OK, I'm building a heavy... But need some help...

[robotwars]

Re: OK, I'm building a heavy... But need some help...

Ok rude wasn't the right word but we should be positive for people if they want to try.

A couple of hawlkers, a roboteq, two boschs, some wheelchair gearboxes, and away you go.

The electronics aren't hard at all, with speed controllers now it's about 8 wires that's all.

With a bit of help anyone can do it. We don't know who exactly is posting on here, their knowledge, or back ground.

I was racing minis at 10 with my dad, at 13 I was stripping, repairing, developing, and building full blown race engines.

That's all.

My email is john@roamingrobots.co.uk

[cliveb]

Re: OK, I'm building a heavy... But need some help...

Hi George, I certainly didn't mean to appear rude and appologise if I did so.If you are going to go for it good luck its a lot of fun, you will make some great friends.I look forward to meeting you inside and outside of the arena.

[George_TeamZog]

Re: OK, I'm building a heavy... But need some help...

Ok, so the speedo should be wotty, and the motors - either Bosch or any other cordless drill motor (I'm leaving out wheelchair motors, too slow).

It's quite funny actually. When I first posted everyone's like 'Oh no, don't build one, safety issues (which I know are important - DON'T WORRY, THE LINK WILL BE FAR AWAY FROM THE WEAPON!!), blah...'
And since Jonno gave you all a right talking to you're now really apologetic. Don't worry though, all of your apologies are accepted. None of you offended me, so dw (no, it doesn't stand for Doctor Who). Basically, I've got £500 (My Nan gave me a £300 check, and the rest is birthday and christmas and stuff I've sold money), and almost all the tools, apart from a welder, but I'm using Polycarb, so I don't need it. I may need a saw though... Meh. I'll use my schools

George@TeamZog

[typhoon_driver]

Re: OK, I'm building a heavy... But need some help...

cordless drills won't be powerful enough. You need bosch 750s, wheelchair motors with the gearbox removed or another similar motor. Something around 750W mark.

500 quid is doable but you're going to struggle. Ironically you could probably buy a second hand heavyweight at that price if you wait around.

[George_TeamZog]

Re: OK, I'm building a heavy... But need some help...

tbh, I would prefer building one, as you get a nice feeling (sounds a bit wrong there) when you finish it. I'm not expecting to complete it in a month, just so then it can compete in fairford...

George@TeamZog

[dgr]

Re: OK, I'm building a heavy... But need some help...

Yeah, cordless drill motors are nowhere near powerful enough. With Bosch's you'll need gears, a gearbox or chain drive, which can get complicated engineering-wise. £500 is do-able, but I wouldn't go expecting too much on that budget. A Wotty alone is close to £300. We built our first heavyweight, Monolith, out of wood and an old wheelchair we got off eBay, using relays to drive it That one still cost us a fair bit, and it lasted for precisely one fight before we had to dismantle it and start again.

[dragonmaster_1]

Re: OK, I'm building a heavy... But need some help...

You could use Bosh 400 if you can get any ask on the forum if any bodys got any spare. I am using them in my new heavy. test vid of them worklng at 12v dont use them at a higher voltage
http://www.youtube.com/watch?v=eqWjG_VuonI

[George_TeamZog]

Re: OK, I'm building a heavy... But need some help...

As long as they don't give that mosfet whistle then they would be good, yes. Nippy. What ratio should I use them at?

George@TeamZog

[George_TeamZog]

Re: OK, I'm building a heavy... But need some help...



Basic CAD Drawing of what it will end up looking like...

George@TeamZog

[daliad100]

Re: OK, I'm building a heavy... But need some help...

Bosch GPA 400 data sheet: http://www.boschmotorsandcontrols.co...2003/index.htm

You can figure out the gear ratio using the circumference of your wheels, how fast you want to go and the rpm of the motor.

[gravity]

Re: OK, I'm building a heavy... But need some help...

For your first heavyweight robot, just go for wheelchair motors + wheelchair gearboxes + wheelchair wheels. Seriously.

does anybody remember this robot ?





Perfect example of a cheap robot, although if you put more time in it it could even look decent

It had wheelchairmotors/gearboxes/wheels, and 1 sidewinder speedcontroller (can be had for 200 gbp) as a drive system, and it frickin rocked. I had so much fun with it, incapacitating BOTH top of the line drive/rambots (storm2 and tornado) in 1 big heavyweight fight, and also putting dantomkia in the pit

So go ahead, get cheap stuff (but DO get a decent speedo) and have a lot of fun !

[robotwars]

Re: OK, I'm building a heavy... But need some help...

the rule of thumb for working out a gearbox ratios...

Take your wheel size in inches and use that gear ratio !

For exambple, 10 inch wheels, use a 10 to 1 ratio.

JOhn

[dgr]

Re: OK, I'm building a heavy... But need some help...

Thats a good tip from Jonno.

I agree about wheelchair motors though, for a first try they are perfect, you don't have to worry about getting them geared up and can even use the wheels that the often come with. You just attach them how you want and you're away.
An earlier team heavy I was involved in, Cabrakan, ran on wheelchair motors and just won last year's best newcomer heavyweight award, so don't count them out as rubbish.

[leorcc]

Re: OK, I'm building a heavy... But need some help...

Put a couple of wheelchair motors on 36V and you have a nice drive train. I did take the brakes of of them though.

[swanaldo]

Re: OK, I'm building a heavy... But need some help...

I believe early on in this thread people were being cautious. I will still say build yourself a featherweight first. The amount of knowledge you can gain will help you on your way to build a heavyweight. Its all fine and dandy to say your parents are backing you but i think your parents dont really understand the task ahead. If i were your parents i would be looking and asking on the forum whats involved in a heavyweight robot.

I personally would start either with one of jonno's ratz or a simple featherweight.

Jonno aparently ticking everyone off........well i think the community were more concerned about your saftey not putting you off building a heavyweight.

Gary had the best idea.......if you really really sure you and your parents can handle a heavy the best thing to do is wait for one to come up for sale and then have a serious lesson on how it works and how to play.