general IMAC questions

[orthobird]

i have a question, just in general, if you were to build an IMAC airplane, not to ever do 3D. the elevators: counterbalance or no counterbalance, and why?

the rudder: counterbalance.... why not without??

the ailerons: area in root of the aileron, would you keep it close to fuselage, or maybe further away???

just some thoughts in my mind i always wonder about.....

:excitement:

 

[IMAC FANATIC]

Mine is being built with no counterbalances anywhere. IMAC only plane, zero 3-d , have yet to fly it so cannot comment on performance, im following the carden pro design so how could it be bad ?

Left the ailerons stock size but heavily considered shorter surface and wider cord, both servoes are as inboard as possible for rotating mass and tapered TE from fat to thin everywhere,For cleaner stall and less violent snaps. also made a tank mount to place fuel over cg so at run off cg never changes, using incidence adjusters this time to play with negative incidence on wings also. Like a giant pattern plane is the end result im looking for.

 

[Flatspinjim]

I built a Carden, straight IMAC plane, no counter balances, short wide ailerons. My impressions, point rolls and rollers are fantastic with the short ailerons. The only downside is they are somewhat speed sensitive. The only time you really notice is on uplines, and it is very minimal. I don't run a lot of throw for general IMAC flying, 13 degrees on ailerons, but do go with 25 for snaps.

No counter balance on rudder, but have PLENTY of authority. Kurt Koelling did a test, one plane with rudder counter balance and one without. He said he had to lower his throws and increase his expo on the plane without.



I also have a Dalton built with rudder counter balance and full length ailerons. I would really like to build another set of wings for it with short ailerons just to compare.

 

[reyn3545]

Just take the wings that you have, split the ailerons and add flaps. Then you can use your radio to decide whether the flaps are flaps or ailerons!

 

[Flatspinjim]

reyn3545;17722 wrote: Just take the wings that you have, split the ailerons and add flaps. Then you can use your radio to decide whether the flaps are flaps or ailerons!

I thought about that also, but when I did my Carden I made the chord wider on the ailerons. Not sure how much difference that would make though.

 

[orthobird]

what about sealing the hinge lines. All of them? Rudder also? what do you use?

 

[grind2tenths]

With out a doubt seal everything and yes the rudder too. I have used covering either clear or match the covering on the plane. Or get you a roll of blenderm surgical tape works well too.

 

[orthobird]

excellent!!! thank you! will do

 

[Stinger]

There has been a lot of experimenting with the size and shape of ailerons over the last couple of years with just as many pro and con views on what is the best.
I have the ailerons on my 42% planes split into three sections.
I did this primarily to over come the problem I have had so much difficulty over the years which is "matching servo".
With a servo on each section operating independently from one another, "binding" servos along with all of the associated issues is a thing of the past. Also my set up time is a fraction of what it used to be.
I discovered many other benefits from the split aileron concept as well.
Now you can select the area of aileron that works the best for you. I use the two outboard sections almost all of the time and the inboard sections for flaps when desirable. My radio is set up so that I can select any combination of sections with a two position switch and a slider switch to employee the flaps if needed.
There are a number of other advantages as well. For example, if you use the same plane for 3D, you would likely want to use all three aileron sections.
My particular radio does not prevent activating the wrong model. If I made that mistake and activated the wrong model, there is no danger of having all the high torque servos fighting each other and the damage that could result.
Just something to think about.

 

[Pistolera]

Steve....I'd still love to set up a crow condition on your Dalton, so the inboard goes up, middle down, and outside remain as ailerons....just to see how it would work on an extended downline. I can envision an 8-point roll on the way down after a hammerhead