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
Attachment 6700Attachment 6701(I know these are from the original sale thread but my camera's broken. I should be getting it fixed soon)

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. :)

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.

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.

Yep, thanks, 20mm seems best.

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 gramAttachment 6712

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.

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

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.

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

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.

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?

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.

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.

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)

The average 550 sized drill motor has very little torque and only a 1/8" shaft - its totally useless as a featherweight weapon motor by itself. You would be better served by a scooter motor and a belt or drive reduction. The disk will need a hub to mount on, hacking up a cheap angle grinder is probably the easiest way to do it.

Hi Theo
Off the shelf cutting discs dont react well to impact, they tend to break and
then wobble and shred up, they need a gradual introduction to the item been
cut-see dead metal approach.
A long while ago pre robot wars I experimented using flexible discs, which
when spun up to grinder speeds would cut through Hdpe but would not break
under inpact.
Re previous post -if you want a angle grinder I have a faulty mains 9 inch hitachi
which you could convert to 12 or 24 volt drive yours or anybodys £5.

Do you know if it's an AC or DC motor? faulty mains implies an AC motor I think. Regardless, I'd love some pictures of it through a PM. Thanks. I've decided to go vertical. It might fit better, cause deeper gouges, but not cause irreparable damage.

The idea is that you replace the AC motor with a new one, probably a large brushless in-runner.

Wow, over a month has passed. Okay, so first an update. Cease&Desist is currently on hold. My priority for the summer while I have the time is to begin work on a new heavyweight (thread pending). That won't be a solo project. Cease and Desist will be back by the end of the year, that's when I can work on the other half. I can promise it will be back. However, I do have plans of using what I have now as a minibot to go with the heavy, so it won't gather dust and go to waste. I want to thank everyone for their help and with that, I bring the diary to a wrap, for now....

Summer over, heavyweight not materializing, Gloucester coming up...... Cease and Desist is back in full force! I'm also making some changes to the overall project.

Firstly, the clusterbot idea will depend on my Sabretooth surviving the event (which it should do). I have a pair of TZ 85s now which I initially intended to use with wheelchair motors, but will work even better in a feather. Again, if it survives, i will have them spare for another half.

Secondly, the name and entire theme of my robot projects will change from law to something else, but i'm keeping the thread (there are countless featherweight build diaries now, making another is plain unnecessary with this). As for the completed half, I just need a battery and a couple of fuses to get it running. Lead acid was considered at first because of their low cost and high capacity, plus I need the weight. But, I tried many types but none could fit. NiMH it is! At the moment, LiPos are too expensive including chargers and I'd prefer to do a couple of events before I feel confident to use them.

The design is getting a slight refresh as well. I'm attatching chain flails to the rear wheel openings and either holes will be made in the wheel guards or I'll remove them all together. It's going to be two wheel drive as you can probably tell, the two other motors will be spares for now. The front wedge is quite blunted and can't get under much, but a small strip of metal or acrylic (yeah i know it's not the best stuff but it'll do the trick), i have an abundance of the stuff.

Thanks for reading.

Does anyone know where I can get some decent wheels from? 80-100mm preferably. I don't have access to a press or any such equipment, so i think the hub nut/melted wheel method is out of the question.

On another note, I have the battery more or less sorted. I'm going for a 3300mAh vapex, but they sell two chargers for it, which one is best? Plus, to anyone who's used them, do they have an automatic power cutoff if the battery is fully charged. The website is very scarce on details. Thanks

You could try Robot Shop they got some wheels there and If I remember right their P&P price is ok.

Just ordered a Vapex, plus I have one spare. Does anyone know the deadline for Gloucester signups? I sent it about a week ago, but no reply as of yet and I just hope it wasn't too late, I just need to know whether to book a hotel or not. Also good luck to anyone competing, I look forward to meeting you all.

Well, she runs. Everything works, though there's still lots to do. Proper motor mounts, more sticky tape to make the wheels fit, fuses and the LED and sort out protection for the battery (though it's a NiMH so I won't have much to worry about). My biggest concern is that the ESC (sabretooth) says it has a signal cutout in mode 6, but it doesn't appear to be working. It's a massive issue now because I have less than a week before the event and if it can't be fixed, it's as good as useless. I hope a new receiver will do the trick.

Any recent pictures Theo?, I'm interested to see the shape and the
sticky tape holding the wheels on :) .

I'll try and get some photos soon, though the wheels are being very difficult at the moment. They are twice as wide as the shaft and I can't cut them down easily. Instead, I'm sawing them in half which seems to be working a charm. If all else fails, I have my eye on some other ones. The tape is merely to enlarge the drill shaft as the mounting hole is slightly larger than it. I can't do the melted nut method because I don't have a pillar drill, and the wheels Antazz sold were too small. I still need to paint the sides and mottom, properly mount the wheels and motors, shock mount the electronics and make a cradle. So much to do, and so little time.

What is the size of the thread hole you'd ideally need?

Just the standard 3/8” drill thread ideally, but I’m heading down to screwfix tomorrow and see what they have to offer. There must be something there that fits. On another note, I received my new radio set today as the old one had no compatible receivers with timeout failsafes.

Hmm... 3/8ths is about 9.6mm... I know B&Q round my way have 10mm thread 100mm castor wheels that, if glued in, would do the job. I was considering them for The Honey Badger. They had a few different wheel sizes/thread sizes so might be worth looking there as well?

Those wheels are the ones I have at the moment. They’re about twice as wide as the drill shaft and almost impossible to cut down without access to a pillar drill and a very wide drill bit. They seem very tough, but not suitable for the job. B&Q was the first place I went for wheels, but screwfix seems to have a much better selection