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
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