From The Ground Up (Advice Thread)

**Roland** · 30th December 2010, 10:33

Ok, so if it's built in (Edit:BEC) it's mandatory?
And if I where to buy a seperate battery pack for the receiver, how would I wire it through the safety switch? OR would I then need two, or perhaps none at all for the reciever battery?
Very helpful thanks.

**woody** · 30th December 2010, 12:03

Originally Posted by Roland

Ok, so if it's built in (Edit:BEC) it's mandatory?

NO ..OPTIONAL

Originally Posted by Roland

And if I where to buy a seperate battery pack for the receiver, how would I wire it through the safety switch? OR would I then need two, or perhaps none at all for the reciever battery?
Very helpful thanks.

You want a removable link in one of the main battery supply wires...this acts as a switch

**psychostorm** · 30th December 2010, 12:28

A BEC is not mandatory, but is one less thing to fail. Hence simplicity until is breaks...

It's best you have a switch for a rx, preferably next to the link. Mainly to stop the battery from draining between the arena and the pits, though partly for safety.

**Roland** · 30th December 2010, 14:09

Thanks everybody.

I've been pondering over the design for a while, and I've decided that want a sturdy machine, as small as I can get it, I had a look at ratios and by the size of my wheels the rest of the chassis should come to around 400mm*256mm! My current problem is I can't fit the drill motors onto the wheels, I've thought of two ways to fix it, the first being my preferred of having the motors parallel to the wheels, but slightly down a bit, and attaching it to the axel on the wheels using bevel gears and of course the other which is to simply expand the machine - which I currently don't want to do for a few reasons: the larger it gets the more surface area I have to cover with armour increasing weight; I'll have to put more support onto the frame and the fact that I expand it means I'm going to have a large amount of empty space, which I want to prevent. So which one would have a larger advantage? :O
My design so far is here: EDIT: IT'S SO BIG HOW DO I MAKE IT SMALLER

**daliad100** · 30th December 2010, 17:39

A picture that large should probably be linked to or I think just uploading it as an attachment and not inserting it will make it smaller.

If you can get chains/belts you can have the motors diagonally with for example the rear motor powering the left side and the front motor powering the right side.

You could also try making the robot shorter and wider so its 400mm wide and 256mm long so it will weigh about the same but you will fit in four drill motors far easier with no extra gears

**Roland** · 30th December 2010, 18:15

Solved the problem earlier but I couldn't edit the post, it's now 470*300*70. I'm all set to go, but I'm not sure on what thickness the steel box section should be, I was thinking 20mm*20mm*2mm but that might be too heavy. Any ideas?
Thanks for the contribution though, I'll keep it in mind.

**Roland** · 31st December 2010, 08:10

problem solved. woop.

**gizz** · 31st December 2010, 11:54

i believe 1mm thickness would do the trick actually. my old fw frame was mad eof 2mm thick box section and it felt like an overkill.
But thena gain i never fought with that chassie so im not 100% sure.

**Roland** · 31st December 2010, 16:51

Oh good. 1mm is what I wanted, the frame was going to come to 7kg which I thought was a slight bit too much, so dropping it to 1mm should reduce that numbrero.

I can't find any duel speed controllers anywheeeeeeere.

Does anybody know where I should look?