HardWired II

HardWired 3 update

So, Jarvis made me a little mockup of HardWired 3, and it looks absolutely awesome.
Attachment 4586

The disc on this one is 150mm, running on a 2:1 ratio from this motor http://www.hobbyking.co.uk/hobbyking...tor_730KV.html which is frankly huge, but big motors are always better, and that'll be a heck of a lot of torque behind the disc.

Dimensions are actually close enough the same as HardWired 2, which is impressive with everything in there, two 270 kv 50mm outrunners for drive (200A brushless ESCs) and batteries for it all. At the minute I think it's all running on 8s, and drive is 100mm wheels on a 5:1 ratio, gives a theoretical top speed of about 21mph, call it about 17 which is fast enough for what I'd need! Small amount of magnetic downforce too, about 5-10kg to help put the power down and prevent it from gyro-dancing with that disc

The armour's all 3.2mm Hardox, and 10mm HDPE on top so should be a brick, with Alumec bulkheads, lands it at about 13kg. Only change I'm thinking of making is the disc being a single-tooth rather than a dual tooth, but I need to learn to single tooth disc a lot better first before attempting that. I also need sleep, so fair warning, I may have misquoted a couple of numbers quite horribly here.

Thanks again to Jarvis/MicroGravity100 for the sketchup model, it's a real hand!

The low gearing on those drive motors is going to be a problem - you will have poor start-up torque and very jerky low speed driving - Mario's new bot Calliope has this problem with 6:1 gearing. I recommend changing to sensored motors or using much more reduction with the sensorless motors. The other advantage with sensored motors is that you don't need so much power, which saves weight and money.

The NTM42's do the job nicely tough after the change over, even on a 6-1 gearratio. The slower running, but way bigger 50mm versions should laugh at the strain. if I see how Caliopes and Valkiri2's 4 kg bearingless disks spin up with only a 1.5-1 gearratio I don't have any doubt these motors will make any featherweight in a unguided rocket.

But yes, Sensored seems a better bet for such low gearratio's.

Hi Mario, you mentioned on the Aussie forum that the outrunners went from stopped to turning at slightly different throttle points and that the dead-band was much wider - did the larger motors fix that? On my ESCs I have a dead-band adjustment and turning it to the minimum helped quite a bit.

These are sensored, the 2000w alien power sensored outrunners with the silver and gold cases - I did initially plan to use the NTMs but that little bit of startup torque is ideal. No idea how sensored outrunners actually perform, but I can't imagine it'd be too different to what you'd expect... Time will tell I suppose!

Well that's different then! Sensored outrunners should have excellent start-up torque and you can likely get more than you need from the 42mm, 1500w model. With it's higher KV, you can gear down a little more and get smoother steering as well. Given that my 95W inrunners can spin the wheels in Mr Mangle, 1,500W motors should be more than adequate.

Loving that Sketchup model looks exactly how i pictured it would when you were talking about it at the champs, if you get this all working how you want i can see it being a properly good machine, tough as a brick, powerful drive and that disc on the front. Man stay away from Hatchet!

Yeah, 8S. Managed to shoehorn one of these into the back. You'd probably only get one fight out of it, but 8S batteries are big, and space was a concern. On 8S and 2:1 the disc speed is ~12,000rpm, and on that 150mm diameter disc tooth speed is ~215mph. That plus the wedge underneath means big hits every time. Disc weight is about 1.2kg. Weight-wise, I made a calculation error and factored in the weapon ESC twice, so realistically weight is about 12.8kg. And that's with basically the same shape as HWII, but half the thickness (all the way around) with 10mm HDPE instead of the stainless. Baseplate is also stainless, 3mm, which is 0.5mm thicker than the stainless base on HWII I believe. Put magnets in and it'd make for one heavy hitter! Drive-wise, this is the one being used, and if anyone else wants to use them I can upload the model to the workshop. On 5:1 top speed is as Matt said, 21mph. I reckon gearing down a little more for a bit more control and torque is a good idea, maybe just to 6:1. So yeah, should be a total brick with a hard hitting weapon and decent rambot drive as a plan B. What's not to love :)?

It looks just like I imagined it too. Space is going to be tight but I guess you are used to that.

As for the Lipo, you should only be doing 1 fight on a battery anyway. Conker 3's drive can last about 6 minutes but the weapon will die after about 4 minutes. They both cut off when the low voltage cut out activates at 3.5V, above the minimum 3.2V with a bit to spare.

The battery should be sized that you can run flat out with everything for 4 minutes; 3:30 if you are feeling frisky. Else you are carting around more weight than you need too and taking up more space. Of course you need a safety margin, hence the extra minute but by the sounds of things that 3.3Ah 8S should do it just right.

EDIT: where is the safety link going btw?

Thought of how I can do scale in Sketchup :D
http://i1234.photobucket.com/albums/...ps4d190eee.png

Aye, definitely Nick! Looking at different options still to see what'll be the best, maybe a 2/3-stage with faster motors would be better, but I'd just worry about space. Still, that's what designing's for I guess! I'm probably going to limit the output on the transmitter side, 2kw is a lot for drive, it's nice to have but I have a feeling it'll not be quite as controllable as I'd like. Still, if I can put that power down on a run up, that's going to leave a very nice bite, and should have plenty enough torque to push things about if needs be, or at least it will in theory. At least I'll have the magnets to help that out! It's nice to have that extra power there though as a 'if worst comes to worst' type thing, since I really don't know how it'll perform in practice!

Sam, it looks awesome doesn't it? Jarvis has done a heck of a job! Hopefully too, would like it to be able to cause a little more damage and carnage next year! Hardwired 2 will still be the relentless brick of the two, I fully intend to make that 100% reliable and indestructible but I think HardWired 3 will become my main competition machine. I'm actually looking into making both machines run the same internals so that I can perform an easy switch in case there's an issue, but I'm not too sure yet.
Big thing this year is going to be spares, I'm kind of going into the unknown here with the brushless stuff - granted, it's somewhat proven in battle, but the last thing I want to do is damage an ESC and have to forfeit the competition. Even more so because spares of anything will be much harder to come by than your bog standard TZ85s or Speed 900s, I'd assume.

Cheers too Jarvis, I can't remember stats for the life of me! May look at battery alternatives (not that big a fan of Zippy but there'll certainly be alternatives!) but on the whole they are pretty scary stats. 6:1 sounds good too, though I'm tempted to see how tests go with HW2, will see how that handles the motors with magnets and see what gear ratio would be optimal. Probably will end up being 6:1 though, no doubt. If I can build it well, it might be in with a shot of actually qualifying this year haha!

Alex, safety link I'd think would go on the top similar to how HardWired 2's is, but I'd like a link door or something on it this time so NST can't tear it off again haha! 3.3ah should be alright, definitely looking at a slightly higher discharge though, max amps for the motor is 60 a side, and for the motor it's 128 so 220A in total, but I want to just have plenty of space with that. Would be fine, I bet, but I just like to have that little bit of insurance, with me being a newbie to the sport and all!

And Jarvis, that Cola can should be underneath that disc - I'm a Pepsi fan ;) Very cool though for seeing the scale of it all, looks pretty small with a cola can next to it!

Matt have a look at the Optipower Lipo's as i've heard people say really good things about them, there's a discount for FRA members as well which helps to soften the blow i think it's around 30% but not entirely sure. I think you'd be fine with 3.3ah as well, if you're running a spinner and your new drive system i imagine you'll be charging after every fight anyway.

Looks good guys. I'd worry about that battery, though. Zippys hardly have a good track record. You'd be better off with a battery that can definitely deliver (basically Optipower, yes I'm a covert).

Also, I think 8s is way overkill. You really don't need a motor capable of putting out 4000w (!) to spin a 1.2kg disc. I have about 1500w (about 3:1) on tap and it spins my little 1.8kg drum to 10,000 as fast as I can move the stick. 720 is also on just 5s.

2 teeth on a 12,000rpm disc, at an unrealistic-for-the-maths 10mph collision speed and allowing for real life, you can hope for at maximum about 6mm of bite, which is really not a lot for a best-case. A single tooth will help that of course.

Hardox front end may actually be more trouble than it's worth next year. Takes one hit from any vert worth its stuff to bend 3.2mm and barely slow down now. You may do better to have something cheap and replaceable that can be bent back at an event or just replaced when it's too mangled. Saves weight too.

I'd focus on making the core of the bot (inner bulkheads, weapon shaft setup, structural (back?) plates, etc) as strong as possible, which can be achieved by downsizing motors and LiPo to gain weight freedom. Could even get a heavier disc in there.

Downsizing of motors, heresy I tell you!

Overall the design does look to be coming together nicely

Yeah, Optipowers are definitely going to be purchased for my machines from now on - they're very good! 8S may well be too, I agree but I'm aiming for OTT power, maybe it's slightly the wrong approach but still. Was tempted actually to run a single tooth disc on a 1:1 ratio from the motor, but I don't know if that'd be a little too fast... Hopefully the torque behind it would mean it'd just carry on going after a hit rather than slowing down, which is what I was aiming for with that motor in particular. Probably don't need something that powerful, but I want to try and push the boundaries a little!

Plan is to go with a single-tooth at some point, with most of the weight on the edge, should be fun! I'd like to aim for 20mm of bite on the disc, again ambitious but it gives a goal to work to. Yeah, I agree with the Hardox sentiment, however there are potential improvements to be made to it in the form of higher grade armour or whatever. Failing that, thicker titanium could work... I suppose it depends on angles though, they're pretty handy on HardWired at the minute, any high risk areas could have extra panels on, or maybe even use HDPE over the top like Explosion does.

There's always refinement to be done, but it'll get there. Research into new types of armour could work too, I have a few ideas and I've been listening to other peoples' for inspiration so could have something even nicer for armour when if gets built!

The kinetic energy of a spinning weapon increases with the square of the rpm, so a single tooth disk at a 1:1 reduction should have 4X the energy and at least theoretically the same amount of bite as a two tooth disk with a 2:1 reduction. Please chose option B so the rest of us have a chance :)

I like reading these big budget robot builds, it's the stuff I can only dream of! Keep going it looks great!

Quote:

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Originally Posted by Flag Captured

that Cola can should be underneath that disc - I'm a Pepsi fan ;)

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Good man. We're a bit of a rare breed unfortunately (or fortunately, as it means more Pepsi for us!)

Finally other Pepsi lovers! I get an unlimited supply at work 8)

Quote:

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Originally Posted by RogueTwoRobots

Good man. We're a bit of a rare breed unfortunately (or fortunately, as it means more Pepsi for us!)

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All hail Pepsi Max!!!

Quote:

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Originally Posted by mrsam

Finally other Pepsi lovers! I get an unlimited supply at work 8)

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Do want.

Surprised there's so many Pepsi fans, I'm among my own people at last haha!



Oh and Nick, I'm keeping the RPM a little lower I think, I wanted to go silly speeds but I've been chatting to Harry Hills, who said it's probably best to keep it slower and keep the reliable hits, and have it running an NTM 50-60 instead. Not ruling out the crazy fast disc yet, but it might not make it into the first version at least...

I agreed with Harry; there is no point to increasing the rpm past a certain point. The NTM motors have a great reputation or check out the SK3 motor range, which comes from the same factory as top Euro brands like Hacker. With the NTM 50-60 380KV motor @ 8S, you will only be getting 11K rpm without load. Under load and with a bit of gearing down, you might not get even 5K at the disk.

The HeliDrive SK3 4962-530kv motor will give you 15K rpm without load and is the same size as the NTM 50-60. It also has more poles which will give it a bit more torque at start-up and reduce the spin-up time.

I'm with Nick here, that SK3 4962 looks perfect for what you want. It also fits perfectly into the model, giving an extra ~400g and 2cm of space behind the motor.

Whats the weight of the disc? That needs taking into consideration before you decide on motor/gearing.

At 150mm diameter, 20mm thick, about 1.2kg.

Single tooth, 5000rpm would give you the reliable hits your after... with a disc so light id aim for 2:1 for a quick spinup.... running a big 6s pack for drive and weapon...450kv motor ish would work well, and give out some decent impacts.

Cokes better

Or if you want to use the sk3 4962 530kv youd be getting around 5500 at the weapon. Wont be the spinner to end all spinners but it will be good... with a robot like your design its all about balance...to much energy in the disc and it wont drive very well and IMO a good drive is more important than an overpowered weapon

Quote:

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Originally Posted by Mouldy

IMO a good drive is more important than an overpowered weapon

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Says the man who built 720 XD

Just went to show this year though. Kept loosing because my drive kept failing lol

What i mean goes for vertical discs more than drums... they have more of a difficult time trying to turn without gyroing which allthough looks cool i imagine its frustrating to drive.

Ah, but that's why the base is stainless, magnets ;)

Quote:

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Originally Posted by Mouldy

Cokes better

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Aldi store brand M8

Be interesting to see the effects magnets have on the brushless drive

Coca-Cola is better than Pepsi, but Pepsi Max is better than Coke Zero. - Both Diets are just horrible.

If i am going out i prefer Coca-Cola - but in my home my mum doesnt let me have it so i prefer Pepsi Max. - Anyone had Coca-Cola out of a glass bottle before? :D

Nice robot btw :P

Shall have a look at those motors, cheers! Still researching into what will be the best balance between torque and speed, I want plenty of power (should be able to use it thanks to the magnets, but we'll see) but not something that's going to be inconvenient to use. The idea of the 30-something thousand RPM single tooth was hilarious and would be lethal theoretically, but I have doubts about how it'd perform in practise...

Really, the idea is a good spinner on a good rambot, it's unrealistic to assume it'll be an amazing rambot and/or an amazing spinner (even more so considering I'm building the thing...) hopefully brushless can help that along a little but I guess we'll see how it works. Brushless and magnets should be interesting I agree Dave, shouldn't be that different from what you'd expect from brushed drive I hope, but it's still pretty much unknown at the minute. Don't know if anyone uses sensored outrunners for drive, or how they perform but the theory says it'll work alright. Will be posting results once I've got a pair ordered for HardWired 2!

Oh and Pepsi Raw, drink of the gods ;) Until they stopped production of it...

Featherweight shenanigans update!

First, HardWired II has been retired from competition, I'll still have it as a whiteboard machine (come at me, spinner bros) but a new one is sorely needed. Can't say too much yet, because it really hasn't been designed extensively, but it'll be running sensored brushless outrunners of the so big it couldn't possibly be a good idea variety, along with much larger wheels than before, HDPE armour, Hardox frame and most likely Hardox scoop to match. Shouldn't be much bigger than the old one, but it does need to be larger to fit everything in. Oh, and lots and lots of shock mounting, after the 720 incident...

Next, HardWired 3 is on hold, Hw2.2 is going to be my main machine for next year, I see no reason why Hw3 would need to be a thing yet. Much as I'd love active weaponry, it'll have to wait for now.

HardWired 1, the flipper, will be going to next year's champs, funds providing. I won't be driving though, my friend will who's been interested in competing, and they insist on having a flipper... Can't say I blame them looking at the top 4! Plan is to make this a Wheely big cheese style machine, designed just for launching stuff high because that's really fun. Mostly HDPE, not sure on the rest so far. Massive wheels though.

Balsa Steel is nearly finished and will be making it's debut at Barnsley, though I have to stress that under no circumstances must anyone push me onto the flame hazard, got it? ...guys?
Should be a fun little machine, 2WD drill box with mostly wood armour, not much innovation but it'll make a heck of a display!

Finally, Riptide has been planned somewhat for the future, designing it as almost a one hit wonder, 7kw motor Buzzbar style, toothed bar... Should be hilarious. Or break itself. Or both. Truth be told, it actually looks a little like NST but that's going to change soon, need some way of keeping it really stable on the ground. Tempted to suggest hardox and magnets, because they solve everything as we already know (I'm kidding, I haven't a clue yet)

So yeah, that's where things are at the minute, progress is halted at present due to a lack of funds, but HW2 and Balsa Steel will be making it to Barnsley, all going well.

NST does actually use magnets in strategic places to make it stable, so that's not a bad call.

Oh really? Well that might be a good idea then, explains a lot!
I'm probably going to try and put some wing style attachments on it and have the wheels out at the sides, a little bit like Caliope's design I suppose, because I imagine it'd have a lot of gyro force in it.

It won't be a majorly serious machine though, far too much power for it's own good! The HardWireds will be my main competition machines for the foreseeable future... Much as I'd like a turbo spinner, I have a feeling the thing will eat itself upon impact...

Unfortunately, HardWired 2 won't be going to the Barnsley event (may bring it along, but not to fight) since the motors in it are soon to be accounted for and given the situation the money is needed so can't risk them being wrecked, especially with that floor flipper! Also needs a lot more TLC than can be done in a week. I say TLC, more hitting things into shape again with a hammer...

Balsa Steel will hopefully be there though. Hopefully I'm not too late to sign up either haha

Also going to have to give the AWS a miss, wanted to take Abandon (the bar spinner) down but money means it's got no chance of being done in time, and I'd struggle to get down there too. Shame, but I'll hopefully be ready for the next beetle event!

Oh and I've finalised my featherweight plans for next year (finally)
Planning to take HW2 and Archangel (ultra silly Spinny thing that Jarvis Cad'ed up) down as whiteboard machines and entrants in any side competitions, with HardWired 3 (something completely different, and that's all you'll find out!) and HardWired 1 (converted into a flipper) for competition. I've got my friend in on the sport, hence two machines! I've got most of the parts for HW1 already sorted, just needs the basic CO2 stuff, probably going to go cheap with a cylinder, ram and servo switch. May use full pressure but I don't know to be honest, depends what I can get the cheapest! Archangel and HW3 are the only 'new' builds but I think I have some materials lined up already for cheap, if not there's always the hope that someone will employ me before next April haha

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It's an abomination.

So yeah, Balsa Steel got finished and was supposed to be at Barnsley, but I couldn't make it there in the end. Trains had other ideas (they were cancelled according to the timetables) and they wouldn't let me take it on the bus there, and I can't drive so... Yeah. That was a bit of a disappointment to say the least. The dog apparently likes using it as a seat now, which was rather funny.

Will be taking it down to BlueWater though, if I can make it down, so hope isn't fully lost! Should have HardWired 2 done up nice for then too, assuming there's featherweights there...