ESC questions & why not USA shipping

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Kyro
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Re: ESC questions & why not USA shipping

Post by Kyro »

these chinese esc's do not have breaking but they do have built in mixing you can turn on or off via a little switch (which i prefer to turn off and do my own mixing via the transmitter)

a fix for breaking (this will add breaking to any esc) is to solder a resistor across the motors...

a carbon film resistor is good enough.

if memory serves me, 5.6k resistor was the one i had best results with but dont hold me to it... (i would have to dig out my old prototype rig and see what ones are on there) but feel free to get yourself a small collection and experiment to see what works best for you.

i will update here when i find my old test rig and let you know which exact resistor i used...
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Shakey
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Re: ESC questions & why not USA shipping

Post by Shakey »

From When I looked at using resistors to add braking:

http://robotwars101.org/forum/viewtopic ... =10#p57290
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Kyro
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Re: ESC questions & why not USA shipping

Post by Kyro »

^ what he said
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MarkR
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Re: ESC questions & why not USA shipping

Post by MarkR »

Nothing should be burning up if you're driving N20 motors from a 2S pack. They won't pull enough current to cause anything to get more than slightly warm, unless there is an electrical fault.

In my experience, a N20 motor will stall at <1A (maybe slightly more if you used the Pololu high power ones, they are absolutely unnecessary for 150g robot drive). So even if you connected two motors in parallel, nothing will be burning.

A reasonably efficient ESC should be dissipating only about 1W even if the motors are stalled, it's not enough to make anything burn.

On the other hand, if there is a short circuit, or the ESC is just faulty, it might catch fire. Even the small lipo are juicy enough to create fires very quickly.

If you have a bench supply, test it on that first, with a low current limit set (e.g. 2A) - but many bench supplies will have a maximum current a lot less than a lipo.
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minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

Kyro wrote: Thu Jan 23, 2020 2:54 am https://www.ebay.com/itm/1-8AX2-ESC-Bru ... Sw3SdeAFMm

about $10 all in on the slow boat from china.

there also appears to be something simmilar rated for a single cell lipo, i would avoid that one.

there is also https://www.ebay.com/itm/Dual-Way-ESC-5 ... Sw9mtd90gz which is a little bigger and can take 3s
about $13

used both, only ever had 1 fail (the bigger one) and that was loss of half a h bridge (drives forward fine steers fine but 1 wheel refuses to reverse)
OK, I ordered 5 of each of these, plus 4 of the Flysky FS i6, and 4 of the fs2a rx.

Again I apologize for the simplisc questions:

How many wheels can I put on a bot with these esc? 2WD only? 4WD? 6WD? - is it just a matter of keeping the stall current for each motor on the channel under the Amp rating for the esc channel (like the sum of all motors on the left side less than 1.8A or 5A for these two)? Or do you need an extra channel for each motor - so like 4 channel esc for 4WD or 6 channels for 6WD?

I guess my next questions will be how do I pick N20 Motors and how do I pick servos (for lifter or flippers) and do I need an esc for the servo? (note - I'm not even thinking about spinners yet).

After that I will need to ask about batteries, chargers and power supplies.

Thank you very much again for all your help.

Sincerely

Matt
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LimaHotel
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Re: ESC questions & why not USA shipping

Post by LimaHotel »

N20s typically have a stall current of <1A. Unless you get Polulu High Power ones, but they're kinda pointless for drive in an ant.

In terms of choosing your N20, I like 500 or 600 rpm ones for drive. I get mine from AliExpress, though I'm aware some people have issues with quality control from some of the chinese sellers. Eba is another good place to find N20s.
Keep in mind - you're (probably) running a 2s lipo for power, so that's nominal voltage of 7.4 volts. So if you get a 6V n20 then it'll be spinning slightly faster than advertised, and if you get a 12V n20 it'll be spinning at near half speed.
When I say 500 / 600 rpm motors, that's 6V. 1000 / 1200 rpm 12V motors will perform roughly the same on 2S lipos.

A 2 channel ESC means it can handle 2 individual signals. Run 2 motors off each channel for 4WD. One channel will be your left drive, and one will be your right.

Servos. Depends what you want them for.
The Towerpro MG90 servo is great value for money, but not really powerful enough for a flipper. Lifter? Sure. But not a flipper so much.
Generally for a Flipper you want a 450 heli servo. They're usually multivoltage (so you can run them direct off Lipo power), and typically have high torque and speed. They aen't the cheapest however, and are around 20g in weight.
I personally use this one: https://www.aliexpress.com/item/32914488572.html
You do not need an Esc for a Servo as they have their own control boards.

Batteries you'll want 2 cell Lithium Polymer (Lipo) batteries, and 180mah is ample for 3 minute fights (Unless you're making some kinda crazy spinner).
You'll need a lipo balance charger to go with it. I have always got my batteries and chargers from Hobbyking, though they seem to have now discontinued the Turnigy batteries I use.
You'll also need a Lipo bag or box to store / charge your batteries in incase they explode.

I... think I've covered everything you asked?
A grabber? I CHALLENGE IT WITH JIGGY!
minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

LimaHotel wrote: Tue Jan 28, 2020 5:54 pm N20s typically have a stall current of <1A. Unless you get Polulu High Power ones, but they're kinda pointless for drive in an ant.

In terms of choosing your N20, I like 500 or 600 rpm ones for drive. I get mine from AliExpress, though I'm aware some people have issues with quality control from some of the chinese sellers. Eba is another good place to find N20s.
Keep in mind - you're (probably) running a 2s lipo for power, so that's nominal voltage of 7.4 volts. So if you get a 6V n20 then it'll be spinning slightly faster than advertised, and if you get a 12V n20 it'll be spinning at near half speed.
When I say 500 / 600 rpm motors, that's 6V. 1000 / 1200 rpm 12V motors will perform roughly the same on 2S lipos.

A 2 channel ESC means it can handle 2 individual signals. Run 2 motors off each channel for 4WD. One channel will be your left drive, and one will be your right.

Servos. Depends what you want them for.
The Towerpro MG90 servo is great value for money, but not really powerful enough for a flipper. Lifter? Sure. But not a flipper so much.
Generally for a Flipper you want a 450 heli servo. They're usually multivoltage (so you can run them direct off Lipo power), and typically have high torque and speed. They aen't the cheapest however, and are around 20g in weight.
I personally use this one: https://www.aliexpress.com/item/32914488572.html
You do not need an Esc for a Servo as they have their own control boards.

Batteries you'll want 2 cell Lithium Polymer (Lipo) batteries, and 180mah is ample for 3 minute fights (Unless you're making some kinda crazy spinner).
You'll need a lipo balance charger to go with it. I have always got my batteries and chargers from Hobbyking, though they seem to have now discontinued the Turnigy batteries I use.
You'll also need a Lipo bag or box to store / charge your batteries in incase they explode.

I... think I've covered everything you asked?
Thank you very much for your help!

Maybe I should start a different thread for the non esc stuff.?

I don't mind spending a little more to get a quality weapon servo.

I also don't mind spending a little more to get a quality charger and power supply.

Maybe I'll make the new thread now for the non esc stuff. May as had well.

Thank you very much again!
minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

Kyro wrote: Fri Jan 24, 2020 7:44 am^ what he said
"Esper runs 2x bustophedon 10a esc's and finished 3rd at aws60 (the biggest antweight event in the uk)"

From another thread, the quote above! why do you use 2x 10a esc's in this bot? Please forgive me that I can't place the bot to the name.

Also why do you generally use the 5a esc's in your bots but use the 1.8 in mantis? I'm guessing that you need the weight savings in mantis due to the complexity and multiple sevos taking up the weight, but is there a different reason?

Thank you again.
minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

LimaHotel wrote: Tue Jan 28, 2020 5:54 pm N20s typically have a stall current of <1A. Unless you get Polulu High Power ones, but they're kinda pointless for drive in an ant.

In terms of choosing your N20, I like 500 or 600 rpm ones for drive. I get mine from AliExpress, though I'm aware some people have issues with quality control from some of the chinese sellers. Eba is another good place to find N20s.
Keep in mind - you're (probably) running a 2s lipo for power, so that's nominal voltage of 7.4 volts. So if you get a 6V n20 then it'll be spinning slightly faster than advertised, and if you get a 12V n20 it'll be spinning at near half speed.
When I say 500 / 600 rpm motors, that's 6V. 1000 / 1200 rpm 12V motors will perform roughly the same on 2S lipos.

A 2 channel ESC means it can handle 2 individual signals. Run 2 motors off each channel for 4WD. One channel will be your left drive, and one will be your right.

Servos. Depends what you want them for.
The Towerpro MG90 servo is great value for money, but not really powerful enough for a flipper. Lifter? Sure. But not a flipper so much.
Generally for a Flipper you want a 450 heli servo. They're usually multivoltage (so you can run them direct off Lipo power), and typically have high torque and speed. They aen't the cheapest however, and are around 20g in weight.
I personally use this one: https://www.aliexpress.com/item/32914488572.html
You do not need an Esc for a Servo as they have their own control boards.

Batteries you'll want 2 cell Lithium Polymer (Lipo) batteries, and 180mah is ample for 3 minute fights (Unless you're making some kinda crazy spinner).
You'll need a lipo balance charger to go with it. I have always got my batteries and chargers from Hobbyking, though they seem to have now discontinued the Turnigy batteries I use.
You'll also need a Lipo bag or box to store / charge your batteries in incase they explode.

I... think I've covered everything you asked?
I reposted your response in the other thread.
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Kyro
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Re: ESC questions & why not USA shipping

Post by Kyro »

minionhunter wrote: Tue Jan 28, 2020 6:51 pm
Kyro wrote: Fri Jan 24, 2020 7:44 am^ what he said
"Esper runs 2x bustophedon 10a esc's and finished 3rd at aws60 (the biggest antweight event in the uk)"

From another thread, the quote above! why do you use 2x 10a esc's in this bot? Please forgive me that I can't place the bot to the name.

Also why do you generally use the 5a esc's in your bots but use the 1.8 in mantis? I'm guessing that you need the weight savings in mantis due to the complexity and multiple sevos taking up the weight, but is there a different reason?

Thank you again.
i purchased the bustophedon esc's back when i started this hobby for testing as they were cheap and relatively small (but heavy) and they have worked flawlessly ever since i put them in Esper and so, never needed to change them out...
they are practically bombproof...


the reason for having 2 of them is that they are single channel so 2 of them are needed along with mixing via my transmitter

Image Esper is the black and white one in the middle...

speaking of mixing via tx, even esc's with built in mixing i generally switch off and do my own as i have far more "tuning" options with my own mixes.

Mantis uses the much smaller and lighter 1.8a dual esc due to size and weight limits of the design (although this latest version comes in at about 4g underweight and should be slightly stronger than Esper is as its built the same way but with thicker parts) but i am slowly moving all my esc's over to these smaller ones as and when i need to as they have all passed my testing with flying colours...
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