After the esc, the other stuff - simplistic questions

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minionhunter
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After the esc, the other stuff - simplistic questions

Post by minionhunter »

I started to ask about other, non-esc questions I had in the esc thread, so I thought I would move them here to avoid cluttering the esc thread when I need to come back to that.

I'm building initial bots (and arena) for myself and kids:
I ordered 4x flysky FS i6 transmitters
(I'll need to ask about mods for this later)
Some fs2a rx for them
(and some extras)
A bunch of cheap esc's from ebay
(I'll need to add some resistors for braking)

Now I need to ask some simplistic questions about other components (no spinner questions here! I can save those for after I get finished with these starting bots)


What am I looking for in a servo for flippers (and what is deemphasized in lifters) . Torque? Speed?

N20 motors - what do I look for here? In buying, Is it worth it to buy a bunch of them cheaply and toss out the bag ones? Again I'm buying for a bunch of bots so maybe so for me.

Is it more productive to buy motor mounts if you don't own a 3D printer or better to order prints of them?

Batteries - I'm assuming I want to use 2s lipo batteries. What do I look for in these? Also should I get a charger for each person or each bot, or are there good chargers that will charge multiple batteries at the same time? What is worth paying more for?

Lipo boxes, do I get one for each battery that I'll charge at the same time? (I'm planning for 4 people) Anything to look for here? Is it good to have extras?

Chargers - what do I look for here? Speed, rating, etc...

Power supply, similar questions

Tires and wheels - are these something to purchase or make since they seem to be destroyed easily? I seem to see that a lot of bots seem to have matched colors and that seems like people make their own. Plus if you need a custom size this seems like making your own is sensible. I haven't looked into this yet. I'm guessing the wheels are printed and tires are cast in silicone. I've done some mold making and casting before.

What type and guage of wire is typically used to connect the parts?

What type of fasteners are typically used to secure parts to the chassis?

I think that's about it for now.

Thank you again very much for your time and help. I'm grateful.

minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Lima's reply from the other thread

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.

minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Also I'm not opposed to spending a little more for quality when it counts.

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Ocracoke
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Re: After the esc, the other stuff - simplistic questions

Post by Ocracoke »

To try and answer a few more of your questions:
What type and guage of wire is typically used to connect the parts?
I typically use 26AWG wire, which I believe is the sort of wiring you'd see on standard JR servo connectors anyway. Never had one burn up on me in the AW class, whatever it is connected to usually dies first (though I have seen that sort of wire catch fire in the heavier classes I fight in before - that was spectacular)
What type of fasteners are typically used to secure parts to the chassis?
I typically use M3 style bolts and cut down where I can. If I need to save weight, I'll use Nylon style M3 bolts and nuts but I've also used bog standard computer case type screws into polycarbonate or wood before and even some generic small self tappers.
Lipo boxes, do I get one for each battery that I'll charge at the same time? (I'm planning for 4 people) Anything to look for here? Is it good to have extras?
I'd typically use one bag and charge as required. All of my robots use 300+mAh batteries (and because I am a rubbish driver :P), I typically find this will last me as long as my involvement in the competition. However, what I do is bring an extra fully charged battery with me and then swap out to that one when one runs down, get that on charge and use the other one and swap again when needed.
Batteries - I'm assuming I want to use 2s lipo batteries. What do I look for in these? Also should I get a charger for each person or each bot, or are there good chargers that will charge multiple batteries at the same time? What is worth paying more for?
Depends on the robot. 2S is a standard but I've heard of 3S Ants as well. For something like a spinner, I'd look for a battery with a high constant C rating and highish capacity but I know Shakey, who is way more experienced with spinner ants than I am, uses 180-210mAh batteries based on what I've read before. Lafiel uses a 2S 35C constant/70C burst 300mAh battery which should be sufficient.

I would honestly stick with a single charger and get multiples of those if needed. Chargers that can handle multiple batteries are quite expensive and similarly, to expand on a earlier remarkIs it more productive to buy motor mounts if you don't own a 3D printer or better to order prints of them? , I'd have one bag per charger as well. It might be a bit overkill but safety first and so on.

With regards to the power supply, the charger I use (Turnigy Accucell 6) runs off of a laptop power supply. Depending on which charger you get, you may get one with it, you'll have to check before you buy.
Is it more productive to buy motor mounts if you don't own a 3D printer or better to order prints of them?
For the price here, I just buy a pair as and when I need them. They shouldn't take too long to print if you do need to print them.
Team Kaizen

AW: Amai, Ikari, Lafiel, Osu, Ramu
BW: Shu!, The Honey Badger
FW: Azriel
MW: Jibril, Kaizen

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MarkR
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Re: After the esc, the other stuff - simplistic questions

Post by MarkR »

About motors - there are some "N10" motors for sale on Aliexpress (thanks for the tip-off, George), I just got some of these:

https://www.aliexpress.com/item/3292382 ... b201603_53

They are a few mm shorter and slightly lighter than N20, I've not tried them yet, but they arrived much sooner than I expected (I thought they wouldn't turn up until after Chinese New Year). I ordered 700rpm 6v variant, that might be too fast, I'll find out soon.
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands

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Kyro
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Re: After the esc, the other stuff - simplistic questions

Post by Kyro »

motor mounts for me are cable ties (zip ties across the pond)

i use 2s 180mah lipo's in every build...

a lipo bag large enough to fit my whole bot in to charge it to save me needing to remove it from the bot each time i charge it.

i use nylon m3 standoffs and m3 machine screws with half nuts for most of my securing (nylon m3 nuts and bolts for parts that wont take much of a beating to save weight if needed)

26awg is mostly what i use (comes standard on most ant sized parts)

as for servo's, for reliable power at a really good price, towerpro mg92b servo's are great... not fast but will lift anything antweight with ease...
there are faster and more powerful ones available but at a cost... it depends on what you want from them really...
Esper and Mantis both run mg92b's for lift so that will give you an idea of speed/power although mantis uses a much faster servo for the grab at about 2.6kg/cm@7.4v (the mg92b runs from 6v)

for wheels i use pololu 32x7mm wheels as these give me plenty of grip... there are other options available from people that make and sell their own which work well (never used them but never hear complaints from those who do, they are just never available in pololu size so i am unable to swap mine out without needing to modify/rebuild my robots)
Team Rocket
Esper(4wd flipper)
Mantis (4wd grab 'n' lift)
Dominus (Vert SPINNAAH)
Breakout(modular cluster)
Remembering Rex (antweight cassius)
Fennec (4wd flea) former world champion

minionhunter
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Joined: Fri Nov 04, 2016 5:36 pm

Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Kyro wrote:
Tue Jan 28, 2020 8:25 pm
motor mounts for me are cable ties (zip ties across the pond)

i use 2s 180mah lipo's in every build...

a lipo bag large enough to fit my whole bot in to charge it to save me needing to remove it from the bot each time i charge it.

i use nylon m3 standoffs and m3 machine screws with half nuts for most of my securing (nylon m3 nuts and bolts for parts that wont take much of a beating to save weight if needed)

26awg is mostly what i use (comes standard on most ant sized parts)

as for servo's, for reliable power at a really good price, towerpro mg92b servo's are great... not fast but will lift anything antweight with ease...
there are faster and more powerful ones available but at a cost... it depends on what you want from them really...
Esper and Mantis both run mg92b's for lift so that will give you an idea of speed/power although mantis uses a much faster servo for the grab at about 2.6kg/cm@7.4v (the mg92b runs from 6v)

for wheels i use pololu 32x7mm wheels as these give me plenty of grip... there are other options available from people that make and sell their own which work well (never used them but never hear complaints from those who do, they are just never available in pololu size so i am unable to swap mine out without needing to modify/rebuild my robots)
Thank you!

Another poster posted this in a different thread (noob questions) MichaelG I think
"
I'm currently using this, the KST DS215MG. Yes, it's a bit pricey, but a very fast servo so will give your flipper a bit extra oomph. https://www.ebay.co.uk/itm/KST-DS215MG- ... SwVzRaq4s7 "

Is this like you would get for a fast servo for a flipper or your grabber?

minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

I just want to say thank you to all of the posters for your help. I'm going to have a lot to research tonight

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Kyro
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Re: After the esc, the other stuff - simplistic questions

Post by Kyro »

that particular servo would be overkill for the grab on Mantis.

but it is ideal for a flipper with a decent bit of ooomph... its a faster servo than the mg92b i mentioned, but costs 4x more.

the servo you choose depends on what you plan on using it for... and your driving style

so the KST is ideal for a flipper that will throw your opponent with a decent bit of force...

the ones i mentioned are ideal for lifting, i dont want to throw my opponent away from me with Esper, i want to get under them and push them around while lifting half or more of their robot away from the floor they need to grip onto to push back... Mantis also doesn't need a fast lift as lifting too fast will throw it off Ballance and make it fall over due to it now being very top heavy...

the grab servo i use is much faster as getting a grip fast is more important than a fast lift with mantis... but i dont need huge power (i used to use mg90 servo for the grab and that was enough to hold flippers shut using much more powerful servo's)

so you need to think about what you want from your servo before choosing which to buy...
Team Rocket
Esper(4wd flipper)
Mantis (4wd grab 'n' lift)
Dominus (Vert SPINNAAH)
Breakout(modular cluster)
Remembering Rex (antweight cassius)
Fennec (4wd flea) former world champion

minionhunter
Posts: 158
Joined: Fri Nov 04, 2016 5:36 pm

Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Kyro wrote:
Tue Jan 28, 2020 9:01 pm
that particular servo would be overkill for the grab on Mantis.

but it is ideal for a flipper with a decent bit of ooomph... its a faster servo than the mg92b i mentioned, but costs 4x more.

the servo you choose depends on what you plan on using it for... and your driving style

so the KST is ideal for a flipper that will throw your opponent with a decent bit of force...

the ones i mentioned are ideal for lifting, i dont want to throw my opponent away from me with Esper, i want to get under them and push them around while lifting half or more of their robot away from the floor they need to grip onto to push back... Mantis also doesn't need a fast lift as lifting too fast will throw it off Ballance and make it fall over due to it now being very top heavy...

the grab servo i use is much faster as getting a grip fast is more important than a fast lift with mantis... but i dont need huge power (i used to use mg90 servo for the grab and that was enough to hold flippers shut using much more powerful servo's)

so you need to think about what you want from your servo before choosing which to buy...
Cool. I'm going to have to drill down with the kids about exactly what they want their bots to do. So are there situations where one would want to switch to a motor instead of a servo? Again not spinners, I'm not there yet, just lifters and flippers, maybe a 4 bar linkage.

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