That was for half a plate, no discount
Full size plate is 1.2 x 2.4 cost $180

2.5mm garolite G10 1m x 2m $250

garolit weighs more then polycarbonate
ploycarb is transparent

I believe polycarb is better to machine and tap and garolite might be a health risk especially if your doing lots of cutting and drilling in class

The polycarb is looking like the best option, garolite is great but as you say there is a health risk. It's also proven hard to locate in Australia...

Here's a rough initial breakdown of what i'm planning everyone please feel free to critique...

Highschool Robot club weekly plan.

Each class 1.5hrs long.

Week:

1.Robot combat introduction, videos, parts discussion and demo robot test drive.
2.Antweight Workshop part 1.
3.Antweight Workshop part 2, testing and tweaking.
4.Antweight Competition, single elimination. Introduction of beetleweights.
5.Beetleweights – discussion of design ideas, cost breakdown with example designs and parts.
6.Beetleweight design finalization. Organization of parts ordering.
7.Beetleweight construction
8.Beetleweight construction

Yes, i've decided to do antweights to start. Main reason is as glen pointed out noob kids are likely to blow up esc's left right and center.. a $2 servo is easier to replace than a $60 esc .


My cnc is now fully paid! Just need to wait out the lead time...

EDIT: This is just term 1, 8 usable weeks max.
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quote:

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Originally posted by dyrodium:
garolite is great but as you say there is a health risk. It's also proven hard to locate in Australia...

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Doi, i should have known that. Still, fibreglass is a no no for school kids.
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quote:

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Originally posted by dyrodium:
Thats because Garolite is a brand-name. From what I can tell Garolite is basically fibreglass mat with Bakelite

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Maybe add this to the curriculum. This might be a really good read for the kids too. Then when they start participating in the club they aren't such social inepts.


Love the antweight idea. Glen had suggested that up at Brisbane when we were talking about it. I agree that the ants seem like a really good place to start.

So are you looking at term 1 next year?
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Whats wrong with fiberglass?
provided they don't grind it theres no real OH&S issues, other than the usual with glue.

I think you might be pushing a bit hard to get a class of kids through that much work in the time, I'd suggest picking one weight class, if you want to we can nerf some ESC's and make up a protective box for them (electrically too), about the only thing you cant easily do is protect from + into motor wire and - into a battery terminal. If you would like to run beetles.

If you do one class you might be able to have 2 rounds, first round normally consists of finding the fail anyway so having a second round with bots that aren't falling apart might be better ;->
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quote:

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Originally posted by Bort:
[img]
Maybe add this to the curriculum. This might be a really good read for the kids too. Then when they start participating in the club they aren't such social inepts.

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put esc into a sealed box, put polarised connector on for batteries, and make sure you have a different connector for the motors, that'll probably eliminate 80% of the issues.

Put a 1.2 ohm resistors on the motor wires, inside the box, that will limit any short circuit current to 10A, and motor current to 5A, which should stop much smoke from getting out.

put a diode on the incoming battery line (a beefy one, it'll need to handle a fair whack of power, perhaps a Schottky to reduce the heat, or a stack of cheapies with decent heat sinking, think about putting a polyfuse on top of the diodes as well) that'll stop reverse polarity from causing issues.

Add a transorb on the motor wires (its a good idea anyway it really should be included in the ESC but nobody other than the IBC and 4QD seems to do it) and also tranzorb and add decent caps onto any brushless you put into the mix.

It sounds like a lot but its like 6 components added and put in the box.

Perhaps look at doing stage 1 and stage 2 ant/beetles IE everybody builds a wedge/lifter then people can add spinners etc after they have had their first event.

marto would be the best person to talk to about how much people can get through in a time period. Also what are you doing for tools and such during the build days?
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quote:

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Originally posted by Valen:
Whats wrong with fiberglass?
provided they don't

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The antweight workshops at the edge were run really well!

The only concern id have is who will absorb the cost of dodgy components like the ESCs in a beetleweight size robot. if they blow up somehow (and god knows they do at some stage) then someone is out of pocket by $60 odd.

Im sure Steve had some servos and such that didnt work but at least those are all of $2 parts that you can just factor in a margin of failure for in the initial cost. Putting in $50-60 extra is a fair amount.

The antweights are almost idiot proof, quick to make and give a good introduction of how everything goes together and works for a completely new builder (when i had a look up at the workshops there was quite a few really young kids building them themselves. like 7-8 y/o) and most of the parts can translate across to a beetle ala radio, lipoly and maybe even drive servos if you use some proper standard sized ones.

Getting the parts will also be heaps easier for an ant too as they can literally all come from hobbyking or any hobbystore for that matter so Angus isnt at the mercy of 3 or 4 international suppliers to come up with the goods for the beetles (banebots/virtualvillage/RMP for the basics at least). Its only his first time organising something like this too so taking that into account is important.

Doing 1 class per week at an hour or two long over a complete term (10-11 weeks?) leaves an eternity of time to get everything done. One class as an introduction + build for one of steve's kits then the next to compete seems realistic enough then possibly elaborate on it or move onto beetles for the remainder. Gives them a taste of combat and what its all about without being overly confusing or complex before providing the time to come up with something more significant for the beetleweights.

My thoughts on the progression was that you could set a budgeted amount of parts to use, like you can either keep the standard size servos from the ants for drive and get some good weapon / armour parts or discard them for a better drive (esc's and 1000rpm motors say) but forgo decent weapon bits. Teaches compromise which is always an important factor in this game and basically every other thing for that matter or something like that.

Feeling contemplative tonight XD

setting a budget is a good idea it'll help stop buying the victory.
I'm just not keen on the idea of changing weight classes, it makes doing the ants first seem a bit of a waste.

I think also these classes are going to be much shorter than the one steve was doing, it feels like anguses are an after school thing? and steves were an all/part day thing.

if you have an hour long class, you only have about 30-45 minutes to do anything with all the screwing around that'll happen.

worst case if you get stuff done super quick, add some more events, they are always cool ;->

HAH they can even have 2V1 against "open class" bots if they want, AKA ones built by us (if you get your ass kicked by a 13 year old you deserve the shame).
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It's an after school thing, mondays 4-5.30.
I see ants as a good intro class, but they're too difficult and expensive to expand on, add pololu motors and a proper esc, you might as well make a beetleweight. Will comment more laters
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Just on your material science: for a given thickness, Garolite is much stiffer than polycarb and does not soften with heat. Garolite G10-fr4 is quite flame retardant, much better than the other materials considered. The electronics is all going to use the broad equivalent to Garolite in their PCBs, so kids will be potentially exposed anyway. If you want to avoid dust inhalation, spray the materila with any kind of light oil while working it - WD40 or even cooking oil will do fine.

The thickness of the material means that neither will ever be tapped or need to hold a thread. Polycarb will not fray & splinter like Garolite, but it will melt at lower temps and burn. It is definitely lower density than Garolite but in the thickness needed for beetles and ants that will not mean so much. Polycarb can be heat formed, allowing interesting shapes.

I would go with polycarb on the cost rather on material properties

So with antweight kits you should be able to go from 0 skill to driving in 1.5hrs no problem. Some people had very little idea on the weekend and they almost got them together in 50min.

They aren't ideal as there is a few components which are pretty cheap.

Few things I would change if you are using them repeatedly or looking at actual robot combat. Use the HXT900 ~ equivalents with bronze gears. The HXT900s work fine for pushy bots but I have to swap mine out every 3 fights in my ant as they die from spinner hits.

Also lipolys might be better but I avoided them for a few reasons. Firstly I grabbed $5 chargers lasttime but these were crappy and 20% were DOA. So I swapped out for AAAs. Also if you leave a lipoly flat for a week its useless.

The other thing which is important is that even if the bots aren't really good that they are reliable. As if they aren't you get people blaming you. You really want to get them in then let them design their own. Then is their fault.

Oh also. I would have ants as semester 1. Then let people get excited and rebuild them. Then move on to Beetles semester 2.

Steve
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Twisted Constructions
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