Quads Seem way too slow.. or heavy.

[coryshad]

I've tried every combination of motors, props, batteries, and pids, but it still feels way underpowered. Top speed seems right, but it takes too long to get there. And pulling out of a drop is where it really doesnt feel like a real quad. It takes full throttle to not slam into the ground doing tricks over the trees. I think maybe the quad is too heavy and carries more inertia then a real one, or just doesn't have realistic acceleration. A well equiped quad can do 100 meters per second per second acceleration, more than 10 times the force of gravity. If I punch out with my real vortex pro it stops falling virtually instantly. Is this something that can be adjusted that I'm missing? or does any one else share my sentiment?

[Boof69]

Join the discussion here: http://steamcommunity.com/app/410340/discussions/0/364039785169760658/

[LuGus Studios]

I guess this is a different one, as he is suggesting they are too heavy, not too floaty?

[Boof69]

Well then let me say that I don't agree that any quads are punching out , accelerating or flying in forward flight at 100 meters per second. That is 223.7 Mph/360Kph. Very high expectation indeed. The fastest claim I could find for a quadcopter of any sort is 93Mph150Kph. I do not agree that it falls immediatly after a throttle cut.It behaves like real life in that it will continue on it's path until gravity exceeds the decreasing velocity. This is actually the phenomenon that makes almost every aerial trick possible. Throttle up, cut throttle, execute maneuver, re-aplly throttle. The fact that I can do tricks in Liftoff confirms correct function. As for needing full throttle not to slam into the ground I am not experiencing that irl or in Liftoff. Throttle should be slowly applied during a fall to prevent this happening. I have made plenty of Liftoff videos demonstrating real life maneuvers and behaving similar if not the same. I would suggest trying different quad setups on the workbench and tuning with higher rotation rates and PID P values. This is essential for the best experience possible.
Here is how the sim is working for me for example. https://www.youtube.com/watch?v=s81yK4R7Kbc

[coryshad]

I never said it fell too fast. floatyness and gravity are a different discussion. I think the floaty feeling comes down to the precieved size of the surroundings. I've spent almost 150 hours playing liftoff, and i've mastered many tricks on here before doing them in real life. The flying and even the floating seem accurate enough to me. but what I'm talking about is the time it takes to overcome the force of gravity and start moving upward again. My math is sound on accelleration, and you are also right about top speed, that is my point. A quad reaches its max speed in a fraction of a second. Force (in newtons) = mass (in Kg) x acceleration (in m/s Square)... My latest build is a boltrc kraken 5x. AUW of 430 grams with 4s turnigy pack. Running zmx v3 2600kv, they put out a max thrust of 1400 grams each. 1400 x 4 motors = 5600 grams thrust. Take away the weight of the quad 430g = we get 5170 grams thrust. There is 102 grams in a Newton so just over 50 newtons force. now lets plug it in, 50 = .43 x Acceleration. Basic algebra leaves 50 / .43 = 116.3 m/s square, take away the force of gravity since we're going straight up. leaves 106.5 meters per second per second acceleration. Figure my quad maxes out at 100mph, thats 44 m/s so in less then half a second I'm traveling at full speed. I realise there is no super high performance quads in the game yet, and my vortex pro is much slower. But lets do the math, I'm running emax rs2205 2300s on it. max thrust 1200 grams or total thrust of 41.4N divided by an AUW of .58Kg = 71.4 m/s/s. So still it hits max speed in a fraction of a second.

When I take of from the gound, in game, and watch the altimiter it seems pretty close, but when I'm falling and try and arrest the fall is where is seems off to me. I've timed it at over a second before it stops falling and starts moving upwards again. I'll admit I dont know the terminal velocity of a quad, but it can't be more then 25m/s and even the heavy, real life vortex pro can stop and start moving back up from terminal velocity in .3 of a second.

I'm not dogging on the sim at all, I love liftoff. This is not meant to be a complaint. It's by far my favorite sim, and the most realistic for me. As i've gotten better as a freestyle pilot though I'm starting to feel the limitations. If it stayed in its current state indefinately I'd still be a happy customer. I'm just trying to help make it better. That is the point of pre-release, no?

I know how to fly too
https://youtu.be/3JVTlJUjgng

[Boof69]

Hi coryshad. I'm sorry if anything I said seemed argumentative in any way. I was simply sharing my sentiment about the sim as asked. Also by posting a video in Liftoff it was not my intension to imply you didn't know how to fly. It was to be in demonstration of how well a good tune in Liftoff could behave. So for the sake of not stepping on any more feelings I will digress. Nice flying by the way.

[coryshad]

No worries, and thank you. I agree with you on most points made, and I was simply trying to validate myself. Since I'm a noob on here, you have no way of knowing if I know what I'm talking about. I agree a good tune in liftoff flys awesome, and I owe my real world skills to the hours spent in liftoff.

Specifically I've been working on inverted yaw spins over trees, and proxy power loops. This is where the acceleration issue is noticable to me, the nature of these tricks means you pull out of them fairly close to the ground and alot of times it just doesn't have the power to not hit the ground. I thought maybe it was perceptual like the floatyness. but if you start at the top of an object, then zero throttle and fall while facing it. Then try and throttle out of the drop. You will see what I'm talking about. You continue falling a fair amount. About a second is what I found it took to come to a stop and start moving upward. A racing quad has more power then that.

I've been thinking about it and i wonder if it could be tied together with the people saying the game feels floaty. If it's the inertia that "feels" off it could be what I'm feeling as well as what people who complain about it being floaty are feeling. A baseball flies higher and consequently longer then a wiffle ball because it has more inertia. It's also harder to stop for the same reason. People think something heavier falls faster but that is not true, gravity accelerates everything at the same speed. So what feels like a light underpowered quad could actually be a heavy powerful quad since it would be harder for gravity to stop, and harder to overcome once gravity got it moving.

Another theory is perhaps it's ground effect with the props that's missing. IRL there is a pocket of compressed air under your quad that keeps it off the ground. And when you goose the throttle a pocket of compressed air is formed under the quad that it pushes against.

[LuGus Studios]

We've been getting a lot of feedback from the community about the flight behaviour. We are blessed by a community that's as passionate about the game and are willing to share their opinion about it.

The difficulty of this is that most of the flight behaviour feedback seems to be based on "feeling", often is inconsistent or sometimes just completely wrong. In the past, with every change we made there were always players who said "what did you do? It was perfect!" and other who say "its still completely wrong". A lot of feedback we get is based on personal opinions and a comparison between experience of a real life quad compared to our digital Vortex, that would not compare in real life either. It's like comparing your personal car to a car in a racing game, it's likely that they might feel different because they are likely different cars.

Liftoff does not "replicate" flight behaviour as some other drone games do, as a result we can't simply change a parameter to get fast results.
Liftoff actively simulates, based on physics, drone configuration, flight controller settings.. simply the combination of many factors and parts. As a results its very hard to get feedback like "its floaty" or "its too heavy" to translate in actual development action points. What we would need is someone with complete and detailed knowledge of the behaviour of every drone part, aerodynamics and real world physics to look at all are simulation systems in detail. To be honest, I think it's fair to say that our simulator programmer is one of the most knowledged people I know in this regards, as he's been researching and working on replicating it almost fulltime for a whole year. We've also worked with masterminds like BorisB, some great technicians at ImmersionRC and some amazing drone pilots. Ofcourse thats not going to change the fact that some people will still be very angry at us for everything we do.

[AESTHTK]

OK, let me try to simplify this discussion...

The difficulty I had starting off is tuning rates, PIDS etc. as well as tuning the work bench set-up. It becomes a multiplier of complexity, and I similarly struggled not to feel underpowered.

So - what is the the best workbench set-up for power to weight and throttle responsiveness?

Battery, props, motors.

If we can answer this, then it might help us to unpack these questions.

I love the modular workbench system (and it will continue to get better) but the current defaults and tuning requirement may continue to present a bit of a hurdle for pilots coming in and not spending the time to optimise their build.

Yes, it's obviously partly down to personal feel, but i'd love to know what Boof and Cory are using as their set-ups above so we can have an objective discussion on differences in preference... ;)

[Boof69]

I'm using the Lobster(Scorpion) motors. Spinning the Propfan(gemfan) 5030 tri blade. The nanotech 4s 1300mah battery. 40° of camera angle. I am using the default settings in the userData.xml. I have set expo on Aileron and Elevator in my Taranis to 60 and 50 on Yaw. I am running the "High" preset. Rotation is 900° on Pitch and Roll. 720° on yaw with these PID settings:


Pitch [ 2 ] [ 2.2 ] [ 0.02]


Roll [ 1.8 ] [ 2.3] [0.02]


Yaw [ 1 ] [1.2] [0.02]

Today after this discussion I set up a custom throttle curve in the Taranis that I feel makes the quad feel more responsive at lower values. It keeps the lowest throttle value to activate control at re-spawn but sharply increases in the first third then becomes linear. Here are some pictures showing the pertinent screens in the Taranis:
https://drive.google.com/open?id=0BwgIlsHXFf2bcHZOWXhmZHg5djA
Setup a new curve, Set it to "Custom" andt edit pints to values shown. Then select the new custom curve in the Trottle channel edit screen. It wil be applied to the special Liftoff setup automatically.

[coryshad]

I'm using custom vortex pro motors, jolt battery, 5050 triblade props (red ones) 50 degree cam, though I change angles alot because I have several quads set up for different types of flying and want to not get too used to a certain angle.

Pids are
Roll - 1.6, 1.5, .02
Pitch - 1.8, 1.5, .02
Yaw - 1, 1.5, .02

Rates are 1100 for pitch and roll, 750 for yaw. 1.5 expo on pitch and roll.

I have an idle up switch set up on my taranis to simulate air mode.

That's a great idea Boof, I'm going to give that a try. I've been thinking about just using some negative throttle expo. But yours seems better.

For some reason the lobster motors are terrible on my game. Not sure why, it barely gains altitude at max throttle. Maybe I should try a reinstall.

[AESTHTK]

Yep, I had set up a custom controller model as well Boof.

On quads i'm used to operating mostly in the bottom 50% of my stick and in Liftoff i'm having to push it up to 70-80% and finding it harder to react fast enough, especially accelerating through corners.

LuGus - maybe something to think about with the throttle curves and settings here... and hopefully this describes 'the feeling' a bit better.

[Boof69]

Originally posted by coryshad:

I'm using custom vortex pro motors, jolt battery, 5050 triblade props (red ones) 50 degree cam, though I change angles alot because I have several quads set up for different types of flying and want to not get too used to a certain angle.

Pids are
Roll - 1.6, 1.5, .02
Pitch - 1.8, 1.5, .02
Yaw - 1, 1.5, .02

Rates are 1100 for pitch and roll, 750 for yaw. 1.5 expo on pitch and roll.

I have an idle up switch set up on my taranis to simulate air mode.

That's a great idea Boof, I'm going to give that a try. I've been thinking about just using some negative throttle expo. But yours seems better.

For some reason the lobster motors are terrible on my game. Not sure why, it barely gains altitude at max throttle. Maybe I should try a reinstall.

I would suggest you stay under 40° of camera angle as per the advice of Mr. Steele and FinalGlideaus. The Lobsters are great with the 5030 tris for me. The more aggressive props prevent the motors from spinning up in time t catch he fall.
I would suggest using more aggressive PIDs this does have an affect on throttle.
I would make one further suggestion that you set your rates to a number divisible by 180.
I have found that doing this allows for rotation to stop easier on the original angle as before the rotation or 180° out. That way you can train to count seconds or parts of seconds while holding a stick command.

[coryshad]

Trying to learn those mattystuntz tricks though haha. Yeah I hear ya, normally I'm at 35 degrees. But I have a new pure X frame with a pod on it that needs like 45-50 degree angle to not just dissapear into the stratosphere, so I've been practicing at those angles. I've never considered that about rates. I picked that because my real quad rates are 1108 degrees a second and I wanted it close. When I turn up the PIDs I get wierd behavior at these high rates, after a snap flip or roll the quad slowly rebounds the opposite way of the move. if I lower PIDs it goes away but the end of the move is sloppy.

[OverDrive]

This may not be useful to the discussion, but when I fly with FPVFreerider (recharged and normal), it feels much closer to how it feels when I fly in real life. I just can't lock in the right settings with liftoff to enjoy it, even though it has features galore so I really want to like it.

[Boof69]

It does take more tweaking than free-rider but that just means there is more room for individual setups. I personally disagree with any argument that free-rider is better in any way but that's obviously just preference.