How Could I Improve...

Sorry but I strongly disagree.

A: shoving in powerfull motors means shoving in bucketloads of batteries. They take up weight, they take up space. That is vital for the design of your robots and how long they will last.

B: giving the specs of your batteries just like giving the amount of gas in your flipper will give you an accurate assesment of the power you will generate. Voltage alone will not do that. Batteries go down in a fight, you will not run as fast in the arena after 4 minutes as you did in the first 4 seconds.

I think that in vapourboteering it should go to the writers choice whether batteries need to be specified or not.

Given that the majority of us not even know what type of batteries there are, and I dont tend to write in the intros what batteries each person uses, I think they shouldnt NEED to be stated.

I really need to know, if a fellow tournament writer could answer this please:
Say someone started an annual tournament called ABC. In the first series, I entered Behemoth and did well enough to be seeded in series 2. But in series 2 I didnt enter Behemoth, but someone else did/it was entered by the writer on a realie team. Would Behemoth still be seeded?

Please?

Yes - it is true and possible - TJS in FFW4 entered Storm 2, and then in the next one, Richard Southworth entered it, and it was seeded 8.

Thanks Paul

quote:

It did in my Mini-Tournament, as Leo stated in his stats Symmertrys batteries wouldnt go the distance.Most vapourboteers make their robots Battlebots specs So I thought Id do that too. Battlebot fights are 3 minutes, not 5.

But thats ok, if Symmetry cant get the job done in 3 minutes it wont do it in 5 minutes either. :)

Well, in practice its up to the writer wether ANYTHING needs to be specified or not.

But while things like armour and weapons are commonly accepted as must-haves, batteries are in a grey zone, I myself kinda agree with Frank though.

Liam, good question. In all cases I have seen, and it happened more than once, a realie would be seeded based on its performance no matter who enters it.

I personally dont look at battery stats in detail, but I think they should be included, if only for the sake of completeness - besides some designs benefit from heavy SLA batteries rather than lighter ones, but thats just me being pedantic probably.

Right so you plant a V8 in a car and say it runs on petrol you think that is enough to predict it will last 30 rounds in the race?

The problem with batteries is I dont have a clue where to start.

I just say NiCads unless I need SLAs for weight (like in a Mjollnir-style torque reaction pickaxe), and work from 1 pack being 12v, stating more if I think I might need more (e.g. for an electric spinner or tracks). /useless

batteries are vital for vapourbots, if you dont list ur batteries then u will never know how far it will run for.

eg, 2x Mag s28-400 and 2x LEM-200 would require 8x 24v 3Ah Nicad Packs that would leave u with no weight for anything else

As for types of batteries thats simple enough to explain.

Nicads and Nimh - there nearly the same, Nicads produce a higher current but you can get high discharge Nimh that can out preform nicads, I have some in the new Tanto. Youll need min of 3 packs for a heavyweight on Mags

SLA (sealed lead acid) or Gell Cells - much heavier but potential higher discharge than nicads

Li-Ion or Li-Po - lighter than nicads, but early tests on the A123 cells show theyre discharge is half what they claim, theyre good but theyre not there yet

2 Mags require 8 batteries?! :S

I always thought that LEMs sucked up more batteries than Mags in the same time frame. :S

(Message edited by kodster on May 06, 2008)

2 mags and 2 lem200 as in used at the same time, sorry that wasnt very clear

Not really the place to ask, but Craig could you give me details of these high discharge Nimh batteries, could be just what I need.

you need a curry and a night out with me mate :) mark if you have my mobile number give me a ring please :)

Mauling Dervish

Shape: Barberous 2 and a bit
Colour: BLACK
Weight: 100kg
Dimensions: 96 X 42 X 42
Armour: 8mm Titanium
Wheels: 2 X Tightly Foam Packed Wheels with Hardox Hubs, based on Stinger
Drive: 2 X C40-500 Magmotors Powered by 4 X 24V NiCad BattlePacks
Speed: 15mph
Ground Clearence: 6.8mm All Around
Turning Circle: Zero
Weapon: 19kg Full Body Drum with 8 X Grade 5 Titanium Teeth, a bit blunt and curved upwards. Its powered by 2 X LEM-130s and spinning at 3000RPM. This also spins upwards to flip AND damage opponents at the same time.
Strengths: Invertible, Flipping it does nothing at all, PSYCHOTIC WEAPON!!!!
Weaknesses: Although EXTREMELY sturdy, wheels kind of exposed.

Looks fine at a glance, but Id change the name. Theres already a similar robot called Dervish.

To have your drum 19kg, your drum would have a wallthickness of 2mm steel,or 3.4mm Ti. Over a distance like almost a meter its not going to be pleasant. :)

even obsidian could punch through that lol

Question: If I had a spring powered flipper, and I wasnt particuarly concerned about resetting it after it had fired, what is the maximum lifting force I would be able to get within 100kgs of robot?

quote:

even obsidian could punch through that lolwell thats a bit optimistic. :)

Joey, I have no idea. I know 400kg is achievable since it has been done before in a dutch robot i know. That one could reset though.

Ive always thought that as long as there is enough weight in the design to fit batteries in then their inclusion is irrelevant, in the 7ish years Ive been entering these things (I think?) Ive not *once* seen a fight end due to batteries running out.

Batteries are implied by the very fact its a piece of electronics, as it is only really a lump of material without power, and writing fights where batteries run out is just far too fickle in terms of accuracy - besides if fights have a finite length then presumably whatever people put in their machiens will last logner than that out of common sense.

To be fair, I have done one or two fights where batteries ran out. They were in last bot standing, and neithere competitor could really knock out the other. Sometimes I hate my own random system:lame:

quote:

Ive always thought that as long as there is enough weight in the design to fit batteries in then their inclusion is irrelevant
Well thats the point, of people shove mags and lems in one machine you better give stats on batteries because a couple of 36V packs of 3600mAh will not cut it, and batteries add to weight. And not in a small way either. 8 packs 36V is 15kg of batteries ergo 15% of the robot.

(Message edited by leo-rcc on May 08, 2008)

lol, there must be some lighter-yet-just-as-powerful batteries out there somewhere...keep looking! :proud:

Actually those are the lightest packs you can find apart from A123, which are as Craig put it not quite there yet although I believe they are usable.

People tend to think of batteries as an afterthought but it really isnt. When you design a robot the power consumption is a vital part of it.

didnt say u couldnt use them, i just know that in testing they dont preform the way they advertise them too

True you didnt say that, my bad. Doesnt change my point though.

Need some advice before making a CAD.

Tira IV

Shape: Cut-off wedge at the front with small scoops (surrounding the disc). The height rises towards the rear then angles down steeply in a tall wedge. There is a curved wedge in under/behind the disc to halt wedges approach. Behind the disc is a pillar of sorts, which is higher than the disc, is a little thin but wider than the discs thickness. It is from this pillar that out of which a spike comes out.

Colour: Red/orange faded stripes, with a bit of black and silver.

Speed: 14mph

Weight: 100kg

Armour: 7mm kevlar sides and rear, and 8mm 7075 aircraft aluminium top and underbelly. There are 7mm titanium/vanadium skirts at the sides and rear that start at half the height of the top edge and angle out at 45 degrees, and are securely placed with several iron bolts. The pillar is made of 3.25mm Hardox. In the (rather minimal) front area is 5mm titanium.

Chassis: 4mm steel ladder chassis. 13mm of urethane rubber is placed around key areas in the sides, front, and rear, between the armour and the chassis so as to avoid being shocked to death easily, even from her own hits.

Drive: 2 S28-400 MagMotors @ 24v, geared to acceleration

Power: 2 NiCad Battlepacks @ 24v

Motivation: 4-wheel-drive on a skid steer system; the wheels are CNC hubs and the tyres are completely made of urethane rubber for superb grip.

Ground Clearance: The scoops and curved wedge under/behind the disc are 0mm, directly between the bottom of the disc and the floor is 15mm. The sides are 10mm without skirts and the rear is 15mm without skirts.

Turning Circle: (does this need to be put? :P) Zero.

Dimensions in CM (LxWxH)
Main body without skirts scoops and disc = 70 x 90 x 30
Altogether = 100 x 110 x 55

Weaponry: A large 50cm diameter vertical flywheel, weighing in at 22kg, constructed from Hardox but with cut holes/markings for better dynamics. The thickness of the flywheel is 15mm, and it has three Hardox teeth, as before, also pointed as before. Powering this disc is 2 LEM130 Lynch Motors @ 36v and 6 NiCad Battlepacks @ 36v. With an RPM value of 3000, it unleashes 126kJ of energy with every blow, and it can accelerate to that 3000RPM within 2.5 seconds.

Srimech: Finally, Tira gets a srimech. The key here is that pillar I mentioned earlier, which houses a pneumatic spike, powered by a 2kg CO2 canister. The spike is 3cm in diameter, is more of a boxy spike than a cylindrical one and is made of titanium. If Tira lands on her back, this will shoot her back onto her wheels in around a second. It fires only 10-15 times, so it doesnt last forever.

Notes: Posted in here because I needed an opinion.

VERY ROUGH WEIGHT CHECK
Body armouring - ~13kg
Skirts - ~5kg
Chassis and shockproofing - ~20kg
Disc - ~22kg
Disc power - ~15kg
Drivetrain - ~10kg
Srimech and power - ~5kg
Other bits - ~10kg
Total = ~100kg

(Message edited by kodster on May 11, 2008)

...and you said mine was overweight? :proud: It actually looks alright to me, no major problems, Im correct in assuming you redid it because SCIV is coming out?

Two things Id do.

1) Shave the armour of the skirts to save some weight. Seriously, skirts are there to prevent flippers, not spinners.

2) Also bring down the KJ count of the weapon to improve reliability.

quote:

1) Shave the armour of the skirts to save some weight. Seriously, skirts are there to prevent flippers, not spinners.

Unfortunately the main armour isnt too strong, so thats why the skirts are thicker. But alright, say...5mm.

quote:

2) Also bring down the KJ count of the weapon to improve reliability.

Erm...okay...to be honest, I wanted something that was very high but not extremely high that itll one-hit KO itself like MeCannibal. Lets see...at 2750rpm it will do about 106kJ. Good?

Joey - You got it. :proud:

Its going to be tight and very close to the weightlimit but I think it is ok.

Well if Leo thinks it is okay, there is no need to comment further. :)

You probably use battlepacks as disposable batteries though, I dont see them lasting more than 1 fight before they melt down.

But thats a choice to make.

I just noticed this thread is longer than just about all of the tournaments here...

Well, it would be. Tournies end eventually.