Drumroll has now been entered into the Rebel Robots featherweight Championships on the 7th February 2009. With six other spinners entered so far, it should hopefully be a smashing show

Update

I cobbled together the old drum over the weekend as I was keen to have a quick test of the Speed 900s to see how they perform. The drum was horribly unbalanced but it was still able to spin. I was running on timing belts and pulleys on a 4:1 ratio. Having read through the lithium use thread a couple of weeks ago I noted that Hannibaltion 3 runs its drive on a 4.5:1 ratio so I wasnt expecting the drum to be spinning much faster than a nippy drive wheel. However it did have enough kick in it to happily toss the target chassis around the back garden.

The fins displayed in my last update post have now been attached and have gone beyond purely cosmetic use. One instance when the drum hit the target chassis, the chassis flew up and would have gone over Drumroll but instead got stopped by the fins and fell back on to the drum resulting in another impact!
So it appears that the fins may well serve as a snare to stop anyone flying over the top of the robot
I did design the fins a little with that in mind but was unsure if it would work or not

There was plenty of torque in the drum at the 4:1 ratio but I am going to sacrifice that for speed and try out a 2.5:1 ratio. Going to stick with pulleys for the moment as its easier to modify them to fit the 6mm output shaft of the Speed 900s. All sprockets above ten teeth (on Technobots) have a bore of more than 6mm so Id have to make some sort of collar or similar to suit, whereas I can just drill a hole in the pulleys

I have a video of the test and a couple of pictures but theyre stuck on my camera just now since my laptops down and out and I cant upload them.

Meanwhile after the test I dismantled Drumroll right down to the bare chassis. I began marking out areas that I could cut out of the nylon to reduce weight as its starting to creep up and predictions are that with the new drum it will be roughly a kilo overweight. I didnt get time to cut everything out before having to come back up to uni but one nylon bulkhead weighed half a kilo before and after slimming it is now weighing in at 250g while still retaining its structural strength. Once I cut and drill out everything else, I hope to have lost around 750g. It may not sound a lot but every little helps