Hot answers tagged

11

BEC: Battery-eliminating circuit. Basically just allows you to use the ESC to power the controls circuit, servos, etc. (hence eliminating the need for a battery) SBEC: Switched battery-eliminating circuit. Just an improved version of the BEC which makes it more energy efficient. UBEC: Similar to SBEC, just more energy-efficient at the expense of being ...


10

This is a setting that is needed for RPM sensing and RPM filtering. An ESC can not sense the RPM of your motors directly, but can sense how often the magnets in the motor bell pass by the coils in its stator (this is called eRPM), and will report that number to the flight controller if you've got bidirectional DSHOT enabled. If your motor bell has x magnets (...


8

ESCs loaded with recent versions of BLHeli (BLHELI_S and BLHELI_32) will support reversible motor direction, either through Dshot commands (obviously only supported when using Dshot signaling) or with zero-throttle centered around the middle throttle position, 1500µs (supports Oneshot/Multishot in addition to Dshot). These modes can be set up in the BLHELI ...


7

A BEC is a Battery Eliminator Circuit. This provides a way for you to power other components, such as servos from a source that is more regulated than VBAT. An SBEC (Switching Battery Eliminator Circuit) and a UBEC (Ultimate Battery Eliminator Circuit) are both versions of BECs that are more efficient. An OPTO is an Opto-coupler, and this isolates the ESC’...


7

This sounds very much like like a PWM/analog ESC miscalibration issue to me. PWM ESCs required signal calibration to ensure that both the RC receiver and the ESC are on the same page about what kind of pulse length constitutes both 0% and 100%, as there can be clock speed discrepancies and other issues with the protocol. I can't exactly find a source I like ...


6

This is an understandably confusing topic because of how the names evolved, and some of those acronyms have become more of a marketing label rather than an actual term. So I'm going to dive a bit deeper into the origins of these names and why the distinction between them exists. The term "BEC", which stands for Battery Elimination Circuit, has its roots in ...


6

The primary thing that high torques affect in a brushless motor is the current flowing through. It obviously affects your ESCs, but also the motors themselves: high currents have been known to melt/burn the insulation on motor windings, which then short out and wreck the motor itself and possibly the ESC as well. If the source of this torque is just a prop,...


6

Technically, you could connect 2 motors if they're exactly the same and it will probably work. However, there is a good possibility of various weird things happening due to this. The problem with connecting more than one motor to a single ESC stems from how these motors are driven. An electric motor works by using electromagnetic coils to pull permanent ...


6

DShot is a protocol that flight controllers use for communicating with ESCs. It stands for 'Digital Shot'. It is a new digital communication protocol developed by Flyduino in collaboration with Betaflight as an alternative to Oneshot and Multishot. Oneshot and Multishot (and standard PWM) all use analogue signals. The length of an electrical pulse ...


6

Without disassembling the motor, and figuring out how the ESC is designed, there is no other way then simply testing it. From my experience, the motors spinning clockwise has usually been the ones that can be wired without crossing any wires and without having to reverse the direction. But that could just be a coincidence, so you should definitely not trust ...


5

The normal blheli startup tones are similar to beep beep beep... boop. boop The first 3 beeps are the ESC's powering on and initializing then there's a pause followed by two more beeps which means the throttle signal has been received. https://youtu.be/_hkzm8ZXsxE?t=58


5

I think most people just copy other builds, and step up a size if they burn out any ESCs. If you want to be more scientific you could test one motor with a watt-meter to measure the current draw. Throttle up slowly so you can watch the current build, to protect the ESC you're using for the test. Also check the motor temperature after 30 seconds or so. This ...


5

It looks like a bad phase to me. Check the resistance of each phase, wire 1 to wire 2, wire 2 to wire 3, and wire 1 to wire 3. If one of those is much higher resistance or shows no continuity, then you've got a bad phase. I suspect this is the issue. Also try swapping the motor to a different arm. This will eliminate the ESC as the issue. If the problem ...


5

As is explained in this forum post, support for DSHOT1200 signaling was indeed removed from Betaflight due to its primary use case being devalued starting in version 4.1. DShot1200 is officially removed from Betaflight 4.1: Dshot1200 is only needed for 32khz looptime, and 32khz looptime isn't supported any more in Betaflight. The highest looptime ...


5

From a technical standpoint it is possible, but there are a number of considerations: Only need one ESC so lighter ESC needs to have a higher current rating to fully power the motors Motors must be identical (more of a problem if home-building with what's on the bench) Loss of redundancy (if a prop jams or motor fails, you have no thrust) Cannot use ...


5

I agree, it looks like a Micro Deans plug. They're good for about 10amps. A red JST plug is good for about 5amps. A speed 400 is pretty inefficient over about 5amps. Personally I'd junk both the ESC and motor and go brushless. You'll save weight, gain efficiency, be able to use a bigger prop and it won't wear out. And that ESC probably doesn't have a lipo-...


5

Aside from quality control issues with the product, the only real way to destroy an ESC faster than the effects or normal wear and tear (minimal) is to mistreat it: Using it with a voltage higher than its rating Using it with a motor that's dramatically too large Drawing more current than its rating Frequently stalling the motor against tree branches or ...


5

If you must use dshot then try this library https://github.com/gueei/DShot-Arduino However, for just playing around, it would be much easier to use PWM protocol and the servo library for Arduino. Most ESC's are backwards compatible so I recommend trying using PWM first and if you must, use DSHOT.


5

I saw a TED talk from a guy who had written quadcopter software to handle losing one motor. Perhaps you can find it. With nothing to counter the unbalanced torque, the quad spun in yaw quite rapidly. Most software would attempt to counter this by increasing power on the motor opposite the dead motor, and decreasing power to the other two. Instead they ...


4

You can, but it's not recommended. First of, you will need an ESC that can handle twice the current of what one motor consumes. The motors will also be seen as one single motor by the ESC, so of one of them has an error or becomes out of sync, both of them will stop.


4

Like you said in your answer, it does depend on the ESC... so you definitely want to look into the specifications for your particular components. However, to be safe, a good rule of thumb suggested on this forum is that you want to be able to put your finger on it without discomfort for five seconds. If your reflex is to withdraw after only 2 seconds, ...


4

Bi-directional DShot can help you here. After updating the BLHeli firmware on your BLHeli_32 ESCs to the latest version (support was added only recently) and the firmware on your flight controller to Betaflight >4.0 (PR on Github), you can go into the Betaflight Configurator app and enable Bi-directional DShot under the Configuration tab. It must be said ...


4

I feel like it's important enough to mention this to create a new answer even though there's a ton of good information here already, as you mention it's the transient currents that kill ESCs. To be perfectly honest we're well within the rating of even 20A (25A 10 second burst) ESCs in terms of sustained current draw on almost any setup you can imagine. It's ...


4

The rpm filters in betaflightwill be off the correct frequency by about 14%, and the rpm reported in the motors tab will be incorrect also. When the rpm notch filter centres are not exactly at the correct frequency, they won’t work as well, leading to increased noise in the motor signal, which may cause hot motors and limited thrust at high throttle.


4

You can calculate the rating using one or both of the following equations; just rearrange and/or substitute values as needed: P = I x V Power (Watts) = Current (Amps) x Voltage (Volts) V = I x R Voltage (Volts) = Current (Amps) x Resistance (Ohms) What you want to solve for is current. You can get some or all of the above numbers from the manufacturer’s ...


4

That looks like a 4 pin Deans Micro Plug, which goes by WS Deans part number 1242. Regarding your wire thickness, as you say it all depends on the expected current. If you can identify the current rating for the smallest wire in the circuit, you could add a similarly rated fuse and do some bench testing and current measurements - and if the fuse blows, then ...


4

Myriad factors contribute to the current draw of a drone motor including supply voltage, motor kV, the propeller geometry (i.e. diameter, number of blades, pitch), ambient atmospheric conditions, etc. One can make educated guesses and estimations of the current a motor will draw under known conditions, but the best and most accurate/reliable method is to ...


4

I think it's a combination of the BEC and stiff controls. 1 amp BECs are often just linear regulators, effectively a transistor that acts like a variable resistor. It takes in battery voltage and turns some of the power into heat so that the remainder is 5v. If you were running a 2 cell battery, it would have to dissipate 7-5=2v but with a 3 cell battery it'...


4

The BLHeli_M Commutation Enhancement feature is intended to increase motor power response times by "overdriving" (my words, may not be the most appropriate analogy) the coils to charge/discharge them more quickly. Source: (rgroups.om) Commutation is a job to charge two of three coils, A B and C, sequentially. Enhancement is an attempt to make the ...


3

So normal startup sequence is three short beeps followed by two long beeps with different tonality. First three beeps means that ESC is powered and activated. Then if the throttle signal is detect goes one long low tone beep. Then if throttle is zero goes one long high tone beep. This signal means the end of the start sequence and ESC is ready to run. ...


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