Sunday, 19 January 2014

Milling.. sort of

Something actually happened robot wise, several somethings in fact, which is a nice change. Ellis decided to grace my presence with a visit in which we talked a lot of shit and did a small amount of robot poking. We would have done more but some tit decided to leave the tires for the wheels in Essex or some such place. At least its gone from the parts for the wheels being spread across two countries to being spread across one. Yay geography.

The wheels themselves are rather brilliant I must say, lovely finish  and they are all within 0.2mm of size.
Ok so I don't need 8 but I want 8, so there! The spares will be handy with my ability to design robots without armour or wheel guards or speed or manoeuvrability etc.

Well I got Massacre roughly layed out to just check if the CAD had errors that I'd missed. Just drew the base roughly on some chopping board in marker pen; it will be hardox for the real thing but not as thick. Damn this thing is tiny... But at the same time it feels quite big? What is this magic? Ah well too late to monkey around with the design any more. It's a bit too late for that. I'll get the aluminium for the frame ordered early February probably. 

Also,  NEW TOYS. Ahem. Mill happened and gosh darn it it's pretty. Not all bells and whistles but its a very very nice machine and I will love it forever, promise. Took a few days to get set up due to college getting in the way (engineering getting in the way of machining)
Spent a bit of time cleaning and generally poking the machine to check levels of niceness. It runs very smooth and is increadibly quiet. Yet to do anything precise with it yet as I don't have a dial indicator and other related items.

With no real devices to ensure any kind of accuracy I forged on ahead just to make some chips and actually make something. These are just some trial beetle bulkhead for a drum/beater. 4wd with two motors and belt driven wheels. Frame uses slots to hold itself together and has a little pocket because I wanted to see how that would go. 

Yay, its looks like what it is supposed to look like!

This was really very fun to make, I'm enjoying the mill so much and I don't even know what I'm doing. 
The machine blows through nylon and HDPE, although I much prefer working with nylon at this stage. Being slightly harder has its advantages. For reference, the black bit is HDPE and the bluey green is nylon. Commence picspam!

 Cheers, Haz.

Thursday, 2 January 2014

Reality happened again

Cost cutting, Yaaay!

Yeah I sort of realised that I had managed to spend about 8-9 months on the design of the robot, leaving me with a worryingly short period in which to actually build the thing. Then I realised that I had even less funds than I thought, due to me not actually having a job atm (can have a job where I build things please, thank you)

The only option was to build Hazard and Brutality at the same time and call it Massacre!

Here you see the first version of the non 6wd design times, basically
exactly the same components as last year's massy. Same drive motors, same ESC and same battery. The weapon system is the new one, because I have the motor already. The gearboxes will be changed from 36:1 to 24:1. This brings the speed up to about 6mph, slow due to the small wheels but with the large weapon at a low height, I don't need massive speed. I know the belt is kind of screwed up... I changed lengths and couldn't be arsed to change it
 it's like it in all the CADs. Yay laziness

The frame is still aluminium, but no longer 7075. Due to expensiveness and companies ignoring my quotes. It has got a lot thicker though, its 15mm 6082. Still keeping the finger joints though. To support the motor shafts even more there will be an additional bearing in the bulkhead as you can see.

Now this was all going very well for the cheap design, even better when I was very kindly sponsored some ESC's by another roboteer. These are Botbitz TZ85 which offer much smoother control than the clunky Electronize and are much smaller. The orange wheels which kind of became a staple in the Massacre designs are Banebots wheels, very grippy, but not all that durable, and fairly costly to boot. With the rather un-wonderful restraints I'm working too, these sadly had to go. Lucky for me I know a guy with a lathe. I mean, he happens to live in another country, but that's easier to deal with than £4 a wheel when I need at least 12!

Anyway he was kind enough to go out and sample the local bike tire collections until he found these ones, which are pretty perfect. Not the massively lumpy off-road tires, but a nice balance. These will be screwed to nylon hubs that will be turned on his lathe. They end up 60mm diameter and 30mm wide, small and with hopefully moderate grip.

And now for something completely different: Beetleweight motor mounts. The appeal of something simple, like a basic wedge (NOT just a plain brick) was too much, so I set about trying to build something. First off I needed a solid way of mounting the 1000rpm ebay motors. A few quick drawings in CAD and I had a plan. Worked out well. If it interests you, there is a video of the making of the mounts. Nothing special, but they work for me.

Picture of the finished mounts here. They are made of 12mm thick nylon. I would like to maybe make an aluminium pair for extra strength. Or maybe even some of the chopping boards I have.

Speaking of chopping boards I realised the other day that if I get the mill, antweight frames become very easy and interesting indeed, and I can do some really cool stuff with them (I give up on competitive antweights) This leads us on to a cluster bot idea I had, Chalk and Cheese. One piece frames made out of the yellow and white chopping boards i have, speed hacked servos and say 160mah lipo cells should have a fun little joke entry that will be pretty solid.

See if something can actually be built soon. Cheers. Haz