2011 Update

I may not be able to do any major robot work until I get a job, but that doesn't stop me from planning.

First up, Drumroll II. I finally got round to fully dissecting it after the UK champs. This is the self-inflicted damage sustained in the first fight:



As you can see, the brushless motor ended up sitting quite wonky, and the shaft got bent which gave it a bit of a growl every time it spun after that. I did as much as I could in the pits afterwards to straighten it all out but didn't have much luck. So it ran almost that squint for the rest of the event; it's no surprise the belt kept jumping off.

With the old setup out, I started trying out the brushless motor/gearbox setup from 360 in the robot and, although it just fits in height-wise, the can of the brushless motor would be rubbing against top/bottom panel (whichever way up I mounted it) and the space was really tight. I've also concluded that UHMWPE, while good in its own right, is the wrong type of chassis material for running a brushless spinner.
So the plan for now is to go back to a Speed 900 and replace the bolts holding the teeth on with some higher tensile, larger diameter ones and get the machine running like that. It won't pack as much of a punch but it should be more reliable. I had very few issues with the drive at the champs, so combined with a more reliable weapon setup it should operate without wrecking itself.

That will be a stop-gap measure; to get the brushless setup running I want to go for a CNC-cut aluminium chassis and get the proper drum made. Add to that some lithium batteries and charging gear and the cost won't be cheap. So once I'm earning, that will be how Drumroll II develops. Until then, a brushed-motor weapon and UHMWPE chassis will suffice.

Carcinus has also been redesigned and is up for a rebuild but I'm now torn between what to do. Build Carcinus first, or finally make use of the Bosch 400 motor I've had for years and build an axe robot?

Introducing GROND (Hammer of the Underworld)





The name comes from the Lord of the Rings. For those of you who have seen the movies or read the book, the huge battering ram from the third film is named after Grond, who was known as the Hammer of the Underworld, hence why I thought it a fitting name for a hammer bot.

The CADs are pretty basic but show the intended aim. Two drill motors driving four wheels through timing belts and pulleys (not modelled), quite similar in that sense to Satan's Mutt. Bosch 400 driving an axe through sprockets and gears, controlled by a Victor 885. Operating voltage not decided on yet; the Bosch is 12V and a few folk say that roughly 18V is the most you can overvolt them to without burning them out. So I may stick with what has become the standard voltage in my machines of 19.2V. The axe reduction was originally planned to be one-stage, using a kart sprocket like most of the other axe robots, but when I tried one in the model, it looked pretty rubbish. I've got a few sprockets and some chain from when I first built Drumroll and was planning to have the drum chain driven. The parts amount to two reductions of 3:1 each, so the intention is to go two-stage with a total ratio of 9:1. This might change when I perform some calcs and see what sort of speeds the axe will be doing.
The middle bulkheads were originally 10mm ali that I was going to get machined but I quite fancy the challenge of doing most of it myself so 15mm in one of the stronger plastics might be the chosen option. It will be nice to try something different, and it can do as a robot for my dad to use until I get Carcinus rebuilt.

Beetleweight plans are still floating about, but I keep changing my mind on the design. For example, after seeing Mute on an episode of Extreme the other day, I want to change my Cassius II replica into a Mute replica, plus I've got ideas to make a couple of scaled-down versions of other heavyweights so it's a toss-up what to build. It probably doesn't help that I've bought no parts yet. The design will probably settle down once I do, but again that's something that is going to wait until employment