newbie outdoor flight report:

1. today i would like to post some observations on how the moblite7 behaves in flight. i attempted a moderately steep dive from about 150ft and notice what seems like “washout” as the more experienced folks mention about whoop behavior. my earlier attempts at a shallower dive angle did not induce washout but today it happened which initially startled me as the whoop made an acute yaw to the left deep into the dive as i recovered! fortunately it did not smack the tree branches as i was close to trees during the dive. is washout a behavior common to whoops?

2. i am now beginning to notice that the mob7 does not exactly handle like its on rails especially during hard banked turns during high speed flight. there seems to be a tendency for slipping out of the turn where if you do not initiate an early turn approaching an obstacle then you may end up hitting it! is this due to the bi-blade props not gripping enough? or is it another whoop inherent behavior?

3. i also took the effort of glancing at the RSSI during flight making sure i do not crash into anything as i multi task! while i have a nice 90 reading during disarm, i get an average of 50-70 which is only at 15-20 meters away. i did a high climb almost overhead only to get an RX loss alarm on the OSD!! funny it actually worked but nonetheless startling. i would think RF unobstructed overhead should be fine but i guess not with this SPI rx.

4. RSSI goes into the 30-40 range or even dips momentarily into the 20s when i am about 50 meters away. while i would like to expect better, i suppose this is the fact on tiny board SPIs…

hoping the knowledgeable folks chime in! cheers!

You may have flown into your own prop-wash depending on how you went into the dive.

Bi-blade props are lighter and faster but the trade-off is less authority in turns. Pilots simply adjust their flying style according to the floaty feel of the quad.

You should try and experiment with tri-blade props to see if you enjoy that flight feel.

(09-Dec-2021, 11:31 AM)kafie1980 Wrote: You may have flown into your own prop-wash depending on how you went into the dive.

Bi-blade props are lighter and faster but the trade-off is less authority in turns. Pilots simply adjust their flying style according to the floaty feel of the quad.

You should try and experiment with tri-blade props to see if you enjoy that flight feel.

coming from a high altitude i started the dive shallow progressively going steeper. the undesired yaw action happened later into the dive as i was intitiating pullout recovery which startled me as i thought i lost control of the quad! are open prop designs more immune to this washout?

Try do the same move a few times to see if you can predict the yaw washout.

The flight characteristics are definitely different on open prop frames.

(09-Dec-2021, 01:39 PM)kafie1980 Wrote: Try do the same move a few times to see if you can predict the yaw washout.

The flight characteristics are definitely different on open prop frames.

i shall try that today! i may be asking too much from a humble tiny whoop to perform outdoors not even thinking if it is supposed to be able to do that. but what the heck this is my only training platform for the time being!

prop options!

btw i would also like to get anyone’s inputs as to what tri-bladed props i may try on the moblite7. off the bat i could try those used on the moblite6 since both whoops use the same AIO. hoping the folks chime in!

cheers!

With props I suggest you buy one set and test them before you order a whole bunch.

flight report for today:

as i fly the moblite7 more outdoors, i discover its unique quirks, behavior and performance limitations:

1. the jello i see may be generated by propeller vibration transmitted to the camera aggravated by the less than rigid whoop frame. in addition the bi-blade prop is not doing any favors as i begin to notice vibes only getting higher in flight with higher power settings. at altitude when i enter into a dive and cut the throttle setting, picture quality immediately improves as the vibes diminish at lower throttle setting.

2. as many suggested and sworn, a multi-blade may benefit my position in mitigating jello at the expense of additional drag and lower flight times. may be worth considering since 6-7 minutes of outdoor cruising is already long enough so the penalty may be deemed acceptable with the benefit of better video feed.

3. thank heavens for quads as they are uniquely stable compared to airplanes! i have induced the washout during dives in various ways. first off was dive recovery with a partial or steep bank where the washout was immediate. sort of like a high speed stall in an airplane. then i did a “level wings” dive recovery thinking this may work it but it still induced washout. hence i think its too much to expect of whoops to fly on rails as it recovers from high speed dives. had i done these maneuvers in an aeronatic airpane i may picking up the pieces instead of writing this report.

Whoops are generally considered to lower authority compared to other quads we fly in the hobby and whoops are not considered for freestyle per se.

3 blade prop an be very efficient if you manage your throttle well. They generate more lift capacity at a lower amp draw. If you are just drifting around and slow cruising, likely you will not experience a significant drop in your flight times. If you note high amp draw with them, either you are pushing your velocities more or the props are too aggressive (over-propping). Steeper pitch will offer more performance at the cost of amp draw…but you will also get quicker throttle response and “performance”.

Hi Hawk,

Consider that a small light weight quad, whether whooped or not, has different flight characteristics than
a larger quad, whether whooped or not. The lighter the quad, the more it will feel "floaty" since these little 
guys are affected by wind, turbulence, and other air movements. Even with the high revving motors, the
little blades are working hard just to get that "authority"

You could try a tri-blade and even a Quad-bladed prop. All of the "tiny" whoops originally came with 
quad-bladed props. Since you are looking for improved "authority", you might consider something like 
these 40mm spare prop for Mobula7 or these Gemfan 1636-4 40mm Quadblade props.
HQProp also makes a 40mm quad-blade prop. I would consider the Gemfan 1636 ones.

Just a thought. 

you have all sent a wealth of info greatly helping me understand the finer points of different quads and its limitations. i learned from past rc plane experience that a multi-bladed prop with an aggressive pitch will suck high amp draw compared to something with lesser pitch. so i got a tri-blade 35mm for the UZ65 which fortunately may have the same amp draw as the stock moblite7 bi-blade prop due to its smaller diameter and slightly lower pitch. i am lowering my expectations of the mob7 coz it has served me very well during the learning process of fpv. if the multi-blade prop does wonders it will be put to good use indoors where i will train for higher speed maneuvering. perhaps this will also mean the demise of poor moblite7 and the furniture bashing goes on once more!

i would also like to get your thoughts on my next move forward into outdoor fpv. i am now beginning to maneuver the mob7 checking to see its perfomance limitations. as i said earlier it does not want anything to do with diving at all! it will washout at all cost if you get a bit hard on recovery.

so i bought the happymodel crux3 as my outdoor trainer. i will not be very nice to this quad at all as i shall be doing the various maneuvers as i did with my 3d heli and airplane… or at least sort of in a quad manner.

a few things come to mind:

1. is this open prop design going to handle aggressive vertical dives with the latest of pullouts without the FC freaking out? of course i shall ease my way into doing it until i get a better feel for the crux3 handling. no pedal to the metal ion day1.

2. while it is rated for 1-2S only but the board itself i have read can take 3S?? is this true? or will the thing blow up in smoke just plugging in a 3S? i had to ask thinking such a low kV motor may still take 3S and just derate the throttle output in order not to fry the ESC.

3. does an open prop design really track like its on rails handling? coz the mob7 tiny as it is has to fly a certain crab angle just to hold its line against a very mild breeze.

4. any surprises i may expect handling and performance wise from an open prop design? as i heard these things fare much better than the whoops with their ungainly prop guards.

It will fly completely different than the whoop style, just something you will have to experience. You will be able to tune and set the Crux to fly the way you describe your desired result in prior posts. I feel you will be pleasantly surprised!

Vertical dives, like camera pointed directly at the ground and flying, or letting it drop by reducing the throttle while the aircraft is in a neutral attitude? Neither will bother the FC, but ensuring that AIRMODE is permanently enabled will help things a lot.

If they are recommending maxing with 2S, I would likely hold off testing 3S until I had another craft to fly after the potential result. You could likely get away with an HV (4.35v/cell) without any issues through. That would get you a little more at the top end of the pack. Even with your pack attached, you will still be around only 100gr, so 2S will likely not be a bore.

"tracking" is really a matter of tuning. I have my 7" tuned lazy and it loves sliding around, but it is a bit loose which I like for that aircraft. My Japalura is tuned tight and it handles like it is on rails. The stock tuning will likely be decent, so fly it. How it feels is subjective and you will likely discover tweaks that bring it more in line with your desires.

As light as that craft will be, it will be a rocket and you will likely get way better results (per your posted observations so far) with it. The micros have been my favorites since I started building them in my humble beginnings. In my experience, there is a weight point where they tend to not carry enough inertia for some maneuvers, but they are awesome in their own rights.

The main thing, enjoy it!

much appreciated inputs kaitylynn!

i have read a lot about “tuning” from many advocates and some who would rather fly and not mess with it, can anyone point me towards the quick and dirty “quad tuning 101 for dummies” if there is such a thing. while there are many to be found in YT videos, i would rather get info from the folks who are into the hobby who would swear by it.

on the get go, my looming fear of messing with PIDs among others is that i may end up with a F%@€D up quad in my lame efforts to tune one! i believe after learning how to fiddle with rates, expo then a thorough understanding of PIDs may be next thing to pursue.