once they were built and of course you would ned to cut out the joiner between the two halves.

 

Nevertheless you could end up with something very good here as like I said I always had trouble getting the C ofG far enough back, however given the moment from the wing tube (roughly where the C of G will be) to the servo location is in the order of four to five times from the distance to the motor box then if that was five then taking a servo weighing say 40 grams out of the tail would equate to removing 200 grams at the front so I think you will end up fine.

 

Indeed tail heavy flies once and mose heavy flies badly but that is extremely far out and pattern planes aren't overly sensitive either.

 

I'll measure mine later on for you but it won't be till at least this evening as right now it's up in the loft where it's been living the past few years.   

[John Lee]

Tastes vary but I set mine up exactly as per the recommendations on page 22 of the manual when I assembled it in 2015 (no ballast needed) & have never felt the need to touch the settings since.

[Philip Lewis 3]

OK just measured mine, C of G measured with slightly heavier batteries than I used to use to fly it with (which I don't have any more), comes out at 165mm from the front of the wing where it meets the fuselage so when flown with the ighter pack would have been behind that.

 

That is right on the back of the wing tube.

 

Tastes do vary and I do like to fly with a fairly rearward C of G than some but not by a lot, nose heavy models can always be trimed to fly straight but won't naturally want to roll axially, they will also require considerable down elevator when in inverted manoeuvres and will pull to the canopy in a vertical up or down line.

 

Check to make sure that those awful screw down linkage stoppers haven't been used as shown on page 7 of the manual, because they WILL come lose and if on the elevator will cost you a plane.  

[Bruce Collinson]

Very useful.

 

Mine (now) has ball links throughout.

 

165/rear of the tube is a long way from 145 and will certainly get it much closer before ballasting.   Funny how often the wing tube is about right for c of g.   Thanks for going into your loft!

 

Bruce.

[Philip Lewis 3]

8 minutes ago, Bruce Collinson said:

165/rear of the tube is a long way from 145 and will certainly get it much closer before ballasting.   Funny how often the wing tube is about right for c of g.   Thanks for going into your loft!

Yes you aren't likely to be far out on the wing tube for an aerobatic plane unless it has a swept wing because generally designers put the wing tube at the fattest part of the wing which is roughly where the C of G will be, 165 as opposed to 145 isn't that great on a plane of this size, it isn't even an inch, glad to be of help, the plane is grateful too as it got a clean from the crud that comes down from the roof in the loft where it's been for the last five years now!

 

Should be quite achiveable with a centrally mounted rudder servo and a pull pull system, enjoy the plane, these really are pussy cats to fly if set up well, just don't use too much control throws, these are designed for precision not 3D and in reality will reuire very small control movements, just enought to flare on landing is a good guide for the elevator for instance.

[MattyB]

23 hours ago, Bruce Collinson said:

Isn't the mantra, c of g forward, flies badly; c of g rearward, flies once?   Nevertheless I take your point but am keen to hear where the c of g sweet spot is.

 

It is, but as I said, it's common knowledge that Silvestri sets up all his models with very forward CGs, well further forward than most people like them. Why he does that I don't know, but every Sebart I've seen has ended up with a CG further back than the marked point in the manual. That can't just be random chance...

 

15 hours ago, Philip Lewis 3 said:

OK just measured mine, C of G measured with slightly heavier batteries than I used to use to fly it with (which I don't have any more), comes out at 165mm from the front of the wing where it meets the fuselage so when flown with the lighter pack would have been behind that.

 

12 hours ago, Bruce Collinson said:

165/rear of the tube is a long way from 145 and will certainly get it much closer before ballasting.   Funny how often the wing tube is about right for c of g.   

 

This sounds pretty much bang on what I'd expect in terms of the amount the CG moved from stock position on a 50e sized Sebart. 20-25mm back from the marked position is (from memory) pretty much where I have ended up with my Miss Wind - the 6S pack has to sit right at the very back of the battery bay, and I think I needed a tiny bit of tail weight to achieve the final position. 

 

PS - Someone else who found 145mm to be too far forward...

Edited December 11, 2023 by MattyB

[Graham Bowers]

Not an Angel, I have a Mythos 50e. The recommended CoG position is 165mm plus or minus 10mm. I started at "middle for diddle" and to get it at 165mm required the 6S Lipo to be as far forward as possible, and the Rx Lipo, Digi switch and optiguard to be as far forward as possible.

 

Over the course of the first 10 flights of so, I evaluated the CoG by flying characteristics.

1) 45 degree climb, roll inverted  test #4 https://ita.bmfa.uk/wp-content/uploads/2023/07/Basic-Trimming-for-Aerobatics-27-07-2023-v1.pdf.

2) Inverted flight.

 

I moved the Rx Lipo, Digi switch and opti guard as far back as possible and the proceeded to move the 6S lipo back 10mm at a time.

 

The final outcome was that it needed a slight touch of "down" to maintain inverted flight - how I like it.

 

I didn't make a note of the final CoG position I'm afraid, and have now taken some of the bits out to do an undercarriage mount repair ;-(

 

My point is that you may well move the servos around to get the "book" CoG and then find you move it back to where it was anyway to get it to fly how you like it.

 

I'd be inclined to add the lead temporarily to get to the "book" CoG and test.

Edited December 11, 2023 by Graham Bowers

[conrad taggart]

There are various versions of this plane with different recommended CofGs !   See facebook posting below .  I went for a 4500 6 cell (620 g) right up to the firewall

...

 

https://www.facebook.com/search/top?q=sebart

 

Most of the posting is copied below 

 

Hope you can help?

I have a Sebart Sukhoi 50e. Unfortunately I don't know which version it is - version 1 or version 2 so I am unsure of which of the recommended C of G's to use.

The colour scheme is black and yellow (which I see a lot of versions 2's on the web) but I don't know whether this scheme was exclusive to version 2.

I have attached a picture of the model below.

Any help would be greatly appreciated.…

See more

 

 

 

 

Paul Carr

If unsure, I would go with the cg that's the furthest forwards of the two model versions, and have a two rates of elevator travel, one at the recommended low rate and the other set at a little more.

Then see how she flies, trim it straight and level, then roll inverted and see how it

pitches. Land and check where the elevator position is. If its slightly up, then you're nose heavy, so lose a little weight from the nose/ slide the battery back a little.

Or let me know when you intend to fly and I'll come up if I'm not deployed

 

Conrad Taggart

Author

Paul Carr Thanks Paul - more or less did what you said.e

 

 

Dries Neyrinck

Top contributor

Go for CG on the wingtube and adjust to your own tast

 

Conrad Taggart

Author

Thanks all sorteded guys - took a 4500 6 cell (620 g) right up to the firewall the c of g was just in front of the wing joiner ! Maiden went well - just a couple of clicks of up trim ....

 

 

Kingsley Veal

Top contributor

Manual says 125mm back from the leading edge. This normally at the wing tube. All the manuals are available on line the CoG section is normally the last page

 

Dave Long

It a v2 same as my one

 

Conrad Taggart

Author

Dave what's makes you say that - spoke to dumfries-model-flying (who are the distributors and sellers of Sebart models) and they reckon it is a version 1 - think it was to do with the distributor named on the plane and how long they were out of business ... but if there is anything i should look for speicifically on the plane please let me know as the CoG's are very different

Edited December 11, 2023 by conrad taggart

[Denis Watkins]

22 hours ago, Bruce Collinson said:

Funny how often the wing tube is about right for c of g.   Thanks for going into your loft!

 

Bruce.

 

Good spot Bruce, one that you will never forget

The wing tube is most commonly fitted at the ( strongest ) thickest part of the wing profile which is aerodynamically too, the best place for the C of G

[Andy Stephenson]

After reading this thread, I checked my Saito 82 powered Angel. It turns out it was set at 145mm at which, it flies well but I always wondered if it could be even better. I added 55g of wheel balance weights to the tail to get it to 165mm. If this works out, I will move the rudder servo to the tail and remove some of the weights.

[Bruce Collinson]

Andy,

 

Do let us know the outcome.

 

Bruce

[Graham Bowers]

2 hours ago, Andy Stephenson said:

After reading this thread, I checked my Saito 82 powered Angel. It turns out it was set at 145mm at which, it flies well but I always wondered if it could be even better. I added 55g of wheel balance weights to the tail to get it to 165mm. If this works out, I will move the rudder servo to the tail and remove some of the weights.

Me being the cautious type, moving the CoG in stages would be appealing 😉

[Andy Stephenson]

2 hours ago, Bruce Collinson said:

Andy,

 

Do let us know the outcome.

 

Bruce

Bruce,

It will be a while before I get out flying again as I hibernate during the winter months so if I remember by the time spring comes, I will report back.

[Philip Lewis 3]

3 hours ago, Andy Stephenson said:

After reading this thread, I checked my Saito 82 powered Angel. It turns out it was set at 145mm at which, it flies well but I always wondered if it could be even better. I added 55g of wheel balance weights to the tail to get it to 165mm. If this works out, I will move the rudder servo to the tail and remove some of the weights.

You can get a likely outcome from taking a look at the current elevator position when the stick is at neutral, if there is a lot of up trim in it (counteracting the nose being heavy) then it is highly likely to fly even better with a more neutral elevator trim, rolls in particular will be more naturally axial with less rudder and elevator input reuired to follow a straight and level line, in, for instance, a slow roll, down and uplines will also be straighter and it will fly invereted more neutrally. Moving the C of G 20mm back on a plane of this size is not going to make it overly sensitive let alone uncontrolable.

 

Hopefully you find that flies much better and like the change.   

[Andy Stephenson]

Kit manufacturers always, without exception, specify a "safe" GC. My AcroWot flew best with the CG 1/2" behind the most rearward point recommended.