Hi Friends,
I'm about to attempt to build my first ant weight robot with my 7 year old and have no previous robot or electronics experience. I've been reading this awesome tutorial and think I understand most of what needs to be done:
http://homepage.ntlworld.com/g0xan/robo ... iagram.htm
Using the links/codes in the tutorial come up with the list of components below, do this look OK?. The only thing I'm not clear on is the speed controller, in the tutorial it mentions using re-purposing a 'servo controller board' I'm not 100% sure go to go about this and what to buy, could someone help me out?
Transmitter
Planet T5 -£51.99
http://www.coolcomponents.co.uk/catalog ... p-910.html
motors
pololu 50:1 Micro Metal Gearmotor HP - £13.00
http://www.hobbytronics.co.uk/mm-gear-m ... =MMGEARMOT
wheels
Pololu Wheel 32x7mm Pair - Black - £5.50
http://www.hobbytronics.co.uk/wheel-32-7?keyword=1087
Pololu Wheel 42x19mm Pair - £5.50
http://www.hobbytronics.co.uk/wheel-42- ... lu%20wheel
motor bracket
Pololu Micro Metal Gearmotor Bracket Extended Pair - £3.79
http://www.hobbytronics.co.uk/motor-con ... racket-ext
weapon servo
Sparkfun Medium Servo - £8.95
http://www.hobbytronics.co.uk/medium-se ... ol%20servo
Voltage regulator
7805 5V 1A Voltage Regulator - £0.40
http://www.hobbytronics.co.uk/voltage-r ... ord=MC7805
switch
Switch Harness with BEC Connector- £4.31
http://www.technobotsonline.com/switch- ... ector.html
battery
HYPERION G3 CX-25C 0320-2S LIPO - £6.92
http://robotbirds.com/catalog/product_i ... ts_id=5743
charger
GT Power B606 balance Charger Li-po NI-MH Battery -£20.50
http://www.giantshark.co.uk/product/170 ... mh-battery
Thanks!
Simon
First Robot
Moderators: BeligerAnt, petec, administrator
- longhairedsi
- Posts: 2
- Joined: Wed Sep 11, 2013 8:19 pm
- Location: Hurstpierpoint, Sussex
Re: First Robot
Hi Simon,
That's a pretty solid looking list of components. The charger looks like a rebadged Accucel 6, which I've used for antweights and featherweights, and is more than up to the job. You will also need a DC power supply to power it. The motors, transmitter and wheels/brackets have all been used before to good effect. The only unknown quantity would be the servo, I've never seen anybody use one of these. But Sparkfun have a pretty good reputation, so I wouldn't worry about that. What do you need a 180 degree servo for? Or is it top secret?
The battery is a fair bit bigger than you would really need for competition. But if you can spare the weight, then that's fine. The one you've linked to is 320mah. I generally use 120mah for a fliper/pusher, and 180mah for a spinner. It's only a saving of about 6-10g, but every bit counts!
As for the speed control, if you want to 're-purpose a servo control board', then get the biggest, cheapest servo you can. Usually you can get a 50g servo for about a fiver. You will need one for each motor. Something like this would be ideal. Take it apart and you will see a small motor. Solder this out of the servo control board, and then solder your pololu motor in its place. Sadly though, I don't think servo boards will handle a HP motor, you may have to go with the standard pololu motors. Or get a proper speed controller.
That's a pretty solid looking list of components. The charger looks like a rebadged Accucel 6, which I've used for antweights and featherweights, and is more than up to the job. You will also need a DC power supply to power it. The motors, transmitter and wheels/brackets have all been used before to good effect. The only unknown quantity would be the servo, I've never seen anybody use one of these. But Sparkfun have a pretty good reputation, so I wouldn't worry about that. What do you need a 180 degree servo for? Or is it top secret?
The battery is a fair bit bigger than you would really need for competition. But if you can spare the weight, then that's fine. The one you've linked to is 320mah. I generally use 120mah for a fliper/pusher, and 180mah for a spinner. It's only a saving of about 6-10g, but every bit counts!
As for the speed control, if you want to 're-purpose a servo control board', then get the biggest, cheapest servo you can. Usually you can get a 50g servo for about a fiver. You will need one for each motor. Something like this would be ideal. Take it apart and you will see a small motor. Solder this out of the servo control board, and then solder your pololu motor in its place. Sadly though, I don't think servo boards will handle a HP motor, you may have to go with the standard pololu motors. Or get a proper speed controller.
- BeligerAnt
- Posts: 1872
- Joined: Wed May 15, 2002 12:00 am
- Location: Brighton
- Contact:
Re: First Robot
Hi Simon, welcome to the forum.
One thing you might need to consider with the Planet T5 is the issue of mixing. Antweights use "tank style" steering and to give a normal response to a joystick they require the 2 joystick channels to be "mixed". Basically one wheel responds to the sum of the forward/reverse and left/right channels, the other motor responds to the difference.
The Planet T5 doesn't include mixing so you would need to add a mixer into the robot. Alternatively you could look for a transmitter with mixing built in - it saves a little weight in the robot! You need "elevon" or "delta wing" mixing - consider the Spektrum DX4e. Alternatively an on-board mixer is not very expensive.
If you go for the DX4e you will need to buy a separate receiver. There are several "DSM2 compatible" receivers which have been used in many ants, you don't need to splash out for a genuine Spektrum one.
One day I will get round to writing a step-by-step guide to making a speed controller out of a servo board but it's unlikely to be very soon. I haven't had a problem with using servo boards with the HP motors, but others have reported that they don't last too long.
Good luck with the build, keep us posted!
One thing you might need to consider with the Planet T5 is the issue of mixing. Antweights use "tank style" steering and to give a normal response to a joystick they require the 2 joystick channels to be "mixed". Basically one wheel responds to the sum of the forward/reverse and left/right channels, the other motor responds to the difference.
The Planet T5 doesn't include mixing so you would need to add a mixer into the robot. Alternatively you could look for a transmitter with mixing built in - it saves a little weight in the robot! You need "elevon" or "delta wing" mixing - consider the Spektrum DX4e. Alternatively an on-board mixer is not very expensive.
If you go for the DX4e you will need to buy a separate receiver. There are several "DSM2 compatible" receivers which have been used in many ants, you don't need to splash out for a genuine Spektrum one.
One day I will get round to writing a step-by-step guide to making a speed controller out of a servo board but it's unlikely to be very soon. I haven't had a problem with using servo boards with the HP motors, but others have reported that they don't last too long.
Good luck with the build, keep us posted!
Gary, Team BeligerAnt
Re: First Robot
Found this online a while back, is what im planning to use:BeligerAnt wrote:One day I will get round to writing a step-by-step guide to making a speed controller out of a servo board but it's unlikely to be very soon. I haven't had a problem with using servo boards with the HP motors, but others have reported that they don't last too long.
http://www.rcgroups.com/forums/showthread.php?t=1715896
- longhairedsi
- Posts: 2
- Joined: Wed Sep 11, 2013 8:19 pm
- Location: Hurstpierpoint, Sussex
Re: First Robot
Thanks guys, very helpful!
@duff
@BeligerAnt
@danjr1
@duff
Hahaha, i wish i had a secret plan but it's more of me not really knowing what to buy .What do you need a 180 degree servo for? Or is it top secret?
Nice info, i didn't know what HP meant, guessing now it's High Power or such like? I'll have a look at proper speed controllers and smaller motorsAs for the speed control, if you want to 're-purpose a servo control board', then get the biggest, cheapest servo you can. Usually you can get a 50g servo for about a fiver. You will need one for each motor. Something like this would be ideal. Take it apart and you will see a small motor. Solder this out of the servo control board, and then solder your pololu motor in its place. Sadly though, I don't think servo boards will handle a HP motor, you may have to go with the standard pololu motors. Or get a proper speed controller.
@BeligerAnt
Nice info, i think I'm going to switch to a Spektrum, I'm trying to keep the build as simple as possible for now.The Planet T5 doesn't include mixing so you would need to add a mixer into the robot. Alternatively you could look for a transmitter with mixing built in - it saves a little weight in the robot! You need "elevon" or "delta wing" mixing - consider the Spektrum DX4e. Alternatively an on-board mixer is not very expensive.
@danjr1
Nice!Found this online a while back, is what im planning to use:
http://www.rcgroups.com/forums/showthread.php?t=1715896