CAD Surfacing bags (or shoes), common?

in another post, fella wrote:

Thanks for posting the bag. It is interesting the different ways of working. When I design bags, I model them in Rhino, surface the model and pull off patterns, then send the whole mess to the factory. The shapes I work with tend to be more complicated and difficult to express to a factory in a sketch and hope to get a reasonable representation without a pile of samples or factory time.

Pierre

Pierre - Im sure I don’t know the software well enough, but are you able to flatten the surfaces you pull off your model? or do you somehow send the bent surfaces to the factory and then they use that to make the fabric flow in a certain way… very interested if you could explain.

Same for shoes, i guess… though from what I have seen here, most designers seem to show only side view illustrations. Are shoes done in CADD ( by ID or engineers)?

any insights?

Clarks shoes in the UK use this system

http://www.shoemaster.co.uk/

I had a bit of training at Uni on it but not much. You have to digitise the last first before you can design on it, but it does generate patterns and grades them too.

Mostly I design in 2D showing both side and top view, but sometimes I design on vac forms or a taped up last. Some factories prefer you to work in 3D like that because they can then cut the pattern directly from your sketch.

without googling it, I’m guessing a “last” is a foot manequin?

I’ve been wondering how you guys get from nice drawings to the nice finished product while visiting here. Paper models seem be useful, but time consuming and tedius. Maybe drawings are sent straight to factories for them to sort out? The surface modeling option appears to give alot more control

we might be making a carry bag soon, so Im trying to get up to speed on all this :wink: , thanks

Yes the last is a foot mannequin - but because it dictates the shape of the shoe (comes in different heel heights and toe shapes) you have to get that developed first. I usually take rough sketches to a last maker, we then go into the last library (last makers keep an example of every last they developed), we try to find similar ones then discuss the last that I want. He then takes a few days to make the last from wood for me.

I then provide this to the factory with either vac forms (plastic vac forms of the last) with my designs drawn on, or 2D drawing, or both.

Depending on the type of shoe, I’ll get a heel made in wood by a heel maker, or do an outsole technical spec and possibly get a model made of that (we usually call it a maquette)

I guess in bag design because there is no ‘last’, you have to think more about conveying the 3D shape to the factory.

Surface modeling for bags is not common, I have seen it used for renderings and have used it maybe twice and have had mixed results because it takes me longer to surface it out and add the details in Rhino than it takes me to draw it by hand in a 3/4 perspective or to do orthographic drawings in Illustrator.

I did have time saving success when I tried it on a fairly complex pattern for a golf bag; the rendering was pretty sweet and I could change colors and materials very quickly, But due to the construction details and small finish details it ended up being a wash.(Sorry but I’m old school. I know how to make patterns and sew and know the basics of construction for footwear and bags and I have had five years relationship with the same sample factory.)

I am exploring it as a means to get more of my commodified stuff done quickly so I can spend more time and spend more of my patternmaker’s time focusing on the more cutting edge stuff (which they actually have an easier time figuring out oddly enough)

I’d assume that you aren’t flattening the pieces in Rhino, You are just “exploding” the view and sending it to the pattern makers for them to figure out , kinda like taping up a sample shoe. AS Pierre said he:" sends the mess" and has them figure it out.

I love that ‘sending the mess’ terminology. :laughing:

Shoenista, you mention you develop shoes in Rhino. For your patternmaking my guess is that you use the unrollsrf command to bring everything down from 3d to 2d, is this correct?

If you had a way to post a mini tutorial on your process (or know of where to find something of that nature, I (and others) would greatly appreciate it).

I work in rhino as well, but have had minimal success in finding good tutorial information for actual work. The tutorials I have found are always explaining only one tool at a time, and never mentioning methodologies for developing products, especially at the design level. That has been the most frustrating thing for me with this software (Rhino). As there is no history (like in Solid Works), everything from saving nomenclature and protocol I have had to “come up with/make up/flounder with” on my own, while I have constantly searched for useable tutorials with real world ways to work. Your suggestions would be greatly appreciated.

I don’t know how to develop shoes in rhino. The only Rhino i know of is this one

I sometimes work in 3D in real life, not on a computer - as in I physically draw the design lines on the last (3D footshaped object) so that the pattern cutter can take the pattern directly off it.

If I did work in 3D on a computer, I’d use shoemaster because it was developed specifically for footwear.

my mistake, I misread the thread following in the Rhino train of thought.

Does anyone have good info in that direction for Rhino? (or just great tutorial locations?)

Haven’t done any shoes, but for bags, I’ve built the main shape in Rhino, then flattened the surfaces using a plug-in called Expander.

http://www.shipconstructor.com/expander.html

Sorry…last post was mine.

[quote=“Travisimo”]in another post, fella wrote:


Pierre - Im sure I don’t know the software well enough, but are you able to flatten the surfaces you pull off your model? or do you somehow send the bent surfaces to the factory and then they use that to make the fabric flow in a certain way… very interested if you could explain.

Same for shoes, i guess… though from what I have seen here, most designers seem to show only side view illustrations. Are shoes done in CADD ( by ID or engineers)?

Hi Travisimo,

I do pull the surfaces off the model with Unroll. The surface must be developable to make it work. The simplest way to think about it is, two of the curves must be straight or at least simple. This does not mean that you have to limit your design, you just have to keep in mind your objective. If you are modeling to have a groovy rendering the surfaces maybe too complex. You can get the same complexity from a series of simpler surfaces that can be developed and then joined together.

For sew products, bag packs etc, I have found working in Rhino to be sculptural. The up side from a design stand point is I can do a quick model, print out 1/4 or full scale patterns, tape it up and look at it. If its a little tweeked, I’ll fix it. This has saved me a sampling round on a number of occasions.

From a sampling stand point, picture the normal arrangement of sittting in the factory conference room looking at first samples. If the proportions are off, you mark up the sample and it takes several days for new patterns and a new sample. With the product modeled, I can change the model, regenerate the patterns and I can get a new sample the next day. This is a much bigger advantage when the product is more complicated in form. The factorys that I have worked with love it.

How common, I have shown a couple of people in the US and Asia and I know of a couple more.

Cheers,

Pete