Total cost?

All things antweight

Moderators: BeligerAnt, petec, administrator

User avatar
Shakey
Posts: 1119
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: Total cost?

Post by Shakey »

Yeah you could just ask rory and buy a kit without RX attached then plug in your own.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!
Yard
Posts: 6
Joined: Sat Jan 02, 2016 7:25 pm
Location: Devon

Re: Total cost?

Post by Yard »

Sorry to be another person to piggyback off this thread with their own question, but what kind of basic tools are needed for antweights and does this tend to affect cost much? I know a soldering iron would be a must, for example.
User avatar
Rhys
Posts: 738
Joined: Tue Oct 29, 2002 12:00 am
Location: Caerphilly, South Wales

Re: Total cost?

Post by Rhys »

It depends on your design really. At the most basic you could probably get away with a soldering iron, pliers, mini screwdriver set, scissors, Stanley knife, a file, a ruler and some gaffer tape.

Luxuries might involve a multi tool, 3d printer and a lathe or mill.
Image
Yard
Posts: 6
Joined: Sat Jan 02, 2016 7:25 pm
Location: Devon

Re: Total cost?

Post by Yard »

That doesn't sound too bad. I'd probably be keeping it basic for my first build anyway. Thanks!
Skillz
Posts: 34
Joined: Tue Aug 23, 2016 4:07 pm
Location: Birmingham

Re: Total cost?

Post by Skillz »

I haven't built anything yet but I purchased a dremel that gives me a lot of options. Also considering a 3D printer but it's not essential
Team Shinobi
hobojoe
Posts: 5
Joined: Thu Sep 01, 2016 1:02 pm

Re: Total cost?

Post by hobojoe »

Thanks guys, I get Rorys kit is the best thing to start with but putting together the electronics for me will not be an issue.
I just need to understand how motor control is achieved and I am set. Still reading to figure this out. "you cant fix what you dont understand" is something I have come to learn.
User avatar
joey_picus
Posts: 1137
Joined: Tue Jan 13, 2009 1:51 pm
Location: Lancaster, Lancashire
Contact:

Re: Total cost?

Post by joey_picus »

From what I've seen, it's always more difficult than you think it is and you must sacrifice at least the first four or five revisions to Our Lord And Saviour George Francis in a cloud of ritual smoke until you have something that works! Good luck with it if you do though - my (non-technical) advice is to see if you can package any controller in a unit with a small 2.4ghz reciever in order to have all the electronics in one module. It makes things a lot more convenient!
Joey McConnell-Farber - Team Picus Telerobotics - http://picus.org.uk/ - @joey_picus
"These dreams go on when I close my eyes...every second of the night, I live another life"
User avatar
Shakey
Posts: 1119
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: Total cost?

Post by Shakey »

So rorys kit and buying your own ESC's and plugging them into an RX are basically the same. The only difference is plugging, realistically if either option breaks it's not a self repair job, it'll require swapping microchips or IC's.

Now on to how ESC work:

The Servo Signal
So the signal that comes out the receiver is known as PWM signal. Let's use seconds as they're nice and big. Imagine every 3 seconds you turn the wire on, depending on how long you turn the wire on represents a number from 1-100%. Turning the wire on for 1 second is 0%, turning it on for 2 is 100%. So your receiver changes this length of turning the wire on to send information. Only now imagine instead of every 3 seconds it does this many times per second.

The ESC
Now that bit of information can't control a motor directly, this is where the ESC steps in. The ESC reads this number from the wire to now how much power to put in the motor. So if the signal is 100% the ESC is turning the motor on fully. It does this much like the receiver. Only it wants power not information, so if we want 100% power it turns the wire on for 3 seconds every 3 seconds. This means it basically doesn't turn it off. If it wants to stay still it turns it on for 0 seconds every 3 seconds, half power is 1.5 seconds every 3 seconds and so on. This is also PWM (but a slightly different kind) and this on and off action is known as switching in ESC's.

Wiring this
All you need to do is plug the servo leads into the receiver and connect the power wires to the battery and the motor wires to the motor. There's honestly not much to learn in this section. If you have more than one speed controller (2 single channels etc.) it's a good idea to remove one of the red servo wires so only one goes to the receiver, this is because both ESC's are providing power at the exact level for the receiver. If both of them try to do this they may disagree on what is exactly the right power and this disagreement can damage the part of the ESC that provides it so only 1 should be used.

Honestly I recommend one of Rorys ESC's+Receiver as I don't think there is much to learn in this wiring step. You get one of the most robust ESC's available in a small, lightweight package already with receiver. It's also a known quantity, so many ants run them and failures are very rare. It simplifies the bot this is a good thing. The less wires to come loose or be yanked out the better. In fighting robots the name of the game is to keep it simple!
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!
hobojoe
Posts: 5
Joined: Thu Sep 01, 2016 1:02 pm

Re: Total cost?

Post by hobojoe »

Thanks Shakey,

I get that you cant just repair an ESC, but you can carry spares and should one pop, swap it out. But thanks for the write up, what I took from it is that looking at motor "drivers" isnt really what I should be looking for, but going out to find brushed ESC's.

I run an FrSky Taranis as my transmitter so mixing for the channels ect will be managed from the radio as there is a lot of control that can be added to it.

I have all the electronics on order, as well as some carbon fibre for the chassis (its a gamble). Looking forward to it all arriving. Sadly the motors are going to be ages.

Thanks for the help.
User avatar
Shakey
Posts: 1119
Joined: Sat Mar 13, 2010 8:38 pm
Location: Reading

Re: Total cost?

Post by Shakey »

My point was to go for something known and trusted to work.

I think you're falling for a common mistake of thinking there needs to be more complexity behind the machines.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!
Post Reply