ESC questions & why not USA shipping

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minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

Kyro wrote: Tue Jan 28, 2020 8:01 pm
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...
Thanks for posting this!
Sweet! Does Esper have the inward slanted wheels?
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Kyro
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Re: ESC questions & why not USA shipping

Post by Kyro »

no i think you are getting confused with doktor power from video's.
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Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
Io(4wd flipper)
minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

Kyro wrote: Tue Jan 28, 2020 8:01 pm
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...
If you were designing an upgrade to these, what would you want them to have?

A brake? Lighter? Higher amps? Another channel? Better bec? What would be ideal for you? Would you want the rx combination? Sturdier? Anything?

What could be sacrificed (if needed or if anything)? Would you take out the mixing or would you want it to be programmable (by you)?

What makes Rory's esc better?

FWIW - I'm both curious about it and I use the thoughts as points where I can search and learn more about things. I'm forever grateful for your time and help.

Also FWIW I found an insect league near me about 2.5 hours drive that fights 1 (US ant) and 3 pound (US beetle I think) bots every (other) month. I'm headed there in March (but won't have a bot for it).
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Kyro
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Re: ESC questions & why not USA shipping

Post by Kyro »

my ideal esc would be about 2a per channel, with a built in receiver that could support another 2 channels.
no mixing built in.
all wires exiting from the same side (makes locating it easier)
in the smallest, lightest package possible while remaining reliable.
i dont need built in breaking as i have my own breaking built into my thumb...

i have never used one of Rory's esc's although i did install one in a bot for someone...

they are very small and light.
what i didnt like is no ability to turn of built in mixing(that i am aware of)
The versions with built in rx only support dsmx/dsm2(cant remember exactly which) protocols
and you are unable to see which polarity the motors are attached with due to the wires used being blue for both although once you know what is what, you can easily replace with red and black for future reference... that last one is just nitpicking really... and the newer versions no longer have a built in rx so again, not much of an issue really.

but i never really hear complaints from people that use them, and they all seem to have a decent service life as every time i hear about one failing its usually always a good few years old.

this is all my personal opinion and as i mentioned i have never owned one so im definitely not the best person to listen to regarding them, but i have shared what i know/have heard. i would definitely get more opinions though...
Team Rocket
Trappist 1(4wd grab 'n' lift)
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minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

Kyro wrote: Tue Jan 28, 2020 9:20 pm my ideal esc would be about 2a per channel, with a built in receiver that could support another 2 channels.
no mixing built in.
all wires exiting from the same side (makes locating it easier)
in the smallest, lightest package possible while remaining reliable.
i dont need built in breaking as i have my own breaking built into my thumb...

i have never used one of Rory's esc's although i did install one in a bot for someone...

they are very small and light.
what i didnt like is no ability to turn of built in mixing(that i am aware of)
The versions with built in rx only support dsmx/dsm2(cant remember exactly which) protocols
and you are unable to see which polarity the motors are attached with due to the wires used being blue for both although once you know what is what, you can easily replace with red and black for future reference... that last one is just nitpicking really... and the newer versions no longer have a built in rx so again, not much of an issue really.

but i never really hear complaints from people that use them, and they all seem to have a decent service life as every time i hear about one failing its usually always a good few years old.

this is all my personal opinion and as i mentioned i have never owned one so im definitely not the best person to listen to regarding them, but i have shared what i know/have heard. i would definitely get more opinions though...
Cool! Thank you!

I would love to hear more opinions. Even things like your comments about the wire locations are really helpful in helping me think about layout which I hadn't given a ton of thought to yet (other than bots that are really short in height).
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LimaHotel
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Re: ESC questions & why not USA shipping

Post by LimaHotel »

Braking can also be achieved using a resistor across the motor terminals - Shakey did a thread on this a while ago, though it's been referenced relatively recently somewhere?
My bots don't all have brake. By which I mean Jiggy Sawdust has brake, and that's because it runs the NanoTwo. I actually find Jiggy hardest to drive of my 3!
Brake is generally what you want, and I DEFINITELY want to achieve braking in Jammin'. I'm planning to try get some little resistors and have a play - I'm hoping I can talk to Alex about it a bit in person on Saturday at Ant Freeze.

Another thing that makes the community built ESCs like Rory's NanoTwo, or Arc's Awesc, is that they're made by people involved in the hobby for people in the hobby. THey're pricey because they aren't mass produced in China, but then again if you buy a proper roboteering esc then the money stays in the hobby and helps to develop it, whereas buying from China is money leaving the sport.
I say this well aware that I use a DasMikro (That is held together with Gluegun but has somehow not actually died yet), Bustophedons (which are bombproof and I expect to function practically forever), cannibalised servo boards, and other mass produced escs in nearly all my builds, BUT I do have that NanoTwo in Jiggy and I also have a Awesc in my toolbox that I haven't decided what to do with yet.
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 10:26 pm Braking can also be achieved using a resistor across the motor terminals - Shakey did a thread on this a while ago, though it's been referenced relatively recently somewhere?
My bots don't all have brake. By which I mean Jiggy Sawdust has brake, and that's because it runs the NanoTwo. I actually find Jiggy hardest to drive of my 3!
Brake is generally what you want, and I DEFINITELY want to achieve braking in Jammin'. I'm planning to try get some little resistors and have a play - I'm hoping I can talk to Alex about it a bit in person on Saturday at Ant Freeze.

Another thing that makes the community built ESCs like Rory's NanoTwo, or Arc's Awesc, is that they're made by people involved in the hobby for people in the hobby. THey're pricey because they aren't mass produced in China, but then again if you buy a proper roboteering esc then the money stays in the hobby and helps to develop it, whereas buying from China is money leaving the sport.
I say this well aware that I use a DasMikro (That is held together with Gluegun but has somehow not actually died yet), Bustophedons (which are bombproof and I expect to function practically forever), cannibalised servo boards, and other mass produced escs in nearly all my builds, BUT I do have that NanoTwo in Jiggy and I also have a Awesc in my toolbox that I haven't decided what to do with yet.
I am 100% for supporting the community. If I could order 20 from Rory I would do it instantly.

That said, I'm going to try the resistor trick once I get them in a month. The link is a little bit up in this thread.

Wish I was going to ant freeze, maybe they will livestream it on YT, otherwise I'll have to watch it Sunday or whenever they put it up. I can't wait! Good luck everyone!
minionhunter
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Re: ESC questions & why not USA shipping

Post by minionhunter »

LimaHotel wrote: Tue Jan 28, 2020 10:26 pm Braking can also be achieved using a resistor across the motor terminals - Shakey did a thread on this a while ago, though it's been referenced relatively recently somewhere?
My bots don't all have brake. By which I mean Jiggy Sawdust has brake, and that's because it runs the NanoTwo. I actually find Jiggy hardest to drive of my 3!
Brake is generally what you want, and I DEFINITELY want to achieve braking in Jammin'. I'm planning to try get some little resistors and have a play - I'm hoping I can talk to Alex about it a bit in person on Saturday at Ant Freeze.

Another thing that makes the community built ESCs like Rory's NanoTwo, or Arc's Awesc, is that they're made by people involved in the hobby for people in the hobby. THey're pricey because they aren't mass produced in China, but then again if you buy a proper roboteering esc then the money stays in the hobby and helps to develop it, whereas buying from China is money leaving the sport.
I say this well aware that I use a DasMikro (That is held together with Gluegun but has somehow not actually died yet), Bustophedons (which are bombproof and I expect to function practically forever), cannibalised servo boards, and other mass produced escs in nearly all my builds, BUT I do have that NanoTwo in Jiggy and I also have a Awesc in my toolbox that I haven't decided what to do with yet.
This is his previous post quoted here
http://robotwars101.org/forum/viewtopic ... =10#p57290

I am paying attention to the cons and still need to calculate the power used. I also wonder what long term effects on the esc would be.

Shakey wrote: Tue Sep 13, 2016 3:57 pm I did some thinking about how to get a centre brake onto these ESC's that's super easy without reflashing the firmware. Something that could be done by a beginner without having to have another roboteer as a middleman flashing them and adding postage onto the cost. So I racked my brain and found a solution.

Resistor Braking
Centre braking is connecting the two terminals of a motor together to create the brake effect. I decided that a carefully valued resistor placed across the motor terminals would provide a brake effect when the ESC is not powering the motor. I experimented a bit and settled on ~50 Ohm as a good value resistor.

The important thing to understand is that this resistor adds extra load to the ESC, I chose ~50 Ohm as it provided a good level of braking with only ~0.17A of additional load at full power. A smaller value resistor would provide a more aggressive brake but would load the ESC more and heat itself up more (~50 Ohm on 2S got warm but no where near enough to worry).

Pros
- Adds Centre braking
- Cheap and Easy to do

Cons
- Resistor heats up
- More load on ESC
- Higher Power Usage

Testing
You can't say crazy stuff like this without a test!
Image
Image
This is 'Why do I exist?', my temporary testing bot. It has a 180mah 2S LiPo, an Orange RX, 2 30:1 motors. The two switches on the back can be used to switch the resistors in and out (turn the brake on and off). It has for an ESC a TinyTwo Rory ESC (I'm so sorry), it is one of rorys early ESC's that doesn't have centre braking so perfect for testing.

And a Test, first with centre braking off, then on, then on on only one side to show it doesn't affect the speed.
https://youtu.be/PubybLylBOs

A neat implementation would look something like this:
Image
MySolderIsOlder
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Re: ESC questions & why not USA shipping

Post by MySolderIsOlder »

Sorry to come in late on this one but going back to the original question about sourcing ESCs, don't ignore the traditional option of making your own, using servo boards. This might have been a bit of a faff in the old analogue days (balancing potentiometers and temperature drift, etc) but now that digital, continuous rotation servos are increasingly widespread it can be a relatively cheap, compact and effective solution. The only challenge is finding the right servo as not all controller boards are equal. Some don't give full duty cycle until you get beyond the pulse width range of standard receivers, while others are not proportional (i.e. they go from 0 to 100% with hardly anything in between, which makes for a very jerky driving style). I've found the latest stock of Feetech FT90R continuous rotation servos are perfect for my needs but be prepared to try a few different suppliers as the previous versions sucked (not proportional) and lots are still out there on stock shelves. Key thing is to make sure you get servos that are a) digital and b) continuous rotation (aka '360').
Obviously going down this route mean you need to do the mixing in the transmitter, though as Kyro has pointed out, this has its own advantages as you can fine tune things like dual rate and exponential response.

There's a lengthy thread on the subject of using digital C/R servo boards here: http://robotwars101.org/forum/viewtopic.php?f=1&t=2861

With the right servo boards and receiver you can make your own version of Shakey's classic Nano2. Won't be as slick but should still be nice and compact. Here's one of my early attempts, using a Redcon CM421 4-ch DSM2 receiver (with the pins removed) and a pair of Feetech servo boards. The tiny jst-ph plug in the 2nd pic BTW is what I use as bind connector.

Image
Image

I've made a few versions of this basic design and several of our robots are using them now. Don't know how much power those controllers would take before burning up but I've had no issues running 4WD pushers with standard N20 motors on 2S lipos. I've also done some spinner variants, with one of the tiny yep 7A brushless controllers from HobbyKing sandwiched in as well - that's what my son's drum spinner ''Recycler' was using at AWS 60 to good effect.

My latest project is a Fleaweight (75g) vert spinner, which uses a similar combo, but with the tiny Orange Rx R614xn receiver:
Image
Clockwise from top, you've got the switch, a tiny strip of Veroboard for the Gnd and Vcc buses, the Rx, brushless controller, and two of the latest Feetech FT90R servo boards.

Image
Those pics were just during testing - obviously I'll shorten some of the wires and neaten the whole thing up before cramming it into the robot!

So - making you own ESCs is a bit more work but can be cheaper than buying ready-made versions, as well as allowing for a smaller, lighter electronics package. And you can decide where you want the wires coming out!
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LimaHotel
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Re: ESC questions & why not USA shipping

Post by LimaHotel »

I will mention that servo boards do not have a built in bec for your receiver. Some receivers are perfectly happy with full 2s lipo, some aren't. If you do need to get a bec to go with it though, they don't add much.
A grabber? I CHALLENGE IT WITH JIGGY!
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