Boring Brick

After many, many years of having an interest in this hobby i've finally found the balls to give it a go. I'm not going to try and make anything too spectacular for my first one so it is going to be as the title suggests...... a boring brick :p.
Specs at the moment are as follows..

Nylon chassis and baseplate probably 10mm with 10mm hdpe around the sides to hopefully suck up the worst of the damage.
4mm stainless wedge at the front, will probably change to hardox at some point
2 Gimson GR02 18v gearboxes with 70mm wheels
TZ85 speed controllers
2 8.4v 3700ah NIMH batteries in series to give 16.8v

Any comments or suggestions please feel free i'm here to learn after all
Pictures to follow when i start the build

A good base to start with. Lots of practice, and you have a machine that can give you a lot of fun in the arena.

But a better name is a must. Boring Brick is a generic name for the class.

Yeah the name needs some work, it's just until i can be bothered to put my mind to it but thanks very much for your comments

All sounds good, will this be invertable?

If so, you might want to change the 10mm Nylon baseplate for a 10mm HDPE one, will take the hits better when flipped over and look at 2x 9.6v batteries instead, be running the motors at slightly over rated voltage to make sure it's not underpowered plus its nothing the TZ85's can't handle

And finally, welcome to the forum :)

Thank you and yes it will be invertable so maybe as you said hdpe would be a better way to go, also i've been looking and pricing and maybe the tz85's are something for the future but would the 30amp botbitz be up to a GR02 running at 19.2v?

Should be fine but if you buy decent esc's the first time round then you can transfer them from bot to bot, I made the mistake of going for cheap esc's first time round and they don't leave room for upgrades to drive trains etc. If you can afford it or are willing to wait just that little bit longer, go for the 85's but the 30's should be upto the job with that spec

Yeah i see what you're saying, i guess i'll have to think on it, also is this a good transmitter http://www.hobbyking.com/hobbyking/s...x_Mode_1_.html
i've been looking around for a half decent one that doesn't completely break the bank, can anyone see any problems with it and if so can you recommend an alternative?

It works. I won't say it will be great or so.

Only the failsafe function can be a problem.

This reciever should solve that issue, but I don't think it's compatible with the RX you propose.
http://www.hobbyking.com/hobbyking/s...Failsafe_.html

Thank you, i'm not too savvy on transmitters and receivers so if anybody could recommend a system that isn't incredibly expensive and that will fail-safe i would be very grateful.

The Orange RX/TX series from Hobbyking ain't to expensive, and do the job fine. Only disadvantage is the hidious appearance.

Yeah the orange seems like a great piece of kit, comes in at about £70 with postage from Hobbyking so i guess i look at it as an investment that can be used on other bots in the future, and yes i agree clear orange plastic looks horrible

might be worth checking your local model shop i managed to get a dx5e for £45 without the rx, i then bought a orange rx for £6-8 off ebay

For £80 you can get a spectrum dx6i:
http://www.f1hobbies.com/shop.php?id=6990&level

I say these are pretty much the best radio set people use (some will use slightly better sets but very few). These are high quality and used by feather weights and most heavyweights. Have lots of different settings and unlike some of the cheaper transmitters won't get 'drowned out' when there are lots of other radios around.

Managed to find a spektrum dx5e for £45 but also a dx4e for £30, would the dx4e still bind to the orange rx? i'm presuming it does but i'm just wanting to make sure

Scrap that last post, after much deliberation i have decided to go for the dx5e, its not really that much more expensive and other people seem to have success with it. Also the design and specs of the machine have changed slightly, parts will be on order as from friday so pictures will follow.
The new design is as follows..
Going for a 10mm hdpe baseplate and top lid instead of nylon as recommended
Sticking with the gr02's for now although ive spotted 3 cordless black and decker 12v drills on ebay, two of them are identical which could be used for the drive and the other i would use as spares and also use the gears to change the other two to all metal gearboxes.
4-5mm stainless wedge, at some point will switch to hardox if necessary.
Decided that a nylon chassis could be prone to cracking if hit by a powerful spinner, and i don't really want to use hdpe as a structural material, so the sides and back will be 10mm ali or steel with hdpe and polycarb on top of that, it might seem like overkill but i'm planning on making this thing as small and as strong as possible.
Still undecided on whether to use the botbitz 85a or 30a speed controllers.
And finally sticking with the two 8.4v 3700ah nimhs, for no other reason than i already have them kicking about and it seems a shame not to use them.

Phew that's a long one, once again all suggestions and comments welcome

Go for the 85's. Easier to upgrade later on.

I think that it will be the 85's as they leave the most room for improvement, the robot now has a name it will be known henceforth as.... Jack of Blades....dun dun. If anybody has played the game fable you'll know that Jack of Blades waas the main villain who wore the possessed mask.

Jack of all Blades sounds more fun tough.

Jack of all blades, I like it

How does polycarbonate usually stand up in the arena? I have a sheet of 12mm that I'm thinking could be the lid, any thoughts?

Polycarbonate is a tad heavier than HDPE and a lot more brittle.

As a lid, 12mm will be more than enough. I use 6mm on the top of Drumroll, it does a fine job of keeping the axes out and the only thing to get through it was a powerful hydraulic crusher.

Good to know, I was slightly worried robots like little hitter or your new axe would go straight through

Well, the arena walls are 10mm polycarb, put it that way! The reason they contain the robots, though, is because they're big and flexible, and loosely mounted into the frame. Without some shock absorption, polycarb cracks/shatters, so some form of bounce in the plate if you use it wouldn't be a bad idea.

Yeah that might be an idea, any suggestions on what I could use to absorb some of the shock? Maybe some thin hdpe under the polycarb?

I've been looking around at speed controllers and i'm considering trying either a sabertooth 2x25 or a scorpion xl instead, is there any reason not to use them?

Varies on a person's experience. Some slate the Sabtertooth ESC's others love them, depends how you treat them. Scorpion's tend to be good all round, though they occasionally have strange happenings when it comes to interpreting signals.

Many people will say though to go for a pair of TZ85A from Botbitz. Treat them right and they should last years of heavy use.

Thats me, but wait and see what others say.

The cool thing with a Sabertooth or other "dual" speed controllers, is that they mix fwd/bck/lft/rgt a lot more reliably than having a single controller per motor and then using a separate mixer. They tend to be a bit dearer, but you will end up with an extremely simple setup i.e. receiver, speedo and battery. Job done.

The Sabertooth's aren't as posh as the XXL's and Vantecs, but then they're half the money. I've been using a Sabertooth 2x12 for ages and even in a recent event and it hasn't given me any jip. I love anything simple and easy to use so Sabertooth suits me. As mentioned above, some folks hate them, some folks will tell you that Botbitz's are the mutts nutts. It's just whichever you like the look of. Most items in a robot take a beating and will need replacing as time goes on so I will usually just buy whatevers cheap lol. But yeah, to sum up the ramblings I recommend the dual controllers for the simplicity factor.

We've used a Scorpion XL in Explosion for coming up to six years now and it broke for the first and only time this year (which is especially good considering how heavily used Explosion is)! Even then the customer service was excellent and they gave us all the information we needed to fix it and we got it going again for Portsmouth 2 weeks later. We also used a Sidewinder in Invasion for years (excessive for most feathers but made by the same company) and never had any issues. We've got a new XXL to put into Combustion so we're sticking with them simply due to how good they've been from experience.

Just for another perspective and to put a good word in for the Robot Power speed controllers :)

The built in mixing of the xl and the sabertooth is what's drawing me to them, how does the 2x12 cope with use in a featherweight? i'll only be using 18v gimsons or overvolted argos drills so nothing too current hungry i wouldn't have thought

If the xl is good enough for the uk champ im sure it's good enough for my robot then

Also what would people recommend for a reliable brushed drum/beater set up, something that could later be upgraded to brushless, i'm not looking to make anything too spectacular just yet just something to make the robot that little bit more exciting and aggressive, i have a lack of any cad software/knowledge but would like to get something waterjet cut or milled, does anybody have any ideas on how i could go about getting something designed and of the potential cost? any help would be greatly appreciated

Grab Emachineshop Basic CAD program that can export as a DXF, totally free and simple as anything.

My 2x12 has taken a battering and has been fine, I will mention that it's shock mounted. Current wise it has an overload cut out so if life gets a bit much it will current limit and so on. There is a red LED on it that flickers if this happens, but I only run the most basic of robots on 14.4V argos drill motors that only pull about 7Amps a side so have never had a problem. If you were moving up to beefy drive trains you'd need a 2x25 or an XL and so on. If you're only running cheap drills you'll be fine with a 2x12, but if you intend to progress to Torpedo 800's, Banebot's 775's and so on in the near future spend your cash on something heavy duty to start with. I can only afford to build basic drill powered stuff at the minute so my 2x12 suits me down to the ground for the time being.

No toy ran 2x12 sabertooth at champs and other events also worked well, being replaced for tz85 as it is going in my beetle weight drum spinner.
2x25 would easy take gimsons,

Thanks very much, i'm also looking for a sheet of hardox to use as a front scoop/wedge for the first incarnation until i get a weapon made but all i can seem to find are big sheets of it and i'd like to avoid buying too much, does anybody know of anywhere i can buy smaller sheets? or if anybody has any going spare about 3 - 4 mm thick i'd be happy to buy it

Ask mario

Is mario Maddox10? i don't want to message the wrong person

Yep, that's me.

Does anybody know of any places that offer workshop spaces for you to use? i don't know if there are any such places but preferably in Birmingham or the West Midlands in general, or would anybody who has their own workshop space be willing to let me use theirs? i have the necessary hand tools to build a robot (drill, jigsaw, angle grinder and so forth) but it's just a thought i had, i would happily pay for the time if required and it would be greatly appreciated.