HardWired II

[daveimi]

Yeah I didn’t mean to come across negative, sorry if I did. I have Asperger’s and it shows at times with me getting the wrong end of the stick.

I just meant if you were worried about money you have a nice drivetrain and 850’s are available and some batteries and weight over the drive would push it in the floor.

I’ve spent hours pouring over the photo’s of the big pushers with their shell’s missing as I’m not a fan of spinners. The one thing I notice is all the battery weight etc. centred over the drive for grip.

Brushless drive sounds nice; you should have a look at that! Also sounds a lot cheaper than I’d realised.

[harry hills]

This is how you weight distribution.

[Flag Captured]

Cheers Sam! Mario's definitely done a great job with it, so if we can get brushless to work I think it just may bump up it's competitiveness, plus it'd be nice to get in on the brushless drive quite early on, show off what it can do haha

No worries at all Dave! No negativity taken from that at all I do get where you're coming from, but it's literally impossible to get any more weight over the drive in HardWired II anyway, I'll post a photo of it's innards sometime - the motors are touching the top plate and back panel and are back to back because of how small the machine is so I literally can't get any more weight over them. Having brushless, depending on the motor, could mean I'll be able to redistribute the weight a bit more by putting a block of steel or something between the motors. It'll probably be something a bit better than that, most likely a battery or something but you get the picture!

[Flag Captured]

And Haz, that will remain my favourite ever modification to a robot. Shame 720 was in that gladiatorfight, wanted to see it in action haha!

[mrsam]

Echo what Matt said i didn't think you came across as negative at all so no worries , in a machine as small as Hardwired it's difficult to distribute the weight any more as everything's already on top of everything else and the 900 sized motors take up most of the robot. With brushless motors especially outrunners you can get the same performance figures you would get from a speed 900 in a much smaller package and if Matt downsized the battery capacity slightly (5000mah is way ott if you ask me) then he could potentially have room for bigger wheels and possibly even some magnets to give more speed and more weight over the wheels.

[razerdave]

Yes you are correct with those figures, but the new one goes up to 10:1 and 6S to keep the speed up.

I should point out, Hardwired II has a lower ratio (less torque) and also about 4kg shy of Satanix (I was tipping the scales on Thursday), an mine also has the vast majority of that weight on/on top of the wheels (my lid is 1.5kg, I have a bar of 10mm steel attached to the motor gearbox plates, my front wedges are hollow).

[Flag Captured]

Yeah, HWII's battery is a bit OTT but I had no idea at the time! And it fits in with the rest of the machine and it's 6.5mm hardox haha
I'm tempted to go with magnets, but they're still debatable in terms of their effectiveness overall... And I'm going for a hardox baseplate next time so I'd have to get creative with mounting them...

Yeah, that's all about right Dave - I need plenty of weight redistribution! And some scales, I genuinely thought HardWired was pushing 13kg... Turns out I was a bit off! Harry's spare bar made a decent counterweight, and did improve handling and grip so it's definitely a priority to adjust weight distribution now...

10:1 on 6s though should be formidable, nothing's going to stop that!

[mrsam]

More weight would definitely be a start but you obviously have to watch your weight distribution as Hatchet proved this year, the wheels were up front and the scooter motor, batteries, esc's and axe head were all at the back of what was really a very squat chassis, even the 2kg scoop from Hardwired wasn't enough to tip the machines weight forward. In short trying to make Hatchet as compact as possible hindered it's overall freedom of movement which is why i'm going for something more like thor which is longer towards to back for better weight distribution, with Hardwired though you shouldn't have too much of a problem because of the size of it but obviously trying to add 3 - 4 kg of weight to something so small is difficult.

[Flag Captured]

Yeah, that'll be ideal - I think you could do with a little more ground clearance too, though you've got the axe in case you get beached...
You could always try 4WD too, if you have any spare weight, that'd mean you've got all your weight underneath wheels. With a lipo and TZ85s, you'd easily be able to manage that!

That's definitely a problem with having it so small, but it's definitely doable. If worst comes to worst, I could always stick a thicker back plate on it too, or a mace like thing to make it a sort of thwackbot. It'd be quite effective but I'm not entirely sure what it'd do for handling!

[mrsam]

Hatchet 2 will definitely have better clearance, i think at the champs it was the first scoop causing a clearance issue as well as the tires having very little tread and just running on the screws as Hatchet ran fine for a while once i'd taken the scoop off. Hatchet 2 will actually have smaller wheels, around 80mm but a thinner baseplate ( 4mm - 5mm aluminium) but the shape won't allow 4 wheel drive as it will get narrower towards the back.

I would love to see HW2 as a thwackbot, they seem quite big in Australia, just a solid fast box with some from of hammer on the back that they spin. i imagine it would affect your control somewhat as the hammer would act as a pendulum but as the robot will spend the majority of time spinning i doubt that would necessarily be a bad thing.

[Flag Captured]

That's true... Definitely keep posting updates with the design though on your page as you do it - the input from other people always helps! I'll be doing that with HardWired III, just having someone else look at it can mean it'll end up with one less problem or something! At least we've got plenty of time till next year's champs though, that's always a good thing!

I'm extremely tempted with the thwackbot thing too, I think it'd be well suited to it if I can get the grip problem sorted. All I'd need really is something like your axe, welded onto the back of my machine, or I'll have another backplate made specifically for it... I initially thought they were a bit more for show than anything but I distinctly remember seeing one that was very damaging and it's an idea that's always been in my head since... If I can get the centre of gravity balanced right too, it'll handle like a dream in theory. I'm tempted to put some spikes on the front too, to act as both catchers and damaging points as well as on the sides so I can cause damage by driving past. Going to stick to getting it running first though, and the weaponry'll come later, but it's something I'd quite like to run! Chances are that I'll run something like a 1.5kg attachment on the back, or a 1.5kg backplate so I can switch them round if needs be... I'd like to leave the weapon on the back but it'd be insanely open a target for some spinners. Though if I could design something well...

The spinning wasn't intentional either a few times! There were a few cases where I started spinning, and intended to go directly to forwards, but it carried on spinning, or there was a delay in response time with the ESCs for some reason - the main one being in the Gianto/Joule fight... that's when I spotted the problems, seems like there was some kind of function kicking in on the ESCs that meant I couldn't go straight from reverse to full forward. It was very intermittent, but I think a rebind sorted it...

[mrsam]

I doubt I'll post much in the wway of designs as atm I don't have a computer good enough for any cad but there will be plenty of updates once the build gets going. I'm actually considering changing the design of Hatchet 1's chassis, as much as I like how it looks it isn't a very efficient shape.

It sounds like a trim issue to me, might be worth experimenting if it happens again

[Flag Captured]

Just do some drawings and/or cardboard aided design haha
If there's one suggestion I'd give, it'd be more angles - I think 30 degrees is the optimum angle, but the ones on HardWired have worked wonders on top of the 6.5-ish mm Hardox. Perfect if you're worried about spinners again! That, and see if you can move that scooter motor down into the bowels of the machine a little more if it'll go, purely because it looks a bit vulnerable there. That, or protect it with some thicker material so that verticals can't get to it again!

Yeah, I'll give it a go eventually if it happens again, not sure what caused it - could be interference but on 2.4ghz I'm not sure that's likely... weird in any case. A lot of the spinning was me just giving up and trying to go all Melty Brain - towards the end of the event I just used to skid so it ended up being the most effective thing to do instead of trying to be all precise!

[mrsam]

Unlikely to be interference, maybe just a signal or trim issue or like you said something in your esc settings.

Not much I can do with the current Hatchet really, the shape can change a bit but component placement will have to remain the same due to size constraints. I was tempted to start the new one as soon as but I think Hatchet has a good few events left in it with a few updates. I'll get some designs/specs on the new one in the next few months , should be a huge improvement as I've learned from my mistakes.

[Flag Captured]

Yeah, maybe - I'm switching to brushless soon anyway on HWII so it'll not be too much of a problem. It's not happened again though so that's a good sign! HWI's getting the old brushed ESCs, maybe motors and then HWIII will use whichever drive system proves itself to be most suitable... I'd like brushless but it depends how it works - if it ends up not being suited to that shape/design/weapon then I'll stick with standard brushed. Brushless would be better though.

That's the best thing too, we both had no idea what we were doing going into this (granted, I had a lot of help from Mario which I really appreciate and has definitely been the reason I lasted more than 15 seconds in the arena) but now we've been part of a competition we know exactly what parts of our machines work and don't and what to change. For me, it's definitely been the most useful part of the ongoing design process!
I'd just leave Hatchet for a while too, give it a few more events and then work out what works and what doesn't - the featherweight shows at heavy events are utter chaos so that'll test your design loads too! I think the general outline of your machine works great, but the internals and chassis need reworking slightly as you've already mentioned... Having LiPos and TZ85s will sort your drive, the drills should still be fine and your axe mech is still fine - refine your body shell and you'll be fine! Just have some angles and try not to leave any 90 degree corners and you'll be sorted. Also, you could try 3mm Hardox for the base, or Ti or something if you wanted to go that route, it'd be pretty rigid!