Seagull Mosquito weight

[Ronos]

Hi, there are a couple of threads on the forum regarding the Seagull Mosquito, but rather than butt in on someone else's thread, I thought I would post a new thread. I am looking for some guidance on the weight of said model. The manual says 13.7-14.1lbs or 6.2-6.4Kg. Right now, I have just had mine on the scales and it is, 15.4lbs or 6.943Kg.which is about 1lb 3oz or 543g over weight, that's with everything in, two battery pks one for the RX and one for the retracts, rx, and I can't see where I can lose over a pound of weight and this is before I have checked the COG, or would it be OK at that weight.

[Former Member]

[This posting has been removed]

[Ronos]

Thanks Ikura, it's powered by two ASP70FS with two 13x6 props, going what people say that set up should be OK

Edited By Ronos on 25/08/2018 14:37:16

[Chris Walby]

Ronos, the issue with "heavy" is that it flies fast so that's no problem, but here is the twist,,,,take off and landings are faster.

Not a problem if you have a very long smooth runway, but more pressure on you if you need to "spot" land it.

See how the C of G looks, you might need the batteries up front, if not shed one (I am using a 3S2200 wedged in the nose!). I spoke to George at 4-Max and have a 20A BEC, he said with that rating (it can handle even higher over load currents) a stalled U/C servo wold just burn out without affecting the RX.

7 Kg or a bit over should be okay, anything over 8 Kg then diet time!

Hope that helps.

[Ronos]

Hi Chris, ditching one battery might be a option, haven't checked CofG yet, my head is spinning with what to go for, 150mm,or 130mm,might just split the difference and go for a little nose heavy, but just a tad.

[Chris Walby]

If it was me...go for 130mm as the other guys say its good, move as much about as you can for 130mm (even change the tail wheel if needed).

As you said, there is not a lot you can do about the weight, so don't worry too much.

I think "us" IC guys will always come out heavy if it was designed for electric, but that's just the way it is, far more important to get the C of G at 130mm as you can easily move things back if you want after a few flights.

Best to see where the C of G is and work at the moment (your engines are slightly heavier and you don't have ali spinners), lots of options for you so no worries at the moment.

.

PS if you need a different tail wheel, let me know and I could make a couple for us (good incentive for me to get on with it!) as I am living in denial until my engines are in

[Ronos]

OK, 130 it is. Thanks for the offer of the tail wheel, I'll PM you.

[Richard Wills 2]

7.8kg for mine, shade over 17lbs, and I would start at 130mm. It feels fine at this weight, I wouldn't worry.

[Ronos]

Thanks Richard, 130mm and mine slightly lighter, have you flown it yet? Interested in its characteristics. I've been told they are very pitch sensitive, that's why the C og G has to be spot on.

[Richard Wills 2]

Yes, it has flown. It is sensitive to the elevator, you really don't need much throw. The ailerons on the other hand are not that powerful, so it can seem worse than it as they feel unbalanced. Lots of aileron travel think I am using 15mm ish and about 8mm on the elevator seems good. Other than that it is nice, a bit of adverse yaw, so a bit of aileron differential helps it. On the whole pretty well behaved now, just don't provoke it, it will bite.

[Ronos]

Richard, its nice to know someone has flown it, it gives us, that's yet to maiden, a bit of confidence. Thanks, feeling less anxious.

[Ronos]

Richard, did you balance yours inverted like it says in the manual?

[Chris Walby]

Hi Richard,

I noticed you mentioned 15 mm Ailerons and 8 mm Elevator and Seagull quote in the manual 15 low and 25 high so thanks for the call on the elevator throw.

Are you using any expo (dirty word to some, but I use it!)?

[Richard Wills 2]

I set 8mm up as a low rate after the first flight, and it has worked well. Expo, yes, I use 25% on everything. If you normally use it, I would do so. Arguments for and against which i'm not going to get into.

Balanced it upright, most of the mass is below the wing.

[Jon H]

I would set the elevator rates as low as you can Chris. In general I take the low rate from the kit instructions and set my low rate about a bit lower and high the same. With a recommendation of 15 I would probably go for 10 and 15. I work on the basis that I should have my bases covered with this at least for the maiden flight. I start with high for takeoff but take great care to not yank at the stick until well clear of the ground. Its also my standard procedure to belly land somewhere soft in the event that the model is 'uncontrollable' in pitch. Its something I have done only twice but its better to do that than try to land and smash the undercarriage. I usually find that most warbird manuals have way too much elevator deflection so ignore them now. As you have a recommendation from Richard of 8 then I would use 8 low and 12 high? something like that.

Personally I don't use any expo until the model is flown and even then its rare I use any and I have never found the need to use more than 10%. I agree with Richard that the argument about whether to use it or not could rage for a week so best not to get into it. I think his recommendation is pretty sound, if you use it normally then use a bit, if you don't then don't.

As for balance, I would go right way up as Richard suggests with gear up and no fuel. This is going to be the model tail heavy condition the model will see so even if its a shade tail heavy two tanks of fuel and lowering the gear will fix it.

I would suggest getting the gear retracted asap on the maiden though. Get the drag off the model, clean up the airframe and go from there.

 

Edited By Jon - Laser Engines on 27/08/2018 23:44:09

[Richard Wills 2]

I have 12mm as my high, still comfortably controllable, but far too much for scale flight.

[Ronos]

Richard, did you fit the tanks that came with the mossie? If you did how much fun time do you get out of full tanks?

[Richard Wills 2]

I fitted 11oz slec square tanks. 10 min flight, not much left when I land.

[Ronos]

Thanks Richard.

[Chris Freeman 3]

I made a ply plate that fits in the nose so that I can attach the required nose weight as far forward as possible. The ASP 52 2 strokes are light so quit a bit of lead was needed and I am using a 2800 5 cell nicad which is as far forward as possible. As I stay in Johannesburg South Africa I also tend to move the CG forward due to the air density. August is our windy month so we have not been able to fly it yet.

[Ronos]

Hi Chris, how far forward have you moved the C of G?

[Chris Freeman 3]

Hi Renos

I am at 128mm, I did not check the total flying weight but it is quit a lot heavier than my Brian Taylor one that was electric and weighed 5.5 kg ready to fly. That was a great flying aircraft.

[Ronos]

Thanks Chris, always nice to know what others are doing. I take it you haven't maiden yet. Let us know how you get on.

[Ronos]

Had the mossie on the CofG stand, battery's as far forward as possible, and it took 525g to get it to balance slightly nose down, which will take the overall weight to just under 7.5kg or 161/2lb. Should I be worried?

[Chris Walby]

Ronos,

I'll weigh mine again and see what it comes out like (not that its flow yet) although reading here and other places I don't think there is a light one out there (especially IC). If its a little overweight it will just fly a bit faster (okay the stall speed will be higher as it won't actually fly faster... yes yes I know they ballast gliders, but that's off topic).

I can't see the point of adding lead if the RX lipo is mounted in the tail! but once you have done what you can then lead it is to get the C of G.

As mentioned earlier up to 7.5 Kg no real issue, over 8 Kg then a diet would benefit it, There is an advantage of increased mass and that is better penetration in windier conditions...aarrr back to glider ballast again.

Off to the shed with the kitchen scales