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tricopter troubles

ibstar

Junior Member
#1
Using a kk2.0 board with 3 dt750 with Davids wire mod, 11x4.7 props, turnigy 30 esc, 40c battery, Just will not fly, gets light on the floor but just not enough lift All posts say this should fly on half throttle, I'm on full and no go, Tried the esc to motor timing makes no difference, I've recalibrated the esc several times on and off the board, everything is working as it should, if I give it full throttle, then move elevator/aleron control then that arm lifts as it should, tricopter weighs in it 900 grams without the battery any ideas ?
 

Cyberdactyl

Misfit Multirotor Monkey
#2
Without knowing more details, my wild guess is you have the stick scaling, either on the KK2 or on your stick set too low.

Don't worry, it will indeed lift 900g + 250g (battery) with no effort once you get it right.

By the way, what is the "wire mod"? Wiring on the inside of the booms?
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#3
It's a little on the heavy side, but even at that it should be airborne easily.

If you've calibrated the ESCs on the kk2 board, that shouldn't be your issue. I'm also assuming you've got the props on the right way (writing up -- pointing at fresh air).

What does the receiver test on the kk2 read for when the stick is at full throttle? min throttle?

BTW, Welcome to the Forum!
 

ibstar

Junior Member
#4
Using 6ex radio in plane mode, dual rates are switched off
Doing the rx test on the kk2.0 shows everything working as it should,
Throttle goes from 0-100 all other channels show 0 then +
or - as you move the sticks either direction
Stick scaleing is on 30-30-50-50 if I remember correctly,
Props are rotating in the correct direction and shifting air in the right direction,
Just wondered if anyone else had had similar problem,
Ordered some 9" props I'll try them when they turn up,
As I read kk2 instructions the scaleing just slows the inputs makes it less twitchy, you still get full move ment
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#5
Using 6ex radio in plane mode, dual rates are switched off
Doing the rx test on the kk2.0 shows everything working as it should,
Throttle goes from 0-100 all other channels show 0 then +
or - as you move the sticks either direction
Stick scaleing is on 30-30-50-50 if I remember correctly,
Props are rotating in the correct direction and shifting air in the right direction,
Just wondered if anyone else had had similar problem,
Ordered some 9" props I'll try them when they turn up,
As I read kk2 instructions the scaleing just slows the inputs makes it less twitchy, you still get full move ment
CD nailed it.

Your stick scaling is a "what does a 100 from the radio mean in throttle setting?" and you've got it set way too low. Boost your throttle stick scaling to about 100 and you'll have a nice liftoff.
 

ibstar

Junior Member
#6
Right I'll go give that a try, so 100 is normal movement, over 100 is more response, and below 100 is lower response ?
As I understood it, it still have 0 at bottom and 100 at top but gave a more gentle curve
Many thanks,
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#7
Right I'll go give that a try, so 100 is normal movement, over 100 is more response, and below 100 is lower response ?
As I understood it, it still have 0 at bottom and 100 at top but gave a more gentle curve
Many thanks,
Scaling isn't so much like a curve as like a dual rate -- If it's at 50, that means 100% throttle in = 50% ESC command out (and 50% in = 25% out). that means if it hovers above mid throttle at 100% scaling, then you'll need more than full throttle to liftoff on 50% scaling.

If it's too hard to find that sweet hover spot, then backing off on the scaling *a little* might make it easier to find, so long as you've kept enough headroom to throttle up when you need to slow and stop a rapid descent.
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#9
Plus, I would reconsider using 9 inch props with the DT750s. It will be like driving around in 2nd gear on the interstate.
But it'll whirr soooo nicely as it tries to lift off the ground! (who knows, it might even make it!)

I agree, the 11x4.7s should be great at 750kv -- plenty of lift for copter and payload to spare (once you've got that scaling thing sorted out). The 9's would be a tremendous loss in lift, possibly too much.
 

Cyberdactyl

Misfit Multirotor Monkey
#10
I used 0947s when I first built my wood quad with DT750s. It was heavy, around 1600g, and boy did it struggle to fly. Once I put 1147s on, it was like night and day.
 

ibstar

Junior Member
#11
Well come morning I'll try the scaleing, its not advisable to
try these things indoors when the wifes home, lol,
The 9" props were just ordered in frustration,
All the others I've seen with the motor/prop combo
Fly so well
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#12
Well come morning I'll try the scaleing, its not advisable to
try these things indoors when the wifes home, lol,
The 9" props were just ordered in frustration,
All the others I've seen with the motor/prop combo
Fly so well
Aren't kitchen floors designed for multirotor low-speed testing areas? It's where I give all of mine their first quick hop . . .

. . . while my wife is upstairs and out of earshot . . .
 

xuzme720

Dedicated foam bender
Mentor
#13
Make sure you are only adjusting the throttle scaling to begin with. I'd leave the others alone until you get airborn and see how it behaves. If it's sluggish in control then you can bring up the other values as needed.
 

ibstar

Junior Member
#14
Aren't kitchen floors designed for multirotor low-speed testing areas? It's where I give all of mine their first quick hop . . .

. . . while my wife is upstairs and out of earshot . . .
Ah, the cats not happy about the kitchen floor either
I use the bed much softer ;)
 

ibstar

Junior Member
#17
And she's airborne !
Had one battery though it and couldn't get it to stop spinning, realised the 4th channel was reversed, I know it's ment to fly by the nose, but not sure I like it that way, changed the yaw from 100 to -100 and the spinning is sorted, ish
Second pack much better, managed some half decent hovers,
Just need to get my flash tool for the board update now, I'm still on v1.2 and understand v1.4 is much better for self leveling, more tweaking tomorrow, but it's up and I'm getting happier lol
Thanks for the help guys, I'm sure I'll be back with more tuning questions lol
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#18
Skip 1.4 and go to 1.6 . . . and consider using 1.6++ rev1.

A well tuned 1.6 is very stable in self level, and the 1.6++ mod includes a SL/acro mix mode, where the centered stick acts like self level, but the farther off center the stick gets the more it acts like acro -- nice balance between stability and agility.

In the mean time, share some pics or video, if you've got 'em!