Burgerman wrote:I would argue many elements of Formula One are modular – for instance the hybrid power unit and battery packs are "off-the-shelf" and common to many of the cars. Even the engines are only made by three or four manufacturers meaning the ultimate design has to be compromised to fit the engine.
Because they have no choice on these specific items. Due to agreed cost reduction and rules. It results in a worse car however. One F1 engineer already said this caused many compromises. In that they cannot shape the engine casing to directly fit rear suspension points in the places they would like so they have to mount the engine and suspension seperately... Likewise he wanted the engines "dry sump" bottom cover to extend in one part under the car for rear protection and streamlining. But the rest of the car is extremely bespoke, even to the point of quite major differences for certain drivers.
So modular bad for ideal design. Always. It benefits cost, manufacturing stock of parts reduced, etc.
Designs is about compromises, and in the case of F1 these are to meet the rules and budget constraints. I'm sure they impact ultimate performance, but to what extent…
In our case, we are always constrained by modules, simply because we can't design every wheelchair as a one-off from the ground up to meet our exacting specific needs. As examples of modules in your current chairs, your speed controller is modular, as are your motors, batteries, rear wheels, front casters and to some extent your chassis (albeit heavily modified). These have all compromised the ultimate design, but to a sensible/affordable degree… We don't have Ferrari's budget!
If you want to evolve this design, you have to have a basis to start from and then have feedback and improvements offered by the community. As an example, someone mentioned the use of modern materials for the chassis, which requires design work and FEM stress analysis to ensure adequate strength. Having done this, it would be daft to only fabricate one chassis – why not make the design public domain and maybe even order a dozen as a community buy to gain cost benefits.
I can immediately see a very simple area that would improve BM's current battery design. It's "module" is made up of the cells, bus bar plates and orange plastic spacers, and here is where improvement can be made. The plastic spacers are designed to create a rectangular battery pack and have been adopted for ease of use.
With 3-D printing, it would be easy to organise the cells in a different arrangement, for instance staggering each row by half a cell space, while closing the row gap. Sure the ends of the cells would no longer be flat, but the overall high would be reduced, lowering the centre of gravity. You would then need to machine new bus bar plates, but if the new spacing design was regular this is a simple CNC task.
It's not an earth-shattering change, but it's not a difficult one to make nor does it have a large cost associated – perhaps £10-20 more than using the off-the-shelf orange spacers. Isn't this the sort of improvement worth adopting?
Coming from the drone racing community, I have seen flight controllers evolve massively in just five years down to open source projects shared amongst the community. Someone initially had the smart idea of harvesting low-cost gyros from Nintendo Wii controllers and made a very low-cost flight controller from these and a domestic appliance micro. The community ran with this design and evolved it, and now you can buy a 32-bit high-speed controller board from China for less than $20 featuring current and voltage monitoring with on-board SD card data logging.
Cheers
Kev