BTEC Level 3 Project

[Shakaka]

Hello,
As part of my BTEC level 3 electronics project I am thinking of building my first ever robot, a featherweight (something I have always wanted to do and I think the the college would prefer a feather to a heavy!) After thinking of a few ideas I have decided that the most likely route I'll take is an electric axe bot.

For the drive motor I will most likely use the good old Argos drill motors for drive motors (unless anybody knows of an alternative that will work just as well?) and the armor will be HDPE along will any bits of scrap metal that my work will allow me to use.

For the axe I was thinking of a 200W scooter motor (see link below)
http://www.ebay.co.uk/itm/ZY-MY-1016...4AAOSwnONZCuJa

Would this motor work well? I have never done this before but after some research, this seems like a good choice.

I have a few questions:
What size wire will be best to use for all of the electronics within the robot? (although I am an apprentice electronics engineer i have no idea :P)

What batteries would be best to use? I like the idea of lipos but i know they can be quite dangerous so what is the best alternative?

What are the best wheels to use and also, what is the best way to fix the wheels to the drill motors? I have watched Ellis' video about using heat to melt some nuts into the wheels but is this the best way to do it?

Also, I know nothing about what speed controllers to use...

I am a complete newbie and have never done anything like this before. I have wanted to do this for a while and this BTEC project seems like the perfect opportunity to do it.

Money is a little bit of an issue but I don't want to make it too cheap and for it to end up being terrible.

I hope people dont mind getting bombarded by questions but I want this to go well :P

Thank you,
Owen

[Shooty]

Well from one newcomer to another, welcome to the board! I Won't be able to answer everything, but I'll see what I can do.

200W seems to be alright for a motor, I know there are a few other builders who've made FW axe's that would know better. This link might help, it's a FW axe mechanism that was for sale. It's been sold, but it's got a lot of detail to learn from, such as shape and parts: http://www.fightingrobots.co.uk/thre...hlight=feather Also be aware that the axe motor is 24V while the cheapest Argos drills are 12V, so keep that in mind when deciding on power.

Lipos are bad when they go wrong, but in FW combat it seems to be rare: at least far less likely than a HW lipo catching fire. The benefits of a Lipo are too good to ignore provided you keep an eye on them: outside of combat, you'd see plenty of warning signs if a Lipo was about to go, such as the pack puffing up.

I believe that Ellis's way is the cheapest, but another alternative I found was Banebot's wheels. They're orderable online, and very useful for Beetles and Feathers. Jamie of RogueTwoRobots made an excellent video showing you how to fit them onto a bot:

So long as you have a grasp on what size the parts are that you want to use and know where you want them, the next step would be to just build a CAD of the design, work on it and/or show it off in a build diary thread to get feedback. Hope I've been able to help out.

[Andy]

Good luck! I built a featherweight as level 3 BTEC project and I think a mate did too, got me a good grade too to be fair

[Maxamuslead]

good luck to you

For ESC i would suggest either looking at botbitz either the 30a or 85a. You can buy them ready to go but it might be better from the BTEC point of view to hack your own Tz85a.

Wheels you can either make your own which is cheaper but harder to get them balanced (if thats the right wording). I got 4 Banebotz wheels from Robotshop.com for a £10-20 with shipping. Depending on how much time you have it could be worth making some CAD designs which again might help you from a BTEC point of view.

[Shakaka]

good luck to you

For ESC i would suggest either looking at botbitz either the 30a or 85a. You can buy them ready to go but it might be better from the BTEC point of view to hack your own Tz85a.

Wheels you can either make your own which is cheaper but harder to get them balanced (if thats the right wording). I got 4 Banebotz wheels from Robotshop.com for a £10-20 with shipping. Depending on how much time you have it could be worth making some CAD designs which again might help you from a BTEC point of view.

I know nothing about cad í ½í¸œ and how would I go about hacking the ESCs?

[Shooty]

Ask and ye shall receive: http://www.fightingrobots.co.uk/thre...-spektrum-dx6i

[Piggeh]

Having just completed a BTEC Level 3 Extended diploma ensure that everything you do will fit the marking criteria, your teacher should be able to give this to you. Get yourself a copy of Fusion 360, its free for doing your CAD modeling and is quite easy to learn, lots of tutorials online. You start with a 2D sketch, then extrude and cut into more shapes. Model all your components (some models can be found online such as GRABCAD) at least roughly so you can move them around to get an idea of the shape of your robot. Look into H bridge circuits, these are essentially how you will control your motors, you don't need to make your own and I wouldn't recommend it, but you should have an understanding of how they work to show how you chose what components you did in your report. Download the FRA build rules , these will help you with things such as LiPo safety and removable links, put the file in the appendix of your report so you can refer to it in your report. If you don't want to use LiPos you can use the drill batteries, they're only 1 amphour or so but will be good enough for the project. Research all the options and justify them and you'll be good.

[Shakaka]

Having just completed a BTEC Level 3 Extended diploma ensure that everything you do will fit the marking criteria, your teacher should be able to give this to you. Get yourself a copy of Fusion 360, its free for doing your CAD modeling and is quite easy to learn, lots of tutorials online. You start with a 2D sketch, then extrude and cut into more shapes. Model all your components (some models can be found online such as GRABCAD) at least roughly so you can move them around to get an idea of the shape of your robot. Look into H bridge circuits, these are essentially how you will control your motors, you don't need to make your own and I wouldn't recommend it, but you should have an understanding of how they work to show how you chose what components you did in your report. Download the FRA build rules , these will help you with things such as LiPo safety and removable links, put the file in the appendix of your report so you can refer to it in your report. If you don't want to use LiPos you can use the drill batteries, they're only 1 amphour or so but will be good enough for the project. Research all the options and justify them and you'll be good.

Thanks piggeh, thats a great help! I will have to have a play with fusion 360 to see if i can get to grips with it!