Which controller?

Right. Been looking at the options out there in the way of esc. originally my dads mate was gonna make me a controller, however once he read into what exactly they do he said he could make one for £20 (that being with a majority of parts already to hand) but it would take 12 months for him to write the software! just to confirm he works in electronics and knows his shit so to speak. with that option out of the window i started looking at (from what i understand) the two main competitors, the Scorpion Xll and the Sabertooth. after a read through both, the Sabertooth figures appealed to me more in the way of current ratings. however i like the flip switch scorpion offers, Flip input reverses motor direction when the robot is inverted. May be operated via an R/C channel or via a mechanical (gravity) or optical etc. switch. what i don't understand is what will i need for this to work? ie what switch? i hear people talking about gyros, is that an option? i have access to optics and sensors through my dads workplace. but how would any kind of switch connect? would any additional circuitry be required? i don't really like the idea of operating it via my transmitter as the system im looking at is only 3ch and i want a weapon. and finally does anyone know if this option could be applied in some way while using the sabertooth controller?


Thanks for your time.

Hi, today I looked into this because I want to use the flip-option without using a channel. When I understand Scorpions manual right, either connecting or disconnecting the signal-wire (orange) with the ground wire (brown), will switch the flip-channel.
So I was thinking of using a mechanical make/break switch with a lever to actuate the button. Hang it upside down (lever with extra weight); no connection = no flip. When the robot is upside down, the lever falls, presses the button; connection = flip.
Easy and cheap.

I am interrested in better options.

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Originally Posted by Marien

Hi, today I looked into this because I want to use the flip-option without using a channel. When I understand Scorpions manual right, either connecting or disconnecting the signal-wire (orange) with the ground wire (brown), will switch the flip-channel.
So I was thinking of using a mechanical make/break switch with a lever to actuate the button. Hang it upside down (lever with extra weight); no connection = no flip. When the robot is upside down, the lever falls, presses the button; connection = flip.
Easy and cheap.

I am interrested in better options.

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Would a mercury switch/tilt switch be simpler? Those may be prone to flipping if the robot's hit hard though (i.e. by 360)

I just found 3 switches at Technobots.

Arh well thats nice and simple. cheers for that. But really i want the sabertooth, is there any off the shelf part that will perform the same function for the sabertooth? i suppose i could just use a tilt switch to flip the polarity just before the motors? really im looking for all my options.

Thanks for the help.

learn to drive with the controls reversed. It's not that hard and far simpler

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Originally Posted by Chris230291

But really i want the sabertooth

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I think it works the same or similair.

The main issue is normally the interface, standard H bridges are quite easy to do.

I started to look at this

http://www.bobblick.com/techref/project ... v2hb2.html

Not finished it yet because we've not even been looking at the robots over the summer and suddenly realised this weekend we had two heavies to get ready for portsmouth.

He can also find some useful projects here

http://tech.groups.yahoo.com/group/osmc/files/

All very useful and quite a bit of programming information if you take a look round it

but yes, you can either learn how to drive upside down or you could also extend the channel direction switch on your tx so it's easily accessible for you to use as a flip switch. How easy that is depends on the tx but it's really not that hard on most of them. It does invalidate the warranty though

Andy

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Originally Posted by widow_twanky

The main issue is normally the interface, standard H bridges are quite easy to do.

I started to look at this

http://www.bobblick.com/techref/project ... v2hb2.html

Not finished it yet because we've not even been looking at the robots over the summer and suddenly realised this weekend we had two heavies to get ready for portsmouth.

He can also find some useful projects here

http://tech.groups.yahoo.com/group/osmc/files/

All very useful and quite a bit of programming information if you take a look round it

but yes, you can either learn how to drive upside down or you could also extend the channel direction switch on your tx so it's easily accessible for you to use as a flip switch. How easy that is depends on the tx but it's really not that hard on most of them. It does invalidate the warranty though

Andy

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Sorry if this sounds like a silly question but what is that? is it (first link) a ESC? sorry i dont know electronics but looks like all the code is there. if so how much current can it take? or is that down to me to change values of something?

Thanks for you help

not sure if this matters but i want to use a wheel control.

While we're on the subject of controllers, how would i control my electric jaw with a planet 5 2.4ghz?

Have the movement on one stick and weapon on the throttle stick.

It does depend on what you are using to control your claw. For example, if its a relay control, you just plug the servo into whichever channel you want to operate the weapon with. Stick up/left = claw goes down, stick down/right = claw goes up, or whichever.

As for speed controllers, I personally like and have used the Scorpion XXL, I would recommend it.

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Originally Posted by razerdave

It does depend on what you are using to control your claw. For example, if its a relay control, you just plug the servo into whichever channel you want to operate the weapon with. Stick up/left = claw goes down, stick down/right = claw goes up, or whichever.

As for speed controllers, I personally like and have used the Scorpion XXL, I would recommend it.

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Even I've only managed to blow one of the scorpions which is nothing short of miraculous for a speedo!!

I have broken the same one twice :P Well, I say I did, the first time I think it was Hornet, second time it was something I did, but I still don't know what it was.

But when it does work it works very well. If you want an example of how good, Little Hitter and Little Flipper both use one and they're some of the most reliable robots on the circuit.

Not many people have mentioned the sabertooth? does that mean its pants? the figures suggest its the better one? however i like the link that widow_twanky sent me. i have a few Q's though, does the first link do the same job as a esc? i understand it like this. i connect my receiver to that Servo Pulse to Dual H-Bridge Interface this does its magic and sends the signal to my h bridge that controls my motors? if this is correct i think i will go down this root. if the more techy people could give me a hand with which electronics i need to make, i can through the schematics at my dad and he can get the pic programed and get necessary bits and bobs. my dad doesnt really know electronics, hes the CAD guy, but he sits next to the software and the electronics guys at work which would be more than happy to help. they actually make sensing and controlling units for industry. they cant really look into it as it'l be done in works time, so if someone could tell me what exactly i need, they'l get me the bits and do the programming and ill solder it all together :D

Cheers for all the input.

my honest answer is to keep it all as simple as possible at first. Buy a commercial controller that plugs into the receiver and get a robot chassis running.

Many people over the years have tried and many have failed to develop their own speedos. A few have succeeded. One thing that all had in common was a great expertise in electronic design.

Even with the heavyweight I won robot wars with, typhoon 2 we had some custom electronics in there to help with the disc spin up in the later variations of the machine and those were no easy feat to develop.

I can understand your enthusiasm but you will save time, money and many a heartache on your first machine if you buy a ready made controller, ie plug and play.

The sabretooth is a nice controller but it's rated specs are somewhat high. Personally I have burned a few out using them to their limits with overvolted drill motors.

Ok thanks for the input. maybe i should buy an off the shelf speedo first to get something running and work on my own speedo after. im just worried that im gonna burn the scorpion out. i think im going to use scooter motors for drive. i checked the stall current by actually stalling an old scooter motor ive had for years. i plan to use the same ones in my robot. it drew 20 amps at stall which i thought was very low? what do you think? i just locked the motor shaft with some pliers and put a multimeter in the circuit to give me that figure. if the batteries were partially flat could this effect the reading? i heard someone saying they use scooter motors with the scorpion xll and runs ok. im just worried it wont be able to handle it.


Thanks

It should be fine. If i remember right (and please someone else correct me if im wrong) the scorpion xxl has current limiting on board anyway?

You will struggle to stall a scooter motor in a featherweight due to the torque they produce. You will be more likely to spin the wheels

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Originally Posted by typhoon_driver

It should be fine. If i remember right (and please someone else correct me if im wrong) the scorpion xxl has current limiting on board anyway?

You will struggle to stall a scooter motor in a featherweight due to the torque they produce. You will be more likely to spin the wheels

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FANSATIC! and yer i forgot they DO have current limiting. i was also worried that there would be no point using up that weight in scooter motors if they only ran at half power. but your advice coupled with my little experiment and what iv'e read online, im happy to go with the scorpion now. i'll hang on a little and see if someone posts something to change my mind though.

one more thing! do you mind telling me what motors you used for the spin in the featherweight typhoon? i remember that it was very impressive.

Cheerrs Dude you're been a massive help.

Anyone know a uk supplier for the scorpion xll? only place i found was robot marketplace.

try robotpower.com

you'll only find them in the us robotpower.com are the makers and usa

i would go for a rick maas upgrade really well done cooling fans and some great upgrades:)

Just to point out that batteries will only deliver a certain amount power. Depends on the rating of the battery so it may well be that your battery has just topped out in terms of current it can deliver.

Cheers guys.

featherweight typhoon was a drill motor, gearbox and all. It wasn't actually that impressive a machine.

Ow right. Maybe it was the middle weight? I remember you entered into a few catargories in robot wars.

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Originally Posted by widow_twanky

Just to point out that batteries will only deliver a certain amount power. Depends on the rating of the battery so it may well be that your battery has just topped out in terms of current it can deliver.

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So how would I work out the max current any battery can deliver? In my test I used two 14.2v lead acid batteries in series. (28.4v) there's no ah rating and there not the batteries I intend to use as there really heavy. If it helps ther by apc and out of one of there power backup units designed for computers when theres a power cut. I was thinking of going with lead acid. but I'll wait for you to tell me there pants haha. If you could answer either questions that would-be awesome.

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Originally Posted by Chris230291

Quote:

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Originally Posted by widow_twanky

Just to point out that batteries will only deliver a certain amount power. Depends on the rating of the battery so it may well be that your battery has just topped out in terms of current it can deliver.

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So how would I work out the max current any battery can deliver? In my test I used two 14.2v lead acid batteries in series. (28.4v) there's no ah rating and there not the batteries I intend to use as there really heavy. If it helps ther by apc and out of one of there power backup units designed for computers when theres a power cut. I was thinking of going with lead acid. but I'll wait for you to tell me there pants haha. If you could answer either questions that would-be awesome.

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You should be able to take the details of the battery and google a data sheet. This should give you battery capacity and maximum discharge capacity.

Andy

PS: BTW if it moves around for three minutes then the batteries are good enough

Cheers mate that's cool I'll have a look. As for the time I have the equation for that somewhere at home. Cant use the batteries I have, there way too heavy. I'm gonna look into some other lead acid batteries but go for ones with as low amp hourage as I can afford to go as to save weight. My plans are far too complicated I think already for the weight limit. My dad is gonna show me how to cad It. He says we can find a weight and even stress test it (get me) and see where to go from there. Now I think I have all the info I need. (cheers guys!) hope to be fighting as soon as and hopefully with a good reliable machine! I'll try and make some sort of a build diaray along the way too.

Cheers guys