RogueTwo Robots

**typhoon_driver** · 1st June 2010, 22:54

Jamie just shorten the forks by 30mm or so if it struggles. You're engineering degree work should tell you why :P

**joey_picus** · 1st June 2010, 23:05

Never mind degree work, I've got virtually no proper engineering knowledge and I've got a good idea why :P

**RogueTwoRobots** · 4th June 2010, 23:29

Indeed, leverage and all that. Not going to bother cutting a bit off just now though, because I've just got it looking all pretty with a paint job

It should manage alright but I'll see how it performs at Edinburgh and then shall take things from there. I've replaced the 15A Electronize controlling the lifter with the Victor 885 that's sitting unused in Drumroll at the moment. Quite a change of rating I know, but at least there's no risk of burning out the controller

Plus the Victor has the brake/coast jumper option and having it on brake allows for some precise lifter positioning.

Both Carcinus and Kaizer are ready to go for Edinburgh. Taking them and all necessary tools to Glasgow with me tomorrow as I won't be home before the event to collect them. Need to give both sets of batteries a few cycles so might borrow a flatmate and go and try to find somewhere quiet to drive them about, preferably away from any possible interaction with the, err, local population (pure aye man, whit's that pure crazy thing there you goat, is tha' liek tha' Robot Wars s**** that wuz oan the telly?)

In other news, the basic chassis for my mini-Cassius II replica kilobot is coming together. Got the base panel, main bulkheads and flipper arm all made (pics tomorrow) so it should just be a case of buying all the remaining components, installing them then armouring up, but when is it ever as simple as it sounds?
I was planning to armour it all in polycarb in the same way as Cassius is but with all the angles on the body, the brittleness of the poly I have and the thickness (3mm probably won't stand up to the spinners that well) I think I might plump for some HDPE and paint decals on to make it look like the heavyweight. Might last a bit longer too.

Not sure what it weighs yet but I will be drilling weight-saving holes regardless. Also need to come up with a name for it, so suggestions welcome

**joey_picus** · 4th June 2010, 23:33

Cassandra?

**RogueTwoRobots** · 8th June 2010, 15:59

The first thing that comes into my head at the mention of Cassandra is the character from Doctor Who, the last human whose remaining skin is spread across a frame, which was just a bit gross :P

Here's a couple of pics of it so far. Hole saws are just to get an idea of the size of the wheels. The battery pack you can just see at the back will be powering the drive motors through the micro-servos and switches and the receiver pack in front will be powering those servos and the servo used for the flipper. The motors will sit between the two packs.

[attachment=2:3cy7uk7i]kb_build (

.JPG[/attachment:3cy7uk7i]

[attachment=1:3cy7uk7i]kb_build (9).JPG[/attachment:3cy7uk7i]
Two battery packs may seem a bit much but I reckon I've got the weight to spare just now and it keeps things relatively simple. If weight turns out to be a problem, I'll look into getting a higher voltage battery pack and power the receiver through a BEC.

Also got Kaizer painted up nicely for Edinburgh

[attachment=0:3cy7uk7i]k3_build (66).JPG[/attachment:3cy7uk7i]
Now it and Carcinus are just undergoing testing to highlight any faults. It's not often there is time for testing due to the robots usually still getting built right up to event time but there's a lot to be said for putting them through their paces over and over! I've only had them up in Glasgow a day but have been able to spot little problems and get them fixed or calibrate things to tweak the handling of the robots. Just need to keep cycling the batteries and bashing them off each other until there's nothing left to break

**death robotics** · 15th June 2010, 18:29

Im liking the front-hinged flipper bot.

It looks like Cassius and Mute rolled into one. Good job.

**RogueTwoRobots** · 15th June 2010, 19:17

It looks like Cassius

That's a good sign, since it is meant to be a miniature replica of Cassius II

**RogueTwoRobots** · 21st June 2010, 15:58

Well the robots had a run around at the weekend over in Edinburgh. Didn't win any fights but neither of them are really melee-winning robots, plus their performance was average-ish. Carcinus only had one fight which it broke down in and as it was the last fight and I've not yet looked at the robots, I don't know what caused that. All other times it ran without any problems; it may have ended up in the pit a few times but not once was it due to my dad's driving. I think he's getting better

Kaizer was a mixed bag of fortunes. It made it in to every fight bar the first one (a problem with the Radio Link tx/rx struggling to find each other among all the other Spektrum sets being activated, much like with Carcinus at Barnsley) but it rarely made it out of the fight still running. Think it got pitted once, stuck on it's back a couple of times and broke down a couple of times due to a connection coming loose. Sustained a few hits from Little Hitter that deformed the top panel several times but nothing a big hammer couldn't fix.

So in terms of upgrades:
Kaizer - the lifter worked but it struggles with traction once it's got a robot hoisted, so it couldn't actually do anything useful with them after that. There was also too much flex in the lifter mechanism/chassis so that needs reinforced/built better. The SLAs did the job okay but when the opportunity arises I will upgrade them to something better. There's a drive relay needing replaced too; it went into its last two fights without reverse on one side but I didn't have a spare with me. Something needs to be done regarding traction with a robot on the lifting arm; one option would be some outriggers to help get some power back through to the wheels, but first I'm going to try the simple method of screwing some bike tyre onto the wheels. It will increase speed and grip, raise the ground clearance a bit (most beneficial for when it's running upside down) and hopefully allow me to lift other robot then push them around. Finally, it will need some sort of armour round the outside. Wasn't a problem during the weekend but come the UK champs I'd prefer to have a steel bumper running round it to try and fend off any spinners.

Carcinus - ran fine in general but it's clear that the claws don't really have any power to them. I've known this for a while but not done much about it because I've just been trying to get it running to a decent degree. Now that it is, I can start to consider other claw drive options. Ideally a Speed 900 through a gearbox onto a lead screw; more realistically, a drill motor direct to a lead screw.
When initially planning to increase the power, I envisaged having to build a new chassis to cope with the forces but to be honest, that's more effort than I can be bothered with at this time. I've now realised that all I need to do is build the claw mechanism into its own self-contained unit (maybe from box-section steel or something) that can be bolted into the robot so that I can avoid having the whole chassis twist and bend from a resulting increase in power. With 4kg currently to spare there should be enough weight to manage this.

And on a side note, I have now decided that I am determined to get a new Drumroll running for the champs. Having driven Little Flipper I've felt how precise a Scorpion XL can be and I've got one waiting to go into Drumroll II. With better control, increased speed and invertibility, it would be a significant increase in my chances of doing well. I can't afford to go full whack with the design yet so some compromises will be made for the champs to cut down on costs but it's mainly little things that shouldn't compromise performance.

**RogueTwoRobots** · 28th July 2010, 21:26

Update

Been a bit quiet on this front lately. Room decorating and moving out of uni accommodation has taken up much of my time, but my room's finished and I'm back up to Glasgow tomorrow to get the last of my things. So tonight, I got back round to doing a bit of work. Nothing majorly important, just doing a bit of cardboard-aided-design:

Pretty similar to the cad layout posted a few pages ago so that's a good start. Can't help but admire the wheels

I couldn't cad the outer armour originally so I posted a pic that had been crudely edited in Paint; thankfully I'm a bit more skillful with cardboard so you can sort of see how it will shape around the robot. Looks a bit shoddy here, but hey it's just to check sizes:

You may notice that there are Nimh packs in there compared with A123s in the original cad; I've decided to leave better batteries to a later upgrade when I've got more pennies. I have the Nimh packs to spare (as Carcinus won't be running at the champs), they fit nicely into the back of the robot and I have the chargers for them so they'll do for one event. I'm going to have to monitor them carefully between fights because the brushless does draw a lot more out of them than the Speed 900s did so they'll need charging a lot, but when they're well cycled the robot can run with the brushless quite well, as I discovered in a couple of whiteboard fights at the tag champs. The drum in this robot will be lighter too than the original Drumroll so theoretically it will be less of a strain on the motor.

The rear wedge is currently hinged at the top, but this means when the robot is upside down the wedge is pretty ineffective so, thanks to some constructive comments, I'm going to hinge it in the middle so it works well both ways round. Also now looking at wiring in a changeover relay to the brushless and alter the tooth design so that the motor can be reversed upside down and the teeth can still get some decent hits in.

Will be a little while before I can get the materials and get started so I can hit the cad again and make the necessary alterations. Looking forward to getting it built though