Team Shakey - Axebot

[Shakey]

So my emergency Maidstone robot (An adorable Kitten) was pretty fun and seemed to get a few laughs despite my fear of Major Damages new flamethrower, but I need a proper robot. So (Since I never posted any) this was AAK after the Maidstone event feeling worse for wear.


And the absolute mess of wiring:


And I am replacing it with an Axe feather weight.
The plan is a Speed 900 powered Axe (Driven by a H-Bridge), 2 gimson 18V 36:1 GR-02's on 75-100mm wheels, 2 electronise speed controllers (Taking them out the old robot), 6S LiPo. All packaged in a 5mm steel shell with Polycarb top and lights... lots of nice lights.

Some initial Pictures:




The axe mechanism was provided by Maddox and is nice and light. The axe head is quite a nice bit of high carbon steel, the spiked side seems to breeze through HDPE without much effort. I plan to have it so I can turn the axe head around to have either the flat or pointed edge as my 'Attacking' swing.

The robot will have blue lights so I can see where it is in the arena, but for the audiences fun whenever I fire the axe it will flash to the red LED's.

Cheers,
Shakey

[Shakey]

*cough* Well I think I thumb twiddled long enough. In the buildup to The Fleet air arm museum where I aim to be running this I have been getting a good deal of work done.

I have the rear armour on, a battery box made up and the front armour and small scoop started.





I was planning to slope the front armour but I decided that in reality I wanted a different chassis design but am finishing this one for Air Arm so i can have a robot and then spend more time on a proper chassis after. The axe will be controlled via an Arduino and a TZ85 with motor braking removed, it will also use the gear channel of my DX6i to remotely arm and disarm the axe for safety (particularly in roaming robots where the link would be put in outside the arena).

The scoop will be fairly short, the aim would be to wedge it under an opponent and then fire the axe sandwiching the other bot between the two, but if it can't get under I should still be able to hit them.

Just got to finish the front and then the extra side armour. Add in a HDPE 8mm top and then wire it all up.

EDIT: I am actually looking for a more powerful drive system for the next iteration, what sortof thing would one have to do nowadays to get S900esque drive but not S900's as they are near impossible to find.

I haven't ground down the welding on the front yet.

[Shakey]

Getting a tonne of work in to try and get this running before yeoville.

Chassis is very nearly done. Just some brackets here and there to be added. I switched the battery box to the other side and turned the axe around. Slightly less rotation but it means it is 'in' as it were when the axe is back so I should be less vulnerable and drive a bit better. Also means that the axe may struggle with taller robots. Also gave it a quick spreay as after loads fo grinding and weld splatter it was looking a bit rough! The Arduino controlling the axe will sit above the two TZ85's that are next to each other and the receiver will be there aswell.




I changed the wheels to a pair with a larger diameter to sort out a slight grounding problem and also to improve grip. Now to add a lid and backstop then wire the thing up!

It isn't pretty but for a second feather *cough*third*cough* (first never saw combat) it's alright, and a huge improvement on the first one I competed with which had 2 out of 4 motors working after just a few fights.

Though my day trip to Gadget Show Live and watching the champs leaves me a little scared :P

[razerdave]

You'll be fine Alex

[Shakey]

Gimli did quite well at the Fleet Air Arm museum!

The axe performed better than I expected leaving a few dents about and putting a few holes in Richie Some noise issues to be worked out though. Managed to win 3 of my 7 fights including pitting another robot which I was pleased with. Had an axe off with LH3 though got stuck upside down (was against the sidewall so no self righting) and attempted to take on Beauty but suffered a failure in one of the GR02s powering the drive (bike tread came of the wheel jamming the wheel and stripping a tooth in the gimpson, this then blew the motor). I have repaired the motor using an old GR01 and have improved the securing of the bike tread on the wheels.



Going to work on the scoop a bit so it can be more effective and on the lid. I'm going to try and improve cooling inside the robot aswell. I got a few suggestions on how to improve the axe control like using a polulu board with the arduino.

The event was great, one of my favourites. Nice and relaxed with plenty of time to socialise and look at the other robots. The arena under Concorde made for a great setting with an interested bunch of onlookers. If anyone has videos or pictures for the event any links would be greatly appreciated! Especially a picture of Stanley and Lionel (two antweights) going head to head in the arena.

[Shakey]

Spent a bit of time improving the front scoop part of Gimli to hopefully help it out in combat a bit:


Started looking at taking the noise out of the axe system so I have better control of it as well. Added some reinforcement to the side triangles which stop people ramming my wheels front on. The rebuilt drive motor works but overall the drive train sounds a tad rougher. Starting to look for alternatives to the GR02's, not overly impressed by their reliability. The nuts on the inside of the battery cover have now been arc welded in place (Interesting task arc welding something so small), no more nuts falling out in fight, the lid also now has the full 3 bolt complement holding it on.

Also while stripping the axe down to work on the robot I found the ali gear in the middle was already showing some damage to the teeth so I am going to order a steel gear to replace it with (I can afford the weight).

[Rapidrory]

Damn, that's a lot of thumb twiddling!

[Shakey]

Well I decided after a good performance of Gimli at Guilford, even managing to put a few holes in bots, to give it a spruce up. So the electronics inside was seriously neatened up. The robot given a nice paintjob and 2 new headlights so it can find it's way around the arenas and see what it is hitting!




I only need to remount the power LED next to the link, mount the link properly and add in limit switches and Gimli won't need any work other than maintenance for fighting.

Although a quite urgent matter of having to replace the ali gear in the axe drive is apparent. It is getting absolutely mashed from the continual shock of hits. Hopefully I can get a steel one and get on a lathe and switch it out.

[daveimi]

Like this Which voltage do you run the axe on? I'm not very good at working out LiPo voltages...

[Shakey]

Like this Which voltage do you run the axe on? I'm not very good at working out LiPo voltages...

6 cell so at the start of a fight it'll be 25.2V (About 24V at the end). Quite overvolted and the S900 is always quite warm at the end of the bout. The drive is only allowed 60% power right now to stop it dying under the overvolt.