Featherweight FBS, What do I need?

[AbundantToast]

Okay Guys after long thought and changing my design sooooo many times I have decided to make a Full-body spinner feather weight, I know it might sound ambitious for a first robot but I have till this time next year to get it done. I think I know most of the stuff I need but someone mentioned a Gyro? not sure what that is but here are the things I think I need.

2x Sabertooth speedos
4x Drill motors
Aluminium/steel box section and sheet.
Wire
1 BEC for weapon
2/3x Speed 900 motors,
Pulleys for weapon (Belts too of course)
Batterys (Probally Nimhs)
Rx - Tx
LED
Removeable link
Car wheel/ truck wheel for shell
steel pipe for weapon shaft
Hardox for shell teeth
Robochallenge Blue wheels (With nut)
And I think that is it?

[typhoon_driver]

You will struggle to fit all that in the weight limit. I'd drop two of the drill motors and one of the sabretooths. You won't need 4 as you're not building a rammer.

You won't need a BEC (battery eliminator circuit) as the sabretooth will be able to power your receiver. I'm going to assume you meant a radio controlled relay (ie battleswitch) and solid state relay for the weapon?

Two speed 900s will be more than enough to power the weapon. Unless you go for uber high spec nimh you won't be able to power 3 speed 900s and drive effectively. A speed 900 is a pretty heavy motor as well.

Throw together some drawings and post them up. Easiest way to see what you have in mind

[AbundantToast]

Thanks alot I will Do, Would it be better to put the two motors at opposite ends of the chassy?

E.G.

One at the top right of the baseplate.
and One at the bottom left of the baseplate?

[Thunder arrow]

Yer I think that would work but put the left wheel at the top of the baseplate
but Im NOT an expert


Theo

[RogueTwoRobots]

but put the left wheel at the top of the baseplate

Doesn't really matter to be honest, you can put one motor at the top left and bottom right, or top right and bottom left.

If you use this method, your robot will rock slightly along the diagonal. A couple of skid pads on your baseplate on opposite sides from your drill motors will reduce that and provide a little stability. The diagonal drive-mount method also makes it slightly easier to drive in a straight line as there is more friction to prevent the robot from veering off.

On that subject, that is what a gyro does. If you push straight forward on your joystick, your robot should drive in a straight line. But some robots veer off (usually due to one motor running faster than the other) however a gyro will detect this and make small adjustments to keep the robot running in a straight line. I personally wouldn't bother with one; they're only really useful if you've got a very fast drive system or if you're a rubbish driver, and the latter can be solved with a bit of driving practice.

[typhoon_driver]

What do you mean by motors? If you mean the drive motors then yeah you can mount them at either end of the chassis. That's what we did with typhoon cadet (the featherweight one) http://www.rampagingchariots.org.uk/typ ... robots.php

It can actually help and make it easier to allow the robot to travel in a straight line. It does make it slightly harder for the robot to turn in a circle as the wheels have to slip but drill motors won't notice it.

[AbundantToast]

Holy ... (Lets not repeat that) I just realised you made the Typhoons/ drove (Clue in the name I supose) a Derp moment indeed... (MEGA FAN BOY MOMENT TOO) ;D.

Now on a serious note would it be easier to have two static wheels too, or maybe belt driven?

[RogueTwoRobots]

Belt drive from two motors so that you have four-wheel-drive is certainly an option. This is the inside of Little Spinner 4, which uses that method (photo borrowed from Dave W's collection ):



Or you could go for the two idling wheels that can be seen in the internal pic of Typhoon Cadet that Gary linked to. Four-wheel-drive will give you more precise control (in my opinion) and will also increase grip (handy if your weapon breaks and you need to push) but just having two drive wheels is still a good compromise if fiddling with belt drives isn't ideal.

[AbundantToast]

Yeah, I'll either belt drive it or idle wheel it ;D I'll post a build diary when I start.
I am asuming everything i listed is all I need (Minus the bec, replaced with a relay)

Thanks
-Toast

[typhoon_driver]

Lol I drove the machines, I was lucky enough to have a group of professional engineers build the machines for me

Team typhoon operated like an F1 team, I worried about driving and the other guys in the team worried about keeping them running.