Starting Point

[zoll]

Hi this is to be my first build, never having built a robot before I am unsure on quite a few things but initially so I can start to get the basics I want to build a very basic robot so not worried about which weight class it fits into for now and then go on to build another for fighting after I have the basics.

First couple of questions are;

I see alot of people using drill motors, how much power do these provide, ideally id like to be able to push a small child round on it, would I therefore need something abit more powerfull like wheel chair motors for example?

Obviously I need a transmitter, what is good starting point, after reading the forums I see most people saying DX6 or planet 5 can anyone recomend either of them or another one entirely.

[muchalucha]

First of a decide a weight class , from what you have said id recomend a feather weight.

some fetaher weights ( FW's) can push around a small child but 2 drill motors wont be up to it. If you want something with more power consider 2 electric scooter gearboxes or look at gold motors ( ask around).

As for the transmitter , planet t 5 2.4 ghz set £ 35 and you got a transimter receiver and on 2.4 ghz !!!

Good luck and welcome to the forum btw .

[zoll]

Cheers for the quick reply, I initially didnt want to limit myself to any weight class so I could just get to grips with the basics and then go on to probably build a FW.

Ive found the following links to motors, are they any good?
Technobots Feather Gold 12V 150W:
http://www.technobots.co.uk/acatalog...Motors_76.html
Scooter motors:
http://cgi.ebay.co.uk/24V-250-Watt-E...item230300239e
or Wheelchair motors
http://cgi.ebay.co.uk/Electric-Wheel...item1e591a48a7

Any with regards to the transmitter its not rli worth me spending extra and getting a different one? (I am on a budget but dont want to buy something thats only good once)

[calumco]

hey,
i would really recommend you look at all the build diary threads to have a look at how other people have gone about making their robots from feathers to heavyweights.

when i first started there was nothing harder then trying to find out what to do or what parts i needed - theres only so much that can be explained to you and looking at alot of build diaries i think would have been very helpful

i would recommend using cordless drills to start with, as they are near enough ready to attach a wheel onto once you've taken the chuck off.

i'd say get a dx5e for £70 or so, the cheaper £35 sets might say 2.4 ghz but they arnt always very reliable or of a good quality- people were talking about it on a thread a while ago somewhere on here.

if you went with 2 drill motors you would need 2 electronize speed controllers here, http://www.electronize.com/ one each of the 15 amp high power forward and reverse controllers,

then theres batteries either sealed lead acid batteries which is what i first used in my first robot, but you soon end up getting better ones and they will just get chucked on a shelf or NIMHs which are what i use from the seller vapertech on ebay.

there was a guy in a similar situation as you a few weeks/ months ago so you could mabye try finding his thread as theres aload of useful info on there.

[muchalucha]

sorry calum but im going to completely disagree with you :P.

I have used the planet T5 and the spektrum dx5 and i prfer the palnet t 5 , regardless of price. The dx5 feels cheap , its too light and just dosent have a nice feel , also the binding method is rather questionable. The planet T5 though feels a lot nicer , it is nicer to hold and use. This is purely subjective, but as for the interferance problems people have created about the planet T5 , well im gona say thats rubbish until any set produces any type of interferance ( hasnt happened yet).

As for motors , ifyou are definitely sure you want this bot to carry children (lol), then scooter motors would be your best bet. They are simialr to drill motors in that they come pretty much pre assembled witjh all the gearing done for you , but they have more power. If your after true power then a pair of gold motors would be good , but you will probably need quite a bit of help on the gearing.

As weight seem unimporant in tyour application id use the sla batteries that come with your scotters or the nicads that come with your drills. Youll get an acceptable run time and you get a charger to.

As for the esc's , if you have a veyr big budget and you dotn require that mcuh fine cotnrol then , (this pains me to say) get 2 electronize esc's. If your budget is smaller and you decide to go with drill motors then a sabertooth 10 A will be fine. If you end up using scooter motors or gold motors then a 15 A electronize is going to be right on the limit ( they relays in them are only rated to 10 A anyway !!!!!) . You coudl always use a switch or relay based system for any of these motors if money is tight.

EDIT: As for the wheel chair motors , they might be a little over kill and any bot you decide to make out of awheel chair is going to have to be a heavy weight , and tbh , no offence but its a bad idea to build a hevay weight as a first robot.

[RogueTwoRobots]

Hi Matt,

Welcome to the forum; plenty of advice to be had on here as you can probably see

Normally I would echo others on here and recommend a featherweight but as you've stated that a) you'd like to have enough power to push a kid around/let a kid ride on it and b) you're not too bothered about a weight class right now, then I think bigger is better in this case.

To have enough power for the 'kid' aspect, either wheelchair motors or scooter motors are the way to go in my view. Wheelchair motors can be quite cheap (like off eBay as you've posted) but are quite slow, so if you want power and speed then the slightly more pricey scooter motors are a good option. In most cases wheelchair motor assemblies are complete, in that they are a motor/gearbox/wheel in one; with the scooter motors, obviously a gear reduction method would be needed. Technobots has a good range of chain and sprockets for a pretty good price and Paul Cooper, the owner, has extensive experience of this sort of stuff and would be able to provide useful information or insights as to what would suit your project best.

What skills/tools do you have at your disposal? If you can weld, a well-designed fabricated box-section chassis would stand up to the punishment that robots take and wheelchair and scooter motors could both be welded or bolted in easily enough.

For radio gear, I'd say you can't go wrong with the Planet 5 system. It's 2.4GHz, and £35 so well suited to a budget. There have been concerns that the signal could be prone to interference due to it being seen as an 'inferior' substitute to the well-respected Spektrum range of equipment, but to date I can gather it has performed well (I currently don't own one myself)
Check out the 'safety issues' thread in the Safety Discussions section to read some posts on the topic.

I'd be best leaving batteries to someone more experienced in heavier machines, as I'm primarily a featherweight builder and am not too sure what is best/required for larger weight classes. You can't go wrong with sealed lead-acid batteries to be honest, but with the low-ish cost of A123s etc, the modern technology could serve you better.
What I will say is that batteries (and speed controllers) is an area where it's usually better to spend a bit more and get a better quality product that will last you longer and can be used in future builds, rather than something that might 'crap out' on you after a little bit of abuse.

Hope that helps you a bit, and good luck with your build

[typhoon_driver]

What weight is the child? When you say push around, are you after a radio controlled equivalent of one of those electric cars that you can get for kids but with a bit more oomph?

[banana_man]

If you wanted to push a small child around, I recommend using four drill motors for 4 wheel drive. Will Thomas's robot whirlpool uses this configuration and can push me around (we have tried it), and I'm no small child. I'm 16 and about 60kg! As to ESCs, I'm not sure, but electronizes are reputed to work with four drills. Other than that, I know that a Scorpion XL/XXL would work, but they are quite expensive.

[zoll]

Thanks for all the great advice so far it been really helpful. I said I wanted to be able to push a small child around not because I actually wanted to do it but because I was kinda unsure how best to describe what sort of power I wanted it to have. In rexs robot challenge I saw him ride on his and thought thats a fair amount of power, how much weaker are drill motors than this?

I dont currently own the materials or the skills to weld, I wondered if it was worth learning as I'm reasonable young and would probably do a lot more things like this. What is the cost of gear ect?

Thanks again, matt

[zoll]

Hmm I really like the sound of 4 drill motors, would the Electronize: RC Speed Control 40A work as a controller for it?