Originally Posted by critical_limit

Very interesting Project.

May I ask for some pics here and the components you have used?
Some more information would be very nice.

Thanx

Thanks for liking it !
----Check some pics @ post 314 #4700

Here are the Specs...components used.

Frame ----Home made frame
Control Board--- KK2-1.2 V @ Y4 Motor Lay-out
Motors--- Turnigy L2215J-900 (200)
ESC---HK 20A 3A UBEC
Props--- Front---11x 4.7
----Back---10x4.5
RX--2801 Pro RX with 2801 Pro TX....

Originally Posted by rcjose

Quad Addict's comments got him censored/banned from OpenPilot and RCG.

Banned from Fpvlab as well!! Fpvlab very rarely bans anyone... He lasted a whole week there, lol.

Hello Guys !
I'm trying to make/build my own home made frame for a VTAIL and I just want some input or advise on what I need to do more on this plan. Please let me know if this will work ...or fly .

Originally Posted by rcjose

From my understanding a linear BEC reduces the voltage down to 5 volts at a constant rate, i.e. always on. A switching BEC reduces the voltage down to 5 volts more like an ESC does, at fast occuring high frequency bursts so it appears that it's not doing so constantly. The linear BEC produces more heat than the switching BEC and is therefore more prone to failure.

I suspect that the KK2 board cannot handle all the high frequency switching from all of the ESCs because it itself does not have 5V regulator onboard?

Close. A linear regulator behave like a variable resistor. Using simple numbers to make the maths easy, if your +5 volt flight electronics (FC, rx etc) draws 1 Amp from the battery then the electronics is consuming 5 watts of power (5V x 1A). This is given off as heat. With the linear regulator this 1A passed from the input to the output of the regulator. If the incoming supply was 12 volts then the total power dissipated is 12volts x 1A = 12 watts. The voltage difference between input and output is 7 volts therefore the power dissipated by the regulator is 7 watts which is more than the power dissipated by the flight electronics. The regulator gets HOT.

A switching regulator works by switching the input voltage on and off to an inductor and capacitor combination. Basically storing energy in the magnetic field of the inductor when "the drive to the inductor is switched on" and recovering energy from the collapsing magnetic field when "the drive to the inductor is switched off" It is this switching action for which the switching regulator name is derived. The inductor - capacitor combination (LC filter) is used to provide a "smoothed" output voltage which is fed into the switching regulator to control the switch on - switch off duty cycle. The drive from the switching regulator is either ON of OFF allowing the output drive stage of the regulator to either be "hard on" or "hard off" and is the reason these types of regulators are very efficient (low losses) compared to a linear regulator. Assuming the switching regulator is 90% efficient (not unreasonable) then the power dissipated by the regulator = 5V * 1A * 10% = 0.5 watts. The switching regulator therefore runs much cooler.

So why can't you connect multiple switching BECs together? This is an implementation problem - the switching BEC are missing a final filter stage the remove the error information used by the switching regulator to control turning the drive outputs on and off. Without this final filter stage the error signals of all regulators are connected together and therefore the incorrect feedback is fed back to the switching regulators - the result, chaos reigns.

Originally Posted by Truglodite

I have my KK2 wired with signal only for M2-3, no grounds, and no 5V. Do yourself a favor and pick up a separate uBEC; it doesn't have to be fancy, but the switching type is better. IMHO you are asking for trouble using an esc built in BEC on a quad... ground loop noise and such.

The root source of the problem is not ground loop noise because it is not a "loop" problem. The issue is due to resistance in the ground path and the high current that flows along this path.

The typical scenario is 0V battery -> ESC 1 (with BEC) -> Flight control electronics. Assume the resistance of the wire between the 0V battery terminal and ESC 1 is 0.1 Ohm and this motor consumes a peak of 20Amps. The voltage dropped across the 0.1 Ohm connection is 0.1 * 20 = 2 Volts. When the motor is idle the current is virtually 0 and therefore the voltage dropped across the wire is 0 volts. We have a 2 volt swing as the motor transitions from idle to full power. This is where the noise comes from.

The reason using a separate BEC is better is the current required to power the FC and Rx is negligible compared to the current required by a motor and therefore the voltage drop along the ground connection is virtually zero (no noise).

For the majority of users a separate BEC is NOT required as long as the correct size wires are used (thin wires = higher resistance = problem), the wires are kelt as short as possible and the ground wires from all ESCs connect together as close to the battery negative terminal as possible.

It would be nice to have in new fw
option to place board as previous KK board ( rotated 45).

Lots of frames have holes for KK, it would be nice to just select option,
no need for additional holes on frame, or board adapter.

Many are replacing old board with new and place for board is already there but tilted.

Option board placement KK or KK2, after that maybe option to choose flight direction as percent of 360 deg.

Originally Posted by asmallri

The root source of the problem is not ground loop noise because it is not a "loop" problem. The issue is due to resistance in the ground path and the high current that flows along this path.

The typical scenario is 0V battery -> ESC 1 (with BEC) -> Flight control electronics. Assume the resistance of the wire between the 0V battery terminal and ESC 1 is 0.1 Ohm and this motor consumes a peak of 20Amps. The voltage dropped across the 0.1 Ohm connection is 0.1 * 20 = 2 Volts. When the motor is idle the current is virtually 0 and therefore the voltage dropped across the wire is 0 volts. We have a 2 volt swing as the motor transitions from idle to full power. This is where the noise comes from.

The reason using a separate BEC is better is the current required to power the FC and Rx is negligible compared to the current required by a motor and therefore the voltage drop along the ground connection is virtually zero (no noise).

For the majority of users a separate BEC is NOT required as long as the correct size wires are used (thin wires = higher resistance = problem), the wires are kelt as short as possible and the ground wires from all ESCs connect together as close to the battery negative terminal as possible.

One of my upcoming videos on my youtube channel is multirotor ESC's for beginners and I just want to get this correct:

Point #1:
The use of all BEC wires with linear bec enabled ESC's on an FC is "up to debate" and really up to the FC circuitry. I have used linear bec enabled esc's with no bec cables removed on all my FC's (original KK, KK2, original Free Flight and Free Flight C10) with no issue.

Point #2:
If FC circuitry cannot handle #1, then power FC with 5V ubec on M1 and leave signal/ground intact for all other esc's.

Point #3:
Same as #2 for switching bec ESC's or use switching ESC on M1 and non bec (OPTO) esc on rest or remove bec wire from switching ESC on rest.

Jose, I have the same problem with the Spektrum Tx and Orange Rx, no throttle input message...I always turn on the Tc first and Rx last but still have the problem. How could you solve that problem? Thanks...

Originally Posted by danielnc06

I have tried it with the hunter vtail 500 frame. And it does roll some under hard yawing....for video under light roll it is smooth and level....quick yawing tends to make on of the fronts dip..this can be countered some with mixer adjustments but i found that you either get good level slow yawing or good level fast yawing... not both.. the vtail was a fun project that gave good hover and straight flying ability but the axis' of rotation felt odd to me while doing fast or aggressive manuevers...tri flyers may like it better... i lost a good bit of efficiency and battery life but that is expected...i gained a small amount of yaw ability but it wasnt worth it imho...my quad has 1047 props so i already hav good yaw ability.. an awesome looking frame and quad.. just wasn't what i was expecting once in a large field flying it.. it took some mixer adjustments after selecting vtail and the tail motors are opposite inojts from what the displays says...at least in my case it was..

Thank you for giving a very detailed response. The Y4 configuration seems to be a better choice then.
I love VTail copters because their orientation is so much easier to see.

Originally Posted by COCO2010

Hello Guys !
I'm trying to make/build my own home made frame for a VTAIL and I just want some input or advise on what I need to do more on this plan. Please let me know if this will work ...or fly .

If you run a line from opposite motor to opposite motor, do the lines cross at the center of where you plan to mount the controller?

Looks really nice. Is that body aluminum?

Originally Posted by AngelT

Jose, I have the same problem with the Spektrum Tx and Orange Rx, no throttle input message...I always turn on the Tc first and Rx last but still have the problem. How could you solve that problem? Thanks...

I turn on my DX6i first and then wait about 5 seconds and then power up the quadcopter. No issues once I started doing that.

Originally Posted by asmallri

Close. A linear regulator behave like a variable resistor. Using simple numbers to make the maths easy, if your +5 volt flight electronics (FC, rx etc) draws 1 Amp from the battery then the electronics is consuming 5 watts of power (5V x 1A). This is given off as heat. With the linear regulator this 1A passed from the input to the output of the regulator. If the incoming supply was 12 volts then the total power dissipated is 12volts x 1A = 12 watts. The voltage difference between input and output is 7 volts therefore the power dissipated by the regulator is 7 watts which is more than the power dissipated by the flight electronics. The regulator gets HOT.

A switching regulator works by switching the input voltage on and off to an inductor and capacitor combination. Basically storing energy in the magnetic field of the inductor when "the drive to the inductor is switched on" and recovering energy from the collapsing magnetic field when "the drive to the inductor is switched off" It is this switching action for which the switching regulator name is derived. The inductor - capacitor combination (LC filter) is used to provide a "smoothed" output voltage which is fed into the switching regulator to control the switch on - switch off duty cycle. The drive from the switching regulator is either ON of OFF allowing the output drive stage of the regulator to either be "hard on" or "hard off" and is the reason these types of regulators are very efficient (low losses) compared to a linear regulator. Assuming the switching regulator is 90% efficient (not unreasonable) then the power dissipated by the regulator = 5V * 1A * 10% = 0.5 watts. The switching regulator therefore runs much cooler.

So why can't you connect multiple switching BECs together? This is an implementation problem - the switching BEC are missing a final filter stage the remove the error information used by the switching regulator to control turning the drive outputs on and off. Without this final filter stage the error signals of all regulators are connected together and therefore the incorrect feedback is fed back to the switching regulators - the result, chaos reigns.

I appreciate the detailed explanation you gave ... it cleared up alot for me.

Many thanks ......

Originally Posted by rcjose

One of my upcoming videos on my youtube channel is multirotor ESC's for beginners and I just want to get this correct:

Point #1:
The use of all BEC wires with linear bec enabled ESC's on an FC is "up to debate" and really up to the FC circuitry. I have used linear bec enabled esc's with no bec cables removed on all my FC's (original KK, KK2, original Free Flight and Free Flight C10) with no issue.

Point #2:
If FC circuitry cannot handle #1, then power FC with 5V ubec on M1 and leave signal/ground intact for all other esc's.

Point #3:
Same as #2 for switching bec ESC's or use switching ESC on M1 and non bec (OPTO) esc on rest or remove bec wire from switching ESC on rest.

Don't forget to mention that with a tri-copter (or anything requiring servos) that there also needs to be a separate power to M2-M8 to drive them. I've seen a fair number of people stumped by this in this topic over the past months (despite it being in the manual).

In fact, I think for the KK2 in case #2, there would be no harm in leaving one of the ESC's/BEC's wired up on M2-M8 regardless, as it doesn't go anywhere else. Would just save pulling one power wire.

cheers,
Andrew

Hello guys,
I am having endless trouble with my quad 450 wanting to flip over when I try to take off. I have checked the blade/motor direction, connections, etc. still no go. Even recalibrated the ESCs and resetted the kk2.0 v 1.2- still flipping over I am stuck now.

Can someone maybe post their quad 450 settings with the kk2.0 and 9x radio with er9x firmware?

Er9x is just using "simple 4 channel" preset

Cant believe I cant even get it to hover!

Originally Posted by momofx

Hello guys,
I am having endless trouble with my quad 450 wanting to flip over when I try to take off. I have checked the blade/motor direction, connections, etc. still no go. Even recalibrated the ESCs and resetted the kk2.0 v 1.2- still flipping over I am stuck now.

Can someone maybe post their quad 450 settings with the kk2.0 and 9x radio with er9x firmware?

Er9x is just using "simple 4 channel" preset

Cant believe I cant even get it to hover!

Is it a dji 450