7 replies to this topic

[mitchb]

Hey, thought I'd throw up some quick renders of one of the projects I'm currently working on for uni. It's for our structures and materials class and the breif was basically to design a personal shopping trolley than can fold flat.

My trolley makes use of the 'Eco' green Bags (http://www.greenbag....au/products.php) as the receptacles for the goods which aren't pictured in the renders. the trolley holds 4 bags which go into the two carrier frames. the bags are locked onto the frame by draping the handles over the slots in the frame and snapping down the retaining clips.

[streamliner]

I like the idea behind it, but right now it looks like something a Mechanical engineer would design. What happened to the design? Where is it? Them wheels don’t look appropriate for a start. That’s my opinion, I may be wrong.

[mitchb]

Thanks for the comment. As I stated the project is for our Structures and and Materials class so the focus is largely on the function and mechanical principles of the design, concentrating on the distribution of forces, structural integrity, human factors etc.

As for where is the design.... where isn't it? A lot of thought has gone into the form,function and structure of the trolley. I have tried to house all the mechanism's within structural components to keep the outside appearance clean, simple and sticking to its geometric form. It does have a large engineering focus, but how does that mean it lacks "design"? Would you like me stick some pretty patterns on it and a brand label to call it "designed"?

I value anyone's opinion that will help me develop my design to its full potential. Stating that "them wheels don't look appropriate" doesn't indicate why you feel this way or how I may potentially resolve this if it is an issue. I welcome any constructive criticism of my work that will help me grow as a designer, but if you have comments to make please elaborate so that I may gain something from it.

Thanks

[MPwr]

I really like the idea, I think what streamliner was trying to say was maybe it looks quite "harsh" get abit of fillet on those edges lol

Things I was wondering:-

-Because it makes use of eco-bags, does this mean the user has to purchase the eco-bags in order to use the product? I would think the majority of shoppers wouldn't be inclined to use the trolley if they had to pay for the bags (I realise this would be a one off payment as you could reuse your bags) how expensive would this be?

-Does the fact that this product uses the eco-bags as a trolley defeat the object of bag packing? I was thinking this only because it seems like a lot of packing and re-packing of bags for many customers to bother with?

-How much shopping can a customer get into the "trolley" as a whole compared to traditional trolleys?

-What are the chances of it falling over?

[streamliner]

Hi mitchb sorry about my sniping remarks I apologise. Yes I’m sure you put a lot of thought and time into the design of your product.

Would you like me stick some pretty patterns on it and a brand label to call it "designed"?

If only design was that easy.

I really like the idea, I think what streamliner was trying to say was maybe it looks quite "harsh" get abit of fillet on those edges lol

Yes that was the general direction I was looking at. The form could be more attractive because you want the user to enjoy touching it, pushing it and reuse it over and over again. From some angles it reminds me of a folding deck chair. If you angled the push handle stem would it be more like a shopping cart handle?

Stating that "them wheels don't look appropriate" doesn't indicate why you feel this way or how I may potentially resolve this if it is an issue. I welcome any constructive criticism of my work that will help me grow as a designer, but if you have comments to make please elaborate so that I may gain something from it.

Regarding your wheel design I think your wheels would have trouble manoeuvring around pebbles, potholes and uneven surfaces. If you increases the size of your wheels and added a thicker rubber profile they may handle a lot better. Maybe also add hubcap into its design to prevent stuff getting tangled inside the axle.

[mitchb]

Hi guys thank you for the much more useful feedback

As far the bags go yes they would be required to purchase their own bags. Here in Sydney the typically sell for 99c a bag in supermarkets so the customer would be looking at a one of payment of ~$4 for the bags.

For the bag packing/unpacking this is one problem that arises from the current checkout method that requires everything to be scanned individually then repacked that does somewhat defeat the purpose. wouldn't it be great if there was a system that could simply scan everything in the bags as you walked through... maybe rfid based... but that's a little beyond me. but that could be a conceptual resolution for this issue.

the bag manufacturer claims that 1 eco bag can hold the same as 4 regular plastic bags with a maximum load of 18kg per bag. so effectively the trolley could hold 16 plastic bags worth of items which from my experience seems comparable to how much a traditional trolley takes.

As for it falling over i don't think this should be too much of an issue. as the bags sit between the front legs this should prevent the load from swinging side to side and potentially toppling it over. and forwards and backwards the wheelbase should be large enough to be to prevent any tipping that way.

Originally I planned the wheels to be much larger, roughly 150mm diameter, but due to the way it folds flat this resulted in it being 300mm deep at the bottom so i reduced the wheels to minimise it's size when folded while trying to retain a size that would adequately handle most reasonable obstacles... that being said they are still larger than the wheels on the current style of shopping trolley. I kept them rather thin and used a spoked design purely as it is so conceptual. If it were to be designed for production i agree with what you're saying, for manufacturing cost, usability etc i think a solid wheel would be much more suitable than the spoked one and thicker tires to absorb bumps etc. I could increase the size of the wheels and retain a narrow folded profile if i mounted the rear leg on the outside of the front leg so that it folded next to the front wheel rather than behind it, however i feel that kind of kill the nice flat profile of the sides and the triangular form when it folds up.

[Crichton]

Hi.

This might be a bit late but just remember that 4 Eco bags have the ability to carry the weight, but not the volume of the 16 plastic bags

Would you want the user loading that kind of weight (nearly 80kg) on a plastic foldable device? If so, will the locking mechanical parts handle stress (I fear your solution might not be up to the task) also smaller wheels need a hard body to handel both the weight of the trolley and roll easy enough..

I'm mentioning it because changing the locking mechanism and wheels alone will make huge differences to the design in terms of foldability, usability, ergonomics and the overall look. It's a form follows function approach I'm talking about..
But I must say I do love the use of a device making use of currenty used products instead of a new collapsing stand alone trolley unit.

Anyways that's just my 2cents, but what was the reaction from your classmates and lecturer to this device?

[Turbofrog]

A few things to consider:

1) Not really related to design, as much as presentation, but always make sure you turn on Perspective when you're doing renderings. Isometric views look really unnatural (possibly also where the 'engineer-y looking' comment came from)

2) Am I right in assuming that the internal mechanism in your tubes is a way to lock the the racks once they're in position (i.e. turn the knob and the two pegs lock into matching holes?) If so, it looks like a slightly cumbersome and overly complicated way to go about it. The knob is very round which would make turning it difficult if there's much load on the racks or friction in the system. Maybe make it a flat knob, more like the side one, but solid - this would also make the locked/unlocked position obvious. It also requires the user to make sure they find the right position for the rack to be in so that they can lock the pegs - do they need to hold the rack there, making it a two-handed operation?

Could you make it spring-loaded so that the pegs automatically click into the holes when the rack is in the right position, and then they only need to turn the knob to compress the springs again when folding it?

3) There are an awful lot of small moving parts for something that needs to relatively cheap and bulletproof. Can you simplify the mechanisms?

Maybe you've already thought about this and just haven't explained it here, but there do seem to be a few little ergonomic, usability, and manufacturing niggles here and there. I do like the attention to detail, though. You're clearly thinking.