Liftoff (FW) build diary

[Liftoff]

Is the 13.6kg weight limit with a full Co2 main tank or it doesn't matter

[Eventorizon]

2.3 Consumables
Maximum weight includes all consumables.

No, the C02 is included in the weight of the machine.

[Liftoff]

Pity, could have saved 200gr!

Not that it will matter much, I'm already 13.4kg, and I still need to pack the batteries, Co2, speed controller and wiring, top cover and worst of all - the titanium armour!
For the local competition its ok as 17kg is the limit, but after its over I'll go over the machine and trim excess material off. This build was done in too much of a hurry I had no time to get to details.
I'm done for now, Blastoff is almost complete but still untested, I'm particularly worried about the pneumatics because of the way the ram and flipper are mounted...have no idea if it will be strong enough to flip something or not... That's for my brother to discover now, gave him a good handover and he should finish it of by the end of the week.

In the meantime I'm packing up my bags (actually my wife is!) as tomorrow morning we're off to the Uk. Hope to meet up with you lads next Sunday at Golchester...

[RogueTwoRobots]

I take it you're competing at Gloucester, rather than just watching? If so, don't worry too much about the weight; the whole point of whiteboard fights is to have fun and, in some cases, do some testing of robots. As a result, some robots are often overweight. And considering the distance you've travelled, I don't think anyone will complain. Best of luck getting it finished

[Liftoff]

I wish I could bring it over for a whiteboard, but unfortunately our local robotwars event is on the same day as Gloucester, it will be for another time.
My brother will finish the robot off and take it to our local event, no time left for me to help, tomorrow at 7 will be in the air!
Will be missing the local event but I'm more than sure that Gloucester will make up for it!

[Eventorizon]

Why is the local limit so bizarre? 17kg isn't in line with anything in the UK, US or anywhere!

[Liftoff]

Good question, but I don't know the exact answer. Keep in mind the level of this event is nowhere near to the events you're used to. Rules are somewhat similar but with just one class of robots.
The event is organised by the University for the engineering students. I'm long past the student age but my brother has been a sudent there for 5 years, and we've competed for these last 5 years.
From next year on we're out of the competition as my brother has graduated and he's out of univ. So the alternatives are come over to the Uk or organise our own event, the first is the easiest option so that's what we'll do.

[Eventorizon]

Have you got a link to the rules? I am curious. I am sure the UK champs dish out more punishment than those machines do.

[Liftoff]

I am sure the UK champs dish out more punishment than those machines do.

Even me! When I said our level is nowhere near the level in the Uk I meant ours is much lower. Last year Will Thomas came over with Inertia but just for a demo, no one in his right mind would have dared him for a match.
Here's the link to the rules:
http://www.ieeesbmalta.org/index.php...8&limitstart=1

[Eventorizon]

Ah, yes I remember now. He ripped up a bit of wood.

The rules are basically the same just with the higher weight limit it seems.

[Liftoff]

Yes the weight limit and dimensions, 500mm x 500mm max.
Regarding the bit of wood, it was actually quite a large piece of wood flying around - and I remember Will getting a bit concerned as the arena was not exactly spinner proof!

[Liftoff]

So, I got the latest update on the final stages of the build which unfortunately are not looking good

Yesterday they managed to complete the robot to a working state in terms of drive, and the pneumatics were working (apart from some minor leaks!) So I was feeling confident that by today it would have been combat ready.

But this afternoon, after finalising the build and taking it out for testing it refused to move...dead! My brother is thinking the receiver went bust, but with no time to buy one looks like its grounded!

Only hope is they borrow one from I don't know where!

[Liftoff]

Guys I'm having a hard time getting this build within the weight limit!

I have gone through plans again and trimmed it further,(for now on sketchup obviously!) But I'm still off the mark by about 500 grams.
One of the heaviest pieces is the base plate which is 3mm thick Aluminium, thats 1.5kg. It is also the part which worries me most as being 1000 series Alu its soft and prone to bending with a good impact.
I was thinking of cutting some pockets in it, but not yet convinced about that, first because it will further weaken the base and secondly it will expose the internals when upside down...

Any ideas of what could be done, or maybe different materials, or maybe I should just risk it!

baseplate.jpg

[Revsmin]

A 10-12mm HDPE base would save you that weight easily, and would be more than enough protection against the ram's power; we use 10mm on Skyfall, it stands up to FP fine.

[Ellis]

10mm HDPE would actually be about 250 grams heavier than the 3mm alu. I have this problem in my machine, too, as in, the baseplate eating up a huge portion of the weight limit. It depends on how structural your base is, but I have been able to drop mine to just 1.2mm ti (only has to hold the electronics in). I wouldn't trust that to handle all of the forces of the ram on its own, unless it's supported around the base of the ram well, but point is, it'd save ~500g.

Saying that I'm not sure how much more I'd trust soft 3mm alu to support those forces, so it's probably a much for a muchness. If there is some sort of strut (some lengths of the 3mm alu on-edge perhaps) support under the ram then I'd expect it to be fine.