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hi, im building my first robot and so far i have almost completed the chassie and it weights about 23kgs, is this too heavy? im gonna enter in as heavyweight upto 100kgs, im gonna use 4 go kart tyres and 2 24v scooter motors and for a weapon im gonna use some kinda flipper, but i want it very powerfull, so just wanna know if ive gone over the top with the chassie by makin it 2 strong and heavy?
thanks
Just my 2 cents.
24V scooters and 4 kart tyres are fairly large and heavy.
Large means a lot of armor to protect everything. Armor does weight a lot.
And a very powerfull flipper.... Any idea how powerfull very powerfull is?
A very powerfull flipper uses a lot op power. Most flippers use CO2.
But if youre very creative, a lot of batteriepower.
In all cases, heavy options.
got pics of the chassis??
was thinking of using very thick perspex for armour? would this be ok or do you have any other suggestions, i will post some pics of the chassie tomorrow.
oh and the flipper i was thinking of somethin like a pneumatic ram, somethin off ebay, what do u suggest for that and what is the max psi i can have it, ive got an idea how to build most of the robot but the flipper i dont really have a clue, so any help would be useful, links, pics, what i need exactly. thanks
http://howto.killerhurtz.co.uk/pneumatics.htmhttp://howto.killerhurtz.co.uk/pneumatics.htm
http://www.teamonslaught.fsnet.co.uk/tech.htmhttp://www.teamonslaught.fsnet.co.uk/tech.htm
http://www.gt-electronics.freeserve.co.uk/c2/technical/technical.htmhttp://www.gt-electronics.freeserve..../technical.htm
http://www.teamdavinci.com/understanding_pneumatics.htmwww.teamdavinci.com/understanding_pneumatics.htm
Enjoy.
they look good, i will have a look thru, if anyone else has more helpful info, just on the general building of the robot, it would be useful, thanks again
NO Perspex.... It shatters.
Polycarb or HDPE is a better alternative.
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(Message edited by woody on October 28, 2007)
ok, where can i get polycarb or hdpe? (what is hdpe?) :)
Heres a link to UHMWPE Ultra High Molecular Weight Polyethylene
Youll find the various descriptions of the shorthand names as you browse the site.:)
http://www.directplasticsonline.co.uk/home.php?cat=3682http://www.directplasticsonline.co.uk/home.php?cat=3682
Polycarbonate is expensive and Id suggest that youd need perhaps 10mm or thicker.
Heres a link to give you a taste of price ....they dont list the thicker sheet.
http://www.westwardplastics.co.uk/d_selector.php?page=2&cat=glazing&subcat1=Polycarb onate%&subcat2=Clearhttp://www.westwardplastics.co.uk/d_...&subcat2=Clear
(Message edited by woody on October 28, 2007)
Technobots stock half, quarter and 1/8 sheets of Polycarbonate in various thicknesses
http://technobots.co.uk/acatalog/Online_Catalogue_Polycarbonate_Sheet_103.htmlhttp://technobots.co.uk/acatalog/Onl...Sheet_103.html
I would agree with the comments about kart tyres - they take up a lot of space and are easily damaged. About the only benefit they have is that they are easy to build into a robot.
Ground clearance is a significant factor in combat success, particularly in the UK with the number of flippers. The problem with four wheels is that getting low ground clearance is not easy - the arena floors are never flat, so if you run the robot too low, you will get grounded.
Generally easier (and lighter) to use just two drive wheels and have the front of the robot sliding on the ground.
the link to direct plastics woody suggested is a very good one. they have a lrage range of stock and are very helpful if you need any help
ok thanks for all comments, one other thing im not too sure about is how i can attatch the kart wheels to my robot, as i dont have any hubs etc... because i want to attatch them to a bar with a sprocket welded on, any ideas?
thanks
(Message edited by mjones40 on October 30, 2007)
i have a few photos on photobucket with kart pics on if thats any help. swanaldo_2007 is the place to look on there.
what kinda chain and sprockets are u using? where u get them, i was thinking of using bicycle chain?
i used a racing kart place at newark to get all the bits but really you dont have to go that exotic because were expensive at the time. there are cheaper options but a little heavier. a bearings place would be the cheaper option. you can get the sprockets and carriers and the hub carriers and wheels from ebay. just make sure they are all the same size. i wouldnt use bike chain. get the kart chain its much stronger and i think it was about 15 quid for chain if i remember so not too bad.
so if i do change the design to 2 wheels, would i get some sort of caster for the front of the robot? if so which do u suggest for me?
You can get ball rollers (like a big ball bearing pressed into a plate), but honestly the most you want is a block of nylon to run on the floor. Dont use a caster or you will induce shopping trolly like handling.
a bearings place should do the ball rollers but i dont think they are cheap. like kane said a block of nylon is another option. there should be a pic on my photobook of the ball rollers so you know what they look like.
Technobots list some ball transfer units.
http://technobots.co.uk/acatalog/Online_Catalogue_Ball_Transfer_Units_392.htmlhttp://technobots.co.uk/acatalog/Onl...Units_392.html
I have a pic of some Kart parts I am selling on http://i227.photobucket.com/albums/dd253/TeamDMac/Picture109.jpghttp://i227.photobucket.com/albums/d...Picture109.jpg
I also have some Ball transfer units.
hi david, yes most of that would be useful, what kinda price u lookin for?
you seem to be seeling alot at the moment dave :)
Hi Marc, 2 chains, 2 sprockets, 2 carriers, 4 bearings,2 shafts, £65.00 plus post, including 2 Ball transfer units.
Dave.
Hi Alex,
Ive got a shelf unit 7ft x 3ft full of Robot bits that I have been collecting for years, just having a little clearence.
Dave, Team DMac.
another quick question, probably a stupid one 2 u guys, u know the rf speed controller, say it has 4 channels, does it use 1 channel for forward and reverse or is it 1 channel for forward the another channel for reverse? thanks
Well .... First I need to check out our points of reference .....What do you think is an rf speed controller?
I will however hazard a guess that you mean a Radio reciever .....in which case each channel will allow you to drive one motor (Foward -Neutral-Reverse)
The Transmitter outputs a signal that corresponds to the stick position .....the reciever takes this signal and passes it on to the main ESC or Electronic Speed Controller which outputs a Pulse Wave Modulated voltage to your motors.
You might find this site heavy going but it has the information you want IF you wish to understand what is going on.
http://robots.freehostia.com/http://robots.freehostia.com/
ok thx, that looks like a good site with lost of info. will check it out.
ok, ive finished my chassie, also mounted the wheels and motors, what do i need now to control them? as in the speed controllers, and all the rf equipment, i have 2x 24v motors that will be running at 36v, and as a weapon i will have a pneumatic flipper, so i need something with 3 channels yes? can you give me some links and names of products i need please.
thanks
Yes you will need at least a 3 Channel Radio set. The recommended set is the Spektrum 2.4Ghz set with a BR6000 reciever which will failsafe on all channels. At the moment there are no others that have been proved to the same level as the spektrum.
As for a speedo, Wotty is about the only good speedo available in the UK. I can supply more info in an email if you want.
hey, ok ive had a look around, this is what ive found, can you tell me if its right,
first a 4ch 40mhz transmitter
http://www.technobots.co.uk/acatalog/Online_Catalogue_4_Channel_Technobots_40MHz_251.ht mlhttp://www.technobots.co.uk/acatalog...chnobots_40MHz _251.html
also i have found a 4qd pro 120 speed controller, here is the link
http://www.technobots.co.uk/acatalog/Online_Catalogue_4QD_Pro_120_Series_355.htmlhttp://www.technobots.co.uk/acatalog...Series_355.htm l
there are 3 on there 12,24 and 36v which will i need, as im running 2x 24v wheelchair motors at 36v, each motor has 2 wires coming off it, 1 red, 1 blue, it goes in forward and reverse by swapping them around on the terminals of a battery, will this speed controller sort all this out? and also will both these products work together, is there anything else i need except batterys to get this robot going via the transmitter?
A sidewinder is only £190 without P&P or taxes at http://www.robotpower.comwww.robotpower.com
Unfortunatly, when a package like that passes customs, the g-vment will rip you off.
The parts youve listed will be o.k.
But the Spektrum Ed recommended is now fairly universally used by the Robot community.
Youll need two 36v 4QD controllers... one for each motor and yes itll sort out the direction of rotation etc..
http://www.4qd.co.uk/prod/pro.htmlhttp://www.4qd.co.uk/prod/pro.html
Dont forget that youll need a battery charger specifically made for the type of batteries your going to use.
Nearly forgot ...Youll also need a special board to go betwen the 4QD speed controllers and the receiver.
http://www.4qd.co.uk/instrs/PDF/dmr203.pdfhttp://www.4qd.co.uk/instrs/PDF/dmr203.pdf
You might find it easier to go with the Sidewinder ....very simple to connect up ....or the Watty mentioned by Ed.
Theres a 2nd hand Sidewinder up for grabs on here at the moment http://www.fightingrobots.co.uk/discus/messages/89/10247.html?1194600753http://www.fightingrobots.co.uk/disc...tml?1194600753
(Message edited by woody on November 11, 2007)
Hi guys (and gals) Ian Watts has sent me an e-mail with the latest info in Wotty developement, it reads as follows:
The Wotty 360 is now under development.
Specs for the Wotty 360 are:-
Voltage 32 Volts.
Current 160 Amps per channel continuous.
400 Amps per channel for one second.
1600 Amps per channel for 1uS.
Upgrade from the Wotty 180 to the Wotty 360 is available. ( Sorry there will be a charge of £40 for this to cover the cost of extra components.)
I will post further info as I get it, Mike.