Tuesday, 17 December 2013

Quit changing things


An eloquent start I think you will agree but I feel it apt to describe the general feeling I'm getting from the whole Massacre built at the moment.

I do tend to get the "one step forward, two steps back" when I try and build something, but with this I'm don't have the advantage of the step forward, so I'm seemingly making up for that with some extra steps back. I'll quit whining (lies) and get on with listing the changes.

I've decided to actually make parts for my own robot, and not totally waterjet flat-pack jigsaw puzzle it, this isn't due to me taking some stupid high ground, its just so much bloody cheaper this way. I have a sheet of Hardox, around about 3-4mm thick which should do fine. I marked out the base to get a rough idea of how much other stuff, like the wedge and wheel guards I could fit on there. Wow. My robot is fucking tiny. Or the base plate is at least. Should be interesting to work on I guess. Making it larger isn't really an option, unless I want a 16kg feather. Weight is going to be a pain anyway despite the thing being almost able to fit inside my pocket (hyperbole, I don't have pockets that big yet although they would be handy)

Main change, and one that slightly pains me is the change of drive motors. I'm switching from the Magnum 775 to the Banebots P60. Reason being is that the Banebots are actually in stock, and are a bit cheaper. I was having to do an order from the Banebots website anyway for 775 motors and wheels. It makes sense to add another $100 or so in gearboxes while I'm there instead of having to get two very large orders from the US and get fucked over twice by bloody customs. The Banebots are a more commonly used motor as well, so lots of the guys at the comp will have spares and stuff that I could buy/rent/borrow/steal so I have to carry less. 2 spare motors, maybe a spare gearbox if I have any spare polly to throw at it (who am I kidding, I won't) The Baneboobs are a tad smaller than the Magnums used to be, so some kind of horribly ghetto enlargement surgery will end up happening. Or I could just change the mounts? Yeah. Best do that instead of buggering about with an expensive gearbox.  You can see the adapted bulkheads, it has ended up probably stronger, due to the general lack of large square holes. No idea on what the cost would be, none of the cutting places are talking to me. Depressing.

In actual progress news, the updatephobic Elvis is lathing away like a bitch, doing cool little odds and sods and found some time in his "busy" schedule to make some prototype Rangleboxes. They are a bit more wooden than the real ones, but that's cool. Part of me wants to see how they react to the 40k rpm. I mean, wood just loves high speeds and friction right?? Right??

Pretty cool eh? I'm not 100% sure but I think the USB isn't a essential component, but then again it could be a traditional Spanish building technique.

Shown is a rather large brushed motor. No idea why, maybe someone is planning to use Rangles in a drive setup.... Nah, nobody would be that stupid would they?

All for now, and how joyously uninteresting it was!
Ta, Haz.

Tuesday, 3 December 2013

Even more Massacre for your money

As the title suggests, Massacre will feature quite prominently in the cluster-fuck of gibberish that will make up approximately 90% of this, but first I'll focus on the beetleweight front of things.

Eggbeater has had a rather large design change, rather influenced by the amazing Dominant Mode and other 4wd drumy and beatery things. This should really help the thing be drivable, as there is weight on the motors, and all the wheels, turning should be easier as it is about four miles wide. Can't really tell from any of the CAD's but O-rings are becoming more of a thing in my lighter designs. (totally not because a friend of mine has just bought a lathe and is capable of making me up pulleys for tuppence, no of course not.) The wheels I plan to use are 35mm ish which even with the 1000rpm motors won't make for a speedy robot, but hey. Big fuck-off beater. I don't need speed. These wheels will have a groove for the belt to slave the second wheel off of, and also space for O-ring tires. Not much grip, but they should be more rugged so they can better stand up to the steel floor of the Slaughterhouse and I don't have to replace them after .4 of a femtosecond. The frame of this is 10mm nylon, down from 12mm but I actually have proper armour in the form of 1 and 2 mm titanium and 5mm aluminium. Lots of this design is spinner fodder, but it looks too cool in my eyes, and it will make some great footage if it does get wrecked.

Swish looking beetles out the way, time for some Massacre related ramblings. Recently all of the everything was changed, prompting me to go for a different kind of weapon setup, to more definitely lock myself into a design and not get distracted again (its really too late in the game for massive design tweaks) To do this, I bit the bullet and ordered a motor from hobbyking, fully expecting a box that was just full of angry wasps and a note saying "haha you trusted us" (I've had two friends rather badly fucked over by HK) But no, it arrived quickly and the motor seems to be very nice indeed. I'm more than a little bit in love with it truth be told.  Once I had got over the initial OMGIGOTMYFRISTPARTFORTHISROBOTHOLDME. I took some photos of the motor, then I opened it up and had a shufti inside it. Well it would have been rude not to! It was fairly nice inside, no way of putting a full 8mm shaft in it, but no real worry there. I can use an adaptor or just have a 5mm shaft that steps up to 8mm at the end made up by some kind person.

I then began the fun fun process of putting the motor into CAD. Took way to long, as I decided that late on a Friday night/early Saturday morning was perfect CADing time. In the end it got done, except for some of the detail on the front. all those angles and spacing and curves in Google ketchup? Fuck that royally. Having this cadded up instead of the black tube was nice cos I could plug it into the Ranglebox and be all posh and take pretty screenshots. Man I really need to find something better to do with my spare time.

Fancymotor in place I could deal with the base plate, or more actually the holes that need to go into it. Because the bulkheads and frame need to be pretty much perfect, I don't quite trust myself to fabricate the base and get the holes lined up (despite the fact that the baseplate was the best part of the last featherweight I built) Maybe if I had a bit more experience with metal work and didn't have work around the shed and annoying the neighbours with late night grinding/drilling. Instead I'm cheating. Will get the base plate water-cut from 4mm plate, I personally wanted stainless due to it being fairly cheap  and resistant to rust (my shed is like where rust comes on holiday, but then finds it likes the local area so much it buys a small property and invites its family and friends over to start a brand new life away from the hustle and bustle of the big rust cities) but general opinion was to go to hardox. I will be doing other parts as well, not just the base i.e. parts for the wedge and the wheel guards and probably a beetleweight disc if I feel that way inclined when I come to sending off for quotes.

That somehow brings me onto another point. Wheel guards. *shudders* Now I don't know how why, but I don't seem to be capable of getting a robot to look good with enclosed wheels.
 I like the look of the exposed wheels, its a hideous design flaw, but I almost can justify it purely from an aesthetics point of view. Almost. So wheel guards have to be a thing, trouble is its very hard to get them to not look like absolute total arse! The ones on the first Massacre were worse than the weapon if that's even possible. I might have cracked it this time, yeah it doesn't look great but there is nothing too ugly about it. It did show me Massacre can do a great impression of a tank.

That little voice in my head called Elvis, (emphasis on the little) seemed intent on nagging Massacre into a better robot with suggestions, like "use a proper material for the base" "don't have the robot going 5mph" and "don't take out the drive motors to save weight for a battery to power the drive motors you tit" came up with another cracker. 8mm thick hardened steels are just too weak, 10mm is where it is apparently at, whatever it is. The bar has been made thicker and wider, and unsurprisingly heaver. Its now nesting somewhere around 3.5kg. Arse. That would make for a killer weapon, but not really anything else. I'm going to be fighting weight like a big weight fighty thing. I suppose there are lots of places to loose weight, but most of them require compromise.

Nothing really more to say, only really some pretty pictures. After a little bit of pissing around I was able to get my ketchup drawing of Massacre shoved rather haphazardly into AutoCAD which is pretty cool. Its not actually functional, but it's a pretty picture.
 Also, have a slightly exploded version of Massacre, this is probably what will happen to it during its first fight. But lets hope not eh.

Cheers for reading. Hopefully before too long actual progress will happen.

Sunday, 17 November 2013

Help! I changed all my everything!

Okay okay, not all of my everything but a lot of shit has gone down with Massacre. First off I quit lying to myself about building the beetleweight version as a prototype, since it requires the same processes and thickness of material I'm just going to get the frames cut at the same time; this saves money and time and the environment! Robuts will still be built but kinda at the same time, so I can take a break from one and go work on its big brother/little sister which should prevent me from being driven permanently and irreversibly insane. Always a plus when that happens.

The point of overhead bar spinners is to, as the name suggests, have the weapon bar ontop of the robot. This means that unless the robot is designed to be superawesomesexyuber low, the weapon is quite high up. The obvious way to get a low height weapon system is to use a right angle bevel or mitre gear setup. This is what version 1 of Massacre had. It did not go well, in fact it was rather the opposite of that. Soured by right angled gearboxes, I designed just a flat motor and pulley into massacre. Needless to say there was a problem with this, nearly all the brushless motors I could find were either the right height but not nearly powerful enough, powerful enough but too long or ran at a ridiculously high voltage, like 10 or 12 lipo cells when I'm only running 5. They all seemed to have very low KV numbers as well. If you have read the previous Massacre buggery related posts, then you will know I sang the praises of two different motors. These, along with a combination of other things put the weapon height quite high, like several miles too high to be useful or it any of the anything. Arse.

My good friend Morris was going on at me about the fact that my design was a little bit very stupid there were some easily fixable flaws that should probably get some attention. First up on the "things to fuck about with" list was the wheels. 73mm wheels were too mainstream were what a lot of the low low pushy bots used, and if I wanted to use them too, it would mean that my blade would always be higher than their wheels. BAD THING #1. 

After a bit of back and forth I decided I was okay with dropping down to 60mm wheels. Now, as you know the smaller the wheel the slower the speed. Massacre was set to be a fairly slow robot by current standards, but my driving ability is similar to that of a small caffeine fuelled monkey with ADD. Who is on fire. And is dead. Slow is good, means I can actually get the robot going in a way that resembles controlled motion if you've never seen it before and don't know what words mean. But the small wheels cut the speed down too much so that almost everything could out-drive/box rush me. BAD THING #2  

Ellis poked at me to go for different gearboxes/motors, everything from baneboobs to custom mega solutions. I think he was convinced the Magnum 775's were filled with wasps and all the evils of the world. I held steady though, and eventually (like 2 bloody days ffs) we made progress. I could swap out the motors from the Magnums ones which where 14.4v ones which I was overvolting to 18.5v to some 18v 775 motors that had a higher speed. This would increase the speed back up to where it was due to fastness but also increase the reliability as I would be running them basically at their intended voltage. GOOD THING #1

This had cut a little bit out of the height, but no where near enough really. This resulted in another Ellis and Harry throw shit around and see what sticks late at night. I'm not sure how, but I was convinced into trying a right angled gearbox once more, so much searching happened again looking for a suitable motor. Many were looked at, and most of those had one little flaw that made them useless or maybe I just have unrealistic standards, I don't know. Eventually we started looking at "inrunner" brushless motors, which generally are very fast but don't have quite as much torque. They also don't have the rotating can of outrunners. I think Ellis threw up a motor that looked almost perfect, 2350kv (qualifies as fucking fast) and 5s and 2400w. The speed was insane, and I would need a massive reduction to get the bar spinning at a sensible speed that would actually engage, but those were doable. GOOD THING #2
Now that I had the Wundermotor I needed to work out the gearing and *shudder* deal with the right angled gearbox. Now this is where Ellis came to the rescue again. Recently he has been moving out of the mudshack that was his old workshop (his words!) into his new building that I have named Fancyhut. Along with the swish new workspaceface he is shortly becoming the proud owner of a lathe. He may not have realised this, but I intend to abuse the fuck out of his new toy/mad skills. He, being better at general accuracy during building was a much better choice to attempt some fancy pseudo-engineering buggery that Massacre calls for. Indeed he has kindly dealt with most of the design of the gearing system, while all I did was sit around, play with numbers and listen to nightcore. I did name the thing though. The Ranglebox (so called because of its box-like nature and general rangleness) Looks so cool! Somebody give that guy a job. Seriously, he is such a bum he needs one. GOOD THING #3

Donde es mi Rangleboxen?
Super awesome chocolaty fudge coated Ranglebox in place I noticed a problem. It would totally tit up the battery mountings. I wanted to run two separate packs, partly because that would make sure neither the drive nor the weapon was being starved of power, but also it would mean I could reuse a pack I already had, saving like 60 quid. But I couldn't do this any more due to lack of space because of unexpected Ranglebox. BAD THING #3

Luckily after not too much searching I found a single pack that would fit and would have more grunt than the two smaller packs, more expense but it was pretty bloody cool. It really is like somebody injected the old pack with steroids, then injected the steroids with steroids. It is capable of a theoretical 390a cont.... now all ratings taken with a pinch of salt yada yada, even if its like half of that I still should be fine. Awesome. GOOD THING #4

Oh, and possible cool feature for Massy, the motor is sensored, so I'm going to try and experiment with sensored weapons. Would lead to some very nice spin ups. Nobody else is really doing this as far as I can tell. It may be a good idea, it may not. Can't hurt to experiment and I can always run it sensorless if it doesn't go to plan. 

Cheers for reading, if you did you must be pretty bored now. Now go outside and play. Also blame Ellis for the large amount of words. Bai. Haz.

Thursday, 31 October 2013

Little Miss Massacre

Ok so Massacre has had even more CAD work on it, namely some corner pieces and more bracing to make it as rigid and tough as possible, and the wedge shape was changed to free up some space and more importantly weight. I was bit worried about how well it would all work, the belts and the waterjetting  because, well. It's all big and scary for a guy who normally just screws plastic together. I forget how I actually came to start designing the beetle (apologies if it was you who prompted it!) But I set out to make a Beetleweight Massacre, trying to keep the processes and build techniques the same just smaller. I've named it Little Miss Massacre for now, as the beetles should be an equal opportunity class, and I might win if she distracts the boys with her shiny spinning bar of death, destruction and something else that begins with d (dragons!)  Now for some specifications on the lady in question, her base plate is 145 x 165 (Massacre 280 x 330) Which is a pretty decent size for a beetle I think, nothing will be a squeeze yet there won't be the several cubic meters of empty space like in dear old Eggbeater.  Her frame is a mix of 10 and 5mm thick 7075 aluminium with 1.2mm titanium base plate and 1mm carbon fibre lid (possibly, maybe more titanium if have the weight. The wedge will be 2-3mm titanium scrap I have.  The frame is a jigsaw puzzle style, exactly like Massacre. She is running 1000rpm "ebay" motors at 3 cell lipo, possibly 4 cells as with small wheels this won't be very fast at all. My other beetle, Eggbeater has a very heavy, fairly slow (4000rpm) weapon with an incredible theoretical amount of power behind it. Little Miss Massacre will have a fairly light, only 3-400g or so of bar but spinning 6-8000rpm powered by a small 400watt brushless outrunner.

Here you can see Little Miss Massacre in relation to Massacre and the Eggbeater CAD the other froody robots are old versions of a rather cool thing that Elvis was planning at one stage.

More on this when something actually happens...actually probably not, I'll probably post some more progressless progress before too long. Cheers anyway. Haz.                                                          

Post competition thing of eternal excitement and joy!

Stupid title is stupid. Anyway, last Saturday was the AWS and in no break with tradition I did not do particuarly well, but I massively enjoyed myself and that's what counts. I had the wonderful Joey McConnell for company over the weekend, he came down Friday and with his rather wonderful, if a bit lacking in the side department, robots. With such beasts as Arcus and The Hurting he had a quite formidable team. I had taken a rather pretentious way of naming my robots for this event, all of my robots were songs on the rather wonderful Sad Sappy Sucker by Modest Mouse. My team is shown to the side.

Four Fingered Fisherman
It was a mixed event, most of my robots having their first fight in the first round.. I think I lost all but one meant I went out of the competition pretty quickly. The standard of antweights is still rising, there were so many really quite good robots and I was pretty much totally outclassed. It didn't help that the controls were almost totally reversed on the robot that actually needed control.  I was able to pick up a much needed battery upgrade for the beetleweights, so soon Eggbeater will be running much better.
Blue Cadet 3, Do You Connect?


Well after the competition I know that I need to, as ever, practice my driving and if I'm going for a spinning weapon it needs to be rather good in order to keep up. Horizontal bars I think do have a very good chance with the competition the way it is at the moment. A powerful bar should blow the opposition away with a good enough hit. Running with this thought I watched a few videos of similar style robots and set about constructing something, just quickly and on the fly. It turned out surprisingly well. Insanely good maker/builder/techno wizard; Jim "the human cnc" Blunden  had kindly donated some parts of his old robots, namely the shell of Barbarian his old undercutter. This had a very nice carbon fibre chassis which has been press ganged into service one again. The bar I'm using is hand made by Jim and is fantastic...somebody give that guy a medal or something! I'm direct driving the bar using a quite large outrunner brushless motor. It spins nicely and should hit quite hard! The drive is 50:1 polou gearmotors and the wheels are 21mm dia Slot car ones (really soft and grippy)

Not really much more I can say really, there will be a fairly meaty Massacre/beetleweight update/ramble soon though. Cheers, Haz.

Saturday, 5 October 2013

Massacre: progress-less progress report

With shouts of joy and whimpers of apprehension I dive back into the maddening world of Massacre. What follows is an overly self indulgent semi coherent ramble about everyone's favourite non-existent, orange-wheeled featherweight.
As Massacre is being designed to be a show off (if I freely admit it, its not as bad, right?) robot. Showing off meaning I can do slightly  more than haphazardly screw HDPE together and add cordless drill motors. I got confused and decided that this meant that this robot had a budget of three quarters of a million pounds. Now, the reality is I've got about £3.50. I'm not going to totally cheap out on all the components in order to cut costs but some things have to change. The motor that I had intended to power the bar is a rather powerful and highly regarded brand of motor; a Scorpion. The one I wanted costs about £130-140. While this is probably a good investment in a quality product, it's still 140 smegging quid, so that's nearly £300 alone on a motor and spare. So fuck that sideways I needed to find something that is a little more...dirt cheap. God bless Hobbyking, that's all I can say. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=30602 $42, that is about £26-27 pounds so even if (or rather when for a 30 quid motor) it breaks down/blows up/turns out to be filled with wasps I can easily have a spare. Yum. It's slightly longer than the other motor, but no worries there, I can still fit it in.
 Now for some pretty pictures, I've drawn up the frame with its lovely slots and tabs and am just checking it fits together. The joys of emachineshop mean that I can print out the drawing of the part to size, and physically check sizes and whether or not things can fit in, in the real world. Bit time consuming but Massacre 1 taught me never to just assume things will work in the real world if they do in CAD. I'm a bit worried about the 10mm aluminium being too thin, but it *should* be fine. The grade it is should mean its stiff enough for a frame and that's really what matters with this.
Well here is slightly more Massacre pretty pictures, I find I try to keep loo kin at and tweaking the design every now and then to make sure everything still fits, works or is a good idea. Changes on this version are a new bar, pretty large which I think it does need to be, in an ideal world I would like titanium as that would be light, not particularly hard, but lighter and fairly tough. For ease, chances are it will be hardox and not have any of them fancy edges on it...unless someone offers their milling skillz for peanuts.
Also featuring on the super new chocolatey fudge coated Massacre is the rear armour. The arse plates are made up of sandwiched layers. This sandwiching of the arse plates (oo er vicar) should reduce the shock of any impacts going through the frame and buggering up alignments and things. Its a 10mm HDPE (soft plastic) plate with a 3mm bit of titanium I have pare over the top of this. Some rubber may end up being added to the mix along with mayonnaise and tomato just to make it a proper sandwich if I ever pluck up the courage to sift through the search results for "rubber sheet". Something tells me robotics might not be the first thing that turns up...

This is just me mucking about, I call this picture "when I grow up I want to be Hazard" or "They said I could be anything, so I became Brutality"

Tl;dr - found cheap motor, thought about rear armour, pissed about making pretty pictures

Thanks for reading, if you read this. Mind you, if you made it this far then  you are either insane, me or a hyper sentient gerbil sent back to the past to escape a nightmarish future or D: all of the above. Cheers!

Tuesday, 1 October 2013


Shane had very kindly got the Slaughterhouse arena set up at the RobotsLive event in Deeside on the 22nd and 23rd of September, so after a long wait we all finally got to have a bit of a bash about with our new machines!
Here you can see the temporary arena, its pretty far away from being finished, but its still looking pretty fucking cool. Lots of the features such as the sign and the scoreboards are not there yet, but its a lot better than nothing, and anyway the plan for this event was to see what works and what doesn't and boy, did I learn a lot about what not to do...

There was a very solid turn out, and a very good selection of beetles. There was the uber-axe of Dave Weston's "Headbanger"  and the solid, reliable lifter of Jamie McHarg's "Flatulence" with the brilliantly engineered RPM, 180 and cobra(?). Also there was my Eggbeater (details of fail coming shortly) and Gonzales made by some guy called Elivs or something idk, he came and ate all my bacon for a few days and I did all his wiring cos I'm a nice person like that. It was a pretty rubbish robot, with the weakest drive possible at this level... no wait.. the opposite of that; it used a featherweight drive system and was pretty much unstoppable provided it didn't cook its own guts.

Gonzales sans top. you can also see about 30% of headbanger and cobra(?)
Oh Eggbeater. Well to start off on a positive note, the weapon was pretty fearsome - not that it actually did any damage mind you but the thought was there and its heart was in the right place  Now for the bad stuff; the battery was so underpowered it wasn't even funny. I couldn't have the drive and the weapon going at the same time, which is kinda important. By the time I realised this and tried to cut the weapon to give me a chance of actually doing something in the fight I found
I only had one side going, and that was going very weakly. upon later inspection it turned out I had burned out a drive motor and esc... without fucking driving. Yaaaay. well done clever monkey, no cake for you.

And now for videos! 

Monday, 9 September 2013

Spins, wins and spiders

So I've been uncharacteristically busy the last few days, first thing was getting the beetleweights all ready to hand back over to Shane at the Euro champs at Norwich on Saturday. Friday evening saw me spin up the full body spinner "The Gimp" for the first time. I had not had a real chance to play with it before as one of the battery packs was legit dead. literally no life from it. Nothing. But it seemed to work fine on the one pack, better than it did on two for some reason I'm not clever enough to understand. It had enough juice to power the weapon.. but it dropped a bit and the drive esc went a bit jittery. No limbs were lost and no cockney orphans were harmed in the name of science so it was all gravy good.
You can see the glory of the full body spinner spinning here. That little motor is such a beast, spins up the 500g odd shell in next to no time. There are some amusing dethspiralz when I go too hard on the throttle. Some time near future there will be a single tooth and counterbalance assembly on it.. scary! All the beetles got a bit of attention on the benches, I'm really pumped to be involved right at the start of this totally kick arse weightclass
All the smaller weight classes, beetle and ants

Also what was totally kick arse? Me getting to control one of the heavyweight competitors. The wonderful Air built by Shane Swan no less. I loved it, I was sharing control with Dave Weston. He was driving and I was operating the flipper. In our heat we faced Storm 2 and cherub and with Dave's rather swish driving skillz we won. However an on-the-spot weight check showed that Air was over weight and we were "disqualified" so the victory went to Storm 2. Later on, in a whiteboard out positions were reversed and I was driving. Against Turbulence and Tilly?..something I forget, apologies.  This could only go all the well ever. Well, I wasn't totally crap. Weston's sharper reflexes helped with the flipper and we were able to get under the other two pretty easily even if I did forget how to forwards occasionally. We somehow won this on a Judges decision.
Me at the bench with the stupid haircut, Air is bottom right 

I took home a new pet
Spider bot, Spider bot does what ever a Spider bot does. Can it swing from a web? No. Its about 13kg.
The wiring needs to be totally re done and some new Lithium polymer batteries can replace the shagged NiCads. It sports a very nice walking mechanism. Slightly obsessed with it now. Its also just crying out for steampunk... I mean.. LOOK AT IT.

In other, less interesting news. I started collage today. A 2 year mechanical engineering course. It seems all well and good so far although maths might skullfuck me a  little. See how it goes. I'm fed up being stupid. I want to learn things now. Machiney things.

Ta. Haz

Tuesday, 3 September 2013

Massacre - Combat robot

A little bit of history. Massacre was my first attempt at a vaguely complicated, offensive featherweight i.e. a spinner. Of course due to lack of engineering skill/common sense/budget it didn't go well, in fact I think I might have actually made the worst spinner ever. It did a grand total of about 4rpm for a period of about 0.4 of a femtosecond. But regardless of this it won a couple of fights and qualified for the second stage.. where it promptly lost but hey ho, still better than my previous one win to two losses last year.
This was Massacre V1.0 The design is basically a copy of the very successful robot Hazard, except with all the functionality and destruction removed and replaced with..um..orange wheels and a stainless steel bar.
I still love the overhead concept and I still believe that they can be an awesome force if properly constructed. I'm just having major problems with that part. I'm starting a 2 year mechanical engineering course next week at collage so that should be able to, if nothing else teach me some nice useful practical skills and some nice bits of maths and physics.
Lack of planning and no real world experience with gears lead to the weapons failure. To combat this I've been planning the setup much more in-depth than before and will be leaving enough time to test that it works in reality. Here's hoping for >5rpm this time! General robot practice is to KISS, you know, Keep It Simple Stupid. That's all well and good if you want to build a boring winning robot, but I want cool shit.
6wd? Check. Overhead bar? Check. Hardox wedge? Double check. Now personally, I think this looks right smegging cool, over complicated maybe and it won't be a world beater, in fact it would not surprise me if this did worse than V1.0.

Parts for this are all major upgrades to the parts used on the V1.0 as I shall now compare.

drive: 4x GR01 550 motor gearboxes (drill motors in a slightly nicer casing) and 4x 73mm Banebots wheels
Power: 1x 18.5v 4000mah Lipo
Weapon: 2kg 10mm 304 stainless steel bar powered by a pair of speed 900 brushed motors
Electrics: 2x 30a electronize (model railway controllers?) (clunky as buggery) and 70a relays for the weapon
Frame: 20mm HDPE bulkheads, 6mm HDPE armour,4mm HDPE lid, 2mm titanium base plate and wedge.

Drive: 2x Magnum 775 motor gearboxes (650watt each), plus belting for 6wd and 6x 73mm Banebots
Power: 2x 18.5v 4000mah Lipos
Weapon: 3kg Hardox/similar bar powered by a  4020 scorpion brushless
Electrics: 2x 85a TZ85 botbitz esc and a 100a or so brushless esc for the weapon.
Frame: 10mm 7075 aluminium, 5mm 6086 aluminium, 10mm HDPE, 4mm Hardox wedge.

Since having 6 separate motors for the wheels would make the world implode with awesome  put me overweight I elected to have a series of belts and pulleys that would  give me the 6wd. Now when using pulleys you have to work out distances (lots of calculators and things available online) between the centres so you don't end up with too much slack or the belt being to tight. I first used this on the Beetleweight to see if it was reliable, and it was so not I put it to use on a featherweight (using larger belts and pulleys obviously) Now the pannels that make up the frame are high grade aluminium and they need holes drilled actually, which then need to be bored out to a large diameter to accommodate bearings. Now precision isn't exactly my forte so I would some assistance. I could get myself a hole saw and a costly sheet of alu to butcher or...
Enter waterjet stage left.
I have wanted to play with a waterjet FOREVER and now I get the chance. Now people knowledgeable in such areas mentioned to me that all the cuts and blow outs (holes, etc) really ramp up the cost so I came up with.. Ze Great Uberlump. Its one long cut around the outside, and only 10 holes so its not totally bank busting allowing me to be able to afford a better material. I do have to put a bit more effort into assembly, popping the panels out airfix style and filing them down myself. Not quite the jigsaw puzzle some people like.. but then again this is just a boring box. That just about covers it for now, when I get my act together and start the build Massacre will feature quite prominently here.

Monday, 2 September 2013

Or at least I try to.

This is not exactly designed to have any pleasure derived from it, its almost purely for my benefit, so if you are reading this, I assume you are me, in which case you probably need to buy milk and walk the dog. I find writing things down is an excellent way of problem solving, gaining inspiration and generally sorting things out outside the headbrain. My memory is extremely patchy at the best of times, and having a "public" place where my design and thought spam can be deposited may stop me solving the same problem over and over again and keep a vague order of my builds.

All right, onto my projects of late. The Beetleweight combat robot was going well until today, and even then it still had some problems. Main problem so far is the god awful weight distribution making the damn thing drive like some kind of horrifically impotent one legged puppy. Not good. having a 500g lump of titanium spinning 4000rpm may seem like a good idea for a weapon, and for a weapon it probably is. Its just that the 500g (probably closer to 7-800g once the motor/gearing are counted) is at one end of the robot.. and the motors are at the other. This of course leads to the drive not being all that great to say the least. Also adding to my drive related woes are the fact that one of the wheels is a couple of millimetres higher than the other! What the arse? How on earth did this happen; I put in extra super special effort to make sure the holes on both pieces were in the same place and I still got fucked over. If only I could CNC mill the bloody thing. Gradually filing down one of the front supports seems to be the only way to fix it, a weight on the back seems to push it down enough to drive okayish but that can't be done as I'm already on the limit. (a limit which has already been increased once... can haz 1.6kg now pls?)
Anyway, today's disaster was in me trying to weight reduce when tired. Using a large forstner bit I tried to hack out some grams from the HDPE front brace in a sort of ill fated mill emulation manoeuvre. To say this didn't work would be an understatement; it left the panel looking like the aftermath of some bizarre and deranged plastic surgery (sadly more or less what happened) But no big deal if it was ugly as all sin right, it didn't have to be seen by anybody? Wrong. Some complete tit had managed to mutilate the wrong side of the part, which would leave the horrible mess on the outside. I managed to bodge it and hope and it turned out okay.. its a little wonky and hole had to be re-drilled for its mounting but its more or less fine. This little bit of wonk however was enough to misalign my "carefully" drilled mounting holes for the rear armour of 3mm polycarbonate, so that had to be readjusted as well. I'm beginning to see why my drive might not be the best there ever was in spite of my care.
A bit of visual aid. You get how it fits together now, you can see the 10mm black HDPE part just behind the very nicely machined beater (17mm Ti) and the 3mm polycarbonate arse plate at the back. The wheel closest to you, the left hand side one is the one that is ever so slightly higher. Which makes me approximately all of the sad ever.
Well that will do for now, will probably post another thing fairly soon on this if there are any changes or developments.
Cheers, Haz.