Questions/builds thread.

[Eventorizon]

Re: Questions/builds thread.

Mine are running off a 14.8V Lipo and I have a 54-46% weight distribution (front to back about the centre of the wheelbase) according to solidworks.

[Ellis]

Re: Questions/builds thread.

We have an unknown distribution (lol), 12v drills at 18v and yes, two Electronize 30a ESCs.

We have more weight over the front wheels. It actually benefits control, we steer around the front of the robot whilst the back wheels slide a little. Makes for some pretty interesting drifting!

Are you using the 14.4v models?

[PJ-27]

Re: Questions/builds thread.

Interestingly you 2 have quite similar robots in design but have taken 2 very different approaches to making them.

Ellis, you have taken a more 'Bitza' approach of using existing materials, blood, sweat, tears and hope!

Alex on the other hand has carefully designed in CAD, bought Li-Po's etc...

Apologies if I've got that all wrong! But there's nothing wrong with either approach, be interesting to see how they pit against each other. Personally I'd like to see them turn out quite equal.

As for the Gimson motors I believe they use Drill motors for power the hrs-550s (various voltages), they just have the massive added advantage of Metal gear boxes, supported shafts and decent mounting points.

[Eventorizon]

Re: Questions/builds thread.

We have to have a dual now! We can't leave without going Mono'a'Mono! (Is that the right spelling of that?)

[harry hills]

Re: Questions/builds thread.

don't forget a compination of the two

4wd drill 18v lifter + 4wd gimpson spinner = 4wd 19.2v lifter lol

[Eventorizon]

Re: Questions/builds thread.

That insane concept did cross my mind for a havey weight robot, have a spinning disc and a lifter on the same side. The arms of the lifter and the two actuators going on either side of the disc, the disc motors below the actuators and have the ESC's and batteries at the sides as per both designs... it would be a mad design, mad build and a mad robot!

[Ellis]

Re: Questions/builds thread.

That insane concept did cross my mind for a havey weight robot, have a spinning disc and a lifter on the same side. The arms of the lifter and the two actuators going on either side of the disc, the disc motors below the actuators and have the ESC's and batteries at the sides as per both designs... it would be a mad design, mad build and a mad robot!

And sadly, currently illegal! D:

Well, we have more or less finished it. We have a few more things to do but nothing too major. Perhaps another day on it to get everything as right as can be.

The top panels have all been quite rushed. We are leaving for the UK on the 31st, and my dad has a music client in from tomorrow (23rd) to the 27th, so we've really had to push. That plus our original cuts on the plastic (mainly the inner bulkheads) being really quite... lacking, means the panels are all a bit twisted and slightly odd. It looks great in pictures, though!

http://s1088.photobucket.com/albums/i32 ... elentless/

It weighs 13.1kg. Will probably be about 13.2kg when 100% complete. The drive has dulled quite some, as expected, not majorly though. We're a bit worried about our battery life. We only have 2.6ah, which has been fine until now, but with the added weight we may be pushing our luck for 3 useful drive minutes. We shall see. I think it's quite uncommon for battles to last the full 3 minutes?

Anyway, off to bed! Let me know what you think.

[blazerbotics]

Re: Questions/builds thread.

Most peoples batteries are capable of doing nearly 2 fights, 2.6ah should be enough but if your using the standard drill cells, then they won't be very good quality, and thats whats letting you down.

[PJ-27]

Re: Questions/builds thread.

Don't worry about it looking uneven, some of the spinners you're up against will soon 're-model' it

As for the cells I'd discharge them and then trickle charge them nice and slowly the night before the event. Then on the morning (at the event) give them a fast charge until they're brimming!
Then after each fight (once they've cooled down, do not charge hot) give them another fast charge.

You get some pretty decent gaps between qualifier fights. They should last fine, plus I'll bring you those spares (they're not made into packs though, so bring some gaffer tape!)

ps. Just looked through the photos, I like the way the armour moves with the lifting mech. Reminds me of a turtle! Pulling it's head in.

[Eventorizon]

Re: Questions/builds thread.

Tormenta is looking AMAZING (He or She?)! I looked through the build album watching it develop and it is very well built, by my standards anyway. Is it going to stay that white colour or is it going to get a make over. I deliberately spent a few more pounds to get my parts on Black so I did not have to paint it afterwards but the day we can buy a black chopping board will be an interesting day to say the least.

[Ellis]

Re: 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!

[Eventorizon]

Re: Questions/builds thread.

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?

[Ellis]

Re: Questions/builds thread.

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?

[ewan]

Re: Questions/builds thread.

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

[Eventorizon]

Re: Questions/builds thread.

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.