Help with choosing parts for a first robot, please.

[Garfie489]

Id recommend a DX6I aswell, just simply because if you ever become interested in the sport it will work out cheaper in the long run.

Also about Links, definitely use one. Much harder to get stuck inside a robot, and if it catches fire theres something nice about holding a little bit of wire to let you know its otherwise all safe :P - plus you will need to use links for the battery, so whilst your doing it you may aswell.

Also, check out the following link for ESCs and Threaded bar - will help with structure and reducing Australian postage

ranglebox.com

[RogueTwoRobots]

Hi Dominic, here are the links to the conversion gear I was talking about earlier. The basic principle is that you solder (or join with connectors if it's easier) the 2.4GHz conversion module into a transmitter of a different frequency, such as 40MHz, and it then transmits on the 2.4GHz frequency. There are three simple connections that need to be made. Positive, negative and signal/PPM.

The positive and negative connections can be easily made as there are many points inside a transmitter on the circuit boards and wires where you can connect to. The signal/PPM wire can be a bit trickier to find, but if the donor transmitter is, for example, a 6-channel Futaba model, they are usually pretty straightforward.

The conversion, or 'hack', module: http://www.giantshark.co.uk/product/...ication-system

You'd also need a compatible receiver;

4-channel: http://www.giantshark.co.uk/product/...ceiver-v8r4-ii
8-channel: http://www.giantshark.co.uk/product/...annel-receiver

And then you'd need a donor transmitter. This is the Futaba Field Force 6 transmitter. I've converted two of these (and a Skysport 6) to run on 2.4GHz and they do a great job: http://www.ebay.co.uk/itm/RC-Futaba-...item2c98680bb0

Unfortunately that's a bit of a higher price than I got mine for a while back, so if you add on the cost of the conversion kit and receiver, it would bring the total cost to around £100 (give or take with P&P). On the whole, that's still a good price for a 6-channel programmable transmitter with six different model memories (allowing specific parameters to be calibrated for up to six different robots). When converted, you can also 'bind' this transmitter with multiple receivers so you can use one transmitter to control several different robots (not all at once!) much like the DX6i. However the added work required to convert the transmitter may mean that for a beginner such as yourself, getting a 2.4GHz radio such as the DX6i may be more tempting as it's all ready to go. Just wanted to offer up an alternative though as the failsafe and bind processes on FrSky gear is ridiculously simple and proven in the arena.

Where in Scotland are you based? The Kinematic Events beetleweight shows will be at a few Hungry Horse pubs in Scotland in early August, and Robots Live are probably going to be at the Glasgow Comic-Con at the end of September if you're looking to get along and watch (or maybe compete in ) some robot fights.

[mrsam]

Welcome to the forum Dominic, probably a bit late now but i'll share my experience. My first event was the UK champs last year and my robot did absolutely awful, despite that i learned so much from that one event that i was able to build a fairly competitive robot this year. Whether your robot is up to the task of fighting or not i would suggest trying to get to an event and put it in some fights, it'll probably lose but it gives you the chance to see how it performs and any problems will show up immediately.

With regards to radio gear, i went for a very cheap Blade tx and whilst it does work it's far from ideal and this year in particular it failed and my robot went into a full speed spin whilst me and another roboteer were leaning over it. Alex (Eventorizon) was kind enough to lend me his Dx6i and i have to say they are well worth the money, very easy to use and just an all round fantastic bit of kit. I used that with an Orange r615 from Hobbyking which is a great, cheap rx, didn't mis a beat all event.

I hope your build goes well, you've definitely come to the right place though, everybody here will offer advice in bucket loads and there is a wealth of useful info to be found reading through build diaries.

[dotDominic]

Thanks very much for all these responses, guys! I've been combing the internet for information about this for the past 2 - 3 weeks, and for whatever reason never thought that the Fighting Robots Association forums would have information about fighting robots!

I'll go ahead and get a Dx6i, then. Building robots is something I've wanted to do since I were a little tot watching it on TV, so I don't think I'm going to lose interest anytime soon. (I'm more concerned about running out of money for this rather than running out of interest.) And I'll definitely include a removable link, thanks!

@RogueTwoRobotics
I live in Perthshire, and by the time Comic-con is on I'll be at University in St. Andrews, so I'm not sure if I will be able to go that. :/ Are there usually any events here in Scotland? I thought they were pretty much always in England, so I've only been to one in Barnsley about 5 years ago. If there were any more local events at suitable dates I'd definitely go, competing or not! :P

[dotDominic]

Ok so my drills arrived yesterday, Yay! But the reverse threaded screw in the clutch seems to have a torx head, and annoyingly I don't have screwdrivers for those. This may seem like a silly question, but does anyone who has opened up Black and Decker drills before know what size screwdriver is generally needed for these? (I'd totally measure it myself but I can't really be accurate as the chuck is in the way.) I'd rather spend money on 1 good screwdriver that fits instead of a pack of different sized naff ones which will get chewed up easily.

I'm starting to think of trying a 4WD wedge robot, but I've just watched a Youtube video showing the insides of Tormenta 2 and noticed that it used only 2 85A Botbitz ESCs for 4 wheel drive. I was just wondering how that is wired, and if people usually use 2 ESCs for 4 Wheel Drive Robots? I thought that only 1 of those ESCs was used for each motor.
Thanks.

[Garfie489]

I tend to buy a ratchet set. Get a screwdriver type ratchet (and the perpendicular ones are handy in tight spaces) - and with those two ratchets just get an entire bit set.

Costs more than a screwdriver, but what you end up with is an interchangeable screwdriver and additional tool for tight spaces which hopefully should be adaptable to any situation. Should only cost about £30 aswell if you find something cheap but has a wide range of bits.

[Shakey]

On the 1 ESC 2 motor front it is very common particularly when using ESCs like the TZ85 that you can keep chucking more motors at all day and it'll be fine :P You simply wire the motors on one side in parallel. So 2 wires from one of the motor wires on the TZ85 to each motors positive, and another 2 wires from the other wire to each motors negative.

[dotDominic]

Ok, great. Thanks very much!

[dotDominic]

Ok, so I'm thinking about to buy a charger for this battery:
http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html, which I'm using to power 4 12v cordless drill motors.
I've read in several other threads/posts on this forum that the IMAX B6 is a good first charger, but it needs a separate power supply. Considering the vast range in prices of power supplies, I'm very unsure which one to buy. Could anyone give me any advice on which would be a suitable (and relatively cheap) power supply for the IMAX B6, please?

[Garfie489]

http://www.amazon.co.uk/dp/B00MPFU3Z...767431_TE_dp_1

[dotDominic]

@Garfie489
Thanks very much. I saw that one, but wasn't sure if it would do the job. (The reviews of it are hardly detailed...) Thanks!

[Garfie489]

Ill admit with my experience of it, its not exactly high power. But as long as its got a decent mains supply i havent had any problems with it.

Just dont expect to put a high amps through it in order to get a quick charge. Balance charge every time, and give the batteries some respect and it shouldnt struggle.

[dotDominic]

Cool, thanks very much! Right now I'm not looking for any really fast charging, just something that works.

Also, just read this thread regarding mixing issues with DX6is and BotBitz ESCs. I imagine everyone on here has already read it, but here it is anyway: http://www.fightingrobots.co.uk/thre...-spektrum-dx6i Not really convinced I'm up to the task of hacking these, particularly when I've never soldered any before. (Not comfortable thinking that one of the first things I try soldering on is an ESC worth £44...) So I'm thinking I might buy a cheaper transmitter which doesn't have this problem. (Or isn't as affected by it.)

But it just made me wonder why people don't control their robots like this, rather than using one control stick:
Dominic's Pretty Naff Diagram.jpg


I imagine this type of control has a name, but I've no idea what it is. I just would've thought that would stop that dead zone in the corners of the control as discussed in the above thread. But since I haven't heard of anyone using it (and that I'm a total newbie to this sort of thing), I'm guessing there is some major problem with trying to control a robot in this way?
Sorry about all these questions.

[Garfie489]

I believe that problem was on the V1s, the V2s i have dont seem to have the same problem.

Also that control type is tank steering effectively. its really hard to be accurate using that system. For example, if you want to go straight down a line, you need to accelerate both sticks at the same rate, and hold them both fully up.

Theres then an added problem of adding a weapon control which is why many use one stick. And also in order to drive that way you need to do the mixing yourself in your head, often itll lead to a very binary and inaccurate form of driving style. My using the mixing included in the transmitter, its just one less thing to think about whilst driving.

Its certainly doable, but its likely to cause more problems than it fixes. You could certainly try learning that way, but its less of a headache to not do it - the driving comes more naturally

[dotDominic]

Superb, thanks very much! I was very worried about having to hack ESCs on my own, so that's a huge relief!

Ah, ok. I understand now. Thanks for the explanation! Might be something to play around with when I'm a bit more experienced but for the time being I'll stick with the more tradition method of control. Thanks for your responses!