Heavy Weight Spinners 2011 !!

Its July, it€™s the time of year where I€™m normally fully booked with educational projects, and 2010 is no different.

It€™s a time of year where I sit back and look at the events from the year so far, what€™s worked, what hasn€™t, and try and come up with new ideas to improve things.

Ok, prepare to be shocked€¦ its one of my ideas, so its going to be shocking.

One of the things which has been lacking of the RR show for a while is €œ destruction €œ. I€™ve known this for quite a while, hear it from the audience, and some of you might have seen the robot I built for Guildford which was supposed to blow up and fall apart.

Unfortunately I underestimated the strength of polycarb and it never fell apart ! Blew up nicely though !

Chatting away to a roboteer the other day we were discussing how we can bring some destruction back for 2011.
One option was to try and encourage roboteers to add sacrificial parts to their robots, but then quite quickly we realised that unless Thor, or Terrorhurtz was in every fight it was a bit pointless.

So here€™s the plan€¦.

Bring back heavyweight spinners.
What I€™m proposing is the concept of allowing spinners to run in the RR Arena, however a whole new set of rules to cover this.

I€™m thinking something along the following guidelines€¦

Limit the use of motor to 1 x bosch 750w only on 24v.
Limit the gear ratio to limit the speed.
Limit the diameter of the disc.
Limit the construction and material of the disc.

Yes the RR arena would need a few upgrades, however I€™m not talking about taking to a Class 2, I€™m proposing a slightly thicker net, and a few other tweaks. A compromise.

Now€¦ what we don€™t want is some Hardox covered boxes with a spinner fitted€¦ what we do want is destruction, a new challenge€¦. Maybe limit the body material of these new robots to Wood, so we have destruction. Ok maybe stick some Hardox on the inside to protect your insides, but the outside something which can be damaged.

And I€™m not saying Iron Awe will ever get to play with these€¦ its about entertainment.. and I€™m sure there€™s enough of us which do it to entertain. But we need to do it in a safe way !! For events to carry on I feel we need some destruction.

I remember when the feather weight BatterBot was formed€¦ it was WOOD taking on Little Spinner and we all loved it when it got smashed up. I want to bring back the destruction and we can do it together if we try.

2011 RR events need something new, and spinners could be the answer.


Discuss €¦.

Limit, limit, limit....................

An opportunity for middleweights by any chance??

Got some wheel chair motors in the shed a sheet of hardox, some angle iron and some thin ali for a nice hardox box which could take some nasty visible damage on a sacrificial skin and still run once a month because it's built like a brick underneath.

Agree to some degree as Hydra was well photgraphed at Guildford because of the damage to it (shouldn't happen now though cos I fixed it :rofl: :rofl: ). Not sure if spinners were back in full force that we'd make as many events due cost of repairing the damage.

Andy

Yes, limit the ammount of energy in the disc: rpm, diameter, mass.
Also: only horizontal discs; vertical discs are much more destructive.

Some destruction has been lacking, it's definitely a key aspect of robot combat, but as ever you are on the ball Jonno with what the events need to keep them exciting.
I think it's sensible to limit the main factors. As you've said, it saves you from having to completely overhaul your arena and it allows a degree of destruction without posing as large a risk to the public as full-on spinners would.
Marien's suggestion of restricting verticals could be a good decision too, as you're likely to get a lot less vertical flying shrapnel from horizontals and most of it will be hitting the polycarb instead of the netting.

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Limit the construction and material of the disc

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Maybe better to not limit this aspect? Dunno, just thinking that if the disc is made from as high a quality as possible, you're less likely to get, say, teeth shearing on it compared to a disc built from less suitable materials?

Quick question as well if this was to go ahead: what would the situation be with the FW spinners? Obviously they're a lot smaller and the chunks that could be torn off them are likely to be a lot smaller and lighter, but we all know the power some of the FW spinners can pack. Would they be allowed to fight freely or would there be restrictions on their motors/disc size/speed etc too?

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Originally Posted by k_c_r

Marien's suggestion of restricting verticals could be a good decision too, as you're likely to get a lot less vertical flying shrapnel from horizontals and most of it will be hitting the polycarb instead of the netting.

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Vertical spinners are supported by the floor and can hit a lot harder then horizontal spinners, that are not supported other then by the robots weight. So the power of a horizontal spinner is limited by the weight of that robot, not the strength of the arena.
Shrapnel will go anywhere, either way.

By the way: even without the Hardox, all robots get built better and better, stronger, with higher reliability. This says that all roboteers are getting more experience, and better at the game. This is good, because it keeps the costs of repairing down, and the fights last longer.
As an organiser I want as much movement en noise (of weapons) as possible. Maybe we can influence this by giving difficult designs a weight advantage over simple designs. Something like:
Hammers: 100% of the max weight - Flippers: 90% - Discs: 85% - Wedges: 70% - Boxes: 60%.

For peoples health, it would be good to go to middleweights, or 80 kg heavyweights. But I fear that this would damage the nummer of now active robots.

Sure, why not, sounds like a nice concept for some destruction.
No competetive element then ? And can we throw flippers in with them ?

By the way Jonno, can you please give us some final info for RIAT ? We still know nothing :(

Yes more for entertainment rather than full on competition, however it could develop into a good full combat class.

Yes we'd have to limit it to horizontal, and not verticle, but it is the way forward for the RR events to survive.

What we need is a few teams who are willing to put something together and lets test them.
Or any ideas... for example I suggested wood as the body material, even if its over the top of a Hardoz chassis.

Wood is great, it absorbs the impacts yet will give us destruction, and I dont think would be too dangerous.

John

Plastic discs would have roughly the same weight and impact as wood, but are stronger. Wood will tear easier along the fibers. So I would go for HDPE (tough) discs or maybe Polycarb (strong) or PMMA (Perspex, brittle).

I think some people might be getting confused on jonnos concept

i believe he would/might limit the disc material to certain metals and the wood concept comes in for the armour

so all the entrants have metal discs of certain restrictions and are outside at least covered in wood to add the destruction element

alex

Hmmm!

Still got SMIDSY's old disc and mounting and the 1mm stainless steel body armour. Not too averse to putting it forward for a trial as I've built around stuff to make sure the spinner can just pop back in.

As we wont be using it for competitions (Too susceptable to axes, hammers, full pressure flippers, low pressure flippers and just about anything else!! :rofl: ) it might just be a good place to start on looking at this. Ready built available robot. Battery packs and speedos are in the way at the moment but can be easily moved.

It's built like a tank at the moment but a sacrificial skin can be added pretty easily.

Anyone fancy chewing the fat at RIAT on how best to do things??

Andy

In my opinion, if we are brining back HW spinners, we may need to consider Tap-Outs or some other kind of rule (say once a robot is not moving or is unable to fight as well as it should, a spinner must not attack it) other wise the ammount of HWs turning up for event will be less and less from where people dont have the money to fix them (even wood can be a bit costly after a while!!)
I know its what we do, but theres some of us who just can't keep up with the ammount of money that goes into these robots.
Following on from the rule idea, maybe once a robot is not fighting as well as it should, let the robots still fight but the spinner must not be used (unless the driver of the slightly broken robot gives permission for an all-out feast lol :P)
Yeah it should be fun, seeing at how most of us love this in the first place for the spinners, but everything must have its limitations in my opinion (this isnt america lol :P)
Matt

Agree completely with you Matt but I think you may have misunderstood a bit. I think Jonno is not proposing a return to full combat competition as this would need a complete rebuild of the arena and would probably increase the cost of venues due to the time taken for the team to build it.

My understanding is that Jonno is essentially proposing a 'demo' class of robots with some robots built to rip apart some sacrificial armour on come specially built cannon fodder. Thus giving the crowd what they want and put on a bit more of a show.

Andy

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Originally Posted by psycho_fling

I think some people might be getting confused on jonnos concept

i believe he would/might limit the disc material to certain metals and the wood concept comes in for the armour

so all the entrants have metal discs of certain restrictions and are outside at least covered in wood to add the destruction element

alex

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Damn and I had just placed an order for a nice large balsa disc for our new weapon system :mrgreen: :mrgreen:

Its nice to see some good thinking going on here, but I am a little worried about the concept of any form of spinner in an arena with a net roof or a single gap in the screening.
A Bosch 750 can get a disc with some pretty serious power in it, and limiting the diamtre isnt nessasarilly going to effect too much. Compare it to the old scorpion Jnr, 1 astroflight (similar/less power to a bosch 750), a tiny diametre disc and thats pretty powerfull! There's no way I would run that in an arena with a net roof after the testing we conducted during our arena build.

It only requires a single bolt to be hit by a disc to have a serious projectile, and after the few close calls in past events I dont think safety can be comprimised by running any form of spinner in a net roof (unless it gets to the point they will hardly damage wood).

I will try and think up some ideas that could make it work....

@ Clive

yeh i had a similar conversation with jonno today, :rofl: :proud:

Can I weld a disk to gravity and try it out at RIAT ?

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Originally Posted by psycho_fling

I think some people might be getting confused on jonnos concept

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Maybe a little bit about where the wood should go :-)
But I am serious about the HDPE disc.

well the whole point of the wood was for the destruction element

Just a few thoughts on the idea

Arena
With regards to bits coming through the roof of the arena my first thought would be to leave the netting as usual and then fit over that 1 of 2 parachutes or similar secured to the sides only and left to rest in folds on top.
As anything makes its way out of the arena the light but strong material from a parachute would wrap around it and then slow its speed down till it had no energy to penetrate the parachute, the trick is in letting it fold onto the old roof material.

Spinner
The main thing to watch is tip speed this will more or less dictate how fast any bit will be flying off the robot. Also I would advise the disc is made with the teeth as one piece. This will eliminate any problems with hard tips breaking off when bolts shear. Case hardened mild steel would be good for this application.

Sacrificial Armour
HDPE would be very good for this as long as it was held on with a hopeless fixing, like Velcro as this would mean you could pick up the same armour parts after the fight and just stick them back on. A few Pyrotechnics and everyone is happy and no repair costs to worry about.

Hope this helps


Craig

Sort out the rules and let me know. I'll build a spinner.

An interesting concept. I'd recommend single piece metal discs, other materials would likely shatter, split or be too unpredictable. You're main problem is limiting the kinetic energy of the weapons and if you go back to basic equations you are therefore either limiting the moment of inertia or the rotational velocity. Rotational velocity is relatively easy to limit however MOI is a bit more tricky.

I'd set yourself a limit of say 500J or 1000J of kinetic energy then work backwords from the worst case disc design to determine the max dimensions and weight of said disc.

As mentioned earlier this may be safer with middleweight sized machines. Audience wouldn't be able to tell the difference and the forces involved are likely to be smaller.

You're roof is gonna be the problem area but as it doesn't have to be see-through would it be possible to throw a few mm of a cheap impact resistant plastic such as HDPE of the top of your current netting?

Velcro armour? Good idea!

I'm watching with interest as I wouldn't mind building a bigger spinner at some point and knowing me, I'll try and push it right to the limits for fun :)

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You're roof is gonna be the problem area but as it doesn't have to be see-through would it be possible to throw a few mm of a cheap impact resistant plastic such as HDPE of the top of your current netting?

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Why not a wood roof? :lol:

This might be useful in calc the moi etc.

http://www.members.toast.net/joerger/root/spinner.xls

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Originally Posted by rallikas

Why not a wood roof? :lol:

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Because you need atleast 18mm of good quality plywood to be as good 3mm polycarbonate for projectile impacts.

how fast did hypno-disc's weapon spin 500 - 750 rpm when it first appeared on tv? would that be too fast for the arena?
with light armour on the other bot = plenty of dammage and from what i can remember the pieces never flew that far. http://www.youtube.com/watch?v=w04BgclPmY8

this sounds like a cool idea jonno, could be what we need to move forward, craigs idea about the parachute is brilliant, when i first read this the first thing that rang alarm bells was the net roofing, but if we have that resolved :mrgreen: obviously there will be other safety aspects we will have to fix/improve, and it will be interesting to see if the fra will let this happen,

as far as limiting the spinner goes, apart from being horizontal, will there be any rpm/motor/voltage restrictions? i have a few spare motors lying around (litton, bosch etc) that i could use...i also have a spare disk so this could be a plausible summer progect :D

the idea of sacraficial armor is good too, hdpe or wood, loosly held on with velcro or a few bolts, the crowd would love it :D

also, would featherweight spinners be allowed? it would be good to get them out more often

jack

Some good comments and suggestions...... I think people get the idea, that its not about FULL COMBAT, its about entertainment and destruction.

Hoping to have some rules sorted after Riat so a few can have a nice summer project if they so wish ready for trials at portsmouth !!!

I did all the spinner / energy calcs / stress analysis at uni for my end project so I know what goes on !

John

Well i think i will take the 750s out of Carnage and the 400s out of Dragonfly and swap them around. Put the 400s on the disc and alter the pullys and run them on 12v. try for about 300 rpm.

I am temted to do a similar thing with SMIDSY.

One of the problems I have with velcro for holding on armour is that you can't control which direction it will fly off. That said if it's a large piece designed to fly off it's unlikely to penetrate the roof netting as much as a spike or something similar.

Anyway, my thoughts on SMIDSY.

As said above run it on 12volts possibly running 12v Bosch 400's (if anyone has two spare!!). Stick a skin of 3mm ali on the outside set off the body with some rubber fixings so things can get underneath and rip it. The put a layer of 1mm ti on top so we can have some nice sparks and stuff, could get expensive if it needs replacing too regularly but we shall see.

Andy

Think i will wait till Jonno posts some rules as Carnages disk is rather large

102 cm tip to tip.

Just been thinking about how to get proper speed control of the disc. Had a look at the wiring diagrams for the NCC speedos and was thinking the simplest soultion to get whatever speed you want is to use a simple relay starter on the ignition switch with the speed pot used in fixed position. Obviously a bit of superglue to fix the potentiometer would save an awful lot of potential errors/mistakes. Just seemed a really simple really easy way of doing it and means that the drive doesn't suffer because of a reduced overall voltage to suit the disc.

Quite sure this facility is available on most other speedos too.

Andy

http://www.4qd.co.uk/wire/prowire.gif

Wouldn't by far the simplest way, especially given that it doesn't take running a speed controller specially for the disc, be to just choose your reduction ratio (pulley diameters, sprocket teeth or whatever you're using) to get the right speed?

That's also easily verifiable when checking the machine over.

Quite sure it would be I was just pointing out that if it's already built like Dragonstrike and SMIDSY that it doesn't take a lot of modifications to get it going slower.

From a personal point of view I'd rather tweak the wiring than anything else.

Andy

you can also turn down the speed down via the spektrum

problem there is if somthing goes wrong with the speed controller and the fets short out then the motor will get full power. So it should be in the rules that you have to limit the speed by gearing correctly or using less batterys.

Hiya,

I think it will most probably be ...

Speed controller used for powering the disc... ( reduce the risk of contactors welding shut )
Specific motor(s) only allowed.
Specific gear ratio specified ( limiting the rpm )
Specific maximum disc diameter
Specific maximum mass

Of course its not going to be, do the maths and come up with a magic figure, its going to be subjective, we just need to work together and see how it goes.

I think ill propose to run a spinner in a very downgraded setup to see results, maybe even outside of an event in the summer. We can then come up with the magic figure.

Like i said, i have been very impressed with the input, and we already have some volunteers, plus 4 teams wanting to build something, so after RIAT we can get on with it.

John

Its great to think of new ideas and trying to get spinners back however call the competition what you like a spinner is a spinner and it doesnt go well with net roofs.

I would concur on that point made by James. After doing archery for many years I know that a sharp arrow weighing 100g tops will quite happily pierce and go through a heavy archery net at the back and the arrows weren't travelling anywhere near as fast as some parts that fly off bots.

A composite type arrangement might work though, a thin plastic such as HDPE or polycarb (2mm) to take the main bite from the projectile and then a net over the top to take the flex, catch the piece and hold it in place.

It is a tricky one but you will never go wrong being too safe and careful

I also concur - having been hit by a bolthead that went clean thru a substantial net roof and hitting me standing some 20m away from an arena leaving a mark on my leg thru my jeans I am certainly unhappy with anything less than a grade 2 arena.