14 replies to this topic

[GeeBee]

Well......good news/bad news. I had the chance to get my quad in the air this weekend (see my blog for build details). Everything went fine, except the quad had a tendency to pogo? I guess you would call it? I would be at a pretty stable hover and suddenly it would start rising straight up, I would correct the throttle a little to stop it and it would head straight for the ground, causing me to really correct the throttle to keep from crashing. Pretty exciting stuff! Could this be caused by my throttle curve settings? Any other ideas would also be appreciated. I have some video, but it's really bad, so didn't really want to post it. I ended up crashing into the side of my house, broke 3 props, so I'm temporarily out of business. I've attached my GCS settings.

 Quad Settings.xml   109.96K   6 downloads

[David J]

Have you flown a quad before? If not, then your flight is fairly typical for a newbie! (I was just the same).  Throttle control is probably one of the toughest things to manage when learning.

I cured this (mostly) by practicing in a simulator.

[astronutski]

Oh man if I had a nickel for every time I do this.....
Assuming David is correct and you are new, like I am, then yes, it's all pilot error LOL.
The sticks are HIGHLY sensitive, well, tons more than I was expecting anyway.  Which I guess is good thing to learn on.  It keeps your focus, demands full attention.
So yes, it is very easy to pogo until you get the hang of just how sensitive the sticks are.  Well, the throttle specifically.  You gotta think about it this way, you've got enough power to lift a lawnmower there so take it easy!

As much as I want to gun it full throttle on takeoff I'm still quite skerred to do so, but am working my way up slowly ;-)
Good luck keep us posted

Edited by astronutski, 21 February 2012 - 11:42 AM.

[Maineiack]

oh ya,,,ive murdered all my frames while learning that darn throttle,

I use a BIG car-wash sponge, cut in half now, strapped to the bottom of my frame, and black pipe insulation on my arms under the motors,
takes alot of the impact out of the landings, except if its wet out,
tends to soak up the water and gets heavy,,lol

or you could use, rolls of toilet paper,,,,did that,,too,,

[2400rdr]

If your transmitter has a sort of "ratchet" feeling on the throttle, open the radio and get rid of that little clicker spring on the back of the stick. It's really hard to have precise control of a heli unless the throttle is perfectly smooth and completely linear. That ratchet action is OK for planes and helps maintain throttle level while using the rudder, but it's no good on helis.

Also, as others noted, small, precise and continuous control movements are pretty crucial for heli flying. Maybe not so much on well stabilized platforms, but finesse still helps.

Rick

[GeeBee]

Thanks for the replys. I just wanted to make sure my setup was OK. Yes I'm very new to quads. I have my transmitter set up as a heli (no ratchet). I've been practicing with micro helis inside the house and have a single rotor (no collective) Blade for outside when it warms up a bit. I'll persevere. I'm allready planning to build a new frame for this quad and board. Thanks again.

[2400rdr]

GeeBee, on 21 February 2012 - 01:57 PM, said:

Thanks for the replys. I just wanted to make sure my setup was OK. Yes I'm very new to quads. I have my transmitter set up as a heli (no ratchet). I've been practicing with micro helis inside the house and have a single rotor (no collective) Blade for outside when it warms up a bit. I'll persevere. I'm allready planning to build a new frame for this quad and board. Thanks again.

Did you readjust the throttle curve in GCS like they suggest? That should make it a little less twitchy around mid throttle where your hover should be. I don't yet know how to read those XML files, so if you attached some screen shots of your configurations in GCS, it might help. BTW- I'm a beginner too, but I've managed to tune mine in so it's pretty flyable. Still a lot to learn though. I think that tuning the PIDs probably involves a little voodoo

Rick

[David J]

First time out I broke my heli-style undercarriage by bouncing all over the field!

Now my quad has Frankenquad 'Rib Bones', which are near indestructable...

http://www.hauntnet....b5db05d05ce218a

[GeeBee]

Rick, Yes I did set my throttle curve to that suggested by Matt in one of his posts. I don't quite understand the settings, but I'm wondering if I haven't missed the "sweet" spot for my particular setup. Once I get rebuilt and back in the air, I'm probably going to try adjusting my curve. As far as the XML file goes. like you I'm a beginner at this whole thing, so I used the GCS and exported my settings. I think that's the proper way to do it, but I'm probably wrong. I think to view it, you import the settings into your GCS. And I'm not even attempting to mess with the PID's yet!

[gs4322]

GeeBee,

Don't feel bad, I got into this hobby last year and a still  have a lot to learn. This forum is great, people have help me a lot.

I would suggest get  a flight Simulator, I use Phoenix. I did crash a lot in the beginning, bot now I hold my own. Also, I built a mini which I use indoor to practice. I have not broken a prop in months now.

Talking about props, I would recommend buy a bunch (tip from this forum). I had my share of broken props. Also, make sure they properly balanced.

For tuning, I read a lot of comments from the forum and the wiki site and ask a lot questions. This has help me immensely.

Before buying parts, I would ask the forum. I made my share of mistakes.

Always think of safety of others and your self.

Hang in there, this hobby is addictive. It may not make you younger, but its fun.

[AlPackin]

to export your UAV Settings

In the GCS goto Files>>Export UAV Settings
name the file whatever, it will save it with a .uav extension (not xml)
the .uav can then be imported back into the GCS if you want others to view it or you have to restore your CC setup

[Baz]

Hi GB
I was having the same problems you are experiencing with throttle control. And I thought it was due to my throttle curve settings.
But as everyone has said, it's more a case of throttle practise and getting the feel of it.
AlPackin-Mat, Seismic and others on the forum are a great help to us newbies.
I'am using a vic 450 frame so I attached large chunks of pool noodle to all four legs as shock absorbers for my heavy landings.
Then I had the idea of fixing squash balls to the landing legs after my landings improved. Great bounce factor.
I found a good method is to load up the frame, add some weight, this slows up the throttle stick response and makes it a bit easier to control while you are learning.
I also found that using a 2s lipo for practising landings and takeoffs decreased the power and made the throttle response a lot less touchy.
As a newbie, I have a long way to go, but watching some of the vids from members on here is inspirational.
So I will keep practising.
Cheers.

[David J]

I tried using the recommended s-shaped throttle curve - but in the end I found the standard straight line easiest to use.  It is more sensitive, but its behaviour is consistent, regardless of the battery voltage.

It's just a case of practice, practice and a bit more practice.  If the UK weather ever improves then I can get out of the back garden in the brief dry spells and into a proper-sized flying field, and maybe I can get some more real practice in as well!  A simulator is good, but you can't beat the real thing...

[GeeBee]

 GeeBee Quad.uav   8.94K   2 downloads AlPackin, Thanks! That's what I needed and David J, I'm leaning towards what you've done, a straight line. I think I would understand what's going on better with that setting.

[alacosta]

Hi, like many, new to all this but have built and tested X Quad and test flown and must say impressed. However my problem is the control ( sticks ) are to sensative very little movement makes drastic flying !!. My question is how to reduce the sensativity - is this done in the TX ie Travel adjust or with settings on the card. Any help and advice for this novice !! would be greatly appreciated