Skipdiving Robotics

[Danny B]

Sometimes the ghetto way is indeed the best! I must admit, I have a slight advantage in that I work as a metal fabricator, so I have access to sheet metal and the equipment for cutting and bending it however I want. But I really admire people who don't let lack of resources stand in their way!

And in case you're curious about the paint job, I haven't even finished yet. I just wanted it to look dark and demonic, hence the robot's name; It's half Japanese, half Spanish, and literally means 'shadow machine'.

[daveimi]

Your name is well cool! Are you still coming to Doncaster Dome? How are you planning to attach the metal to the plastic body? (always up for nicking ideas!)

[Danny B]

I'm definitely still coming to Doncaster, I've come too far to miss this opportunity!
As for the armour, I'm making the metal shell separately (since it's bigger and encloses the wheels), then attaching it into the original screwholes used for the plastic lid. Here's what it looks like with the shell on.
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[SamO]

Looks like a pretty good first robot Dan

[Danny B]

Thanks

[daveimi]

That looks really good!

[Danny B]

Thanks! I'll be interested to see what yours looks like when it's fully decorated!

[daveimi]

Well I've been up to all sorts over the last few days. First sticking point was failsafing modes but that's sorted now, taking transmitter apart was a bit hairy! I undercoated Rag N Bone and have painted it, I have a feeling it may want another coat. I've made a removable link and finally found a method to attach it securely enough so that the hole thing doesn't come away in my hand when I pull the link out! I'm going to put that on the robot this week at some point. The thing I'm most excited about though is I've managed to get hold of a fully working electric wheelchair! I've been flying up and down the driveway on it till the batteries went flat. Haven't laughed like that in a long time. Anyway, I've started sketching heavyweight ideas, favourites at the minute are a bigger version of Rag N Bone with a movable spike, or something completely different like a big thwack bot. If it were to be a thwack bot it'll hit side to side as opposed to up and over like Saint and Stinger. I will photograph my doodles at some point no doubt. Anyway, here are some pictures.

[Danny B]

Wow, that looks very impressive! Can't wait to see it up close for real!

[daveimi]

It's pretty naff lol, loads of stuff is exposed and I'm not really that into it, I want to add some more to near the wheels to cover it up a bit better. But the robot thing is going in the right direction and I'm sticking with this design just adding to it between now and Doncaster. I need to add my removable link and LED in still at some point. I've been getting distracted with ideas for a heavyweight but should really concentrate on Rag N Bone for a bit before I start cannibalizing the wheelchair. I didn't know whether to build a bigger version of Rag N Bone.

[Danny B]

Well, if you're looking for extra armourment, I would recommend using Perspex. Since it's fairly strong and less than half the weight of even aluminium, it's good if you don't have much weight left to work with. Also, I might recommend adding some extra weight to the end of the arm to give it a bit more momentum when you're spinning.

As for the heavyweight, how fast does that wheelchair go? I reckon if you want a competitive bot, it needs to be capable of at least 12mph. Do you plan on adding some extra battery power?

[RogueTwoRobots]

Perspex is a big no-no in combat robots, far too prone to shattering.

If you're after clear material, polycarb (Lexan/Makrolon being brand names) is your best bet.

[Danny B]

Fair enough. I'm glad you mentioned it, I was about to use it on my bot too!

[daveimi]

Haha glad you mentioned that about the polycarb! Yeah well originally the spear/arm was going to be a home-made hammer/axe with interchangeable heads. Then after trying it out the spike got under everything great and you don't really see it in the vids but it's quite quick. So you sort of scoop under stuff and keep accelerating and smack it into a wall etc (well...at least my old tool box does!). So I placed all the components the opposite side of the axles to balance it out with x-box style steering on my transmitter. It's super controlled and maneuverable but I did really want a thwack bot lol.

The wheel chair is quite quick, jogging pace really, so at a guess I would say 8mph? I can't make anything really accurate (axles/gears/bearing blocks etc.) so my secret technique to robot building is to buy in the hard bits pre-built ie. gear-motors and speedo / receiver and make everything else out of found parts. In Rag N Bone I bought the motors, speedo and radio gear and built the rest from found parts. The plan is to build a heavy in the same vein. I know there is a lot of specific stuff recommended, but you be amazed at how thrown out industrial racking can be turned into box section and shelves into 3mm sheet steel. The plan is to cut out the frame of the chair where the motor assemblies bolt up, and work them into a new base plate. The wheel chair was only £30 so that's my motors, gearboxes, wheels etc sorted, now the scrounge is on for speedo and batteries. But other than that I find everything I need in bins lol.

I'm just trying to sort out a half decent shape / design and will set to with the heavy, big decision at the minute is which weapon, or just build something passive as a first go.

[Danny B]

Why don't you just drill a horizontal hole in the end of the arm and use a pin or bolt to mount some heads through that? I used a similar technique for the chisel weapon on mine, only it mounts to the crossbar between the front stumps instead.

As for shapes etc for the HW, I personally prefer the method used by the Razer team; Design the weapon first, then build the chassis around that.