I'm Thinking Of Building A Feather, And Need Some Advice

Hi, Im new. My name is Kevin, Im 17 and I live in Canada. I have watched robotwars since series 3. I watched battlebots too. But my dad cut the cable tv in 2002. So I havent been watching much robot wars, but I have been keeping in touch with it.

As I said Im thinking of building a feather-weight but I will wait till Im older to build it, but Im saying it now so you people can give ideas.

I have two designs in my mind for a feather-weight. Opinions or suggestions please. There are:

a)a wedge with a Firestorm/Cassius flipper/sirmech powered by a electric actuator. The outside is all probably going to be alimunim about 10-15 mm.

b)a wedge or a inverrable box with a spinner powered by a fan motor.

The drive motors will be drill motors. Batteries were going to be Ni-Cds. But they expenisive. for three it would be 75 pounds (150 dollars in my money). I wanted to keep it cheap. Or should I use SLAs?. 15 pounds (35 dollars in my money) for 5 of them. Im going to Radioshack to see if they had a 3 channel tx and rx. I was thinking of using a old RC car but I was worried it wouldnt take the strain. I also need 3 speed controllers.

Im going for about 12kg (30 pounds).I found out that my grandpa has some old aircraft alinimnum. That must be strong but heavy.

Im just worried about the electronics, because that will be the hard part of the robot. if I have a 3 channel tx and rx, and I push forward oon the tx, will it send forward to all the motors? Because one of my motors in the weapon.

Another problem has came up. i have to use mechincal speed controllers instead of electrical because of cost. What is the difference? the poeple at the store says it wouldnt work with two speed controllers together for steering the robot. So the receiver picks up the signal and sends it to the servo and the servo sends the motion to the speed controller. is that right? Im stupid compared to you guys.

The people at the store, dont understand the tank steering. They said, if youre going to steer, you would have to reverse the poplarity of the motor.

What if the mech speed controller didnt have reverse? will the servos and speed controllers be easier to break? Would it be a good idea would be spares?

What would the skin be made of? Poly and ali? how thick to becasue the body should weigh 10-15 pounds.

This year, I checked what sort of robots are competiting in the 30 pound (12kg) class mostly all are spinners. Why are spinners so popular? Are they very effective?

But I still think a Firestorm-type robot (Its my favourite robot. If youre going to copy, copy from the best) with the flipper is a good idea. Using a electric actuator would be a good idea too. How quick would the actuator go with 12 kgs on it?

Another name that would be good for the robot is Wolf.

Is it true that robots arent cheap?

Thank you for reading this, give ideas, sughgestions or critisims

Kevin Smith

Welcome Kevin.
First thing: youre not stupid. Youre actually asking intelligent questions and have obviously already formed serious ideas. Thats very very nice.

Wait for the guys to recover from having fallen off their chairs before they can start giving you answers. You must have taken them by surprise.

Sorry I cant help you, but for the spinner part. They have been popular when Robot Wars was still on TV because of the destructability involved. When the tv shows ended and the roboteers turned to live shows this popularity quickly ended due to safety reasons (not every arena is strong enough to contain a spinner and the damages it can inflict) and the lack of willing adversaries (when you want to compete once a month you dont have the money and time to completely rebuild your robot again so you tend to avoid the nasty ones).

These days we go for spectacular fights but with the least structural damage as possible, and flippers are the most favourite weapons now I guess. Thwack-bots are also nice (no moving weapon, the robot IS the weapon). Your initial choice for a scrimech/flipper will not be boring at all... what counts is how well you master this technical challenge and we stand ready to admire the accomplished.
You have good ideas lad. Keep on working !

Go with Babeths suggestion for your first trial bot .........perhaps 2 off battery operated drills?

That will initially solve your battery and motor problems... its also possible to use the inbuilt speed control and reversing switch.

Ask here ........ http://www.robowars.org/forum/index.phphttp://www.robowars.org/forum/index.php ..if you decide to go the cheap switching route.

OR if your pocket can stand it this speed controller does 2 motors and connects easily to the radio controller....

http://www.roguerobotics.com/store/index.php?main_page=product_info&cPath=61&products _id=132http://www.roguerobotics.com/store/i...o&cPath=61&pro ducts_id=132
More info here ...
http://www.robot-e.rdelectronics.co.uk/htm/md22tech.htmhttp://www.robot-e.rdelectronics.co.uk/htm/md22tech.htm

Hi Kevin

Good to see robot Wars still has its international appeal.

Most people here in the UK use specially made NiCad or RC NiCad batteries now as its quite competative. But if your not going to overload it (probably rules out a spinner) you could possibly use the batteries from the drills that are providing the motors.

In response to your questions about the transmitter. It should be possible (however it isnt normally done this way). With a three channel transmitter it would be possible to control three motors individually. So pushing forward on the left stick will only effect one channel on the receiver which U could use control your left motor. Similarly for your right stick & motor.

As I say this isnt how it is normally done Im also not sure about these mechanical speed controllers.

I used to have an RC car with a mechancal speed control it simply used a servo to turn a metal arm which ran other a three or four contacts one reversed the motor for reverse the other two or three contacts provided various forwards speeds (I believe by dumping the current through various resistors). Is this the type of mechanical speed control you mean?

If so Im not sure if the steering will be very easy and as you only have one speed in reverse it would be impossible to steer in reverse. Oh and you definately want to have a reverse or youll always be getting tangled up with other robots or stuck against the barrier. There is also the risk of the RC power failing and your servos staying in the same place and your robot running away out of control.

Steering is normally done off of one stick for forward and steer (I know there are exceptions out there). And either a two channel electronic speed controller that takes in the speed and steer signal from the receiver OR two single channel electronic speed controllers and an interface to take in the speed and steer signals from the receiver and control each speed controller. This gives you an infinately variable speed in both forward and reverse rather than a series of discrete speeds as youd get from the mech speed controller I described above. This will make steering much better.

These electronic speed controllers can be very expensive for a top of the range one but there are some cheaper alternatives around. Not my field of expetise really but Im sure someone else could advise you of the options.

As for a weapon either sound good to me but as I said above the batteries may rule out a spinner. Also as others have said spinners are destructive and require good areans to contain them. So Id go for a flipper/lifter. (Yes everone I know mines a spinner:)).

Hope this helps best of luck.

Richard Wenman
Team Mayhem

Couldnt you wire the servos and speed controllers so all the directions could have on one channel?

Think it might be time to create a newbies look here section of the forum with some threads in.

FRA Forum Admin
http://www.fightingrobots.co.uk/forumhttp://www.fightingrobots.co.uk/forum

No Kevin unfortunately you cannot, THat would mean you would only have control of say backwards and forwards.

You want control of backwards and forwards and left and right.

Hence the need for 2 channels

Couldnt you put the 2 channels on one control stick on the transmitter? I dont want my two hands doing the driving, and none available for the flipper. Or would it just take time practicing? I also want to make sure that the robot can get under all robots, how would I make sure of that?

You can definately do full control on one stick with most four channel transmitters but I think (I could be wrong) that most three channel Transmitters have two separate driving sticks (with only one channel per stick) then a knob or swich for the 3rd channel. This would sadly mean youd have to quickly move hands to operate the third channel.

And as for a wedge to beat all other wedges, that im afraid is a thing of fiction. All you can do is make the scraping edge of the wedge out of as hard a material as possible (i.e titanium), and have a really thin leading edge, almost like a plane scraping over the ground. A wedge like this though would get plauged with driving problems on most wooden floored seamed arenas...

Ok, if I got a four channel transmitter, how would I wire it up for full direction in one stick controller.

I think I should have a wood base frame, and wrap aluminum or ploycarb around it.

You would have to invest in a mixer in order to give you full control on one stick unless you spend a few more bucks on the TX and get one with built in mixing

Revised link ........

http://www.robot-electronics.co.uk/htm/md22tech.htmhttp://www.robot-electronics.co.uk/htm/md22tech.htm

Note that the other link for the MD22 is Canadian.

Hey Kevin. You dont necessarily have to have a completely flush wedge to be able to get under other robots. I went for a similar idea to yours on my first bot and made the wedge completely flat against the arena floor. After I had seen the other competitors I realised that the majority of them actually have a fair bit of ground clearance so most wedges could get under them even if they dont graze the floor. :) And with arena surfaces sometimes being uneven, it might be best not to have a super flat edge.

Regards
Lenny

If you have a flat piece of metal coming out from your wedge so that that can go under your opponents then you will be more effective. What I am clumsily trying to say is the front can be like the front of Bigger Brothers flipper.

You might find this site helpful http://www.robotcombat.com/tips.htmlhttp://www.robotcombat.com/tips.html

I plan to use an electric window actuator from a car as the flipper. How fast would it work with a 12kg robot on top of it?

Slow. It would be a lifter rather than a flipper. If its not gas or spring, I cant see anything being a flipper.

Not even if I over-juice the electric actuator?

A CO2 flipper pops in a fraction of a second. An electric motor system will never manage that. If it did, no one would use CO2 for all the trouble it is.

Crank back a spring with an electric actuator and that is a different matter.

Storm II manages about 30ms for full stroke from down to up, and even thats not true flipper territory.

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

I thought the electric actuator was a good idea. I didnt expect it to be fast, but reliable and guarentees flipping the other robot on its side/back.

The Co2 flipper is too costly and confusing for me, but then Im stupid compared to you.

Kevin, Storm II is an electric system rather than CO2 - and we chose it for all the reasons youve just stated, that and you dont run out of gas :)

Also, dont make assumptions youre stupid in comparison to people. Im the person who put my robot in the arena without screwing the bottom on, drive forward and the insides fell out !

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

How does your electric system work? Could I make a smaller version of it work in my feather?

I consider myself such a newbie. I dont know how to build anything or wire anything together. Im good with making models.

http://www.teamstorm.com/heavies/storm2/series7/weaparmour/armagain.gifhttp://www.teamstorm.com/heavies/sto...r/armagain.gif

Thats a pic of the insides of Eds lifter. Anyone could make one somewhat similar scaled down for a featherweight (the 1hp astro motors being a great alternative to the mini-mag used in storm II for the lifter, in featherweights) but the big issue is cost and required skills and time. Storm IIs lifter is incredibly simple in principle but it is made to the highest standards by the looks of it. Ok, your on a low budget so youll probably not be able to get your hands on some of the more exotic motors around.

One of the most promising systems to be used with an electric motor is a four bar lifter (as used in Storm II and Biohazard). With the right gearing and geometry of the four bars, an everyday cheap cordless drill motor could be used to turn over most featherweight machines. Ok, you wont be able to toss another feather into the air but if you put your mind to it Im sure you could come up with a cheap yet effective solution.

A very interesting solution. I will seriously consider it. But is there a way to use a drill motor and the gears to power the flipper I was originally planning to use?

I like your idea and solution.

How fast can a two 12V drill motors push a 12kg featherweight?

depends on how much the other feather is pushing back, how much friction each robot has on the ground etc

i think if u are looking a serious spinner, u really would have to go for 4 drills or at least 2 drills on 4wd.

Wouldnt 4 drill motors suck the power from the battery faster?

How many batteries in the robot should I use?

They might draw more current. But that is by no means certain. it al depends on gearing and the type of drill motor you have. and wether youre tansmission system is aligned properly and so on. The less work a motor has to do, the less current it will draw.

The amount of batteries also depend on what type you use, how many amps/hour and so on.

i can tell u from personnal experience that 2 of the batteries that come from the cordless drills can run 4 drill motors for 10minutes before becoming sluggish.

We used two drills for drive and two to spin a heavy disc in our lightweight typhoon robots and they could easily last a 5 minute battle.

Some people dont like the batteries and that is fair, they arent the best. But to be honest they come with the drill so you might aswell use them at least at first!

Which kind of battery is better, Ni-Cds or SLAs?

Would you connect the batteries to the motors or to the speed controllers?

Hiya Kevin,

Nicads will be better in a feather. More current, less weight, faster charging, take up less space. You connect the batteries to the Speed COntrollers, and the speed controllers will provide power to the motors.

Have a read on stuff like this here matey, it will all make sense. Well most of it anyway.
http://www.stupoo2000.pwp.blueyonder.co.uk/teamkat/technical.htmhttp://www.stupoo2000.pwp.blueyonder.../technical.htm

Mr Stu

Thanks Stu,

BTW I added you on my msn.

I think I will just build a wooden one just to see if everything works. But that wont be for a couple of years. I need to finish school and do university.

How long did it take you people to build your first feather?

All of ours have took about a couple of weeks. It depends on what skills/knowledge you already have and what design/weapon your going with. Some feathers have been built in a few days some have taken years!

Have you seen the Zeobots? http://www.technobots.co.uk/contents/en-uk/d608.htmlhttp://www.technobots.co.uk/contents/en-uk/d608.html i dont know what your budget is, but these seem similar to your original ideas, then with any extra weight you can bolt more armour on.

alan
http://www.blazerbotics.co.ukwww.blazerbotics.co.uk

Thanks for the links. I was thinking of using 5mm ali around.

Another design idea I had is a Stinger/Blade Runner (from Battlebots) design where I just spin around with spikes on a tail.

i made my first one a thwacker, was a great learning curve and its still the australian no 1 ranked robot despite having been retired for almost 3 events hehe.

your first robot need not be a tapped together, welded up master piece. take speed hump or tread for example. they use an old tire and some nylon ag pipe, kiddy cars and drill motors and old drill nicads and they never seem to break down, they always do well, they cost bugger all and they are (often) build literally the night before the event.

http://www.robowars.org/forum/album_pic.php?pic_id=964&sid=d517a9d3ec16840b7f63e 38d8a7cf706http://www.robowars.org/forum/album_...3ec16840b7f63e 38d8a7cf706

http://www.robowars.org/forum/album_pic.php?pic_id=966&sid=d517a9d3ec16840b7f63e 38d8a7cf706http://www.robowars.org/forum/album_...3ec16840b7f63e 38d8a7cf706

i think the best advice anyone could give a new builder is to just go out and build anything you can, practice makes perfect..

Or I could buy one of those combat Zeobot kits. Buying that guarentees that my first robot wont be a piece of ......... Have those combat Zeo bots been tried in battle before?

Paul cooper has the 8wd zeobot fighting with a custom shell and does very good. photo here: http://www.teammad.co.uk/flatpack.JPGwww.teammad.co.uk/flatpack.JPG

Just to get everyones opinion one last time, what sounds like the best design for a first time robot?

-A Firestorm type
-A Storm 2 type
-A Stinger type

A Stinger style bot itself would be very hard for a first time builder in my opinion. However a thwackbot like Cobra would be a good start. Unless you have experience in pneumatics to acheive a Firestorm design, Id go for the Storm 2 style design.
Im building a rambot like Storm 2 at the moment because I found it was the most acheiveable design to start off with considering my budget, tools and experience. The choice is yours to choose which design you think will win and is also buildable for you.

Hope thats some sort of help!