RogueTwo Robots

[RogueTwoRobots]

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

[psycho_fling]

sounds good look forward to the video

how tall is drumroll?

[RogueTwoRobots]

Keep that claw away from it!

Main chassis height is 90mm, about 140mm to the top of the fins, and probably (just a guess) 250mm-275mm with the roll cage on.

Thats probably a perfect munching height for Crumple Zone - thankfully Crumple Zone has three other less-lethal sides that I can go for

[john]

alex, do u own venom?

o 4get that i saw a pic of it on your website but its under pictures not your bots page

(Message edited by john on November 26, 200

[leorcc]

quote:

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.

The trick is, I drive slowly.

[RogueTwoRobots]

That makes sense...having the Speed 900s on that sort of ratio is very fast indeed, but since Im using the motors for a spinner, Im gonna be going for even more speed!

[RogueTwoRobots]

Ive resorted to doing what I do every time exams roll around - start designing robots! I think its the fact that Im consciously aware that Im supposed to be studying that I try not to get distracted by other stuff, but I fail every time

Anyway, Im now toying with the idea of getting the next incarnation of Kaizer up and running. A brief bit of history: http://i31.photobucket.com/albums/c367/ayrshirerobotics/UKRG%202006/kaizer_pits1.jpg>Kaizer Mk1 was the first robot built by Team Terminal Damage that moved away from the Rexs Robot Challenge era of the team. Drill motors, 4WD, speed controllers - it became changed times.
Mk1 was built to compete in the 2006 UK Robotic Games. Building the robot was a good learning process but it was not up to the rigours of open featherweight combat.
http://i31.photobucket.com/albums/c367/ayrshirerobotics/Kaizer%20Mk2%20-%20Build/k2_build72.jpg>Mk2 was the upgraded version, designed to suit the open circuit but some plonker (who could that be? ) used 2mm aluminium chequer plate as the main chassis material meaning it buckled and bent easily, and several axe hits and beatings from raptor spinners later it became clear that retirement time was upon it.
After that I focused on getting Drumroll running reliably and effectively and now that its almost there, I think its time to bring Kaizer back into the action.

I really liked the look of Mk2, with the side bumper rails and paint job, so Ill be aiming to keep a similar look to the new one. However, itll be increased in size as Mk2 was small and hideously underweight. Going to stick with 4WD, and will have some form of lifting weapon on it.
My initial plan is to stick a linear actuator in it and have Panic Attack style forks at the front. My overall desired plan (which might take a few practice runs to get right) is to have a 4-bar-lifter in there, probably powered by a Speed 900 transmitting through a threaded rod.

With exams before Christmas this year, I have my holidays free to roboticize so hopefully a new batch of build pictures will be on their way soon

Jamie
Team Terminal Damage
http://www.ayrshirerobotics.vze.comwww.ayrshirerobotics.vze.com

[RogueTwoRobots]

Hi Lewis,

The current chassis height is 90mm, the drum is 114mm and the wheels are 75mm, so invertibility doesnt really work
However I have my reasons for having such small wheels and sacrificing invertibility.

The first incarnation of Drumroll (basically before it had the drum) had 100mm blue wheels but the robot was very fast, so much so that most of the time it was uncontrollable. The best way I figured to drop the speed was to decrease the wheel diameter, plus the 100mm wheels took up too much space in the new chassis. I had used a roll-cage in a previous competition and it worked flawlessly so I decided to keep the smaller wheels for increased controllability, then add a roll-cage to deal with the self-righting. I toyed with the idea of a self-righting arm or a second set of wheels (similar to Crushtacean) but they were too much hassle and too heavy. The roll-cage is lightweight and effective so Ive stuck with that.

However its still an issue that Im not fully settled with, and after having seen how other drumbots deal with invertibility (I was impressed with the design of Proteus, a US drumbot) when its comes time to give Drumroll a new chassis, I will be taking the invertible approach