Unable to make quadcopter lift off ground

likwidchz · Post by **likwidchz** » Sun Apr 08, 2012 6:21 am

Hi everyone,

The problem : 2 of the 4 motors spin like no ones business when I throttle up, and the other 2 just do whatever they want.

What I have tried : Looking over the code again not knowing C like a boss "like I should" not sure how to diagnose it all.

How I tried to solve the issue : I looked over the code... not sure.. Thought my motors were faulty, I connected each channel to my receiver and they throttle up very well.

This is the code I have edited

Code: Select all

#define QUADX
#define RCAUXPIN8
#define CRIUS_SE

I have a T7C transmitter, the receiver is connected properly, although I do not know why 2 motors dont seem to work quite right??

On a side note, what all do I have to enable to get 3-4 mode switching inputs enabled on the MultiWii ? I see how to enable 1 additional input with

Code: Select all

#define RCAUXPIN8

Although I plan on needing 4 more inputs when I switch this to a turnigy 9x setup with 8 channels.

Thanks guys,

Hopefully its one of those "Stupid problems"
--Aaron

bill516 · Post by **bill516** » Sun Apr 08, 2012 1:10 pm

Have you calibrated the max min for each esc. Cant help you with a Crius board but the pro mini uses pins 3 9 10 and 11 as the outputs to the motors you dont need to enable anything other than define the type of copter, are your motor signals lines connected to the right pins.

likwidchz · Post by **likwidchz** » Sun Apr 08, 2012 5:37 pm

I'm not sure what you mean by calibrated the min and max?

I see that the max is 1850 by default can go up to 2000
I set the min at 1000 as my tx/rx combo can put out a 900 micro second signal

ANy other ideas?

I know, on things like this its always something very minor and overlooked.. I just don't know what that might be.

--Aaron

bill516 · Post by **bill516** » Sun Apr 08, 2012 10:27 pm

Calibrate max and min is so the esc knows what the throttle max and min values are and nothing to do with the multiwii sketch. If you look at the instructions for an esc, if you have any, it tells you to connect the esc and motor put throttle to max and switch on Tx, then when it beeps move throttle to min you will get some more beeps when you have done this and the esc is calibrated. Switch off Tx and then when you power up again throttle at min as usual you will find that the motor will now respond to the throttle movement. You have to do this for all the esc's individually not all together, it might work sometmes doing them alltogether but one by one is sure fire.

Because Tx's are different for each make you have to be able to make the max min in the software adjustable so you can get full range of operation. If it wasnt like this some Tx's might only move half the value in the software even though the stick is moved fully one way.

likwidchz · Post by **likwidchz** » Sun Apr 15, 2012 11:05 pm

This isn't the problem.

When I connect a receiver to the motors individually they all respond.

I'm not quite sure what the deal is honestly as within the GUI it shows all 4 motors responding when I rotate the quad copter around to various positions. two of the motors do not seem to respond correctly and I'm not sure what the problem is it seems really trivial. Do you have any other ideas?

--Aaron

refractions · Post by **refractions** » Mon Apr 16, 2012 8:43 am

Have you tried connecting the 2 "faulty" motors to the "working" motor outputs? eg if top left isnt working, but top right is - swap the leads to the esc`s and see if the motor responds - this will rule out the motors and esc`s.

Iain

likwidchz · Post by **likwidchz** » Mon Apr 16, 2012 2:58 pm

I have connected the receiver to the motors individually and they all throttle up perfect.... However I will swap the motor leads like you say and see if anything is different. I expect the same problem honestly.

It has to do with the signal from the MultiWii Board thats getting output to the esc's..shouldn't I be able to connect a servo to each of the 4 motor output channels, when I throttle up the servos should start turning, then when I tilt the copter the servos should change position?

PatrikE · Post by **PatrikE** » Mon Apr 16, 2012 8:05 pm

The pwm on motorpins is 490hz.
Normal servos use 50hz.

The servos can be destroyed if you connect them to 490..
Digital servos can usually handle it but not analog servos.

likwidchz · Post by **likwidchz** » Tue Apr 17, 2012 3:13 am

Alright thanks for the Info Patrike, however I'm not any closer to figuring out why this has issues, could someone fill me in on more things I can test?

I'm really at a loss, the config I have is so miniscule I can't think why it doesn't function.

Thank you,
--Aaron

bill516 · Post by **bill516** » Wed Apr 18, 2012 9:32 am

You might try telling us what you have in your quad, motors esc's, sensors and board, see if there is something amiss there.

Have you swopped the motors over that was suggested in an earlier post. Without that info we wont know if it is a problem with the motors or esc's, if the same results after swopping then we can rule out the motors and esc's and look to the board or whatever you use.

likwidchz · Post by **likwidchz** » Fri Apr 20, 2012 2:43 am

Hi,

I have tried to put on on two different versions of the code, quadX and quadP thinking something was slightly off with that ... however not the case.
The code I have is very very minimal, I enabled both aux inputs
and set the board type, MultiWiiSE, along with setting min throttle.

I have also calibrated the gyro, and mag, along with the accelerometer.

Seeing as two motors performed differently then the other two I have tried disconnecting them and connecting them individually to channel 3 of my t7C "throttle" and throttled them each up, each motor performs how it should..LOTS OF AIR COMES OFF IT! I have one of those Programming cards for the turnigy ESC's but have not attempted to use it..all of the esc's perform the same way when directly connected to the receiver.

Turnigy 2213 22turn 924kv 17A Outrunner
TURNIGY Plush 25amp Speed Controller
ZIPPY Flightmax 5000mAh 3S1P 30C
MultiwiiSE
T7C receiver/transmitter.

I know this is a long shot but is it a stretch that the output pins on the MultiWiiSE have issues? Humor me... I don't know.
You guys are the experts..

Thanks a bunch,
--Aaron

bill516 · Post by **bill516** » Fri Apr 20, 2012 9:37 am

I would use your programming card first it might make all the difference, you will get a visual indication that all esc's have the same settings. After you set the esc's retest and see if it has made a difference, cant remember if you need to reset max min again after programming.

If the prog card doesnt make a difference you need to do what refractions said in an earlier post and that is swop the esc's to different motors. Connecting them individually to the rx will not tell you anything unless you have some way of measuring the rpm's and the thrust, lots of air comes off it is not a valid test, how do you know if you are producing 1Kg of or 1.5Kg thrust. If you swop the esc's and fault moves with it then the esc's are at fault, if the fault stays the same then the motors are at fault. Had a look at the motors on HK are you sure you have got 4 motors the same, looking at HK they have two 2213 motors but the difference is number of turns and the wrapperon the case, it would not be a suprise if you had mis-identified motors. The only way you will really know is by re-winding so they are all the same, or do as below.

The only other thing you can do is make a thrust stand (http://www.rcgroups.com/forums/showthre ... rust+stand ) you dont need anything as elaborate as in the link. A see saw/teeter totter with motor at one end and scales at the other end, just make sure the pivot piont is relatively friction free, and measure the thrust of each motor with each esc, that means 16 tests.

You can test the multiwii by swopping the motor signal lines but only after you have ruled out the esc's and motors.

bill516 · Post by **bill516** » Fri Apr 20, 2012 9:38 am

I would use your programming card first it might make all the difference, you will get a visual indication that all esc's have the same settings. After you set the esc's retest and see if it has made a difference, cant remember if you need to reset max min again after programming.

If the prog card doesnt make a difference you need to do what refractions said in an earlier post and that is swop the esc's to different motors. Connecting them individually to the rx will not tell you anything unless you have some way of measuring the rpm's and the thrust, lots of air comes off it is not a valid test, how do you know if you are producing 1Kg of or 1.5Kg thrust. If you swop the esc's and fault moves with it then the esc's are at fault, if the fault stays the same then the motors are at fault. Had a look at the motors on HK are you sure you have got 4 motors the same, looking at HK they have two 2213 motors but the difference is number of turns and the wrapperon the case, it would not be a suprise if you had mis-identified motors. The only way you will really know is by re-winding so they are all the same, or do as below.

The only other thing you can do is make a thrust stand (http://www.rcgroups.com/forums/showthre ... rust+stand ) you dont need anything as elaborate as in the link. A see saw/teeter totter with motor at one end and scales at the other end, just make sure the pivot piont is relatively friction free, and measure the thrust of each motor with each esc, that means 16 tests.

You can test the multiwii by swopping the motor signal lines but only after you have ruled out the esc's and motors.

likwidchz · Post by **likwidchz** » Sat Apr 21, 2012 2:35 am

Alright I had no idea what the problem was, although it has to do with the following items if not All of them.
Honestly I'll admit fault. I needed to get all channels configured to 1000-2000 1500 centered, I thought I did this eairler however they were 947-2100... so I missed something there.
Once I did that within the GUI I disconnected the MultiWii board, connected the RX to each motor and set the max/min rate from what you said on an earlier post.

I have one remaining problem,
I have followed the guide to attach the props two right hand two left hand and oriented the quad in the correct position while I connect each of the 4 pins to the controller board, however I notice one motor spins the incorrect direction, I do however have the correct prop on the motor for the direction its suppose to spin within the motor connection diagram. so I'm not sure what's going on, that pin is D10.

How do I enable Aux 3?

Thank you bill

--Aaron

Pyrofer · Post by **Pyrofer** » Sat Apr 21, 2012 9:48 am

Just swap any 2 of the motor wires on that motor, job done.

likwidchz · Post by **likwidchz** » Sat Apr 21, 2012 10:03 am

Thanks Pyro,

How do I enable Aux3?

--Aaron

bill516 · Post by **bill516** » Sat Apr 21, 2012 11:38 am

At least your moving forward, I would never have thought to check the Tx settings so good for you on finding that. Cant help on the Aux3 though I'm still using v1.9.

likwidchz · Post by **likwidchz** » Sun Apr 22, 2012 4:10 pm

Yes moving forward!

Alright I took it out for its first flight and the copter did a bit of a horizontal to slightly vertical and then scraped some props and I went "OH SHIT" and turned it off...I don't actually know what to do now to verify what could cause this problem. buying a scale isn't a bad idea by the way.

What should I do?

Thanks,
--Aaron

bill516 · Post by **bill516** » Sun Apr 22, 2012 5:01 pm

No matter how good a builder we are there are always variables that cannot be taken into account so it is unlikely you have a perfectly balanced model, although it does happen. This why you need trim, you dont say if you were in gyro or accro mode but you need to start in gyro mode and trim. That is using the trims on the Tx, you can get a rough idea of trim by using the GUI, and matching the motor outputs then do a flight test adjust trims as needed. Once you have it trimmed in gyro mode then is time to start trim in accro mode. Trimming in accro mode means you have to try in in flight then land go into accro trim mode, adjust and try flight again. As with gyro mode you can get an rough idea of trim needed by using the GUI and matching motor outputs but the final settings will only be realised by flight trials.

I dont need to tell you to take props off if trimming in GUI do I.

Trimming needs to be done in still air early morning or later in the evening are the best times unless you have a very still day, or access to a large indoor area.

Not sure if I am right in saying, but I'm sure I read if you calibrate your acc it looses the settings you have arrived at. So if you calibrated acc after you have trimmed in accro you will lose those settings.

likwidchz · Post by **likwidchz** » Tue Apr 24, 2012 2:23 am

Bill, I'm using
Newbies guide to CRIUS MultiWii SE board and software.pdf

I'm not sure if the default values are way off, Should I take the values from that pdf and put those in for every thing?
Pitch
Yaw,
Alt,
Alt/velocity
Level
Mag?

Maybe I need the "TOTAL NOOB guide" or something. I enjoy building things! but I like building them so when settings arnt right they dont go smashing into walls and breaking parts :\ like to be pretty close the first time if you know what I mean.

And looking at the screenshot those are my default values, the copter basically lifts off and flips, luckily I didn't break a prop. I already broke one on the carpet!

This why you need trim, you dont say if you were in gyro or accro mode but you need to start in gyro mode and trim. That is using the trims on the Tx, you can get a rough idea of trim by using the GUI, and matching the motor outputs then do a flight test adjust trims as needed. Once you have it trimmed in gyro mode then is time to start trim in accro mode. Trimming in accro mode means you have to try in in flight then land go into accro trim mode, adjust and try flight again. As with gyro mode you can get an rough idea of trim needed by using the GUI and matching motor outputs but the final settings will only be realised by flight trials.

I dont need to tell you to take props off if trimming in GUI do I.

Trimming needs to be done in still air early morning or later in the evening are the best times unless you have a very still day, or access to a large indoor area.

Not sure if I am right in saying, but I'm sure I read if you calibrate your acc it looses the settings you have arrived at. So if you calibrated acc after you have trimmed in accro you will lose those settings.

Can you expand a bunch on all that?

I'm not sure what looses settings and what doesn't.

Thanks --Aaron

bill516 · Post by **bill516** » Tue Apr 24, 2012 10:39 am

Have you looked at the links at the bottom of the connecting elements tab. There is some good info in them of setting up and what things mean, its worth a read if nothing else as the multiwii has progressed a great deal since there were first written but that are still as valid. They really take you back to basics whereas a lot of people and things have moved on since then, not me by the way I'm a dinosaur, still stuck in the past.

The default values are as you have in your screen shot, so in theory your quad should fly with them, but theres always a but. You may need to reduce the rc rate to get it to be less twitchy, I'm sufferng to same problem at the moment after making some changes to my tri. I might get to have a go at tweaking today as the wind seems to have died down and the rain has stopped.

I'm sure you understand the concept of trim but if not. Trim is a way of neutralising any descrepancy that may have been built into an aircraft at manufacture, i.e centre of gravity is not where is should be due to variance in materials etc. To us, props may balance perfectly but there may be a difference in weight, same with motors, add this to where we fit them in you a/c, at the end of long arms then that weight is multiplied. Trim is the method by which we counteract that weight difference so the a/c flies straight and level hands free, or in our case hovers, its not really hands free but enough so you can take your hand off the stick to flick a switch or scratch your nose .

If we didnt have gyros we would be forever fighting to stay in the hover, gyros re-act quicker than we can as they sense movement before we can see it and re-act. In accro mode we en-able the accelerometers which detect any movement from the set attitude, so a gust of wind from the left would cause the a/c to move to the right but the gyros and acc will detect that and compensate keeping the a/c steady ish. It wont stay exactly where it is as you need other references for that i.e compass, altitude and gps, but it will stay level. We dont need to worry about gyros as they are calibrated at power up of the a/c, but they do drift over time. The accelerometers need to calibrated at least once to let the sensor know what is level, if you calibrated on a slope it would take that as being level and you screen display would show as level. If you tried to fly in this condition you would be forever flighting to keep it level as we see it but it would always want to revert to its "learned" level, calibrated on a level surface and our level would be the same its "learned" level. Once we have a level we all agree on then you need to trim out the dispcrepancies that we had to trim out in gyro mode. Prop up one side of your quad and calibrate, you will see the pitch and roll indicators come to level, take the prop away and the roll will move to one side saying its not level, re-calibrate and all will be well.

I'm not 100% sure if I'm right on this bit but by trimming the acc we are now telling it that the level it "learned" is not quite right so we adjust it. Lets say the left side was heavier than the right, the a/c will always want to tip to the left, when we trim the acc what we are in effect doing is telling the accelerometer what it thought was level, is tilted to the right and it needs to tilt to the left. Now when we fly and the a/c wants to tip to the left because of the weight the acc will see it is moving away from level and counteract it. This trim setting is held in the arduinos eeprom so when you power up the settings will there, if you re-calibrate your acc you wipe those settings out and you will have to enter the trim via the sticks again.

Tx trim tells the Tx what the true pot center for the selected a/c is. settings are kept in Tx memory and dont change unless you move trim switches
Acc Trim tell the accelerometer what true level is for selected a/c. setting are lost if acc is recalibrated.

Hope that clears things up for you, more importantly I hope I'm right, I'm sure someone will point out my errors if I'm wrong.

Update on my tri. I had an intermittant connection to my nunchuck which caused me problems, I couldnt clamp the nuchuck and wmp down without the nunchuck going off line. I found a duff joint I can now clamp wmp and nunchuck down and it is not affected by vibration. Clamping it down has stopped the problem I had with it wanting to flip over every time applied power as the wmp and nunchuck are very sensitve. I also reduced the rc rate to .60 which made it more docile, now I've got to get back to tunning pids but at least I have sorted my main problem the flipping.

Have you had you quad hooked up to the GUI and watched the sensor trace without props it safer, unless you feel confident to hold it in your hand with props on. You shouldnt need full power to test the vibration with it in your hand, if its vibration the quad will be trying to twist itself out of your hand at about half power or less. With it hooked up to the GUI and the display resembles a heart monitor in panic then you have vibration prolems which will cause your quad to flip, if its nearly a flat line your looking good. If you have vibration under control and trim baIanced you will feel it is very firm in your hand and it will resist you trying to move it esp in pitch and roll, I can get mine up to about 3 on the display before I see any bad peaks and it doesnt want to try and turn round an bite me when I hold it. A flat or almost flat line is king to a stable machine.

likwidchz · Post by **likwidchz** » Sat Apr 28, 2012 6:53 pm

Thanks for the lengthy reply!

I had balanced the props with some tape on each prop using a paperclip taped to the edge of a desk and tossed the prop on it.

So I did a bit more testing, this time in a house and realized that the trim adjustment was SO MINOR... literally less then 5 clicks on my t7C that I thought something was wrong until I adjusted it.

OK now onto the next bit, I'm not sure what to really adjust although the best I can explain is the copter wobbles when attempting to hover.. imagine putting a plate ontop of a basket ball and having the plate off center about 10 degrees and then attempting to rotate around the axis off set.

Make sense?

I dont really know which P values to start tweaking!

Hey.. slowly but surely! Kinda excited I had it hovering for about 3 seconds before I landed it

--Aaron

bill516 · Post by **bill516** » Sat Apr 28, 2012 10:21 pm

In the house may be causing you the problems, if the room is not big enough you are creating your own turbulance which is coming back to your copter and making it unstable, also depending on how high you are you might in ground effect. Ground effect is basically a cushion of air that you are trying to balance on top of, get to one side of it and you will fall off. How high this cushion is varies with the size of a/c and the type of ground, hard ground, concrete tarmac etc will give a higher cushion than grass, even grass will have its differences depending on how long the grass is. It is good to learn to hover within ground effect as you have to go through it to get back onto the ground, unless you do it quick the way but tends to break things.

PID tweaking is a dark art and something I am not fully sure of at the moment. There is a link in the faq section to pid theory and tuning, I have read it but it made my head hurt. I read somewhere that you increase P until it wobbles then back it off till its stable again. I cant remember where I read it or what the rest of it said, I think it was on this site the guide by shikra seems to be a good place to start link on the faq page.

likwidchz · Post by **likwidchz** » Wed May 02, 2012 3:25 am

Thanks for your help thus so far, honestly I need to probably put it in a garage and increase throttle a bit until one side doesn't pop up before the other. Hopefully my trims wont be horribly off.

As for another question to anyone who is listening, how do you get all 4 Aux inputs to work? I can only get two.

--Aaron

PatrikE · Post by **PatrikE** » Wed May 02, 2012 11:01 am

likwidchz wrote:As for another question to anyone who is listening, how do you get all 4 Aux inputs to work? I can only get two.
--Aaron

You must use PPM-reciver to ba able to use all AUX channels.

likwidchz · Post by **likwidchz** » Thu May 03, 2012 1:24 am

Thanks Patrick,

I have a Turnigy 9x and one of the cheep FS-R8B rx's and I've taken it apart and can't find the PPM out on the board so, I'll post on another forum.

--Aaron

likwidchz · Post by **likwidchz** » Sat May 05, 2012 10:07 pm

Alright.

I'm kinda not sure what the problem is however I'll explain whats happening.

I turn on the copter and give it some throttle and two motors seem to push more air then the other two. so I use the trims and compensate in the opposite direction, this does not help as drastic as I would like it.

one idea would be to get 4 "crack scales" or whatever and weigh the copter on it and read all 4 values and almost compensate by adding on weight? Someone else mentioned a scale to measure the output of the motors.

I know a copter cant be perfectly balanced but I'm running out of ideas. And since I'm testing this on the carpet in a house I have broke some props, now I ordered 6 sets of 8 "SO I WONT HAVE TO DEAL WITH THIS" I'm down to my last two and they are CW and one CCW so I hope if I break two its those two.

also I ordered the Turnigy DIY telemetry module along with the receiver that has PPM out, as I'll need to get those aux channels functioning.

Although as for getting this working is there a way to get your settings dailed in without breaking props? other then on grass and away from hard objects? ... I almost want to make something that goes around the props... i need some ideas..

Maybe what I need is video of this thing and input from you guys? what do you think.

--Aaron

Pyrofer · Post by **Pyrofer** » Mon May 07, 2012 9:44 pm

Ok, Power it up WHEN LEVEL on the ground.
Connect via serial and calibrate the acc.
Center your manual trims, do the roll/pitch trim via the controller.

Pick up the quad. Hold it SAFELY in your hand, and make sure all your bits are clear of the props. Hold on tight and arm it.
Slowly give it throttle so you can feel how its pulling. It should not be lifting any more on any one side than than the other.

If it still does...
Unplug all your ESC servo wires. plug them ONE at a time into the throttle channel and calibrate the power by turning on with max throttle, drop to zero and then power down. Do this for each esc.
Verify this by removing all the props and check each one directly on the throttle channel to see if they spin the same speed.
I would advise that you buy a Servo tester. These have 5 sets of pins connected together so you can calibrate the throttle on all 4 at the same time.I did this, it also helps test without getting the RC bit or controller involved.

bill516 · Post by **bill516** » Tue May 08, 2012 8:43 am

Thought occured to me last night, where is you CofG it should be bang in the middle for a quad or as near as. To see where it should be take a string and pass it from from opposite motors where they cross should be your CofG. That is the theoretical CofG your actual CofG might be to one side/forward or rear of that, move battery to compensate if you can. If CofG is spot on then you should need very little trim.

likwidchz · Post by **likwidchz** » Fri May 25, 2012 2:17 am

I was outside fiddling with this for a while and the trims are very strange..

it wants to lift off and immediately tilt left so I give it a couple clicks to the right to compensate which seems like it does nothing then I lift off and it drifts one direction so I compensate and it doesn't want to hover.... This is kind of a shot in the dark.. I'm kinda looking for a guide on how to set all the values initially P/I/E values.

I guess what I'm looking for are default values, then an order of what to look for increase/decrease and what not..

Maybe first I need to adjust the trims ?? I wouldn't mind talking to someone on skype to avoid 100 forum posts to get this thing ironed out.

Thanks,
--Aaron

bill516 · Post by **bill516** » Fri May 25, 2012 2:56 pm

Reduce rc rate to about .6, rc rate at .9 is nearly as twitchy as you can make it. Just have it in gyro only mode no acc or other sensors active at the mo, then either set up Tx trim in flight or land and trim and fly again until you get hands off or nearly hands off hover.

likwidchz · Post by **likwidchz** » Mon May 28, 2012 5:20 pm

Perhaps a dumb question...

"Just have it in gyro only mode no acc or other sensors active at the moment""

How do I do this?

Thank you,
--Aaron

bill516 · Post by **bill516** » Mon May 28, 2012 7:45 pm

For gyro only mode you dont click on any of the check boxes to active the sensors. When you come to enable sensors if you have a three position switch then you can set aux 1 i.e. Stable to low, which is the acc, mag to mid and baro to high, gyro is on by default or whatever combination you choose. If you just have a two position switch then you use aux 1 and aux2 and use two switches on your Tx. If you select all three boxes for one sensor then it will be on all the time i.e Stable, copter will always be in stable mode. Dont forget to click on write after you have made or changed selections in the check boxes, failure to click write will mean the settings will not be written to the controller and you will be coming back here saying my stable mode or whatever doesnt work, its been done before.

likwidchz · Post by **likwidchz** » Fri Jul 06, 2012 9:10 pm

Hi Bill,

Long time since the last update/post

I ended up connecting a FRSKY D8RSP to my quad and enabled PPM mode.. lets just say I like this a lot better and I get all 8 channels.
On to business.

So it turns out setting my rc rate to .6 from .9 helped, except I had to lower it even further to .48 and its probably going to be somewhere between .40 and .55 for the sweet spot.
After playing with this in the front yard trying to set trims it toppled over and it broke one of the arms... which is totally no bueno.

Is the RC rate one of those things that if the sweet spot is lets say as an example .50 on either side of the value .55 or .45 that it will be wobbly? there does not seem to be a complete guide on how to adjust values and what to look for, it's kind of annoying I see all these quad copters in videos and people build them and they just work fine. Is there a step by step guide on what to adjust first, then what to look for while adjusting, then once that value is set what to move onto next?

I ended up getting this multi wii configuration LCD that I have no idea what to do with maybe you could be of some assistance?

do you have skype? or does anyone have skype that could help me with this... I can't imagine it taking that long but communication via forums for ... well what I think seems to be completed is kind of difficult.

So, possibly glue them or order some more arms just for fun I enabled ACC mode and didn't really notice it doing much on or off on my copter.

Thanks a bunch,
--Aaron

bill516 · Post by **bill516** » Sat Jul 07, 2012 11:51 am

Well your going in the right direction, glad you reduced the rc rate down before you flew imagine what it would have been like at .9. The only reason I suggest .6 is that is what I fly at and that is probably because I have been flying helis and they are a totally different nightmare altogether.

If you flicked from acro to stable mode and didnt notice a difference that is good it means the trim difference between acro and stable is nil or as near as. The only difference between the two modes is stable mode self levels if you let go off the sticks. Only flight will really tell if there is a difference, but if you have it trimmed in acro mode then its just a quick flick of the switch and you know you can control it again if it does something unexpected.

I found that when trimming my copter I would hover see what stick position I needed then land and moved the Tx trim, if I did it in flight I was always looking at the Tx to find the trim switch and lost control of the copter broke a few props that way. Once you get it somewhere near then it is easier to do in flight as it doesnt move around as much, then when you get it spot on it just sits there hovering and you think well that was easy. I also found it easier to sort the Yaw out first as that way I could take my hand off the throttle to adjust or flick any switches.

A step by step guide does not exist for these copters basically because there are so many different types but a rough guide is
Read everthing you can about multicopters, a very goodplace to start is the home page of MultiWii.com
Buy the bits and build copter.
Calibrate ecs's.
Verify correct opertation of gyro and acc, baro and mag (if fitted) in GUI, adjust sensor orientation if required in config.h.
Verify motor rotation and trim in acro mode using Tx trim and GUI to balance motor rpms. If props fitted be very careful.
Check and cure any vibration problem before proceeding. Very important to do this as you wont get a stable copter with vibrations.
Reduce rc rate in GUI to .6 or lower to make it less responsive.
test fly and adjust Tx trim as required.
Adjust acc trim in GUI to balance motor rpms, requires use of stick trim function,or use the in flight method, quicker and I think easier,
http://ncopters.blogspot.de/2012/04/how ... on-in.html a good guide for inflight calibration of acc.
PID leave P at default reduce I and D to zero. Increase P until copter oscillates then reduce it a bit. Repeat for I and D. This is where it comes down to an individuals copter and type of flying as to what setting are required.
MAG Baro and GPS cant help with as I havnt got them sorted myself, hard to fly without props.
LCD havnt got that yet either still waiting for the slow boat from China.

What I have written above is a very condensed version of the Connecting Elements, Software, FAQ's and various links on the home page. I think I have put all the steps in a logical order.

likwidchz · Post by **likwidchz** » Sat Jul 07, 2012 8:54 pm

If you flicked from acro to stable mode and didnt notice a difference that is good it means the trim difference between acro and stable is nil or as near as. The only difference between the two modes is stable mode self levels if you let go off the sticks. Only flight will really tell if there is a difference, but if you have it trimmed in acro mode then its just a quick flick of the switch and you know you can control it again if it does something unexpected.

I lied actually, looking at it again there is a large difference :\

I'm taking a laptop outside none of this running back and forth to adjust this nonsense... hopefully I'll get somewhere.. I ended up ordering another quad copter and going to order some more brackets so this one will be the beat up one... the frame is 30 bucks!@ its funny.

I also ordered about 20 props too..... just to make sure, I also want to make some sort of frame around the props and top so they don't get all beat up every time I take a sub 3 foot fall...

I'll poke around with it more, thanks... honestly it seems like this shouldn't be this difficult you know?

Dave66 · Post by **Dave66** » Mon Jul 23, 2012 8:31 am

I'm using the SE board, it flies great. What size props, how much does it weight, is it putting out enough thrust for the weight (including that 5000 battery)? You want about 2:1 on power to weight. From reading the posts it sounds like the rest is ok. I would install 2.1, center all trims, subtrims, etc, and soften up the ail/elv stick. Leave the default pids in place, almost any quad will fly with these numbers.

Read and understand this (you may have already): http://fpvcentral.net/wp-content/upload ... -22-12.pdf

The first few times you have to lift off quickly to 4-6 feet, level off for a few seconds, then land. Too close to the ground and the gyros (and you) are fighting ground effect, after awhile skimming the ground will be easy, but not now. Adjust the Tx trim and try again.

Once you can hover I would enable Headfree and Mag at all times until you feel good about heading control, it will save you.

To protect your props goto Hobby Town USA and enter "training" in the search box. See the kit with the rod and ball setup? Mount the rod under the arm of the quad with the ball extending beyond the prop. I used these on helis and my first quad. Good luck

likwidchz · Post by **likwidchz** » Wed Aug 08, 2012 2:58 am

Hi Dave,

The problem I'm having which... well It seems like a problem... I havent been able to get the thing hovering at all it seems to drift forward when I give it throttle.
Looking at a few guides they say "adjust trims" and not adjusting it on the transmitter... which makes sense, as it seems like that is for very very fine adjustment.

SO the guides say do the inflight ACC calibration when I try this nothing happens, after looking in the config It mentions to uncomment "#define INFLIGHT_ACC_CALIBRATION" when I do and hit compile it shits on me and then says
compile error on the SENSORS tab on line 'toggleBeep = 2; //buzzer for indicatiing the end of calibration"

http://pastebin.com/xRyeZawx that is a link to my config, I'm not sure what the next step is.. the SE from the looks of it does not have a buzzer on it as far as I can tell...??

I honestly know the problems I have had with this have been probably very very minor and could be figured out in about 10 minutes with the right person helping me.
this is one of those stupid problems

Thank you Bill, Dave,

Honestly at this point it might be good for a skype call or something?? wouldn't take too long I'm sure of it.
--Aaron

Edit* -- I have a multiwii LCD too that I would like to connect up but not sure where it goes.... I'm guessing this snit something that's mounted on the quad right, just connect when needed...?

bill516 · Post by **bill516** » Wed Aug 08, 2012 11:11 am

There are two methods for trimming, using the Tx trim or the stick trim. Both trim in a similar manner but they affect two different things. Tx trim affects the motor output from your Tx when in gyro only (acro) mode, so that when you throttle up all the motors throttle up at the same rate (remember when you did throttle calibration on the esc's) the Tx uses that info to set its output to the esc, stick trim affects the gyro and accelerometer. With all things being equal your CofG will be spot on and your copter will to be perfectly level in flight, but all things are not equal and it will more than likely want to lean in one direction or another. This will be down to variances in the materials used, although they may weigh the same the balance of them is likely to be different and this will show up in flight as the CofG not being where it should be, hence leaning.

When you calibrate your acc your copter has to be level, imagine you are on a 10 degree slope and you put your copter down and hit calibrate. What you have just done is tell the gyro and acc that level is 10deg to one side, now when you get airborne you see your copter level with the horizon but your gyro and acc see that it is leaning 10deg to one side and will try to correct it to where you told it was level. So you calibrate on level ground but as with the Tx trim (acro mode) the CofG will be off so you need to trim the acc (stable mode) to bring the CofG back to where it should be. This is where the in flight calibration is so much quicker as you just fly flick a switch land and flick the switch again, but you must be able to control your copter in the air to do this.

As for your in flight calibration you need to assign a switch on your Tx as well as assign an aux in the sketch, I use aux on pin 12 which needs to be un-commented.

LCD on or off its you choice, as you cant do anything with it in flight I would just hook it up when needed, why carry extra weight.

tovrin · Post by **tovrin** » Wed Aug 08, 2012 4:22 pm

Bill hit it on the head, but i wanted to mention that i believe you have to make sure you enable the buzzer in the sketch, i havent played with the inflight config in a moment, but i remember when i did i had to enable the buzzer or i got the same error you listed

likwidchz · Post by **likwidchz** » Thu Aug 09, 2012 3:34 am

Hi Bill, Tovrin,

I enabled buzzer... honestly didn't even see it in the config although I don't see a buzzer anywhere on the board, do I have to wire this up? I have the multiWii SE, it does compile now, although the inflight ACC calibration does not seem to do anything, I saw the link that Bill posted earlier and tried it. Do I have to make a buzzer and attach it to the board along with configuring which pin makes it buzz and what not?

So I have calibrated my esc's however I'm not powering them with the reciever only off the multiwii board, the board is connected to my RX via PPM will this matter? The craft seems to drift to one side I believe forward.

The strange thing is, I press the right stick left and it wants to tilt left, but I press the right stick right and it wants to spin... is that normal? spinning should happen with the yaw on the left stick correct?
I have the correct channel ordered specified.

I would really like to see if someone has time to skype about this? since this thread is quite large, might clear up some quick noobish questions.

Thanks both of you for help,
--Aaron

Attached is a photo of what it does when I throttle up.

----Also should I try this outside in the garage on the cement, someone had mentioned that the floor/carpet might cause weird problems..... I just dont know :\ and also is it possible to hover at a foot off the ground? or do you really need to be 3-4 feet off the ground?... honestly I don't want to get it that high last time that happened it broke the stupid arm off and I had to glue the thing, I'll try and make a set of training wheels for the thing or something, or put it in the grass... something just isnt right.

ganu_shankar · Post by **ganu_shankar** » Mon Dec 17, 2012 7:08 am

Hi Aron
Did you problem got resolved. My quad is also behaving the same way as yours.
Was curious to know if you have solved the problem

Ganu

tovrin · Post by **tovrin** » Tue Dec 18, 2012 5:10 pm

The strange thing is, I press the right stick left and it wants to tilt left, but I press the right stick right and it wants to spin... is that normal? spinning should happen with the yaw on the left stick correct?

this is a clue to the real problem. almost sounds like you have an ESC that didn't get its min\max calibrated properly. when you tilt left it lowers throttle to both left motors, raises throttle to both right motors, and it tilts. when you tilt right it should lower both right throttles, raise both left throttles, and tilt right, but if one of your left ESC isn't set right it will not raise throttle same as other left ESC, and the copter will spin instead of tilting. in theory.

it isn't necessarily the min/max calibration either, if your throttle curve settings within the ESC programming are different, you will get a similar throttle problem.

i could be way off base on what i believe is wrong, BUT i'm certain that i'm on track with the fact that this is a clue to the actual problem.