So there have been quite a few developments in the last year and I thought it might be time to collect the best shopping list for new comers. This will make its way onto the wiki once its semi complete.
Drive Train
2 x Bunnings Drills or Kmart Drills I think are cheaper
2 x Bunnings red wheels
(Might suggest ultra simple foam wheels after more testing)
Wire
What gauge do people think on Low Power Feather?
Shell
I would mostly scrounge steel. Cutting board is too expensive these days to really armour a bot with. But still good for internal mounts.
What have I forgotten? _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Sun Jun 03, 2012 1:52 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
I would use 12g wire up to the ESCs and 12 or 14g to the motors.
Unless you were planning on a removable link power switch using the XT60 connectors, throw in something that can take 30 to 50A.
I can't believe that with all the other advances, we still recommend Bunnings red wheels - they have terrible grip, are quite brittle and the hubs barely work! Whatever happened to those import wheels we were promised?
Its implied in the Shell section, but how about some nuts & screws recommendations? Many bots fail when their undersized cheapo sheet steel screws pull out or shear off; I would recommend M6 screws and nylock nuts as a much stronger alternative.
I went the XT60s as they seem to come with most ESCs and batteries these days. Might be a little oversized but they seem pretty robust. I personally am still using EC3s but am slowly moving to XT60s.
With the Red Wheels I know its a bit sad. But Banebots really need slotted shafts, Colsons need custom hubs (and RMP shipping destroys you) and thats really the main other options.
Joined: 08 Nov 2006
Posts: 1265
Location: Adelaide
I always go 12 gauge wire but with everything above used you could easy get away with 14 maybe even 16 gauge.
EDIT: Agree with glen bellow. Jaycars 12gauge is horrible. Hobbyking had decent 12gauge and cheap IMHO. _________________ Remember to trust me, I am an Engineer.
With the Red Wheels I know its a bit sad. But Banebots really need slotted shafts, Colsons need custom hubs (and RMP shipping destroys you) and thats really the main other options.
Steve
What commercial wheels don't need any customizing?
I solve it rather easely by using HDPE bar of the right diameter and turn my own centers. (or had
them
CNC milled by one of the UK Robot War Gurus Mike Lambert)
Carpenters tape and a lot of small self tapping screws fix biketyre to the wheel.
I learned that using a more smooth tyre works better than the knobbly , but very soft mud-tyres from BMX or heavy duty MTB's
Not perfect, but cheap and sturdy.
One of Satanix 1.666"s wheels survived a full hit from NST.
TAN uses a large version of these, and after 10 years in use, still going strong.
Nice but yes red wheels just screw onto the drill thread and then you add a washer to hold them on. Tried and tested. So thats why we like them.
Very little grip and a bit small but for first timer its a very easy way to get started. _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Sun Jun 03, 2012 3:46 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
If you're doing that just lathe a rod of aluminium as a hub for a quarter the cost (plastic in Australia is hard to get and expensive, that's why none of our robots are made from it). But the noob in the title kinda indicates that the people this list would apply too don't have the methods to turn up custom parts like that.
I wonder if that + a few recessed custom belts would be a good setup. Easy to change the belts, when they wear down. Realistically if you are going to the effort to turn Ali hubs for colsons with the ridiculous effort and cost it is to get a few wheels posted here this might be a better alternative.
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
Cast wheels are probably going to be the cheapest, easiest and best way to get the job done. Just hasn't been too much demand for featherweight wheels lately it seems _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Box section for sure... So cheap and gives their bots a fighting chance due to the added air armour for the frame. 3mm wall would do it and probably even thinner for most fights ( I don't think it would matter for demon considering it will cut straight through 6).
Hmm yeh, The Evil Spike bot with just 2 layers of box section went up agains Demon with minimal issues. (Just make sure you weld it properly) Tacking it then finishing later doesn't work too well when you forget the finishing it later part.
hahah yeah it had significant issues before it was welded properly!
Agree, box section. I had a 5mm mild shell (2.5 x2 sandwiched) on a feather that went up against demon and he cut through it like cheese. Mild sheet / shell = nothing against any kind of half decent spinner in the current comp. _________________ <Patrician|Away> what does your robot do, sam
<bovril> it collects data about the surrounding environment, then discards it and drives into walls
Mon Jun 04, 2012 12:39 am
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
Box section is probably the cheapest armour you could use, but its soooo hard to say what will work and what wont 'cause it depends on pretty well everything.
Cobras wedge was 3mm mild steel and lasted for an eternity against even against modern spinners (went up against bender, demon, scissorhands a couple of times) on account of it having such a huge angle to it.
I can't remember what the back of inspector general was made from (was it hardox or a stainless gas bottle?) but that was near on impervious too.
but at a minimum 3-6mm is probably something of an extreme ballpark figure for steel. Having a strong structure and being able to take that damage and keep working is probably more worthwhile then the external armour itself anyway. _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
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the jaycar 12g is super unwieldy in a little robot without much room. T
