Cease & Desist - New featherweight

[Theo]

Okay, I've found an excuse to bother people with my robot building without coming off as annoying (sorry). Welcome to my build diary! After nearly a year of brainstorming ideas and nothing happening, I bought a shell off Harry that's working a treat (Thank you) and four motors from Colin (Again, thank you) to form Cease & Desist. My original idea was a 360⁰ lifter but decided I was both ineffective and impractical. The second idea is a longer project, a clusterbot. Overall, the current robot weighs in at 5.8kg (excluding speed controllers and batteries), excluding extra weight to be competitive, leaving an extra 7.6kg to work with, lets round that to 6 to be sure. The first part, and the part I'm working on now, the 4WD 'Cease' will be a basic 4wd pusher with a spring loaded front wedge to get underneath the others. Part 2 is 'Desist', a torque reaction axe/hammer similar to swordfish (if its for sale, I'll gladly buy it) with an interchangeable axe and claw hammer on the end. First thing on the list, modifying the drill motors. I need to buy the grub screws but all my local hardware shops don't have any, I'm assuming a big chain might (B&Q, Screwfix, Wickes). Also, one of the drill motors seemed to have a left threaded chuck screw missing, though if I can get a good grip on the wheel, it shouldn't be an issue, or I can get one on eBay. Does anyone out of experience know where, I can get grub screws, and what measurement they should be. Thanks, and I look forward to getting this finished!This is what I have so far
IMG_6629.jpgIMG_66281.jpg(I know these are from the original sale thread but my camera's broken. I should be getting it fixed soon)