Cease & Desist - New featherweight

[overkill]

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.

[team death]

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.

[Theo]

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.

[overkill]

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

[Theo]

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....

[Theo]

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.

[Theo]

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

[sean retro]

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

[Theo]

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.

[Theo]

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.

[team death]

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

[Theo]

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.

[Ocracoke]

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

[Theo]

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.

[Ocracoke]

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?