Test MEDIUM production metal clips

Conclusion; with some small changes, this principle can work. The elastic can be attached tightly on the metal clips from the sheetmetal

DIY context

The panel is making in a plate of ABS of 5mm of thickness, which is cutting by the laser cutter, in the same way as the beams that reinforced the panel and th 

Consult 25/04 3 concepts

DIY
- Thickness: the same everywhere
- Snap connection for the ribs
- Nest well!!!
- Optional ribs in the middle
- Rethink about the handle: hard, but flexible (maybe flexible silicon tube)
shops: Euroshop, Gamma, Brico, Action


MEDIUM
- The dimple is not possible --> better just a hole with a plastic insert: 12mm eyelets
- The attaching lips need to be tested: check
- Coating: powder coating or two component coating
http://www.protechantislipcoatings.com/?gclid=CjwKEAjw85DIBRCy2aT0hPmS1jkSJAC1m9UvrKCRWOfqPULHc9IH3s-nmDHeoBKbFqIkLxYLK96J6hoCc3rw_wcB
Better: https://www.verfwebwinkel.be/rust-oleum-supergrip-7100ns-antislip-coating-5-lit.html?gclid=CjwKEAjwutXIBRDV7-SDvdiNsUoSJACIlTqlhbYHN5D8x50roAaHUjWe2DuwQdFPbTFtWIqEhQyRthoCXq_w_wcB
- Thing aboat the finish of the rubber bands: we would add  package with one long rubber band. Benefits: the user can decide in the beginning how long and how many of a specific lenght he needs. This gives him maximum freedom for the decision. Also, it's sheaper. We don't think the ends will come out because there's a tight fit. For the finishing of the cutted rubber bands, the user kan burn it easily.



MASS
- Material: rethink the material, is ABS the best solution?
- Material: choose one material for everything so it can be made and recycled easily
- The handel can be made way easier, so not the injection molded one, but maybe an extrusion of a rope with a flexible tube around it

Concept MASS production CAD

The panel is injection molded ABS with ribs on one side, to make the panel stronger and protect the spanners.

The spanners are also injection molded parts out of ABS.

Handle: cilinder that can be folded open en where you can put one or two ropes in

On the rope, we attach a s-hook:

To attach the panels on each other, we will make elastics like this

Prototypes of different ways to use the panels

Concept MEDIUM production CAD

Panels: sheetmetal, holes are lasered, edges en notches are bend

Handel: Synthetic rope with at each end a s-hook, (the CAD model gives a simplistic representation of these ropes and hooks because these are standard available) To give a comfortable grip, we add a rubber patch with press studs

Panel with slots where you can put the rubber bands under to create a structure of tools

 s-hook

 To attach the panel onto each other, we will buy elastics like this

Sheet metal design guidelines stamping

Source: http://www.qualitytool.com/resources/Design-Handbook-Rev3.pdf

Corners: May be sharp, however to reduce tooling costs, specify radii of ½ material thickness or a minimum of .015”

Notches and Tabs: should not be narrower than 1.5X the material thickness. Length of notches can be up to 5X length of material thickness. That's why we can't use the system for the attaching pieces like in the DIY, because there's too much detail

Cutoffs: There are three kinds of cutoffs in blanking: straight/square, half round or partial radius and full radius. The square cutoff is the most economical. The full radius is not recommended as it leaves an unavoidable “feather edge” burr along the outside material edge. 

Piercing: 

Holes: Minimum diameter of holes should be equal or greater than 1.2 X material thickness, and 2X material thickness for stainless steel or high tensile materials. 

Edge-to-hole: Allow 2x material thickness (“web”) to prevent bulging of material 

Forming: 

Guidelines are similar to CNC press brake: 

Bend Relief: Provide bend relief along L shaped features (Width=2*T and Depth=T +R) 

Edge bulging: restrictive tolerances on V bends may result in edge bulging—provide bend relief accordingly. 

Hole-to-form: distance from hole-to-form—to avoid hole distortion, place holes no less than 2.5 times the material thickness + bend radius from the bend itself. (we have holes next to a bend, but the tollerances of the holes are not so important. So we can take account with it, but it's not necessairy)

Slot-to-form: long slots should be spaced 4 X the material thickness plus the bend radius. 

Bead:  depth = max. 3*thickness

Drawing: 

Shapes: A myriad of shapes can be formed through multiple draws. Round shapes offer that greatest ease and economy in drawing. Then next best option is square with adequate corner radii. Costs increase for combinations of basic shapes and irregular shapes. 

Radii: To facilitate drawing, keep radii as generous as possible: punch and die radius should be a minimum of four times the material thickness. The part radius should be at no less than six times the material thickness with appropriate drawing-quality material. 

Another good source: file:///C:/Users/Lucas/Downloads/sheetmetal_guidelines1.pdf

Task management till deadline 25/04

To obtain max efficiency, we allocated one production volume (diy, medium or mass) per member of the team.
The big guidelines are settled. The person will elaborate that specific production volume in detail. So he has to decide on his context what's the best solution without consultation of the other. This again, to have max efficienty.

Mass production: Maarten
Medium production: Lucas
DIY: Alex

Exploration small pieces for the rubber bands

https://www.sinclair-rush.co.uk/category/1280/snap-fit-clipshttps://www.aliexpress.com/popular/snap-link-cufflinks.html
https://www.aliexpress.com/w/wholesale-black-hairclip.html

Idea for hinge - the medium batch

The circular lips (above and below) are to push on with your finger so the 2 circular plates break up. This way, you can put the another pair op circular lips inbetween. Then, you can put a metal bar through te holes.

It is also possible to put 3 op them together.

It is made op stainless steel. Production technique: sheet metal folding.

Something to work on: can it be made strong enough?

DIY hinge further exploration

Zipper Industrial velcro, doesn't get dirty
Hinge + pin   Press studs  Fabric loops 2 pin system (there also can be 3 of them for 3 panels) Rope lock, a washer connected with a piece of rope

Finaly after making a matrix we chose for the heavy duty joint.