Questions/builds thread.

Thanks guys! We won't be painting it, we'll just clean up the white and leave it at that. Don't think paint would stick very well anyway. We quite like the white, under studio lights it should almost glow. :)

As for batteries, if we replace them it's a matter of replacing them now. If we order today from ebay then we SHOULD get them here before the 31st. Maybe.

Would 3 of these in series be sufficient? http://www.ebay.co.uk/itm/6V-3300mAh-Su ... 5645b92771

Could we keep our current charger, the 18v drill one? And the discharge rate on those is just 30a, would that be enough? We're likely to be drawing quite a bit more than that.

It's a real bummer that our drill batteries may not work. Today we'll test drive it and time how long it lasts. If it starts fading after a minute, we may be in trouble. We hadn't predicted this of course, when we were testing it before it weighed 5kgs less, meaning the motors worked less hard, and so it could go for 4-5 minutes no problem.

Here's hoping, again!

3300mAh at 18V, I would say definitely. I drove Conker around uni for about 30 mins and only took 2000mAh out of my lipo. So even if I trebled the average drain it would still give me 10 mins drive time in combat!

(Though I would get someone else's thoughts to cos I have 0 experience in combat)

Out of Interest, will it run upside down with the back wheels touching the ground?

It's painful, but yes. On a smooth floor it should drive around enough to be considered active. When upside down we have little weight of the wheels and only 2 contact the ground anyway, so it's by no means perfectly invertible, but it does drive. Sort of.

Possible breakthrough: it just finished charging but after feeling the top panels, only one side is as warm as the batteries used to get when charging (alarmingly hot, but right). The other side is warm but hardly, whilst as I say the other side is too hot to touch.

Does this mean we're only properly charging the fully heated side? Or perhaps does it mean that the really hot side has a high resistance, maybe due to shoddy cells, and so it not only gets very hot but doesn't charge properly?

I feel more confident in saying it's the cooler side that is somehow wrong. Until now it has driven fine when both sides have been equally hot after charging. We may have a dodgy cell somewhere.

I can't diagnose it yet, but we may be running on half capacity, or more or less half. They're two 1.3ah packs in parallel, one side is hot, the other warm, any idea what that could mean?

What it means is you need to get some non-drill cells! Be a shame if that's what lets you down in combat, especially as it looks so good

You might just have to bite it and buy some racing packs just so you have quality cells, Ewan is right, it would be such a shame to see a brilliant design fail due to shoddy batteries.

Just spotted your second qualifier!

Inertia XL v Tormenta v NST

I have to fight them to but not at the same time! Talk about a baptism of fire!

Where are you staying when in the UK? It would probably be easier to buy cells from eBay/Vapextech when you're over here than try and get them posted out to Spain before the 31st. With two weeks between you arriving and the event, it could possibly lessen the rush.

It looks brilliant though. Don't worry about the wonky armour panels. I always used to try and get everything to match up and have no gaps or squint lines, but you don't really notice in the arena and no-one else is that bothered by it :)

I think you have made a really nice job of it, lets have more screws holding those side panels on, they might flex and absorb a knock that wont stop them being ripped off...........love the Design, more screws and could you also let us know the dimensions of the beasty!

Thanks for the comments and concerns.

I measured the voltages of the cells and they all measure the same. No issue there. We don't quite understand the issue of why one gets so hot and the other only warm.

I am looking at batteries, and:

Is 30a maximum discharge enough? The maths say 30a isn't enough, but our current batteries, although they get hot, seem to to the job, and I doubt they're designed to give 30a discharge as drill cells. Would paying double and going for 60a be worth it?

I can't seem to find a fast enough charging charger that doesn't cost more than the batteries themselves. Any help with this? Is there a golden charger that everyone uses?

What do you guys recommend we do? We could get 3x 6v batteries, put 'em in series and use our current charger, or buy two 9.6v packs and buy a new charger?

Decisions! All of them costly! :uhoh:

Thanks for the kind words guys, really!

If you can afford it the /best/ you're going to get will be li-po's, but they don't actually have to cost a huge amount, for example:

Charger for up to 6 cell 5amp charging http://robotbirds.com/catalog/product_i ... ts_id=6248 £20
Or if you don't have a power supply here's one with a supply built in http://robotbirds.com/catalog/product_i ... ts_id=6247 £40
And an 18.5V battery UK stock http://robotbirds.com/catalog/product_i ... ts_id=4892 £37

That's all just 2 minutes browsing, you could find a little cheaper if you looked.
For your machine 30A continuous output ought to be 'enough' in most scenarios though.

get yourself on msn sometime Elis, then i can inflate your ego with praise :lol:

30a cont should be plenty, it'll probably have a slow burst though (Nicad is better for this than Nimh, but the latter has advantages for drive that I forget, Li-Po solves all problems!)

I was just going to say you might want to look into getting a proper charger if your using the drill ones.

I got mine for £8 on ebay, but it tooks weeks to come, and you guys just don't have that time.

I can lend you a couple of Ni-cad Nimh chargers for the event, but they only fast charge up to 8.4v, I dunno what size packs you're running.

I got my Lipo's from here (these guys were so quick, ordered it on a wednesday night, turned up thursday morning no extra cost)...

http://ElectriFlyer.co.uk/

One of these would cover all your power needs assuming that you draw the same amount...

http://ElectriFlyer.co.uk/gens-ace-5s-3300mah-30c/

As for charging...

http://www.ebay.co.uk/itm/Turnigy-Accuc ... 1628wt_905

This will charge Lipo's,LiFe,NiCad,NiMh and Pb. Full balance charging, fast charge, standard charge, storage modes and discharge. Easy to use to. Only thing is that it comes with a US plug so you would need an adaptor or just cut off the US plug and fit an UK or EU plug. Simple :)

By what you are describing I would say the capacity in the hot pack has gone. I have had 2 examples of that in recent months, voltage registering what it should, but as soon as you hook it up to try and drive anything it falls flat.

If I was you I'd get some new packs from component shop, they do a wide variety of packs. As for a charger, I'd get yourself a Pro peak constellation. It does all but LiFePo batteries.

Thanks for the help and links guys. We can't really go LiPo; all plastic robot, it would mean quite some doing to get the thing LiPo safe, and we don't have the time to do that.

We're likely going to get a ton of NiMH cells. We sent an email to Component Shop earlier, asking for a quote regarding custom packs. We're looking for about an end result of 5000mah, 60a discharge, from two packs. If their price is too high we will make them ourselves.

Still researching. No point in purchasing until Monday anyway, so we have a few days to work things out. The cheapest we will be able to get the batteries will be about £60, for the raw cells alone. We can't justify another £40 on top of that for a charger without eliminating all other routes, including that of our current charger.

Thanks again guys. All suggestions are being taken in. Interesting to hear about the odd behaviour with capacity, Dave. Sounds like more or less what we have come across...

Edit: why is the pro peak so expensive here in comparison to here?

May be coming to end-of-life and they are clearing their stock.

Hi guys. We have ordered new batteries and a charger. Many thanks to Dave for helping out with the postage!

Quick question: what exactly is a cradle? Is the purpose of it to raise the robot's wheels off the table/floor to reduce the possibility of it escaping if it came alive? Can it be as simple as a couple of bits of wood?

Thanks.

Quote:

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Originally Posted by Relentless

Quick question: what exactly is a cradle? Is the purpose of it to raise the robot's wheels off the table/floor to reduce the possibility of it escaping if it came alive? Can it be as simple as a couple of bits of wood?

Thanks.

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Yup :)

Yup, just a couple of bits of wood will do, so long as it raises your robot's wheels off the ground. If you screw them together (in something like a square or 'H' shape) it makes it a little sturdier and easier to carry around.

EDIT: Tony beat me to it :)

My bot was similar in shape to yours (4wd, but with no lifter) and I nailed 2 pieces of wood into an X shape, nice and easy.

I like the edit you've made to your list of bots about Carcinus Jamie :lol:

Quote:

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Originally Posted by Anttazz

I like the edit you've made to your list of bots about Carcinus Jamie :lol:

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Just telling it like it is 8)

Oh good. I have a bit of old bed which should do the trick. :wink:

Thanks.

Funny you should mention that. Drumroll's cradle is made up of old/broken bed spars :)

Quote:

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Originally Posted by k_c_r

Funny you should mention that. Drumroll's cradle is made up of old/broken bed spars :)

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you should be more careful where you test it jamie :lol:

I think someone asked how big the robot is a page or so back. It's almost perfectly 50cm x 50cm.

It's going to look like a middleweight next to 540. :lol:

Well, Tormenta's story ends here. After ten fights, three at Yeovil and seven at the champs, it's going into an early retirement.

Original side panels replaced as they were destroyed. Original lifter panel got equally destroyed. Back panels also replaced. Baseplate smashed in two places, all four bulkheads shattered, both front armour panels cracked and in one case halved. Every plastic gear that could have stripped, stripped, and in once case, broken in two. Two split gearboxes, one burnt out motor. Dead ESC relay, obliterated receiver battery and buckled to buggery lifter arms.

But!

When we got it home it was still functional, be it after a fashion. Two drive motors still worked and the lifter did too (admittedly only once: upwards!) Must say, pretty proud. :lol:

RIP Tormenta!

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I can't speak for my dad (though I suspect he had a blast too), but I certainly had the time of my life. We learned so much, from so many interesting and just generally brilliant people. It was utterly fantastic. I can't wait to do it all over again. The robot getting mullered is insignificant. I would have gone for the experience alone.

I shall make a thread for Tormenta 2 soon. We have already stripped Tormenta, allowing us to see the real extent of the damage. We took some pics of halfway through the process, some of them are hilarious... http://s1088.photobucket.com/albums/i32 ... elentless/ - personal favourite is the close up of the damaged gears (what's scary is that's not all of them!)

Everything we have learned will be going into the second generation. Roll on Tormenta 2! Oh, and, I promise: no chopping boards are going anywhere near it. :)

Any videos we recorded will be uploaded and posted here over the coming week(s).

Thanks for everything!

Quote:

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Originally Posted by Relentless

Oh, and, I promise: no chopping boards are going anywhere near it. :)

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But we loved the chopping boards!

What is the extra drill motor and chain in the middle of Tormenta II for? Are you going for a fork lifter like Kaiser/Panic Attack?

Still a lifter, but a lifter with a twist. I believe what we have in mind has only ever been done once, in America. :wink:

I am guessing either like this one...

http://www.instructables.com/id/30lb-Fighting-Robot/

or like this...

http://www.youtube.com/watch?v=DXHnvCNGjqQ

Well after the first outing of Spur it showed up the weakness of a linear actuator for a lifter - there is simply no give when you get flipped. I already had the chain, motor and sprockets to move over to a design similar to Team Near Chaos but didn't have the time to do it before Aylesbury. My assumption is that in a flip the motor , if not powered, will allow some rotation protecting the forks
The other one to look at is Sewer Snake

Sewer Snake style is the aim. The drill is actually from the dump, but it's fully functional (just a bit grubby). Think it was thrown out purely because it was a bit ratty and the battery had died.

Considering Sewer Snake's success, we're hoping this lifter'll be a little more interesting than a threaded rod setup. We intend to build it for the German event in September, and depending on how that goes, enter it at the UK champs next year. We may have a third machine to enter by then too, though that's way down the line.

I'll go into more detail of what we have planned for Tormenta 2 when I make a thread for it.

Oh, and, starting the process of uploading the footage we got from Yeovil and the champs. I'll link any uploads here.

This is my idea for a lifter it's a heavy weight called Cherub :D


http://www.youtube.com/watch?v=_YNVaiSAXsU

Feel free to pick my brain about the stuff I did in Nyx. One thing I'd list as an absolute must if you're using an electric drive for weapon power is a torque limiter of some sort. With the dewalts it was the difference between a fully functional weapon and snapping shafts constantly.

Tormenta 2... that will be interesting!

why no chopping boards, whats wrong with mending it with plasters :wink:
my good pics of the NEC
http://i1161.photobucket.com/albums/...DSC_0765-1.jpg
http://i1161.photobucket.com/albums/...DSC_0819-1.jpg
http://i1161.photobucket.com/albums/...DSC_0863-1.jpg

Just so you know, Sewer Snake doesn't use limit switches or torque limiters.

We'll look into the torque limiting business. We have already toyed with keeping the drill's already existing limiter in place. We won't be using limit switches, I don't think. If all goes well, the thing will be too fast for them to make sense anyway. With a large enough ESC and a bit of practice, I reckon it will be fine. Quite far down the line that, though. :)

I have started uploading footage to here: http://www.youtube.com/user/TeamExpat - subscribe if you wish; we have quite a few recordings of various fights.

did component.shop pay you to advertise that sticker?

No, they didn't. The stickers came with the batteries, and their service was genuinely good, so we stuck a few on the machine. :)