6LikesBuilding an ESC. Building a Brushless ESC. Making your own electrickary.
04-04-2018, 06:14 PM
#16
The hardest part is going to be to make a brushless sensored esc that is close to what is available on a commercially available esc. For racing, esc performance and adjustability are really important, and I'm not going to take a step backwards. Good luck coming up with something better than Tekin.
04-04-2018, 07:52 PM
#17
What are you trying to tell me there? Are you sure that's the hardest part? Are you trying to tell me where the market is, or telling me what you'd want in an ESC? Why not say what you'd like in an ESC? I'll listen. :-)
I've been in the pits a lot, and heard people talking about their ESCs. The adjustments they do are pretty minor for the most part. Then again, most people aren't running boost on their escs, so there's not a whole lot to adjust.
Tekin makes expensive ESCs. For a bunch of reasons, good reasons. I like tekin, I have for decades. (literally, my first esc was a Tekin 410s) They do all kinds of magic. And you pay for it. Someone needs to be paid to do the code, someone needs to do the phone and pc software. Someone needs to do a whole bunch of things... Those things all add up to something that's not ideal for someone who only runs blinky classes, and really just cares about forward, and brake settings. Heck, last weekend I found a guy who was accidentlly running boost!
Have you noticed that the hobbywing 120 amp ESCs have $17 clones? At $17, someone is making a profit, and I bet that profit is in the $8 range. And have you noticed how big the hobbywing 60amp, and juststock escs are? Have you looked at what ~really good~ fets cost? fet drivers? and how big they are? Have you noticed that most of the ESCs on the market have fans on them? ... Fans are not a good sign. There are a bunch of ways to make ESCs run cooler, but it seems most of the time that's not being done.
I'm still poking at it. I know what I want. We'll see what I come up with. if it costs me $400-500 to run my own ESC, i'm prepared for that. I know I want 3-4 of them. If nobody else wants one, it won't hurt me one bit. :-)
I've beat around the bush a bit. I want a tiny ESC. Tekin Tiny. I want simple on esc programming without boxes, or cards, or cables. I want a 5amp BEC. I braking with both forward and reverse. I want to select motor direction. I want to be able to turn off reverse. And if I can manage it, I'd like current limiting.
Can I do it? Who knows. :-)
I've been in the pits a lot, and heard people talking about their ESCs. The adjustments they do are pretty minor for the most part. Then again, most people aren't running boost on their escs, so there's not a whole lot to adjust.
Tekin makes expensive ESCs. For a bunch of reasons, good reasons. I like tekin, I have for decades. (literally, my first esc was a Tekin 410s) They do all kinds of magic. And you pay for it. Someone needs to be paid to do the code, someone needs to do the phone and pc software. Someone needs to do a whole bunch of things... Those things all add up to something that's not ideal for someone who only runs blinky classes, and really just cares about forward, and brake settings. Heck, last weekend I found a guy who was accidentlly running boost!
Have you noticed that the hobbywing 120 amp ESCs have $17 clones? At $17, someone is making a profit, and I bet that profit is in the $8 range. And have you noticed how big the hobbywing 60amp, and juststock escs are? Have you looked at what ~really good~ fets cost? fet drivers? and how big they are? Have you noticed that most of the ESCs on the market have fans on them? ... Fans are not a good sign. There are a bunch of ways to make ESCs run cooler, but it seems most of the time that's not being done.
I'm still poking at it. I know what I want. We'll see what I come up with. if it costs me $400-500 to run my own ESC, i'm prepared for that. I know I want 3-4 of them. If nobody else wants one, it won't hurt me one bit. :-)
I've beat around the bush a bit. I want a tiny ESC. Tekin Tiny. I want simple on esc programming without boxes, or cards, or cables. I want a 5amp BEC. I braking with both forward and reverse. I want to select motor direction. I want to be able to turn off reverse. And if I can manage it, I'd like current limiting.
Can I do it? Who knows. :-)
04-04-2018, 11:48 PM
#18
I'm sitting here digging through an ESC.
First, you can tell where an ESC came from, based on chip choices.
Here's what I've found:
Toshiba TPCA8087 mosfets. https://toshiba.semicon-storage.com/....TPCA8087.html
Those are the main power Mosfets.
I also found three International Rectifier Half Bridge drivers. Most likely, clones... IR2003 is the part number on the chip. https://www.infineon.com/dgdl/irs200...535675afec2780
There's also a 32 volt boost converter, which I believe is used to drive the half bridge chips output.
The boost converter is run by a MP2403 which.. is one of those chips that is really sneaky and is hard to find. The best data I could find on it is a related chip on mouser. Which is why I said 32v. https://www.mouser.com/ProductDetail...7EM6sXRw%3D%3D
There's also a linear LDO vreg, that's for feeding the BEC.
That covers everything except the microcontroller.
Mind.. I've never built a brushless controller before ;-) so i'm using a little reverse engineering to get me bootstrapped.
First, you can tell where an ESC came from, based on chip choices.
Here's what I've found:
Toshiba TPCA8087 mosfets. https://toshiba.semicon-storage.com/....TPCA8087.html
Those are the main power Mosfets.
I also found three International Rectifier Half Bridge drivers. Most likely, clones... IR2003 is the part number on the chip. https://www.infineon.com/dgdl/irs200...535675afec2780
There's also a 32 volt boost converter, which I believe is used to drive the half bridge chips output.
The boost converter is run by a MP2403 which.. is one of those chips that is really sneaky and is hard to find. The best data I could find on it is a related chip on mouser. Which is why I said 32v. https://www.mouser.com/ProductDetail...7EM6sXRw%3D%3D
There's also a linear LDO vreg, that's for feeding the BEC.
That covers everything except the microcontroller.
Mind.. I've never built a brushless controller before ;-) so i'm using a little reverse engineering to get me bootstrapped.
04-05-2018, 04:26 AM
#19
Creating your own ESC can be an excellent learning experience, not to mention satisfying and fun. Those are great reasons to do it. No other reasons are necessary!
I'm very interested to see what you come up with. You've already determined that the hardware design isn't terribly complicated; the execution (layout) will be a challenge. The most interesting thing will be the software!
I suspect you already know this, but make sure you have a good idea of what the processor needs to accomplish, and the priorities of those tasks, before you begin the hardware design. There is at least one ESC on the market that does silly stuff in the hardware (like NOT putting all of the sensor signals on the same port), and this makes the software cumbersome and slow.
I'm very interested to see what you come up with. You've already determined that the hardware design isn't terribly complicated; the execution (layout) will be a challenge. The most interesting thing will be the software!
I suspect you already know this, but make sure you have a good idea of what the processor needs to accomplish, and the priorities of those tasks, before you begin the hardware design. There is at least one ESC on the market that does silly stuff in the hardware (like NOT putting all of the sensor signals on the same port), and this makes the software cumbersome and slow.
04-05-2018, 08:39 AM
#20
A long time ago, I was involved in the development of a controller board for a paintball gun. That's where I got my first tastes of microcontrollers. At the time, rate of fire was the hot ticket, and to do that well, required careful balancing of interrupts, and timing. To make an interface that works well, and feels good, is... more tricky than most people would imagine.
Amusingly, adding paint detection to the breach, slowed the system down, a lot. Ours less than most, but still, it was a problem.
We'll see if I can manage it. :-)
Have you heard of the eevblog, the amp hour, or embedded.fm?
Amusingly, adding paint detection to the breach, slowed the system down, a lot. Ours less than most, but still, it was a problem.
We'll see if I can manage it. :-)
Have you heard of the eevblog, the amp hour, or embedded.fm?
04-05-2018, 08:44 AM
#21
A long time ago, I was involved in the development of a controller board for a paintball gun. That's where I got my first tastes of microcontrollers. At the time, rate of fire was the hot ticket, and to do that well, required careful balancing of interrupts, and timing. To make an interface that works well, and feels good, is... more tricky than most people would imagine.
Amusingly, adding paint detection to the breach, slowed the system down, a lot. Ours less than most, but still, it was a problem.
We'll see if I can manage it. :-)
Have you heard of the eevblog, the amp hour, or embedded.fm?
Amusingly, adding paint detection to the breach, slowed the system down, a lot. Ours less than most, but still, it was a problem.
We'll see if I can manage it. :-)
Have you heard of the eevblog, the amp hour, or embedded.fm?
If those items you refer to are internet items, then no, I'm not familiar with them. Curiosity says I need to take a look.
04-05-2018, 09:15 AM
#22
Eevblog is Dave Jones, he does a little youtube channel where he goes into all sorts of (mostly) embedded electronics, design, and testing.
The Amp Hour is a podcast where Dave and Chris Gammel discuss what's going on with electronics. There are also interviews with people that range from silicon designers up to and including your usual hackerspace rejects.
Embedded.fm is nearly the same thing, but is more about embedded software and applications. With Elicia and Christopher White. They're consultants who've done projects ranging from toys to fitbits. And they do great interviews too, in their case ranging from business, to Jeri Ellsworth, to the reporter behind the embedded (as in war journalist) podcast.
It's fun stuff. But only if you have a long commute. :-)
The Amp Hour is a podcast where Dave and Chris Gammel discuss what's going on with electronics. There are also interviews with people that range from silicon designers up to and including your usual hackerspace rejects.
Embedded.fm is nearly the same thing, but is more about embedded software and applications. With Elicia and Christopher White. They're consultants who've done projects ranging from toys to fitbits. And they do great interviews too, in their case ranging from business, to Jeri Ellsworth, to the reporter behind the embedded (as in war journalist) podcast.
It's fun stuff. But only if you have a long commute. :-)
04-05-2018, 01:44 PM
#23
Yes, I am saying that if I would be in the market for an esc to replace the Tekin I have, I am not going to take a step backwards in terms of adjustability or performance.
Throttle and brake minimums, drag brake, throttle curves, throttle and brake frequncies are all adjustments I make regularly, even in blinky mode. Add in the data logging that Tekin can do, and you've got a pretty tall order to make your own esc better than a Tekin.
I don't doubt you can assemble the components to make your own functional esc. I doubt you will be able to make it perform nearly as well as top of the line esc's. You may not feel held back by a basic esc, but many people would.
Throttle and brake minimums, drag brake, throttle curves, throttle and brake frequncies are all adjustments I make regularly, even in blinky mode. Add in the data logging that Tekin can do, and you've got a pretty tall order to make your own esc better than a Tekin.
I don't doubt you can assemble the components to make your own functional esc. I doubt you will be able to make it perform nearly as well as top of the line esc's. You may not feel held back by a basic esc, but many people would.
04-05-2018, 02:05 PM
#24
If you see how much (low) an ESC can be priced I would not even try to make one.
But I have always said that the better stock setup a sensorless system is. No fouling and shimming with a sensorplate....
The main reason why people do not want it is because the startup stotter athough that is only an issue with the start and should not be an issue until the finish.
But my Idea to give a sensorless a better start is not try to sense the rotor at low rpm but just start with a simple 3 phase rotating magnetic field. At that point at the start the motor can drop back just an half turn max but then it will follow the rotating magnetic field.
You could use a sensor from a sensored motor just to sense the rotating speed that when a certain rpm is reached it will switch over to sense the rotor position by itself or meanwhile try to sense the rotor and when the signal is strong enough it will switch over to read the rotor position.
That will give a much smoother start to a sensorless brushless system.
But I have always said that the better stock setup a sensorless system is. No fouling and shimming with a sensorplate....
The main reason why people do not want it is because the startup stotter athough that is only an issue with the start and should not be an issue until the finish.
But my Idea to give a sensorless a better start is not try to sense the rotor at low rpm but just start with a simple 3 phase rotating magnetic field. At that point at the start the motor can drop back just an half turn max but then it will follow the rotating magnetic field.
You could use a sensor from a sensored motor just to sense the rotating speed that when a certain rpm is reached it will switch over to sense the rotor position by itself or meanwhile try to sense the rotor and when the signal is strong enough it will switch over to read the rotor position.
That will give a much smoother start to a sensorless brushless system.
04-05-2018, 04:02 PM
#25
If my car goes backwards when the race starts (even a little bit) I am not going to be happy. I have raced with sensorless systems before, and that is one thing that really bothered me about sensorless setups. Also, if you spin out and your car rolls backwards, that confuses sensorless systems too. Which causes them to cog for a second. If I have already lost time because of a spin out, I don't want to lose more time while the esc figures out what to do.
The full sensored system is a way to control timing. A hybrid system that drops sensor would be much harder for ROAR to verify that there is no timing being added when not using the sensor.
The Tekin RX8's are only hybrid systems, but they don't have to be "blinky" Tekin 1/10th scale esc's drop blinky if you run them in dual drive mode (hybrid mode).
The full sensored system is a way to control timing. A hybrid system that drops sensor would be much harder for ROAR to verify that there is no timing being added when not using the sensor.
The Tekin RX8's are only hybrid systems, but they don't have to be "blinky" Tekin 1/10th scale esc's drop blinky if you run them in dual drive mode (hybrid mode).
04-05-2018, 04:43 PM
#26
Nero the board you worked on was it a was.wicked airsports
04-05-2018, 11:47 PM
#28
If my car goes backwards when the race starts (even a little bit) I am not going to be happy. I have raced with sensorless systems before, and that is one thing that really bothered me about sensorless setups. Also, if you spin out and your car rolls backwards, that confuses sensorless systems too. Which causes them to cog for a second. If I have already lost time because of a spin out, I don't want to lose more time while the esc figures out what to do.
The cogging at the start is mainly caused that the coils can not sense the rotor. Although we call it sensorless, in a way it is still sensored but by the motor coils. Sensing the rotor gives feedback to the ESC of the position so it will adapt the powering of the coils so the rotor always follows the magnetic field. At low speed there is not much induction voltage made in the coils so the ESC does not read the position of the rotor correctly than only some spikes causing all kind of weird movements we call cogging.
My sugestion is not to read the position of the rotor at low speed but just create a simple 3 phase rotating magnetic field that the rotor just wil follow without any cogging. Yes, at the most unlucky starting position of the rotor it will turn back an half turn at the start, with a 4.0 FDR that will be an 1/8th turn on the tire but then directly it will drive smooth without any cogging.
I have done some stock racing and have seen a lot and the 1st thing people do while it is forbidden is try to get more timing from the sensors. Getting rid of the sensors as a timing instrument will eliminate a huge factor on cheating and tolerances.
But OK, another thing you can do is to read out all sensor positions at 1st throttle as a motor analizer and from there calculate a correction factor on each sensor that will be used in the total timing. Also then people can try to get more timing from the sensor but the ESC will bring it back to lets say 28 degrees (most sensors are at 30 degrees or higher)
04-06-2018, 07:26 AM
#29
That is the way sensorless setups work, they pick one set of coils to start from and then it rolls from there. And it doesn't happen every time you start from full stop, but often enough that it did happen during racing.
One thing that seemed to really help that not happen is the number of poles of the motor. 2 pole motors (like 1/10th scale uses) have a much harder time starting. The last time I ran sensorless was with a 4 pole motor in a borrowed SCT, and it had no problem starting the right way. Rolling backwards still tripped it up though.
A while ago I thought the sensor assembly was going out on one of my Tekin esc's (turns out it was a bad sensor wire). So I put it into dual drive (hybrid mode) and it worked very well.
One thing that seemed to really help that not happen is the number of poles of the motor. 2 pole motors (like 1/10th scale uses) have a much harder time starting. The last time I ran sensorless was with a 4 pole motor in a borrowed SCT, and it had no problem starting the right way. Rolling backwards still tripped it up though.
A while ago I thought the sensor assembly was going out on one of my Tekin esc's (turns out it was a bad sensor wire). So I put it into dual drive (hybrid mode) and it worked very well.
04-09-2018, 04:20 PM
#30
What are you trying to tell me there? Are you sure that's the hardest part? Are you trying to tell me where the market is, or telling me what you'd want in an ESC? Why not say what you'd like in an ESC? I'll listen. :-)
I've been in the pits a lot, and heard people talking about their ESCs. The adjustments they do are pretty minor for the most part. Then again, most people aren't running boost on their escs, so there's not a whole lot to adjust.
Tekin makes expensive ESCs. For a bunch of reasons, good reasons. I like tekin, I have for decades. (literally, my first esc was a Tekin 410s) They do all kinds of magic. And you pay for it. Someone needs to be paid to do the code, someone needs to do the phone and pc software. Someone needs to do a whole bunch of things... Those things all add up to something that's not ideal for someone who only runs blinky classes, and really just cares about forward, and brake settings. Heck, last weekend I found a guy who was accidentlly running boost!
Have you noticed that the hobbywing 120 amp ESCs have $17 clones? At $17, someone is making a profit, and I bet that profit is in the $8 range. And have you noticed how big the hobbywing 60amp, and juststock escs are? Have you looked at what ~really good~ fets cost? fet drivers? and how big they are? Have you noticed that most of the ESCs on the market have fans on them? ... Fans are not a good sign. There are a bunch of ways to make ESCs run cooler, but it seems most of the time that's not being done.
I'm still poking at it. I know what I want. We'll see what I come up with. if it costs me $400-500 to run my own ESC, i'm prepared for that. I know I want 3-4 of them. If nobody else wants one, it won't hurt me one bit. :-)
I've beat around the bush a bit. I want a tiny ESC. Tekin Tiny. I want simple on esc programming without boxes, or cards, or cables. I want a 5amp BEC. I braking with both forward and reverse. I want to select motor direction. I want to be able to turn off reverse. And if I can manage it, I'd like current limiting.
Can I do it? Who knows. :-)
I've been in the pits a lot, and heard people talking about their ESCs. The adjustments they do are pretty minor for the most part. Then again, most people aren't running boost on their escs, so there's not a whole lot to adjust.
Tekin makes expensive ESCs. For a bunch of reasons, good reasons. I like tekin, I have for decades. (literally, my first esc was a Tekin 410s) They do all kinds of magic. And you pay for it. Someone needs to be paid to do the code, someone needs to do the phone and pc software. Someone needs to do a whole bunch of things... Those things all add up to something that's not ideal for someone who only runs blinky classes, and really just cares about forward, and brake settings. Heck, last weekend I found a guy who was accidentlly running boost!
Have you noticed that the hobbywing 120 amp ESCs have $17 clones? At $17, someone is making a profit, and I bet that profit is in the $8 range. And have you noticed how big the hobbywing 60amp, and juststock escs are? Have you looked at what ~really good~ fets cost? fet drivers? and how big they are? Have you noticed that most of the ESCs on the market have fans on them? ... Fans are not a good sign. There are a bunch of ways to make ESCs run cooler, but it seems most of the time that's not being done.
I'm still poking at it. I know what I want. We'll see what I come up with. if it costs me $400-500 to run my own ESC, i'm prepared for that. I know I want 3-4 of them. If nobody else wants one, it won't hurt me one bit. :-)
I've beat around the bush a bit. I want a tiny ESC. Tekin Tiny. I want simple on esc programming without boxes, or cards, or cables. I want a 5amp BEC. I braking with both forward and reverse. I want to select motor direction. I want to be able to turn off reverse. And if I can manage it, I'd like current limiting.
Can I do it? Who knows. :-)