HardWired II

[harry hills]

I think you should do a proper layout in sketchup of all components, including wheels, teeth and just generally everything. Shrink and improve

Just a general point I feel like making here, not aimed at anyone or designed to be aggressive or offensive. When people use sketchup for CAD I sort of don't get the logic behind making hollow boxes and shapes that vaguely look like the whole robot and then colouring it in. I guess it is good to get a general impression of the shape of the robot but it doesn't allow you to do things like effectively plan interior space or thickness of panels or even just where things will go or if they will work. Its a totally dumb and basic software but it is more than usable for in depth robot design, look at Rango and the most recent of Jarvis's designs.

Cheers. Harry.

[Revsmin]

I'm agreed with Haz, Sketchup is easy to use and gives a good way to plan both the interior and exterior of a robot. Me and Ellis have put some models up on the workshop, I've recently done the Scorpion XXL, GR01 and Banebots 775s. As for an example of how it can be used:

[mrsam]

Nooby sketchup question time, which template do people start with and where's the workshop

[harry hills]

If this gets more in depth we should probably move it elsewhere. I mostly use architectural millimetres. The models are in the Google model warehouse. Or if you want I'm more than happy to drop you an email with standard parts if you want.

[Flag Captured]

What's the plan for when it gets flipped? Are the wheels going to be large enough for it to drive inverted or will there be some self-righting mechanism? I'm not sure that thick HDPE over 6mm Hardox is effective; just using thicker Hardox is likely to be better.

Most likely going to have chunky wheels that stick above the top on the back, but that'll probably only be the back two if the design runs how I'm thinking it might. Rather hoping that the disc would have enough power to knock it back over if it pivots on the back wheels but that's a pretty huge ask...

Probably just going to be 3.2 frame, with layered HDPE bolted onto that - 6.4mm on HardWired II worked fine, but for a slightly larger machine with a 1.5-2kg disc on the front (what I'm aiming for, at least) it doesn't leave me a whole lot of room weight-wise. Also, I can replace HDPE, probably have a rough time bending 6mm Hardox back into shape with only the most basic of tools...


Comments noted, returning to sketchup when I've got a spare minute to start again on the refurbished design of it. I won't lie, I have no idea what I'm doing and this model was literally just a 'this is the sort of thing I'm going for' to work upon - keeping the design similar though, just with improvements - I like the stealth bomber type shape! Will be using plenty of provisional parts too, the brushless drive research that's ongoing means things might change, but for now I'll be using 42mm NTMs with those Gen 1 turnigy trackstar ESCs. I can't design them for the life of me, so the ESC will just be a box labelled ESC with the right dimensions...

[Flag Captured]

Given up on Sketchup, I can't do it for toffee. And all my attempts end up looking like a slightly wider and shorter Rango or K2 for some reason... Not that there's anything wrong with that but I don't want to look like I'm nicking designs! Back to pen and paper, I think!

In other news, just taken HardWired apart fully for the first time since the champs, actually loads more issues than I first thought. First thing is that the damage caused by that hit from 720 was more than just cosmetic, it's actually bent the wheel in slightly, so the gear was grinding a fair bit when I gave it a little test run direct from a battery (can't figure out the problem with my TZ85...) that needs looking at, and a little bit of cleanup on the wheel holes because they're catching very slightly.

The top supports have bent too, but that should be resolved with the new lid being welded on, and made of Hardox (come at me, axes) as well as the baseplate having a little bit of damage. The main shell (bar a slight bend from NST/720 and gouge from the front courtesy of Ironside) is pretty much undamaged, discounting the scratches. Very impressed, the HDPE panels on the side will take most of the shocks out for next year, so it'll be practically indestructible. Playing around with the idea of a shock mounted 6mm hardox front panel on the scoop (it's just that one panel with HWII on there, not the entire front) to give something hard for spinners to hit and fly off into the distance, but not causing any shock damage to myself, but it's still up in the air.

Next job now is finding out why this TZ85 isn't working, need to get the heatsink off and have a look at the circuitry and see if something's come loose. Oh, and finishing off Balsa Steel, just need to actually get the balsa wood to mount on the sides - it's part timber, part plywood, part balsa wood, means it's solid enough to drive properly without smashing itself up, whilst almost guaranteed to splinter into a million pieces in the first hit. Sorted.

[daveimi]

Plywood....Good Man!!!

[Flag Captured]

Plywood is brilliant! Won't stand up to a spinner hit but it's a fun material to use haha
Or at least, I'm assuming not... maybe I'm underestimating the power of wood as armour!

[maddox10]

If 19th century ships of the line used wood as armor, why wouldn't we?

Wood is natures own carbonfibre...

[Flag Captured]

That is very true! Suppose it's just how you mount it, and the thickness that you use of it. I'm going to be mounting it well but not using strong enough material to take a hit so pieces will just fly!

Might do a competitive wooden bot sometime in the future, seems like it'd be a fun thing to do

[Flag Captured]

HardWired 3 update

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

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!

[overkill]

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.

[maddox10]

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.

[overkill]

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.

[Flag Captured]

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!