having ran timingila for quite a while at dojo and also wanting to enter fc at some point with another bot i realised it really wasnt going to be feasible to bring both timingila and another robot to an event. so needing something more sensible, at least in the size department
i had also been watching chris’s sportsman with the massive horizontal saw and wanted to achieve something similar, but didn’t like how easy it seemed to damage the blade. so had the brainwave of using a giant endmill! after a little big of googling i found a couple old stock endmill at around 4-4.5inch diameter and matched the tooth count required
sadly most of them are over the tooth count. but bought the whole lot anyway as it was cheaper than trying to buy one individually new
a beefy 4.7 kilos
now dojo has several requirements for spinning weapons in the sportsman class (namely drills and saws) it must be commercially available, it must meet the tooth per diameter requirements and it must spin at its factory set limits. so after a bit of back and forth with the dojo committee about what defines a saw i got the go ahead! will only be spinning at 4k to start with (roughly 40mph tip speed) to see what the damage is like and if i can up it or not as end goal is to chew and wheels at plastic armour, not to roof stuff
first design was this
i think id recently finished watching shreddit bro rip it up on bounty hunters and was feeling inspired. however the cost of all the cnc ali and it feeling far too try hardy for me meant i redesigned it into something a little more silly
an angled track with a rear powered wheel. not sure what i was thinking at the time but id never seen anything with angled tracks and having seen harrys post about casting them for beetle figured i could achieve something similar at feather. ultimatly dropped this idea too as although its fun it also seemed like a massive nightmare to keep the thing running throught the day as the tracks would be massive targets as well as having the top armour directly mounted to the drive motors might lead to some interesting results if it was hit with a hammer. keeping the track system in my back pocket for the future though. would be a fun drive system
in the end i settled on this
what i felt like would be a good combo between the two previous incarnations. angled but still a little sensible, plus it kinda gave it a lock jaw feel as the head is articulated. also drew up an alternative head if the spinner broke or was too much damage
the drive is battenbox 18v with belt drive to the front wheels. which are cambered at 20 degrees and then machined to sit flat with the floor. not really every effective if it gets inverted but oh well it looks cool!
its all 15mm hdpe laser etched then cut on a bandsaw before being hammered then screwed together giving me this
stayed like this for a couple months while i was focusing on dolos. restarted it last month and got it to this point
wheels all finished machined the hub and pulley was pressed and glued into the endmill (took allot of cleaning to get the 50 years of grime off!) and the shafts fitted
turns out some idiot (me) had butchered my bushings pushing them into the hubs so had to ream them back out.
then with the bank holiday a few weeks back i finally finished up the bot into a photogenic state just minus the belts with some 2mm ali i got from an old cabinet inplace of the 4mm hdpe in the cad
and with the suggestion of googly eyes it kinda completed the look
and finally got it driving and spinning last weekend. IMG_1851.mov - Google Drive
very pleased overall with this robot, still a few additions to make, need to fit the drive pulley flanges rush order some slightly longer belts (its bending the front wheels in as the belts are 5mm too short) and make a proper link and led hole. weight at the moment is 13kg on the dot with everything fitted so likely wont have weight for the long forks but should be able to get a few smaller ones on to help get under stuff and mabye some long hdpe forks just in case
haven’t built up the non spinney head yet. hopefully Gunna run a new version of timingila at bevs in august but if not this guy will be making an appearance but its intended event is dojo in June. looking forward to seeing how much damage it does with its 5kg endmill!
