How to make an antweight

[Laser]

Hello everyone,

This has come up a lot on the FRA and robotwars 101 so I'm going to make a guide on how to make an antweight robot.
So let's get started,

The Basics

Antweight robots have to weigh under 150g and fit in a 4 cube.
for more info on the rules visit http://www.antweight.co.uk/rules.htm

Preparing the robot

Building an antweight can be very dangerous if you use tools incorrectly, so if in doubt get a parent to do it or supervise you.

First of all you will want to think of the type of robot you want to build e.g. pusher, axe, spinner(not recommended for beginners) or a flipper. In this guide we will be making a pusher.

Then start doing sketches on what you will want your robot to look like.

Then you will need to get all your components together.

Parts

This is what I used

dsm2 rx http://www.ebay.co.uk/itm/Orange-6ch-Re ... 27c1a4ad3e
Spektrum dx5e http://www.horizonhobby.co.uk/aeroonlin ... 6dx5e.html
160mah 1s lipo http://www.hobbyking.com/hobbyking/stor ... _Etc_.html
300rpm micro motors http://www.ebay.co.uk/itm/6V-300RPM-Tor ... 3366bf48bd
Sabertooth 2x5a http://www.technobotsonline.com/saberto ... 30698.html
1.2mm aluminium http://www.forwardmetals.co.uk/acatalog ... mm_48.html
2mm HDPE http://www.directplasticsonline.co.uk/H ... Black/2mm/

Tools needed

Saw of some sort(preferably a hack saw)
scissors
tin snips
ruler
scribe
soldering iron and solder
drill(hand or pillar)
2.5mm and 3mm drill bit
m2.5 bolts and nuts
m3 bolts and nuts


Let's get started

Step 1

I made the base out of 1.2mm aluminium to cut it I used a hack saw. I marked out an 90mm x 110mm rectangle. I then marked 10 mm from the 90mm edge and folded both sides. To fold the sides I put it in a vice and hit it with a hammer

Here is it on my hand for size


Step 2

I then got all the components together, this is what they look like
The sabertooth 2x5a with micro motors on

The reciver(rx)



You can either use 2 1s lipos wired in series or 1 2s lipo



The wheels I used are Lego wheels that I modded so they screw onto the shaft of the motor directly



Step 3


I then placed all the components on the base to see where they would go


Step 4

I then made mounts for the motors out of 10mm x 45mm strips of 2mm HDPE.
I marked out 6mm from the edge then 10mm, then 12mm, then 10mm again.
I then got my soldering iron to heat up across the line to bend them at right angles to make this.



I held the motor in with double sided sticky pads.

Step 5

I marked out 5mm from the edge a 12 x 30mm rectangle, I then cut it out for the wheels to go.


I did this on both sides.

Step 6

I drilled 4 3mm holes(2 on either side) on the motor mounts to attatch them to the base. I then drilled through the plastic and into the metal. I then bolted the 2 together by using m3x5 bolts and fastened them with 3mm nuts




Step 7

I then needed to mount the sabertooth 2x5a. I couldn't mount it directly to the base as it is metal and it would short circuit. So I made a 2mm Hdpe base. I measured around the sabertooth, marked it on the 2mm hdpe and cut it out with scissors. I then drilled 2 2.5mm holes, where they are on the sabertooth, into the hdpe and the into the aluminium. I then fastened them together using m2.5x10mm bolts and nuts



I then got the rx and put 2 layers of tape on the bottom of it so it couldnt short circuit, and then used double sided sticky pads to stick it on the motor mount




Total weight so far


Step 8

I used double sided sticky pads to hold the battery down


Step 9

I used 2mm HDPE as armour. I marked out a 160mm x 90mm rectangle and cut it out with scissors



I then marked 30mm from either end of the hdpe.
!!THE NEXT PART IS DANGEROUS!!

I got a pan and put some boiling water in and then put the HDPE in. I then let it heat up for 30 seconds then took it out and bent along the line to 90*. I did this on either side to make this


Step 10

Put the armour on your robot

[Bodge Job]

Looking good, but maybe a wireing diagram would help? As that is one of the most ask things is how to wire it up (with out the magic smoke pouring out)

[razerdave]

Thats a very good starter guide Ben, well done

[harry hills]

The question of how do I wire up my robot gets asked all the time. This is a rather lengthy guide with pictures to try and answer the questions.

This guide is aimed at using 2 cell lipos, however it can be extended to 3 cells please do not try to run servos on 3 cells. Also I can't be taken responsable if you want to run parts above there recomeded voltages and they break - its your choice!

The guide is split into 3 sections with pictures referenced below. Each section will have a simple sum to find out what you need, if your number doesn't reference a picture then you are doing something odd or silly. For instance running motor drive on 5V when you have a 2 cell lipo. How difficult it will be to make each set up is shown in brakets, not including modifing drive servos (eg 1/5 is easy, 5/5 requires lots of soldering)

Section A is for pusher/ram bots
Section B covers servo and spinner weapons
Section C has additional information
I will try and include a Section D later for Pete W control boards

For voltage regulators please see this guide:
http://www.windisch.co.uk/robots/how..._regulator.htm


----------------------------------------------------------------------
Section A - Pusher/Ram robots

A little bit of maths for you to ask what you want in your robot

Start with 0:

Drive
Servo drive +0
Motor drive +1

What voltage do you want to run on
4.8V (4 cell NiMh/Nicad) / 5V regulated/ 6V (5 cell NiMh/Nicad) +0
7.4V (2 cell lipo) +2

What type of battery are you using
NiMh/Nicad +0
Lipo +4

Please see the following picture labeled A# for how to wire the robot

A0 - servo drive with NiMh (0/5)


A1 - Motor drive NiMh only need the extra wire if running on 4.8V(2/5)


A4 - Servo drive Lipo (2/5)


A6 - Servo drive on Lipo Voltage (3/5)


A7 - Motor drive on Lipo Voltage (1/5)



------------------------------------------
Section B - Weapons

Use the sum to get to the picture that is right for you

Start with 0

Drive
Servo +0
Motor +1

What voltage will this run on
4.8V (4 cell NiMh/Nicad) / 5V regulated/ 6V (5 cell NiMh/Nicad) +0
7.4V (2 cell lipo) +2

What weapon
Servo +0
Motor +4

What voltage will this run on
4.8V (4 cell NiMh/Nicad) / 5V regulated/ 6V (5 cell NiMh/Nicad) +0
7.4V (2 cell lipo) +8

What type of battery will you be using
NiMh/Nicad +0
Lipo +16

Please see the following picture labeled B## for how to wire the robot

B0 - Servo drive and servo weapon (0/5)


B1 - Motor drive and servo weapon (3/5)


B4 - Servo drive brushed motor weapon (3/5)


B5 - Motor drive brushed weapon (4/5)


B16 - All 5V servos lipo battery (2/5)


B18 - Servo drive on 7.4V weapon servo on regulator (3/5)


B19 - Motor drive on 7.4V weapon servo on regulator (New anticide set up) (2/5)


B24 - Drive servos on regulator weapon servo on lipo (3/5)


B26 - All servos running on lipos (4/5)


B27 - Motor drive and servo weapon on lipos (3/5)


B28 - 5V servo drive lipo spinner (3/5)


B30 - lipo servo drive and spinner - do not try on 3 lipo (5/5)


B31 - motor drive and spinner (kwijebo set up) (4/5)



------------------------------------------------------------------
Section C - Additional information

C0 - flip channel on sabertooth controller to reverse drive when upside down (0/5)


C1 - A battery charge point can be added so the batteries don't need removing to charge them (2/5)


C2 - This is about as complicated as an antweight can get, when the BEC voltage regulator on a motor control board isn't powerful enough a secondary one needs to be added. Also shown in the charge port.



------------------------------------------------------------------------

Any feedback is useful, or please suggest other set ups that aren't covered. I hope this helps future builders.

[Laser]

Looking good, but maybe a wireing diagram would help? As that is one of the most ask things is how to wire it up (with out the magic smoke pouring out)

I forgot to add that

Thats a very good starter guide Ben, well done

Thanks Dave

[razerdave]

Just need to get you to an AWS now :P

[Laser]

Just need to get you to an AWS now :P

ah thats not all of the robot thats just the rolling chasis. that is the rolling chasis of Evil Pig Sty II

[Laser]

Thanks to the mod who just stickied it

[kane]

:wink:

[PJ-27]

Very nicely made, sticky worthy.