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Whatever your doing to this old girl, your doing it well, it could not have gone to a better caretaker
'Tis a definate mate, it'll be all sorted out by then. Ian.
What size are those props Ian they look huge for a 22 My old one runs same as it did when new but I find a 18x6 wood is a struggle for it. A 16x6 or 15x8 swings better but still no race engine.
Looking forward to seeing this one in the air Ian, that additional tail area should make knife edge easierSteve
Aye up Sir IanI have a Z26 which has had a bash,I am willing to donate free . The secondary coil is bu@@red due to the earthing tag being bust and the insulator block and carb are damaged .I have turned it over in my lathe, the crank isn't perfect but not miles out . Von Sheephoven has had the silencer for his geared Z22 already .Its no prize but you could probably fix it with bits off one of the 22's( and a bash with Alan Cantwell's hammer if required)Regards Alan
I now think that apart from lightening the aileron by replacing the hardwood trailing edge, I'll balance them by replacing a strip of leading edge with lead, cast to the section of the bits to be replaced. Am I right in thinking that the full size practice is to 'over' balance so the surface is deflected up? Or would neutral be more betterer in this instance?
More weight it is then cheers Mark
More weight it is then
It would upset me to add 6 oz to etch wing tip. I think you are worrying about the ailerons 'rattling' as you taxi, it ain't going to happen! You will probably taxi a short distance over grass, but the time the big soft wheals transmit a shock all the way out to the wing tip it will disappear.If it was an Extra or the like, a mass balance might be a good idea but as it still has an Aerodynamic balance and given that this thing is probably going to be the slowest model you have ever seen fly, all you need is a good servo mounting and some stiff no slop linkage. I would attack the wood behind the hinges with a Dremel sander before adding painful weight if you still consider it necessary.Just me; i hate weight.
Standing by to be shot down in flames for a 'dumb-ass' idea but.... Would there be any benefit in spring loading the aileron to dampen the effect of bumps; would the benefit outweigh the additional servo power required to deflect the control surfaces?Garry
I'm trying to remember my rotation of rigid bodies .Is any additional weight away from the centre of rotation (hinge line) going to increase the moment of inertia of the aileron? I think is does .If I am correct then adding a balance weight will increase torque loads on the control links/servos not reduce them when travelling over bumpy ground. (I'm a chemist not a physicist / engineer )Alan
. Now let's look at what is happening the flutter case. The aileron is trying to move, but it is constrained by the hinges and the horn - it's constrained at a single point. If we rigidly mount a counterbalance at this point then the constraint and the balance have little or no spring coupling between them, so they will always be in phase and the primary flutter mode disappears.
But if we use a distributed counterbalance the tornsional stiffness of the aileron becomes a spring between the mas and the constraining point. This introduces phase lags and leads to a high risk of a torsional flutter mode.
I will just play devils advocate here a moment.It is a scale model; right? you have to put the horn where it belongs. End of story. If you feel you have to have the ailerons mass balanced for and aft that's OK and a good thing but unnecessary on a slow flying model that is sure to be over engineered. (for the non scale vibration)However, adding weight to etch wing tip will add a momentum lag in all directions that may be noticed on the aileron control reaction and the rudder. That might spoil your day at a critical moment. Over fussy? yes. but so is the scientific missive above. Not wrong, actually very interesting and truthful, just not for a model HP42