Official 90mm Avanti S EDF Sport Jet Thread

[paulrkytek]

I would think that it is not important to have the same mAh and C ratings for both batteries, as long as you treat the combined pack as if it had the lower specs of the two. For example, if using a 6S 5200 mAh, 80 C battery in series with a 2S 6200 mAh, 120 C battery, you must treat the 2-battery 8S pack as if it had only 5200 mAh, 80 C ratings overall. The 2S battery will be used only "lightly".

I am saying this because my recent research into available 2S LiPo batteries to pair with my 6S packs (mostly SMC and Admiral) has found very few viable options in soft-pack choices and I don't want to incur the weight penalty of the hard-case batteries (mostly used for surface vehicles). One option I am considering is a 2S Zeee (Amazon.com: Zeee 2S 6200mAh Lipo Battery 7.4V 120C with XT60 Connector (2 Pack) | Soft Case RC Car Battery for RC Vehicles RC Truck Tank Truggy Boat Racing Hobby Models : Toys & Games), to pair it with an SMC 6S (5200 mAh, 75 C).

Your thoughts?

If you did this how does your radio, telemetry and esc LVC appear and is it smart telemetry so that it gives you individual cell readings/warnings to ensure you know the 6s pack is running out or is it based on total voltage of both packs together and will you get LVC warning at the right time ? I would have thought same mah for both lipos takes out the risk of a false reading but I guess it is down to what you are comfortable with. Maybe run em down to lvc on the ground first ?

[Giovanni_L]

Can anyone tell me what is the maximum usable width of the battery compartment in the 90mm Avanti-S?

[mszulen]

85mm wall to wall. Walls are vertical. Last few cm close to the connector box are bit narrower. Anyway, you have like 25cm long area with that width.

[Giovanni_L]

85mm wall to wall. Walls are vertical. Last few cm close to the connector box are bit narrower. Anyway, you have like 25cm long area with that width.

Thanks!

[mszulen]

Today we had a very nice and pretty warm weather (as for this season): 9 degrees C with lots of Sun and no wind.
Perfect weather for the maiden.
I've also the 80mm version so I'll be comparing those 2.

All settings as per manual. Battery 6s 5500mAh. Take off weight 3.9kg

First positive surprise: Plane takes off by itself without the need to pull the elevator (diving nose wheel of 80mm version was a nightmare to take off on grass compared to this).
CG seem to be pretty good (way better than original one of 80mm version)
Throws - as suspected - too much ailerons and elevator on low rate for me. Reduced by around 20% each. Now, the roll rate is ab. 0.8-1 rotation per second. Haven't tried high rates (most likely I'll program the original low rates as high rates).

After landing, I've noticed that the elevators are visibly down (from the zero point). I'm wondering if it's CG or something else.
I've also had to trim the ailerons to the right. Could be either the EDF torque or the flaps aren't 100% level (to be checked).

Landing was another surprise compared to 80mm version. First, I tried to land with a bit of throttle and full flaps. Plane just went through the whole runway and I had to go around. Second try was on zero throttle and only then it landed nicely (but still gliding pretty well).

Perhaps adding flaps would help to slow it down?

Second flight was to check gyro. Model was even more rock solid (this plane doesn't seem to need gyro at all).

Regarding the power system - 6s is definitely not overpowered It has nice vertical but pretty limited.
I'm going to swap the fans and use the 4068-1750kV version on 6s to see what changes.