Im Sean and live in greensbourough Victoria.
im going to try to build my first robot which will be a featherweight robot. construction will start as soon as my exams are over (13th of nov) still in the planning stage as u will see I just post any ideas I have and will work everything out latter and ATM as I have no computer I will be regularly using im going to post my possibilities and anything else which would be useful for me later. If anything sound better then another or u don’t think it will be work I will be grateful for advice from more experienced people so feel free to comment or advice on anything I post


Speed controller: Probably IBC

RC as I don’t have one DSM/Spektrum 2.4ghz, Skysport FM 4ch Radio w/3 Servos or 6ch GWS transmitters with battery and charger
All mentioned and seam to be reliable


Drive: 200W DC MOTOR (SC200) for a scooter or 300W DC MOTOR (SC300) with CHAIN & SPROCKET SET (CHAINSP) from oatley or
drill motors as described in the wiki most likely

wheels: most likely red plastic bunnings or go-kart if size/weight permits and work with drill motor

frame aluminum or steel pipes welded or bolted together.

Weapon: static spikes and Pneumatic spike if weight allows (size should be planed for)

Armor: none?

Batteries : SLA or NiCad prob NiCad as it’s a feather weight. To check out http://cgi.ebay.com.au/8-NEW-AA-2500mAh-Set-NIMH-Rechargeable-Batteries_W0QQitemZ200044256680QQihZ010QQcategoryZ43445QQcmdZViewItem or something like that

To find out
if there is an Australian company that sells the spectrum in aus with BR6000 not separately or how much it costs in postage and other fees to get it from The robot market place and if extra cost is worth it in the long run

are drills little more expensive better for robot use?
When u have to say if u are going to robowars (highly unlikely but worth checking out)

Do battery research

Last edited by seanet1310 on Sun Nov 19, 2006 11:53 am; edited 1 time in total

just be wary of scooter motors and the IBC i think garry has been having problems with that combination. IBC + drill motors seems to work well.

Those batteries are pretty light on, most people use C or sub-C sized cells.
Batteries are a big expense usually. (if your using something other than what comes with the drills) to start with go the drill nicads.
if your doing penumatics then you probably won't need more than that for a while.
Alternatly look at the A123 cells, they may be the "next big thing"
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The scooter motors that have been causing me all the trouble are the 250 w gear motor.

They have rare earth magnets and kick out some nasty square wave inductance that causes big problems.

The 200-300 W motors are easy on controllers and our Ultibot runs them overvolted with an IBC no problem.

If you were going to use them I would recommend bigger wheels than the red wheels.

They are on the heavy side for a Feather, Plenty of Feathers work OK with just the 100w scooter motors.

cool thanks for the advice. drill motors it is then they seam reliable and i can alwasy experiment later once i have a working system.
ill probably use the drill ones to start with but by reading the wiki it would be best to get some better cells when i do would something like 3300mAh http://cgi.ebay.com.au/4-C-Cell-NIMH-Rechargeable-Batteries-3300mA-Solder-Tabs_W0QQitemZ6002464372QQihZ009QQcategoryZ84443QQcmdZViewItem be a prity good choice?

edit just saw your post Rotwang. so ill re put the scooter motors as an option but change them down to 100Watt

Drill Motors are relatively reliable, but the gearboxes are usually not . At least not in the cheaper type of drills.. if you buy DeWalt hammerdrills or Panasonics or one of the $100+ ones you will probably get better gears..

They are very powerful for their weight, but it takes electrical power to make pushing power so they are also inefficient amp-sucking beasts.

If you need pushing and shoving power in light weight, then drills are good. But you will need to be nice to the gearboxes, or maybe talk to Andrew (totally recycled) about getting some of his strengthened drill motor and gearboxes.

You will also need *good* batteries to power drills through a hard 3 minute match, SLA's will struggle unless well size-matched and kept in tip-top condition.

Scooter motors are much easier on your battery and speed controller, as well as being a lot more efficient at converting amps to torque.

However, they are much heavier for their power level, are limited to one type of hard-to-replace wheel, require a specific layout for the drive belt, limiting your design somewhat, and the drive belts can be prone to breaking unless replaced with a good quality belt.

Both motors have optimum applications, it depends on what your robots requirements are. Do

you need efficiency and reliability more, or power and less weight at the cost of reliability ? There is no "best" motor for all robot designs.
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For a start robot drills work really well, they're really easy to setup and use, plus they work really well with the IBC.
Also regarding their problems, I never had problems with my drives when I ran the 12v drills at 12v. I think regarding reliability they're gearbox is more reliable than having to worry about the belts with 100W setups.
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i wouldn't worry about batteries just yet.
Wait until theres another group buy or something and get a bunch from master instruments. Plan-b ran on drills for ages and Roadkill won several comps on them ;->
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Mechanical engineers build weapons, civil engineers build targets

Admittedly most of the problems I had with breaking gearboxes were with overvolted drills.. although a fair few people have had trouble at stock voltages as well.

Drill Batteries ? Well, if the budget is really tight maybe. Ask Gary how time has to be spent testing and cycling them to be competitive with them
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quote:

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Ask Gary how time has to be spent testing and cycling them to be competitive with them

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At ~$40-$60 per pack for 10xCP2400's, when you take into account the time spent making, testing and cycling the things (unless you just slap the drill packs in the bot as they are)

Then compare the performance and failure rate of 1200-1500mah hooflungdung cells against Sanyo's, the budget would have to be really tight or your time worth nothing to make drill cells a more sensible option.

Sometimes doing things the cheap way costs you more in the long run.
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hehe, I disagree with the drill cells.

For 12v applications, just yank them out of the box, stretch them out, wrap in tape, done. Takes all of 2 minutes.

Run a couple of packs in parralell, or series for 24v for a weapon.

I still have original drill motors and cells used on 12v that are still running fine after 2 years or use!

For anyone, drill cells and cheap and super easy and effective.

O..K..

Can we have someone tell us what the highest ranked bot that regularly uses cheap drill cells is please ?

http://rankings.robowars.org/modern%20rankings.htm

It has to have actually competed more than a couple of times too. Looks like its down in the 40's to me.. Effective huh ?
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Roadkill ran on drill cells up to really recently... 23rd.
And that's taking into account it's recent pwnage at events too lol.
WAIT! Bloody mongrel... 15... stealth (also with cheapo batteries... maybe not drill cells...5!)
DOUBLE EDIT: Wait... doesn't reboot use drill cells?!
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Hey, you can still have an effective robot that is not number 1 on the ranking

We are talking first builders here, the drill cells are a great way to get your robot going for no extra outlay.

Of course you might want to move onto bigger and better things down the track but they make a great starting point.

Your robot design and evolution is more important, a robot like Stealth could have run from drill cells, but Dumhed didn't cos he had other batteries already lying around.

Speedbump beat the leighweight running drill cells (never going to let that one die!)


Sure, you unlikely to build a high power spinner with drill cells, but that is not a great first robot anyway.

I have always run drill cells and they have never let me down. They cost me nothing extra when buying drills, I can abuse them all I want and chuck them away if they have problems.

I have seen people chuck away batteries worth more than my entire robot after shorting a pack out. I have in fact shorted a drill cell pack out, and killed it. Luckily I had about 50 spare


To me having an effective robot is not all about the rankings, its about getting a robot going, competing, having fun, learning and being able to do it within your budget

Sure, having fun is the idea of the game, but winning is the name..

Winning in a mean spirited, nasty no fun way isnt likely to garner you much respect or enjoyment, however, everybody *wants* to win and when someone asks advice, they are usually hoping that your advice will help them avoid some of the mistakes you have made along the way to improve their chances of winning.

If your advice is to have an experienced competitor design your machine, buy $10k worth of off-the-shelf parts, have them assembled by Nasa, then hand over the controls to an experienced driver, chances are they wont, even although its probably good advice to win.

So what they really want is advice that will increase their fun factor (maximum reliable drive time) and their chance of winning/ranking at hopefully not too much a cost.

What is probably needed here before everyone chips in with too much advice is a *realistic* idea of the builders overall budget.

If someone wants to "go racing" with a total of a couple of hundred $ in their pocket to kit out the whole package, then drill cells are an excellent idea. you need to cut every corner you can, and they will work "ok", for a while, maybe, up to a point.

If (as mentioned in post 1) the builder is spending hours on their frame, another 300 on their ESC (IBC), another 300 on their radio (Spektrum), $100+ on a charger (which you will need regardless of cells), then some more on their wheels, drive, weapons etc. then advising them to use drill cells is wrong , because they will definitely be the weak link in the combination and will limit/let down the better gear.

For under another $100 you can have 2x reliable powerful sanyo packs you can count on, and slam charge back into quickly that will only be a small % of the overall cost of the bot.

If hypothethical builder B was instead working with servo switching, ebay radio's, 2nd hand drills, and other low budget gear, then drill cells would be a good match to that budget of machine.
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