RE: ZN Line Xigris
 

Thanks for the suggestions guys, I will try out a few different things to see if I can reduce the mixing. Funny thing is that a good friend of mine built a C2 from a kit this winter, and he set it up according to JPZ, and he didn't have any mixers active except for the down-line elevator mix that is common to many F3A models nowadays. His model was sadly damaged in a collision with some trees, however he will try and do some measurements on the "left-overs" so that we can compare. Also I have asked JPZ for his setup, and he has promised to come back to me with his setup as well.

By the way, I have the Pletti Xtra 30-9 EVO 2 in the Xigris, and you need to be careful about the prop on this motor, it does have a higher KV rating than the 30-10. I'm presently running a MAG 5 (20.2x16) that was recommended to me by Manfred Greve, and it is a beast with that prop. The other day I put on my Hyperion E-meter to check the wattage etc. on the ground, and here are the results using Rhino 4900mAh 20C packs:

37.87 Volts
101.76 Amps
3854 Watts [sm=omg_smile.gif]
6765 RPM

I'm not sure how accurate the E-meter is, however it feels like a lot of power, and certainly more than the 30-10 on an APC 20x15 or a PT Model 20.5x14 on the same packs. Not that I'm lacking power with the 30-10, however there is significantly more power in the 30-9. I'm thinking that it would probably be a good idea to prop down a bit...

RE: ZN Line Xigris
 

I second that. I'm running the 30-9 with a APCE 20,5 x 14 (as I did with my 30-10) and it consumes to much current. I haven't had the time to measure it yet, but after the first two flights I reduced my upper end thottle ATV by 30% as my batteries got too hot. I will prop down to get the power consumption down as well. I will have some flights with my e-logger one of these days and report back.

Best regards - Paul

RE: ZN Line Xigris
 

I never could understand the 'Plettenberg' comment about reducing the windings and have the same revs.

(It is only on the German text version of the website)
So wurde das Magnetsystem weiter optimiert und die Windungszahl gesenkt. Dies bewirkt einen geringeren Innenwiderstand und einen höheren Wirkungsgrad bei gleichzeitig höherer Leistung. Die Drehzahl des neuen Motors hat sich im Vergleich zu seinem Vorgänger nicht geändert, so dass die gleichen Luftschrauben verwendet werden können.

RE: ZN Line Xigris
 

Hi,

Just for your information, JPZ has now published his settings on znline.com.

[link=http://www.znline.com/content.php?langue=english]http://www.znline.com/content.php?langue=english[/link]

CANOPY FLOOR: -2.75°
STAB: 0°
WING:0°
AIRFLOW: -0.5°

RE: ZN Line Xigris
 

Regarding the Plettenberg 30-9 EVO II:

I just posted some readings from my logger here: http://www.rcuniverse.com/forum/fb.asp?m=9850583

Very consistent with Mortens.

RE: ZN Line Xigris
 

What about settings for the C1 ?

RE: ZN Line Xigris
 

Translated with google:
Thus, the magnetic system was further optimized and reduced the number of turns. This results in a lower internal resistance and a higher efficiency and an improvement in performance. The speed of the new engine has compared to its predecessor is not changed, so that the same air screws

Not exactly my experience.........:eek:

By the way - congratulations with the finals (football) :)

RE: ZN Line Xigris
 

For the C1, I have mine set as follows,

Motor - at factory downthrust (about -0.5), and added 1 degree of right

Wing - 0.7 positive

Stab - 0

CG - 280mm from the TE at the wing root

No pitch couple in KE, about 2-3% down elevator at idle. Roll is about 3% both ways (need right ail with right rudder)

RE: ZN Line Xigris
 

Don't think the dihedral is set right either with the C2... it acts like it doesn't have enough, rolls out of KE with rudder. Anybody else have this?

T

RE: ZN Line Xigris
 

Is the canopy floor equal on both the C1 and C2? Would be nice to have a datum on the C1 as well :)

RE: ZN Line Xigris
 

Matt,
Have done som calculations on the Xigris C2. Some questions araise why?????
Static margin approx 0,400
TVC approx 0,900
Center of lift for aircraft, approx 10cm (4inches) from TE.
Calc is done for CG at 25%.

Regards

RE: ZN Line Xigris
 

It is the same fuse for both models so canopy is the same.

RE: ZN Line Xigris
 

The settings on the C2 that JPZ has given ..where are the CG placed...I started with what he told us in the beginning but for me it was to fare forward I think I moved the battery about 4-5 cm back....and the cg ..maybe 2 cm .
Maybe JPZ can clear this for us?

RE: ZN Line Xigris
 

Dag,

If you are asking for my opinion as to why the numbers are set-up as they are, I don't know. I doubt that many "designers" take the time to do the math before they commit to building a model. Through trial and error eventually these models arrive at a reasonable compromise. But that's through many iterations by several builders.

The other thing is that many tend to build similar to existing...don't know enough to depart from the norm by a large amount to see new and improved behaviors. At least to try and detrmine if the new is indeed improved.

I saw my friend Ed Alt's Xigris C1 but didn't see it long enough to get design specs. By eyeballing the thing, I don't think the designed surfaces would be my first choice. The fuse is okay if not a little too deep. Wing and stab leave a lot to be desired in my opinion.

If you have a kit, I suggest you design new wings and stabs as we've discussed. It will improve in every practical way

RE: ZN Line Xigris
 

Matt,
Further back in this thread it is mentioned that C1 and C2 have equal size stab. C2 has a narrower wing so in the first place the stab may have been smaller, but still too large for my liking. Re-design (1st shot)of the stab for C2 shows the following:
TVC 0,716
Static margin 29%
Center of lift aircraft 14,5 cm from TE

I assume that this will take some workload off the stab and hence will be easier to trim, time will show!

By the way, the fuselage is of very good quality!!!!!!!

Regards

RE: ZN Line Xigris
 

Matt,

Just FYI, the wings and stab of C1 are virtually identical to the Integral, one of the most successful models in recent memory!

There is absolutely nothing wrong with the C1 as it is, new wings stabs are not required. I flew a totally stock kit at the WC, I think my results would not be decent if the model didn't fly well.

For the C2, I can't comment because I have not flown mine as yet.

RE: ZN Line Xigris
 

Thanks, Chad !

RE: ZN Line Xigris
 

Hi Rune,

I have asked JPZ for the CG as well, and he has promised to measure it. I will report back when I hear from him.

RE: ZN Line Xigris
 

Not debating people having done well with this or that design Chad. Flying skill always will trump a less than ideally conceived plane such as the Integral for example. What I am saying is that having seen, albeit from a distance, some of these models, they could be made to fly easier, better, with less pilot load, with relatively simple changes.

Had a chance to fly Dave Lockhart's Bravo a couple weeks ago. Dave flies this plane absolutely great. I expect him to fly it into the fInal this year. However the amount of control command the plane requires to execute the maneuvers is too high. Dave has learned the plane's character and as I said, flies it super, but I think it could be made significantly easier (less control volume) to fly just as well. I am talking agility with precision.

I definitely liked it's "Mohawk"'s response.

RE: ZN Line Xigris
 

Thinn,
According to my measurments I have found that a datum line placed traditionally between center of propdrive and stab tube. Then I measure the top of fuselage to be +4,7 degrees. Then it make sense to discuss wing angles.

Regards

RE: ZN Line Xigris
 

Thanks to both of you! I'll start with the ZN recommendations and work my way from there.. There should be marks on the fuse-side, but unfortunately, on my model, they're not visable. Not a big problem, just easier with a good datum!

RE: ZN Line Xigris
 

Mola,
See other post here re. datum line. If my measurment and stab tube is on the same place, then cockpit floor is on -3,8. Fuselage datum line will then fly with an angle nose up of 1,05 degree approx.

Regards

RE: ZN Line Xigris
 

thats fine! just been out flyin the C2 with a sharkfin at the toop...rudder is back as it was with the toopwing but less mixing

RE: ZN Line Xigris
 

Mola,
Are you still waiting for CG measurement of the C2 that was promised to you from ZN?

Regards

RE: ZN Line Xigris
 

Has anyone had any better luck trimming their C2 since the last post on this thread?
I just took delivery of a C2 kit and now I'm wondering if I should try to trade in the wings for the C1 version.