Dan want to build spinny spinny smashy smashy thing!

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Hogi
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Dan want to build spinny spinny smashy smashy thing!

Post by Hogi »

hi guys. after seeing the spinners at antweight open i would like to build one. i have a few questions though.

which motor and ESC would you recommend?

is there anywhere i can get a blade cut? i don't have the tools to do it myself.
Daniel Jackson.

Team Hectic.

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Super antweights: territorial.

Fleaweights: fleadom fighter, gaztons.

Featherweights: hectic (under construction)
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Shakey
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Shakey »

The motor I use in HExa-Chopper isn't made anymore and I wouldn't recommend the one in HSOD (I have to do a lot of careful design to stop the motor dying on hits).

But a flat outrunner motor is good. Shorter the internal shaft of the motor the better so it cannot be bent (That is HSOD's problem, it will bend its motor shaft if I hadn't made it so that when it hits it actually jams the adapter between the disc and the motor into the chassis taking the force off the motor).

For ESC's I just use the Red plush hobbyking ESC's. 12A plush in HSOD, 6A in Hexa-Chopper.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!
Hogi
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Hogi »

thanks alex. your spinners are AWESOME!!!
Daniel Jackson.

Team Hectic.

Many antweights

Super antweights: territorial.

Fleaweights: fleadom fighter, gaztons.

Featherweights: hectic (under construction)
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BeligerAnt
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by BeligerAnt »

Far be it from me to dissuade anyone from building a spinner, but please don't underestimate the potential dangers of getting a spinner running. At the very least you need some safety goggles or a polycarbonate shield to put between you and the spinner in case it doesn't go completely to plan first time!
The most important thing is to make sure the motor and disc are balanced and the motor securely attached to the robot (or clamped to a bench for the first test). Also increase the speed slowly, as problems tend to get worse at higher speeds. Everything can seem fine at low speed and suddenly go very wrong at higher speed.

(Safety lecture over ;) )

You can use almost any brushless motor you like to fit the size/weight constraints of your design, although there are a bewildering array!
If you don't want to use HobbyKing (OK in my experience if you choose things that are in stock at the UK warehouse) I would recommend Robotbirds http://robotbirds.com/catalog/

To give you some idea, Antipathy uses an 18mm Robotbirds motor which is at the smaller end of the scale, and a 6A speed controller:
http://robotbirds.com/catalog/product_i ... ts_id=1416
http://robotbirds.com/catalog/product_i ... ts_id=7850

Bigger motors might need a 10A or 12A controller, look at the motor datasheet for the maximum current. If you need some help, just ask :)

James recently got some new blades for Antipathy made by LaserMaster http://www.lasermaster.co.uk/ or you may be able to find a similar firm locally.
Gary, Team BeligerAnt
Rapidrory
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Rapidrory »

Yeah, my advice is much the same as Alex's; a flat wide motor with ~10A esc (the 6A in Hexa-Chopper is a bit low really for the size of motor). The 10A Plush ESC is what I use in both my spinners and it works great for a pretty low price. The motor I use in Flail Whale is the kinda type you're looking for, it was a HD3011-1900KV Outrunner (can't give the link as HK website is down atm). At 96W It's a little too powerful if anything; something more in the 60W range is what I use in Why Wait? and it's much more controllable.

One important point is motor speed isn't everything; most big spinner hits are at less than full power as the blade can get a proper bite at low speeds. Both Flail Whale and Why Wait? are run on a 2 cell lipo, as the blades were just too fast on 3 cell making them uncontrollable.
The power of the a hit is down to the size of the bite and the momentum of the blade. Momentum is governed by the weight and speed of the blade, whereas bite is determined by the number of teeth and speed of the blade (and also forward speed of the robot). As speed goes up, momentum goes up but bite goes down so ideally you want to keep the weight of the blade high and the speed fairly low to keep good momentum and good bite. Why Wait? gets it's big hits as it has a fairly heavy blade (15g) with a single tooth spinning at a relatively low speed. Anticyclone is another robot with a fairly slow but heavy disc; the results speak for themselves :P

Controllability is another big factor; You can have a great blade, but if you can't drive it round the arena then it's going to be fairly useless. Usually the best way is to keep the center of mass over the wheels, and keep the wheels in line with the blade as much as possible. For example, the blade on Anticlone is directly between the wheels, with most of the weight over them, so it's a very stable robot to drive. Another thing to be aware of is that the higher the momentum of your blade, the harder your robot is to control due to the gyroscopic effects. It's something you'll need to balance with the power of the hits in order to make a really awesome spinner.

Balancing the blade can be tricky, but if you're buying one (Will might sell you one) it's usually not too hard to do. If it's slightly off balance it's not too bad, but it'll make your robot more uncontrollable due to the vibration caused.

You'll also need to make sure your robot's chassis can take the force of the hits. All the force you put into someone's robot is also put into your robot, so the spinner mount needs to be very solid. Some flexibility in the mount can also be useful, as it absorbs the hits, though too much flexibility can cause the blade to hit your own robot which isn't ideal (as Why Wait? did a few times).

Also, I second the safety lecture from Gary; I still have a mark on my finger from about two weeks ago where I picked up Why Wait? before it had finished spinning down entirely, and I've also had blades fall off during testing with spectacular results, so something solid between you and the spinner is probably a good idea...

Here's how to wire it all up on a NanoTwo Kit:

Image
Last edited by Rapidrory on Sun Nov 23, 2014 5:15 pm, edited 1 time in total.
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
haz
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by haz »

Do you want an inertia disc Dan? I got one I int doing nothing with. Give us a few coppers for postage and its yours.
Hogi
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Hogi »

thanks for all your help guys. tbh i don't think i'm ready for this yet. i think i'll do some experiments with a shufflebot mechanism instead. oh well, thanks again anyway... wouldn't want to go smashing up anyone's robot anyway really. will post in my build thread when there are any developments on my shufflebot. gonna try and make one that can actually push something? possibly aided by a weapon of some description.
Last edited by Hogi on Sun Nov 23, 2014 5:26 pm, edited 1 time in total.
Daniel Jackson.

Team Hectic.

Many antweights

Super antweights: territorial.

Fleaweights: fleadom fighter, gaztons.

Featherweights: hectic (under construction)
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Shakey
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Shakey »

Hogi wrote:thanks alex. your spinners are AWESOME!!!
Thankyou! :D

When you do want to test please do be careful! I have my own polycarb arena to test in but really as long as you have something decent between you and the spinner/shrapnel it is okay. It's just about being sensible with them. Gary has some good advice on how to do initial tests, but make sure you are protected every time you try to run it, just because it survived testing it doesn't mean it's not going to fail the next time.

On controllability it is tricky trying to get that balance. On my spinners I typically never get close to 100% throttle and most my hits are done on about 40% just so I can still drive the robot (And by drive I mean control the drift as they float around the arena :P). Anything you can do to reduce the vibration from the disc that makes it to your wheels will help.

One thing to think about is what will happen to your robot when it hits something. You don't want your robot flinging itself around so make sure that your hits still leave you firmly planted on the floor without flipping over. Also that your chassis and importantly the spinner motor itself will survive the hit. No matter how securely you think the motor is held it will still move when it is hit. You have to make sure your disc has room to flex and won't hit any of itself in the process.
Nuts And Bots - For all your components and ready built antweights!

Alex Shakespeare - Team Shakey / Nuts And Bots / Team Nuts:
AWS 44, 45, 49, 51 & 55 Winner - Far too many robots!
Rapidrory
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Rapidrory »

Hogi wrote:thanks for all your help guys. tbh i don't think i'm ready for this yet.
You said that about Fleaweights and then went on to win the FWS a few weeks later :roll:

It's certainly not something you want to rush, but my advise would be to pick up a brushless ESC and motor next time you do a hobbyking order (usually between £15 and £20 for the lot), wire them up, and have a play with the setup just to get a feel for it. Then, when you're confident with it, you can start building a chassis about it and attach a blade. They're not particularly difficult to build, but as with any robot, building a good one rarely happens first time.
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
Hogi
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Re: Dan want to build spinny spinny smashy smashy thing!

Post by Hogi »

yeah i suppose so. i think maybe a horrizontal spinner like variant or combatant with the spinner mounted directly onto the chasis might work best. haz, i'll take you up on your offer, how much do you want for the disc? * writes to santa * i suppose that means projects shuffletron and spinny spinny smashy smashy will be running simultaneously then. :D
Daniel Jackson.

Team Hectic.

Many antweights

Super antweights: territorial.

Fleaweights: fleadom fighter, gaztons.

Featherweights: hectic (under construction)
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