Originally Posted by
bandicootf16
Hi Bem
In your first post you were trying to determine what to use for a datum. In post #11 you measured the wing and stab at 0.1 degrees so a so called zero zero set up. I assume that you used the 1.5 degrees down thrust as your reference to measure the flying surface incidences. With a zero zero set up you will require up elevator to put the wing into positive to fly level as you have found. To remove the up elevator trim you could decrease the elevator incidence or increase the wing incidence.
Hi,
Yes I use the 1.5 degree down trust as the reference (since the nosering should have that and I thought that is rather reliable and is the same on all Galactika coming out from the mould at Oaxi.
Seems more natural to remove any up-trim with more positive incidence on the wing. It is after all the main lifting surface, and just leave the other surfaces as stabilizing and control (ideally the stab should not provide much or any lift, just a stabilizing and control surface to change attitude.
Originally Posted by
bandicootf16
If you crank some up into the stab you will effectively change the sit of the fuse and this will result in less down thrust and less negative on the canaliser. So if the wing is now sitting 1.0 degrees in level flight you will have 0.5 down thrust and - 0.4 on the canaliser. This would seem to be a good starting point for further trimming.
OK, that is one alternative to add some positive incidence to the stab, but I think for reason mentioned earlier it is better to work on wing incidence now that the plane has adjustable wing incidence.
Originally Posted by
bandicootf16
If you leave the elevator and increase the wing incidence to 1.0 then the sit of the fuse is unchanged and you still have 1.5 down thrust and - 1.4 on the canaliser.
Exactly, that was my findings the other evening when I was working on this.
Only flights and careful evaluation what to be changed to correct undesired flight behavior can determine what incidence on wing and stab will be in the end and what down- (and right-) trust the plane flies best with. But to start with I will test now with as close as possible factory recommended settings as a starting point.
Originally Posted by
bandicootf16
It would be interesting to know how CPLR sets up his Galactika. I assume he is flying a Oxai built model that come out of the same mould as yours. So the relationship between the canaliser and nose ring (thrust angles) is fixed. However there are options to change thrust angles but the spinner will not be aligned with nose ring.
If one examine the photos that are available on CPLR homepage it seems to bee exactly as my factory built Galactika EP (except CPLR use YS engine).
I prepared the motor mount to be easy to change engine angle. I have 0,1 millimeter titanium shims I can control this with, just to built up with some washer(s)/shimms between the nosering and engine mount to get desired trust direction change. Spinner will of course be slightly out of alignment but I left 1.8 millimeter free space betten nosering and backplate of spinner just to leave room for some tilting of engine in direction needed (if needed).
So it would be not problem at all for me to change engine direction.
Originally Posted by
bandicootf16
So it is possible to use the canaliser as your datum and set every thing else to this. But the question is at what angle should it be in level flight. Only CPLR can answer this. It is interesting that you were given a range of -0.3 to-0.8 degees. If you operate in this range by altering the wing and stab incidences then this would give a range of 0.4 to 0.9 degees down thrust assuming the spinner is aligned with the nose ring. This should be adequate to get the model dialed in. The stated 1.5 degrees down thrust is just confusing and should be ignored.
Yes, I was thinking of using the T-canard as reference and then set rest of incidence in relation to that.
Just curious - did You not get any Oxai factory incidence and motor/engine down trust values with Your Galactik plane?
Originally Posted by
bandicootf16
I only have 20 flights on my Galactik and my set up is 0.5 down thrust, wing 1.0 and stab 0.0. I did cut the nose to install a contra but was very carefull to maintain the design down thrust. Before cutting I measured the right thrust at 1.5 degrees. For some reason the Galactik/Galactika needs a lot of positive on the wing. Some have speculated that it is due to the large sweep angle on the wing. I still have a lot of trimming to do but it flys great and it shouldn't take long once I get it flying again.
In my paper about Oxai factory setting I got from the dealer it say 2.5 degree right trust on engine for my Galactika EP.
What did You use as reference line on Your Galactik?
It is good to know that I probably also need to increase wing positive incidence, and that should not be any surprise for me. After all Galactik and Galactika is almost same plane just slightly different wing (and maybe stab) and the T-Canard has little different shape on Galactika compared to Galactik.
Originally Posted by
bandicootf16
With 5000mah Zippy Compacts I'm sitting on about 4950g and CG at 210mm or maybe a fraction further back.
Out of the box with the stabs at zero I had 1.6 down thrust and - 1.5 on the canaliser. I didn't measure the wing. I had to add a large amount of positive. I started at 1.25 but the model climbed so I'm at 1.0 now. May have to take a little more out. I'm leaving the stab alone at this stage to maintain the 0.5 down at this stage.
David
OK, nice to have Your values to compare with mine.
Yesterday evening i set the incidences on my Galactika.
A have now (measured everthing twice to be sure it was repetable, and it was):
1.5 degree down trust on engine shaft (as reference line)
Both wing half: + 0.6 degrees
Stab: 0 degees (but unfortunately the right stab half has +0.2 degree incidence when the left as 0 degrees. To bad that each stab half is not individually adjustable, only whole stab as one unit is adjustable for incidence)
T-canard: -1.2 degrees
I will testfly this setup on Friday evening if weather permit.
Yesterday I got the 4 mm Jeti anti spark that i will mount on the cable to battery, I will fix that this evening.
/Bo