RogueTwo Robots

[RogueTwoRobots]

Re: RogueTwo Robots

The lipo access is not the quickest in the world admittedly. I looked at several different positions for the lipo that allowed the easiest access but there weren't a lot of options that didn't have the lipo covered by some sort of electrical connections or ESCs.

To remove: there are four M6 bolts in the base that I take off, which allows the outer and rear bulkheads to lift away, leaving good access to the innards. I then remove the two wing-nuts holding on the Scorpion and link and move it to the side. Then the four smaller M4 bolts holding the white cover on the lipo. So a bit fiddly, but with a screw gun and the right drivers, I imagine I will be able to remove it in just under a minute.

The lipo is a 'Gens Ace' brand I bought from Giant Cod. Not a well-known brand as they seem quite new, but have good reports so far so I'm trying my luck with them to see how they go.
Rough dimensions (from memory) are about 120mm long, 35mm wide and 25-30mm high and that is for an 18.5V, 2200mAh 40C battery. Not sure if that will be enough for a battle, will need to do some testing to find out. If not, Giant Cod now have a 5000mAh, 50C version that I could upgrade to, probably without having to worry about space or weight.

http://www.giantcod.co.uk/gens-2200mah- ... 06486.html (2200mAh battery)
http://www.giantcod.co.uk/cell-lipo-bat ... 1_130.html (5-cell packs, different ratings)

And the bolts holding the battery down are just tapped into the Nylon. It tends to hold threads better than HDPE so will suffice so long as I don't over-tighten them.

[Mouldy]

Re: RogueTwo Robots

looks ok, id be abit worried only running 2.2amp though... how many amps does drumroll normaly pull? Will be more once uve gone brushless...

[RogueTwoRobots]

Re: RogueTwo Robots

No idea what the usual current-draw per battle is, only recently got a charger that tells me how much it puts back in to the batteries. The 2200mAh battery was the one with the best 'C' rating they had at the time so I went with it, but the higher capacity ones are a more recent addition. I know over-discharging isn't good for lipos, so if the tests show that the robot is going to be draining the pack quite severely, I'll just get a bigger pack and put the current one into Carcinus, as it's not a current hungry bot.

[RogueTwoRobots]

Re: RogueTwo Robots

Not much of an update, but just to display Kenny's handiwork before I shove them in a tube and weld them shut:

[jonny]

Re: RogueTwo Robots

Coolio my noolio :P what are they made from?

[RogueTwoRobots]

Re: RogueTwo Robots

Just stainless steel. Shiny stainless steel

[billy breach]

Re: RogueTwo Robots

Nice handy work

[Anttazz]

Re: RogueTwo Robots

Looks excellent man, do they add any useful weight to the drum compared to the old style ones. Although most of the advantage will be the the speed increase/reliability i'm sure.

[RogueTwoRobots]

Re: RogueTwo Robots

Technically they should, as the old ones were just flat circular discs, whereas these have the hollow innards and thicker outer rims. But any inertia increase will probably be minimal. Should be more reliable though yeah, and will spin much more freely compared to the old bearings.

[Anttazz]

Re: RogueTwo Robots

Really need to get my drum made

Also, was just digging around photobucket earlier, once you have the end caps and brushless setup all fitted you need to have a Drumroll II vs LCD monitor round 2 :P

[RogueTwoRobots]

Re: RogueTwo Robots

Update

Ah, the toxic aroma of welding and grinding fumes! Spent most of today welding the endcaps into the drum and making a mount for the brushless motor. My welding's getting better but the angle grinder is currently still my favourite welding accessory

Anyway, got the new endcaps welded into place on the drum. Bolted the timing pulley onto it too and fitted it into the robot. Just the perfect width:



(excuse the lower quality photos, couldn't be bothered going back in to get my proper camera)
Spins much better and a lot more free than the old drum. Spent a bit of time trying to balance it too, and while I think I've made it better, I won't know for sure how good it is until I spin it up. But it seems pretty un-biased for now. With everything bolted/welded in place, the total weight is 2.35kg, which is a bit heavier than the previous assembly. Whether that will make much of a difference, again I won't know until I spin it up/fight it.
Once I've checked the balance, I'll give it a nice coat of paint and probably the spiral I had on the drum back at the 2009 tag champs.

Onto the brushless mount, I've probably went a little overkill with 5mm steel but nothing should be going anywhere!





So there's the main faceplate that bolts to the chassis, to which the brushless motor also bolts. Then, heeding the advice of others, I made up a rear plate to lend some support to the back of the motor. I haven't used a bearing here, just a couple of zinc shaft collets that I had (one welded to the plate, one on the shaft). Despite not being bearings, the shaft spins in them nice and smoothly, so it's enough to make me happy.
I thought about making the mount as entirely one piece - in a U-shape - to have it as one solid unit but I quickly realised that once the motor was in, there would've been no way to get it out. So that's why I opted to do it in two pieces. They need to get tidied up a bit (cut the corners off/down a bit and grind everything so it's all nice and clean) and then I'll get them primed and painted and that'll be another thing ticked off the list.

And finally, made a start on getting the outer armour and wedge back together again. The first step was to alter the design so that rather than having two side pieces that bolted on, it would be one single piece that wrapped around the whole robot. The back panel is all that's done so far:



It's the same 5mm mild steel as used in the brushless mount. Once the sides (4mm hardox) are welded on, I'll cut some pivot points for the rear wedge and weld them onto this back panel. Then hopefully the armour will actually protect the robot, as opposed to it falling off in almost every fight.

So that's that for a day. Should have more updates tomorrow, although not sure what I'll actually focus on, as Carcinus is at the stage of needing re-wired, which is tempting. Either way, at the current rate of progress I'll have both robots finished by mid-February, which will leave over a month for plenty of testing :twisted:

[Mouldy]

Re: RogueTwo Robots

Looking good Jamie- what ratio you using for the drive on the drum?

[RogueTwoRobots]

Re: RogueTwo Robots

Not 100% sure yet on the ratio Dave. The original small pulley I bought gave a 4:1 ratio but with the increased brushless shaft size of 8mm, that pulley is too small in diameter to fit grub screws into for securing in place. So I've yet to buy a new one (gonna have a look on Technobots shortly) but will probably aim nearer to a 2.5:1. Think Boner ran that ratio at the champs and seemed fine, and this drum is almost 2kg lighter.

[Anttazz]

Re: RogueTwo Robots

You'll be just in time to do some more child educating then?

Looking good, will be very interesting to see what sort of power you can get with it now. Looks a lot more secure now too with the new fit, hopefully it runs the way you've wanted it to since you made it, and if it doesn't, you can't blame cutting corners any more :wink:

[PJ-27]

Re: RogueTwo Robots

Looking good Jamie! Give us a spin-up vid soon!