Hi people. I'm from the Brisbane northside and the kids and I attended two events at The Edge and a robot workshop put on by QRSC. Very keen to get involved and build a bot or two.

I went to the recycle shop at the local tip and picked up a razer scooter minus its rear wheel and some wiring, a few kiddy cars with motors and batteries, and I have a few ideas about building a rammer with these bits to learn about driving (and probably about rebuilding if we meet a spinner ). I also have some Bosch Rexroth frame lengths which will help at the prototype stages, probably not so much in actual combat.

Some questions about materials though - does anyone use the lithuanian titanium plate available on ebay? It seems much cheaper than the stuff from the states. Questions about authenticity and grade of the material are of most concern.

Am I allowed to use a wire broom type face on my rammer to dissipate some of the kinetic energy of a spinner? I realise it won't be a very fearsome offensive weapon but seems like it might be a useful armour. I'm thinking of making it out of steel guy wire threaded through a drilled aluminium plate at the front of the bot. The idea would be not to entangle the spinner, but give it something to "chew" on that will rob it of its momentum.

For a better weapon somewhere down the track, I am contemplating a four bar mechanism rigged as a lifter / flipper depending on whether it's pneumatic or electric powered. It should be easy enough to integrate with the previously mentioned defensive bristles, provided I don't blow the weight budget.

See you soon, hopefully,

Kato and the kids!

Welcome to the forum Kato.

I have never hard of Lithuanian titanium, do you have a link? You are right to question the quality, it could be a cheaper grade relabeled. The stuff most people use is 6AL-V4. There are several other grades but they are much softer.

The wire broom idea is fine IMHO - several other bots have used similar ideas - Sproing uses spring steel rods to absorb impact and keep spinners at arm's length very effectively.

4-bar lifters can be very effective as long as you protect the arm from spinners. I would think about powering it with electricity; its much easier to get it going and as long as you use a large motor, it should be fast.

Hellooo welcome and all that

Did you mean the soviet body armour on ebay? not sure what cold war time titanium is grade wise but its a fairly thin at 1.5mm.

I bought a pair of grade 5 1.2mm and 2.5mm sheets 300x300 off ebay UK years ago and it was about $50 with shipping. There certainly are bargains to be had

Everything else there looks pretty good parts and design wise. Happy building! (and new year ;p)

oops my bad, Lithuanian Ti from http://shop.ebay.com.au/rupucis371/m.html

Latvian! Latvian! (slaps head)

Haha jagshemash!

Hmmm nice find. Looks like most of it is grade 2 which is softer than grade 5, but also less brittle (i find the thin grade 5 to be very brittle really) and i know alot of the UK guys use grade 2 in their robots. Though im not sure if they use it as outside armour or just as framework.

For the money i think that it'd be a good buy. Definitely getting myself some of that tube

"similar in hardness to soft iron"

That doesn't sound so good! From the heat transfer coils, I guess this is all ex-industrial where they processed something really corrosive. I haven't checked, but I think grade 2 is almost pure titanium and is probably not worth using - might as well use steels sheet for a lot less money.

Hey Kato,

I assume you were the one who came and saw me at the edge. I still have absolutely no idea why it does the turning thing. Phillips doesn't do it so I am thinking it might be the radio but I still don't know exactly why.

Steve
_________________
Steven Martin
Twisted Constructions
http://www.botbitz.com

@Marto - Not overly stressed about the turning ant. Ordering some stuff from HK so I'll get a cable for the TX and try to sort it out.

Major score today - another visit to the recycle shop, another couple of scooters with SLA batteries and motors and a ride on toy with motor and battery. Bought a winch but the motor is a bit dicey, will have a better look at it later. It also has about 20 metres of steel winch cable for my ablative bristles!

@Nick - we now have a large motor or three! There are two nearly identical 100 W scooter motors for drive and a single big 250 W for weapon duty. Plus three working sets of 24 V SLAs to power them. We're having a tough time deciding what to do - I think a rammer may be just the *first* thing we do.

Whinch motors can be really good - Ask Aaron about the hacked whinches he and Andrew made. Their performance was excellent and I don't recall them ever failing.

quote:

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Originally posted by Nick:
Whinch motors can be really good - Ask Aaron about the hacked whinches he and Andrew made. Their performance was excellent and I don't recall them ever failing.

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Yeah, you should definitely do that! If you had keyed shafts and maybe lighter wheels, T2M could still be very competitive, It was my favourite wedge back in the day.