Well it's practicaly set in stone now, team dyrodium's next major bot will be a drum bot!
Introducing Ti-Lust



Specs;
Drives: First version will be 12v drills overvolted to 18v, then an eventual upgrade will see 18v DSE drills at 18 or 24v eh eh.

Weapon: Composite drum weapon, made up of four 20mm "slices" of bizalloy lazer cut, then bolted together with really good bolts! Teeth are part of the drum so no risk of them snapping of. The weapon motor is a low profile but high power, salvaged at PnP at 18v it should have easily enough to spin the drum at a nice speed. I'm also planning to form the bearings into the drum as well, making either the two outside or two inner sections so they accept the bearings. Not sure about going with friction or belt drive yet.

Armour: Well it wouldn't be called Ti-Lust for nothing would it? Rear and side armour is 5.5mm thick, and the front two wedges are 2.5mm. The under front and base as well as titanium side supports are good old aluminium...

Also my problem is my GWS only charges up to 14.4v, so i'll have to have two split packs, but 18v doesn't split evenly, so I may run at 16.8v instead.
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Last edited by dyrodium on Mon Jul 03, 2006 9:33 pm; edited 1 time in total

Looks promising so far and you are getting good at Rhino, I see! Where is the weapon motor in the design, I can't see it in that view? While I don't like friction drive, it might be a good choice in that design, particularly if the weapon motor is low-revving and you can use a larger wheel to drive the drum. It might pay to commision Jake to make a custom UHMW drive wheel; you would get excellent power transfer and a proper hub that will run smoother.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

yeah that looks cool as heck Angus, very cool, one thing in new orbit i wanna do is slight wedge before disc setup whether it be fixed (as part of the frame) or attachable but thats a good idea and i like alot

One idea i reckonis if u moved drive wheels so that they were firther back or poking through the rear and had some sort of arm up top it could maybe run inverted as it would rest on arm and wheels would hit ground

Only part would be when u hit opponent with drum spinning downwards and your bot does a backflip but meh
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Andrew Welch, Team Unconventional Robotics

when you get stuff laser or water (or plasma) cut, it changes through the depth of the cut.
IE if you got a 10mm circle cut, the "top" would be 10mm but the bottom would be 9
so that could make your bolting scheme a little more difficult perhaps.

Also ballancing could be non trivial.
have you thaught of going for a more triangular shape, boxes are pretty weak as a rule.
And perhaps some slope on the sides?
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Mechanical engineers build weapons, civil engineers build targets

The taper in waterjetted holes is significant but it is easy to accurately drill them out; you just need a sharp new drill bit and a drill press that you can clamp the part to. My thick Ti blade parts drilled out just fine, so steel (even Bisalloy) should be fine.

It's hard to be sure about the balancing, but from the other plasma and waterjet parts we already have, I would guess that the parts will be balanced within themselves and the only problem will be if they move and run off centre. If the bolts run through tight clearance holes this should not be a problem. An even better solution would be to use smaller bolts and have seperate holes for locating pins that would be a tight fit in their holes and would make the drum structure more rigid. They are also the best way to stop the drum breaking from shearing where the segments join. Long locating pins like this are best made from 'brill blanks' pieces of hardened and presicion ground rod used to make drill bits; they are available in hundreds of sizes and are really cheap.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Thanks for all the imput! I would definately like the design to be more angled, but i'm assuming cutting the titanium would be a simple shear job, and the more angles in it the more likely they'll say it needs to be waterjet cut.
The weapon motor is that motor i found at PnP last Nick, it's hidden in that view and the cad i did of it looks crap anyway The motor has a diameter of 7cm, and is about 12cm long.
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I might have no school tomorrow, and might be able to go to the CBC bearings store in Artarmon. I think i've settled on a 20mm shaft, but just checking if that's reasonable or not. I might also see if they have any suitable pully's for the weapon. OH and cut to size plastics might be getting a visit if I can find it... hmm, lot's of public transport!
Lindsay, how close is Whiting Street to the Artarmon Train station? Walking distance?
Thanks!
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20mm thick 4140 steel shaft will be plenty strong... Or since your going Titanic, just buy a Titanium shaft? I'm sure you can afford it
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https://www.halfdonethings.com/

I probably could, but it wouldn't be local = shipping time. Time is money lol, and with international shipping, it's a tonne of it!
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perhaps get yer plan finished first?
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Mechanical engineers build weapons, civil engineers build targets

Yeah, but this is the only chance i'll have till about a month, at least!
I'll see, worth a look anyway, but find actualy buying the parts spurs a project into happening instead of constantly "designing" it but never making it.
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Cut to size plastic is directly opposite to CBC bearings. They way they work is; you ring up and say what you want to have cut, they give you a price, you either fall of your chair or order it, they ring up about a day later and say its ready for collection. If you ring up about 9 am, they might cut it the same day, but never while you wait.

Whiting St is about 15 minutes walk from the Artarmon station; get yourself a Whereis map and its easy to find.

About that axle: I have some spare .75" hardened and polished rod that was used in Orbit's weapon. The actual diameter is 18.92mm so you could call it 19mm rather than 3/4". The specs are at the bottom of this page: http://www.tea.net.au/admin/uploads/TEApgs33to34.pdf and I have around 400mm of it left.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

By saying i'll be visiting cut to size plastics I didn't mean i'll be buying plastic So would bearings with an ID of 19mm be suitable?
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I would go with an imperial 3/4" bearing just in case. The shaft is hardened to RC 62 on the surface (that's about the same hardness as a file!), so it would be impossible to reduce it's size if a 19mm bearing didn't fit. It is also likely that there would be a wider range of bearings for 3/4" than for 19mm, which isn't a standard metric size.

Just for fun, you or Glen can find out how strong Ti tubing would be as an axle in Solidworks with the Cosmo FEA program. I am told that Ti tube has some impressive figures and will be featuring in a popular US bot before long...
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

I forgot: Cut to size is dead boring - just a tiny counter and almost zero product. If you go around the back, it might be different, but they are probably not going to like you dumpster diving during business hours

I think its time I went diving on the North shore soon; there are several other plastics companies around artarmon and Chatswood and many engineering places too.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion