After the esc, the other stuff - simplistic questions

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

Post by Kyro »

imo, servo's are the best to begin with over motors to power lifter/flippers... motors are good for axe's though but would require another esc to be wired in to make it work where as servo's have their own built in esc's so i would say to stick with servo's all the way as there are more options available...
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Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
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minionhunter
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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)
Sorry I just thought about this.

Cable ties: Do you punch holes in the bottom to get them to work? Like wrap around the motor and through the bottom of the bot? Or do you fasten them with a different method of attachment like screws? That's pretty creative and I would guess saves some weight.
minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Kyro wrote: Tue Jan 28, 2020 10:36 pm imo, servo's are the best to begin with over motors to power lifter/flippers... motors are good for axe's though but would require another esc to be wired in to make it work where as servo's have their own built in esc's so i would say to stick with servo's all the way as there are more options available...
Cool. Nope, not into axes, spikes or hammers.

I do need a way to explain how much I'm spending on this to my wife... Or I need to figure out how to hide or disguise it.
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Kyro
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Re: After the esc, the other stuff - simplistic questions

Post by Kyro »

i do indeed make holes and slip cable ties through... unless 1 takes a direct hit from a spinner, they are plenty strong enough... I usually have 2 per motor... the weight of 8 cut to size to hold motors weighs barely 1g in a 4wd bot.
Team Rocket
Trappist 1(4wd grab 'n' lift)
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minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Do you get servo arms with the servo or do you have to purchase them separately? I can't really tell from the ones I've seen on the sites what exactly comes with them. Some are really vague and have tons of pictures. I'm trying to buy a bunch at once to save but I run into the problem of what comes with them.

Also for servos - am I supposed to be looking at the speed and the force they generate for what I want to use them for?

So other considerations then, would be weight, plastic gears and box, and if they are continuous rotation? I think I have that right.
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Kyro
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Re: After the esc, the other stuff - simplistic questions

Post by Kyro »

servo's usually come with 4 horns, the horn screw, attachment screws and sometimes rubber grommits with little brass inserts...

what i look for in a weapon servo is metal geared, weight, power and speed...

however none of this matters if you're looking for servo's to use the esc's from for drive...

you want to look for voltage and 360° rotation mainly...

ones that can take direct 2s voltage are better for esc's...

ideally, also look out for ones that have an adjustment screw built into the main board (usually a hole for access on the bottom of the servo) which allows you to adjust where "0" is... once set a blob of hot glue to keep them set is handy...
Team Rocket
Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
Io(4wd flipper)
minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

Kyro wrote: Wed Jan 29, 2020 9:11 pm servo's usually come with 4 horns, the horn screw, attachment screws and sometimes rubber grommits with little brass inserts...

what i look for in a weapon servo is metal geared, weight, power and speed...

however none of this matters if you're looking for servo's to use the esc's from for drive...

you want to look for voltage and 360° rotation mainly...

ones that can take direct 2s voltage are better for esc's...

ideally, also look out for ones that have an adjustment screw built into the main board (usually a hole for access on the bottom of the servo) which allows you to adjust where "0" is... once set a blob of hot glue to keep them set is handy...
Are the tower pro mg90 and mg92 that you use metal geared? I see tons of these on ebay and they don't all look the same. For the nylon geared ones I see prices around $10 for 10 of them with $0.50 shipping. Even the metal geared MG90 are similar in price. While the KST DS215mg is $30 with $3 shipping as the absolute best price I've found (but free shipping if I go over $100 - so if I buy 4 that makes them $30 each). I realize the quality is higher for the kst but the price difference is enormous.

Also is there any advantage to buying the KST DS215mg over the Kingmax KM1203MD? They appear to be about the same. If I'm reading it correctly the torque looks higher on the kingmax but the speed might be slightly faster for the KST (but maybe not at the higher voltages of the 2s lipo). That makes me think the kingmax might be a little better.
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Kyro
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Re: After the esc, the other stuff - simplistic questions

Post by Kyro »

the mg90 and mg92b are very different servo's but do indeed have metal gears (mg in the name stands for metal gear)

for your use (fun for the kids) do you need to spend $120 on 4 servo's or would probably about $32 for 4 servo's (mg92b) be a better option?

the mg92b is the best servo i use and i find it fully capable for what i need it for... obviously if your needs are more then go for the kst or kingmax... but i doubt you would be disappointed with a mg92b...
Team Rocket
Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
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minionhunter
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Re: After the esc, the other stuff - simplistic questions

Post by minionhunter »

MarkR wrote: Tue Jan 28, 2020 7:32 pm 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.
I am ordering 10 of these. I'm going to order soon and was wondering if you know about the speed and if the 700 is too much or not. I'll just try the 700 if I don't hear back. That should be a good start.

Do you have a trusted seller on aliexpress for the n20 motors? I'll order a bunch. Maybe it is just seeing how it goes.
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Kyro
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Re: After the esc, the other stuff - simplistic questions

Post by Kyro »

700 is pretty fast, but if you follow my youtube link on how to set up mixing, it also shows how you can limit the top speed easily...

i use 600rpm motors but could happily go up to 700...
Team Rocket
Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
Io(4wd flipper)
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