Build types

Would someone be able to explaine pros and cons of using a chassis and bolted armour and a single piece welded shell? Trying to decide which method could be potentially used for something

My 10p... if you use a chassis then any armour you bolt to it can easily be repaired/replaced where as if its a monocoque then any damage to the structure is much harder to repair.
On the flip-side, monocoques are harder to rip apart with say spinners as they can be built with stronger joins or welds. The panels on a chassis are collectively strong but if one it removed then the others are much more vulnerable.

Bigger brother Vs Hypnodisc is a great example of a chassis and panel set up, as for monocoques... I cant think of one... Wheely Big Cheese perhaps?

WJ and I did build Project One. No armor except some small bits of recycled 10mm pig-feeding trough HDPE on the steel spaceframe.
After that team Warlock did Project 2:Hex'em bolt on compound armor plates- PC over HDPE ,

My assistance on Gravity ,sturdy steel frame with light PC armor, and Tough As Nails- still using the original Hardox monocoque armor/frame/weapon.

Then with team RCC.
Hannibal , bolted ali monocoque.
Obsidian. From flimsy bolted 1mm ti/ 4mm Carbonfiber to semi monocoque 20-30mm HDPE

The rebuild of Mantis -with a welded shell Hardox/Stainless steel bolted on the original double chassis-

Bullfrog 2012, a monocoque Hardox shell.

I guess my 12 years of roboteering gave me a clue.

Concidering Bigger Brother. That was a welded mild steel shell on top of a double mild steel box section frame.
I was there when it got resurrected from a pile of mobile scrap steel armor to a combat ready robot after the beating it recieved of Hypnodisk. Anglegrinding, sledgehammering and welding. No rocket science, no expensive tools nor special skills. Just reparing.

And another point. The only real damage Storm II recieved in series 7, the ripped off front armor panel. Mild steel box section weld frame failure. The Ti plate was only scratched.

Are you able to use thinner armour as it is supported rather than using thicker but only has its own strength to go on?

Both types should weigh out about the same im guessing?

As far as I know, most people try to make the supporting structure as strong as possible, and add armor according to weight left.

And whatever setup you use, the end result is 100 kg or less.
It's just what the capabilities and preferences are.

I guess the fact that Tough As nails still is using the original armor/weapon, and that for a decade actively participating in events, and even being tested with disks (Pulveriser @full speed, makes a nice rip in the weld) tells enough.

My aim is to have a tough chassis but armour will probably be a mix of 4mm hardox, 3mm Ti, 3mm mild steel, 5-10mm T6 ali and most likely some 10mm polycarb. Fair amount mixed in there :lol:

the last wild thing had a very sturdy box section chassis and something like 10mm polycarbonate and that took a hell of a beating from vertical discs

https://www.youtube.com/watch?v=wkjgxOxzNGE

so as long as the chassis is well built

So much depends on the type of robot you want to build the available skills, money and time.

Saint has a welded Hardox equivalent drum with conveyor belt wrapped round that, the top is 20mm UHMWPE or RG1000 nothing has ever got close to penetrating either.

Cherub has a welded lid and sides so the bodywork for the robot comes off in two bits, the back panel and the rest. this is welded 5mm steel again nothing has yet penetrated it.

I don't like bits just bolted on as they usually weigh more and protect less. but this is what I did with Seraph using only 4mm studs and screws. and only 8mm HDPE for protection. works well for that type of robot.

So in conclusion it's
Horses for courses. :D