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A couple of photos with the cover off (since it doesn't look very good!)
RIght way up;
http://i1228.photobucket.com/albums/...ioverOffUp.jpg
And upside down;
http://i1228.photobucket.com/albums/...verOffDown.jpg
Also had a weigh in and it's 110g over weight, so that's the next thing to deal with. Also found a couple of nasty cracks in the blade, so looking to replace that before it breaks off if anyone has an old lawnmower kicking about?
use a smaller battery, I'm only using a 11.1v 1000mah lipo.
also for the blade have a look at flymo blades.
You could be right there, 2200Mah lasts quite a while.
Also you'd probably be better off making your own possibly lighter blade, lawn mower cutters aren't exactly designed for this kind of use...
But that's not very Bitza!
But it isn't bitza is it
Not meaning the steal the guys (who are making the arena) thunder, but would RoboChallenge be interesting in hosting a few BW fights since they do have a full combat arena?
I thought they normally did more than one event a year, although since I've got into the sport there has only been the FW Champs, at which I'm assuming most people would be more preoccupied with their FWs. Just thinking it's another potential venue to run these machines.
Looking forward to the BW arena being at RR and RL events though since it'll be easy enough for people to sling their BWs in with their non-spinning robots for the trip to the event.
I have a bit of dosh laying around (well, my parents owe it to me, and they don't have it yet but... details!) and I'm considering bashing together a chopping board/bits around the house beetleweight in the meantime, since our FW kind of... stopped ages ago.
So, I'll probably get some of those good old MFA como drill motors... everyone seems to be using them. I'd probably get the 30:1 12-24v ones.
I'd like to know, just in case I go ahead and make one, if the http://www.technobotsonline.com/saberto ... oller.html esc would be able to handle two of said motors?
Thanks.
Edit: typical me, after 6 seconds just looking around it would seem that 10 would be overkill?
Those motors are like 2w or something silly, can't find them on the Technobots website anymore but there amp draw is very low.
The 5a Sabertooth would be closer in rating, but it's only marginally cheaper than the 12a versions, so most people put the slight extra in and get the better ESC. It is heavier though.
Thanks, PJ.
I happen to have this motor... I bought it years ago from Maplin because I wanted it when my dad went there. It's this one http://www.cornwallmodelboats.co.uk/aca ... 540_1.html. I really am quite bad with numbers and whatnot but, how do you think something like this would do as a drum weapon motor for a beetle? Underpowered? Overkill? My extremely limited knowledge tells me it would be in the right order.
Admittedly I am very surprised by the RPM that it can apparently achieve. It's quite light, has a great mount, etc. Problem is the shaft isn't ideal but as I said, just wondering since I have one. :)
I feel terribly nooby asking all of these otherwise obvious questions! :uhoh: Thanks again.
Asking noon questions is fine, that's how we all learn. Just remember, building robots isn't just about asking lots of questions, it's about actually making stuff and then seeing if it works. Trial and error is a great way to learn since your doing stuff in practice, plus you never know you may come up with something better than the norm!
As for that motor it's a little heavy, and you can by a brushless setup that'll work in a beetle for say £25? Which most likely be less thab a brushed once you account for battleswitches relays or ESC, not to mention the extra weight.
hey, is anybody taking beetles to worthing?
my friend alex is taking his flipper shell and maybe his drum spinner.
cool, if he disables the drum, i'll fight him!
yeh, if i have finished Rocky by then i will fight, although, i would have to diable the drum any way due the the fact theres no arena to contain the monsterous, badly centered, drum spinner that its hopefully going to be...... lol
Talk to Alan, maybe before the show on sunday, you can run the kilobot spinners in there ? Can't see it being too big of a risk.
it will proberbly drive faster with its drum than with its wheels :proud:
haha yeh, but it probably wont be working by the werhing event anyway... even if it is, the LiPos wont even have arrived by then... so it would be overweight...
well mines underweight so it works out :lol: fried the weapon servo in mine soit may have to be a wedge thwackbot instead of the lifter
haha cool, but any sugestions for the teeth on Rocky's drum????
how big is the drum and what is it made from?
I'm interested to know too. I planned to make a drum beetleweight, but due to having no access to precision tools nor money, I had to drop it.
drums about 5 long and is made from a piece of scaffolding
sounds cool. i got some large nylon rod from school which i may use as a sub par drum sometime
Ben it's actuly a 6 (14cm) long, and I think it has a 50mm out side diamiter...
I had plenty of metal for the actual drum, it was making the sides strong and solid that was proving difficult. How do you plan to do it?
I was going to have 15mm HDPE sides with the shaft going though them, I was going to have bearings mounted in the drum, so the shaft won't be spinning, and a belt going round the drum...
That's exactly what I had planned. I mean literally the same, lol! I just don't know how you would connect the HDPE side with the actual drum? Bolts?
And what do you plan for teeth?
Yeh I was going to use a m12 peice of studding that went all the way though the robot...
Ellis, have a quick look at this video:
http://www.youtube.com/watch?v=YSSrLTkTeNs
It's the drum from the old Drumroll but the principle remains the same and can be scaled down for beetleweights. The easiest way to secure everything would be to bolt the solid drum shaft to the HDPE bulkhead sides that you are planning on having; the hard part of that could be drilling and tapping a hole in the end of the drum shaft, especially if it's a tough material. Additionally, having a bulkhead running across the width of your robot, just behind your drum (as can be seen in the video), that also bolts to the sides will lend more strength to the overall setup.
Yeh, mines a really dirt cheap version, all I have had to buy for rocky Is a few bolts (for the teeth, a battery, and a few bearings... Lol, and a quick question. Do shuffelbots get any weight allowance? Thanks...
Thanks Jamie. I planned to pretty much copy Drumroll, haha!
I was going to do exactly the same. The shaft traveling the length of the robot and securing into HDPE/other plastic side bulkheads (I actually have the shaft and bearings right in front of me, lol). My problem is... well maybe I should have phrased it differently... I meant, I have a metal tube, basically a toilet roll out of some kind of steel. The problem is mounting bearings into the sides of it strongly (cheaply!). I planned to cut a circle of HDPE with a diameter the same as the inner diameter of the tube, then put a bolt all the way through it an the tube, securing them together.
I can't do that though because it would clash with the shaft. So I wondered how I'd make a strong but lightweight and affordable join of the two pieces. I'd simply press fit the bearings into the HDPE circle, but attaching that circle to the end of the tube is my problem.
It sounds like it should be easy, I know, but I have no access to precision tools, so cutting a perfect circle out of HDPE is already a challenge! Ah well, all part of the fun I guess. :)
Yeh I had that problem too, but in the end I just decided to use some HUGE motor bike bearings which fit strate in the 4mm steel tube...
Lol! Surely they're massively heavy? Mine are ~2cm in diameter and have a bore of about... 7-8mm? Not entirely sure. From an old pair of skates! :wink:
Yeh, mine are 40mm in diamiter 17mm bore and they are about 12pm wide!!! But the entire of my robot is wayyy over weight, so I'm not to worried about it...
Ellis, instead of running a bolt all the way through the tube and the HDPE endcaps, just use bolts that go in slightly less than halfway, and put them at 120° intervals around the circumference of the drum (I used to fit them 180° apart, but that allows the endcap to turn out of line).
That way, you'll have your endcaps secured to the drum tube, but you'll also be able to cut a clearance hole for your shaft to go through. As for cutting the circles, yeah it'll be a pain to get them perfect, but with the sizes and forces we're talking about, a dodgy circle shouldn't have too much of a detrimental effect on the drum performance.
if your overly bothered about the circles use a hole saw
Yeah. I figured that on this scale, perfection isn't really necessary. I have no robot to mount a drum onto/into, but just for the hell of it I might see what I can do tomorrow. I've got some 20mm chopping board which just screams use me. Using 3 bolts actually makes perfect sense, Jamie. That's the kind of thing that wouldn't have occurred to me! Also, the reason I didn't just think I could use bolts that go in a little less than halfway is because I'm not sure how much I'd trust the plastic to hold a thread (keep the bolt tight) and to not catastrophically fail at high speed.
I guess I'll find out one way or another! :wink:
Thanks again.
Too much text!
Photos people, I wanna see your BW creations.
I will put some up when it's finished (tomorrow or saterday) lol