Tuesday, 25 February 2014

Massacre build 3

Being more than a little bummed out with college and trying to figure out what direction to take with my life (can someone pay me to build things for them??) I needed to do something I enjoyed lest I go mad and murder everyone with scientific calculator.

Some parts of Massacre are very designed, while other bits aren't. I purposely did this to allow for reality to kick in as what works in my CAD and in my head may not be transferred to the real world. Designing on the fly always seems to pan out better than relying theoretical stuff. For me anyway. One of these parts was the Rangleboxen, which is angle grinder gears shoved into a prettier case a right angled gearbox for the weapon. Because running 2.4Kw through shady £4 Chinese gears is a good idea right?
Now for my next trick I shall attempt to turn this pile of components into a fully functioning gearbox for a remote controlled death machine. (AA batteries not included)
Chopping up some 10mm 6082 aluminum with a hacksaw because I am too poor for a bandsaw hardcore like that.
Ewww, non machined edges. Quickly someone mill that thing!
That's better. Skimmed it down to 50mm high, its 100mm long here; I then shortened it down to 60mm long. Also featuring is wundermotter and an array of measuring tools
After the digital calliper was press ganged into service as a ghetto lay out tool and a screw as a centre punch (wow such precision, much engineering) I had super legit markings and could go and bore the holes on the milling machine. WTF is up with brushless motors though. They all boast eleventy bajillion watts and infinite torque but then come with M3 mounting holes. Using M4 atm and may step up to M5 for more hardcoreness.
Vanity pic outside where the light was better. It wasn't raining for once but everything was sill a bit damp and very muddy. Trying to match up to my buddy Ellis with the legitness of our motor mounts. His is 5mm aluminium and nice and curvy with 12.9 high tensile M3 for added poshness whereas mine is a big bastard at 10mm thick legit aluminium with M4  bolts. Only stainless so I loose points there. I will be doing more work to my mount, M6 mounting holes and will try and put a pocket in so I can sit the motor further into the mount for strength.
Ghetto machining time. The boss on the ranglegear was being a right pain in the arse. Some silly non standard diameter OD so I couldn't fit a bearing over it. It was also too long and would have sat the entire Rangle assembly up too high which would have put the blade height up. Unacceptable in a silly low overhead bot.  A simple solution would have been to turn the OD down to say 17mm and stick a bearing around that. Super low profile. But to do that I would have needed a lathe and Ellis was too pussy sensible to want to do mystery hardish steels with a machine that isn't totally rigid. So my other option was to lop a couple mm off the bottom of the boss on the mill. It's shit like this why I'll never be an engineer.
Crap photo but you get the idea. How are you gonna make the bearing pockets without a boring head Harry, they are kinda important? Well person who is not me, the sensible thing to do would indeed be to buy a boring head and use the right tool for the right job. But that is quite expensive (promise I'll buy proper things soon) My plan is to beast out most of the material with a big fuck off drillbit, then ream the hole to 26mm. <£20 solution and it should sort of work. A bit. Maybe.
Back to H4XX0Ring up the aluminium. This time 15mm thick 6082 which is what the robot is totally made out of because who needs underweight robots amirite?
The two outer bulkheads rough cut. A few years ago this would have been job done. Ah such memories. Now to shoehorn these bad boys onto a hobby sized milling machine! *dreams of Bridgeport*
I worked real hard to contain the maximum amount of cringe in one picture. Proper machiney people have probably vomited in disgust at this point.
Thankfully I didn't died. I still have all my fingers and now have a slightly more robot shaped robot! Luckily all the rest of the work can be done in the vice and doesn't require any massively dodgy setups. No more angles for me. Box with a weapon from here on in.
Pretend-O-Bot evolved. It's still 30mm wider than it will be but it has the beginnings of the wedge now. Temporary shafts in place still. I like this robot. The lowness is really appealing. Its made it a right pain though. speaking of which...
Why are the drive motors covered in masking tape? Harry? Well due to the small wheels and general lowness of the frame, I only had a few mm of ground clearance, which in a real world situation is a bad idea and would leave me grounded if the floor panels got bent up or there was a lot of debris or shrapnel in the arena. How to gain some ground clearance without major changes? Hmm well I could pocket the base plate so the motors sit lower down but the baseplate is hardened steel. Basically unmillable for me. So I had to get real creative.
harry... wut r u doin... stahp..

Yeah so I'm milling my gearboxes, all the cool kids are doing it. Don't judge me. There is an unnecessary 2mm or so of material that can go without any adverse effects to operation. Good enough for me!
For this I had to bust out my cutest set of parallels. Big hand for chibiparralels everyone.
Well, somehow this actually worked. No idea how or why but it did. I take that as a good sign for Massacre. Done all 4 motors without any hitches. Quick blast off a battery shows they work as new.

Well that's it for now. Long and very picture spammed but it could be interesting or useful if you are that way inclined. I'll post again when I've done something else.
Cheers, Haz.

Friday, 21 February 2014

Massacre Build 2

I bought some aluminium.

I paid for the cutting on the bars.

I took pictures.

Holy fuck I actually did things? Something is wrong here. But yes, Massacre went from an idea in my headbrain and in CAD to semi Pretend-O-Bot in a day or so. I was happily bumbling away in the shed working on some motor mounts for Shane Swan's beetleweight "RPM" when my Dad knocked on the door struggling under the weight of my lovely aluminium package. Needless to say it was ripped open pretty sharpish!
The 15x50mm bar was unavailable so I ended up with 2" by 5/8", imperial-bot go! Also, instead of 2" square bar I got sent 2" diameter round. Bugger. That has put a slight hold on any gearbox making, I've sent them an email to try and get it sorted. If not I can ghetto up a box from 10mm plate pretty easily.

Well, I've been playing around with it, just getting a feel for how roboty it is. Rough lay out (none of the components are in their correct positions) Can't get over how low the frame is and the really scary part is that it won't be getting much higher. Such is the life for a robot that needs a low weapon. Speaking of which, the blade height looks to be around 70mm or so, hopefully enough to catch a few of the low wedges.           

A bit more pretending/picture spam. Added in the weapon motor and rangle gears and a random bit of steel round to be Shaft Simulator 2014. The frame ends up 30mm narrower than this when actually assembled how its supposed to. Can't really do that just yet as I haven't marked any of it out to carve up on the mill yet. It will be interesting to work on to say the least. Oh and in the last picture there is a piece of carbon fibre to add poshness and professionalism. That's totally how it works right? Battery is a 5s (18.5v) lithium polymer.
Now why did we need to see another pointless render of Massacre? I hear you cry noiselessly. Well its because of the bar. It's happening. Like really. wow. A very kind and extremely helpful roboteer named Mario was good enough to sort out material and cutting of the bar out of  8mm Creusabro 8000 which is a steel similar to Hardox or Bisalloy. I've nicknamed it "Come-at-me-bro" for now. In a week or two I should have 3kg of spinny death, which is always nice. 

Cheers, Haz.

Tuesday, 11 February 2014

Beetleweight Build

Began the rebuild of my Beetleweight combat robot, Eggbeater. It has changed a lot since last time, namely the 4 wheel drive and proper armour. That CAD picture might seem familiar, I've had a similar one knocking around for ages (that one looked less garish) but I've had to change out the nylon for some blue chopping board. The reasons for this are cheapness and blueness. Valid reasons as I'm sure you'll agree. Now of course I don't expect chopping board to perform anything like nylon, and I shall probably change it out fairly soon (after it explodes in it's first fight most likely)

This was after the first day of building, first I jig-sawed out some chopping board blocks, then cleaned them up on the milling machine. Then I marked out, drilled and bored out the holes where they were needed and the pockets for the motors to sit in. Then I machined the rest of the frame into shape. The curves on the back were fairly simple to do using a jig I had already made up. The curves around the weapon mount were more difficult as I had already bored them out to 26mm to fit the bearings. I hole-sawed out a 26mm plug to sit in the middle of the hole, sanded a few tenths of a millimetre off it and lubed it up. It worked great.                  
These are some rather wonderful pulleys that my good friend Ellis made up on his lathe. Every time I need round parts I just bully him until he makes something shiny. Here are 5 (4+1 spare) drive/hub pulleys, one slightly shorter one to fit on a brushless motor and a large pulley to fit on the eggbeater weapon.
The drive pulleys are actually pretty clever. The wheels I want to use are Banebots ones, which have a 1/2" hex bore. The adaptors for which are too bloody expensive for me, so I thought I would have a go at making my own hex adaptors onto the body of the pulleys (why they have quite a lot of meat one end) I poked the numbers and grudgingly did some maths and began making chips.
Here is the robot with all the pulley blanks on. Just to test the pulley groves I slung a couple of hair bands on as to be pseudo belts. Well it certainly looks like a thing!

Ok well that went better than expected. The pulleys have now been fully "hexifyed" and have been pressed into the Banebots wheels. I made the hex slightly oversize so the press fit would be pretty fookin tight. You can also see where I added a grubscrew by drilling and tapping a hole in the hex so it fits on the "D" shaft of the motors without slipping.

Here you can see the parts of the robot being put together. I made the belts up from some material kindly given me by the multi AWS winner, Scott. The belt was cut to length, then using a jig clamped in place and melted together to create like a large O ring belt. Works surprisingly well although it needs to be tighter than I thought. I think I can cut another 5-10mm out of the belt length and improve the drive.

That's pretty much it for now. I need to get the armour made when my aluminium arrives and source some thin carbon fibre or .5mm titanium for the base plate. Will update again soon with either more of this, or some Massacre.
Cheers, Haz.

Friday, 7 February 2014

Massacre build part one

That's right, build!



Ok well I haven't started attacking metal yet but by the time this gets read I'll have ordered the material for the frame. I did however do some work on the wheels, and wheels are kind of important for a robot. Taking the rather swish nylon wheels that Ellis made (that I still haven't paid him for, oops) and getting the tread put on them. The wheels are 30mm wide and handily the bike tire in question had a 30mm wide bit of tread with the same pattern (different patten either side of it) so I could make some snazzy looking wheels. We had a bit of a worry weather the screw heads would stick up further than the tread but it turned out to be fine. I only stuck a couple screws in because I'll have to take the tire off to press the nut into the wheels so it can mate with the drill shaft. Pics:

Yep, those are definitely wheels. You may be wondering why exactly I decided to stick the tires on before pressing the inserts into the wheels. My awns er is because A, I didn't have any inserts yet and B because I wanted to have a propperish looking pretendobot.                                                                                      

There you can see Massacre roughly being formed with the wheels of wheelyness and the shaft of chunk (which will be cut down a lot to stop it being so massive and chunky)                                                     

That's all for now, probably more progress next week. Cheers, Haz.