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Cease & Desist - New featherweight

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  • Cease & Desist - New featherweight

    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)
    Last edited by Theo; 20 May 2017, 22:58.

  • #2
    Here's what you want for grub screws: http://www.ebay.co.uk/itm/HIGH-TENSI...9eiKkiMwAIX0tg

    Some 8mm long M5s should do you fine. Might want to find an M5 tap as well, makes your life a whole lot easier. I like the clusterbot idea, hope you can get it in under weight.

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    • #3
      Thanks so much, I found some reverse thread chuck screws on eBay too for about a fiver. The motors I bought seem to be a pair of B&Q drills, a wickes one and another unknown make, two of the chuck screws matched so the missing one must be a different type. they ranged from 22mm (one) to 16mm (pair), I'm going to play safe and get a 20mm screw to be on the safe side while not being too big. I don't suppose you have any useful measurements of yours for reference? These are the only motors I've ever bought so I don't really know the average size of the screws. Thanks anyways for the link to the grub screws, I'm going to place an order tomorrow, thanks.
      Last edited by Theo; 21 May 2017, 00:12.

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      • #4
        The left-hand screws on my machine are just under 20mm long. They're all from exactly the same model of drill. Always worth buying screws on the longer side if you don't know though, if it ends up being too long you can always just get a hacksaw and cut a bit off.

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        • #5
          Yep, thanks, 20mm seems best.

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          • #6
            Hi Theo
            I thought you might be interested in how I was to fit those motors in my middleweight
            which I never finished.
            I bought 4 car exhaust clamps to fit round the body of the drills without stripping them
            down and welded them to a lightweight but strong strip of steel-the motors in thier
            original drill formation clamped into the frame and were very secure,this frame was to
            be bolted to the bodywork and then spindled wheels -probably nylon tyred could be
            offered to the chuck,tightened and the jaws of the chuck welded shut.
            I disscussed how you could use servos in your electrics for quick soloution-
            heres a pic I took of the frame I made with measurements if it helps with ideas-
            You can have the frame if you can use it and are passing sometime to collect.
            total width 15"" clamp sizes 2"" and 2 1/2" weight 400 gramDSCN1749.jpg

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            • #7
              Hi Colin. Unfortunately, I've already modified the motors and they aren't in the original formation, they didn't quite fit in the chassis with the chucks. The main issue at the moment is finding decent speed controllers, I fear the servo drive might not be too reliable, plus the source of the non-working drill in testing turned out to be a disconnected cable in the switch (works now). But regardless, thank you for the offer, I'm sorry.

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              • #8
                A bit of an update, after advice, the hobbwying quicrun doesn't seem enough to run the motors. I messaged Rory to see if the Feather2 could run four motors, but I've had no response, and the manual document says it can only run 2. My current thoughts are leaning towards getting 2 Botbitz 85A controllers, as a couple of people have said to me they use them on 4WD bots. However, buying both of those will take up my entire budget, the clusterbot idea will be a long gone memory, something I'd rather not like to happen. With that in mind, I'm going to get a couple of pre-owned Feather2s or Sabretooths (Sabreteeth?). Any combination, so long as there are 2. I really want to make a clusterbot, and this will be the only way. Does anyone have any spare Sabretooth 2x12, feather2, scorpion xl/xxl controllers or indeed any dual controllers for feathers lying around going spare? If so, please PM me. I'd like to get this ready for the upcoming events, if sign up isn't already over (the site gives extremely few details on deadlines). thank you so much
                Last edited by Theo; 14 June 2017, 20:35.

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                • #9
                  Second update, first half done! (Speed controller kindly donated by Dave). Cease is completed, barring batteries. It looks a tad empty, so why not saw it in half? Seriously, I realised I have no HDPE left for Desist, so I was wondering whether cutting it in half and bolting an axe onto the non-wedge side would be a decent idea. Also, there's a load of weight left over, why not cover it in aluminium chequer plate? I'll post a picture of it soon.

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                  • #10
                    any reason why you cant order any more HDPE or is the Aluminium chequer plate something you already have ?

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                    • #11
                      I realised it would be a good design, size and shape for two small halves. The aluminium chequer plate is mostly cosmetic, as I'll have loads of weight left even as a cluster, but also provide a bit more protection, albeit not much. Mainly, though the shell I bought (while working a treat for construction) has quite a few marks on it, and sandpaper isn't cutting it. The only accessible way to smoother it out is with rasp, but that still make marks and shaves away at the HDPE. Aluminium chequer plate is light, cheap, easy to work with and (in my eyes) beautiful.

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                      • #12
                        Just watched a tutorial on grub screws saying if I put them in too far, it can break the gearbox. Rushed over to the motors straight away to check for anything and the bottom plate was bending. I jut hope it hasn't damaged the gears, I bent the plastic back in place and loosened the screws. I already have a motor with the first stage of gears slightly broken (still useable), so I know the signs but luckily none came up. They still moved freely with no screws and jammed with them in, it seems normal. I have no working batteries to test the motors with so I have no idea of making sure. I mean, the drill batteries take hours to charge, so that might be tomorrow's job. I also can't shake off the thoughts of making a heavyweight. My idea is a very shallow wedge with a small wall around its perimeter and the tip being a small lifting wedge. The idea is to drive under other robots, lift the wedge, trapping them on the top of the wedge and drive them into the pit. Either that or remake Roadblock. Let's focus on this for now, one thing at a time, eh?

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                        • #13
                          The way I put grubscrews in, there's still a few degrees of play in the wheels as the tip of the screw moves between the two 'ridges' on the gearbox clutch plate. Basically the screw isn't really pressing against the plate, but it is captive inside the geometry of it. I don't know if this is the optimal way, but it's not given me any trouble so far.

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                          • #14
                            You can't break gears themselves by screwing the grub screws too far into the gearbox. The grub screws are pressing down on the outer ring gear and if they are in too far, the ring can be pushed out the back of the gearbox, breaking the motor mounting plate along the way. What Rory is doing is the optimal way to set the grub screws up. If your grub screws have a point on the end, filing it flat will tighten things up a bit.

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                            • #15
                              As the cluster idea will take a while longer (making it a summer project), to pass the time, why not bolt a cutting disc to one of the spare drill motors without the gearbox?. I understand I won't give optimal torque, but it seems easy enough and would b great to slice into HDPE. the question remains, vertical or horizontal? vertical can concentrate a cut into a smaller area (putting less strain on the disc and cutting deeper potentially) or going horizontal (larger area but less effective cuts)

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