Intro: Discreet Spring Loaded Shopping Bag Holder
This is an approach to make a way for a persons with reduced functions in their hands for holding a plastic bag in a discreet way.
its ment to be "hidden" under the sleeve, and bump it at the hip to release..
This is not for heavy bags!
There is two versons, one fully printed mechanism, and one reinforced.
*Filament, PLA or ABS. nylon or alu for slider.
*Glue, Cyanoacrylat, epoxy and contact glue
*plaster cast of a hand
Gif of prototype test:
Step 1: Springloaded Mechanism
Print the hook and the box in PLA or ABS, slider in stiff Nylon, or make it in Alu(saw and drill/mill)
Print at 0.1mm z resolution
The assembly for the springloaded mechanism shows in the picture above
glue on springs to slider at the two knobs
after calibrating, glue the box togheter with cyanoacrylat(superglue)
Step 2: The Button
The button is printable (knapp111.stl)
Print in stiff material, but i will recommend to use a metal screw, due to duration.
M3 bolt, and buttonhead.stl
Grind the head of bolt to chamber it like picture above(blue)
and cut it to right height(right feel of height distal from box).
thread the hole in the buttonhead with a m3 tap, and screw the bolt in.
Adjust it`s travel by turning the bolt. Make sure it`s not going to far down.
The button is calibrated to right pressure release with slices of a soft material.
I used EVAsot.(quess its like 30shore) hight of slice is crusial ;)
Glue the slice to top of bolthead, an then to the base of the box.
tape the box or just hold it together for testing under calibrating
Step 3: Slider
The plastic slider is kind of weak for lateral movements when extended.
Print in strong material thats not brittle, like a stiff nylon.
I did not have any nylon at the time, so i had to mill it in Alu.
Quess ABS would hold for some time too, but i didnt risk it.
Step 4: The Hook
Print in PLA or ABS
glue it with cyanoacrylat to slider
Print it flat, like the direction that picture above shows
I used 0.1mm z resolution
no brim or raft
Step 5: The Brace
For the brace i used wet formed leather, same as for leather knife
for this part, you need a plaster cast of the hand for perfect fit.
wet the leather over night.
stamp leather to cast(smooth side in), aim for the opening, so you dont ruin the parts you will use.
stretch it at much as you can around the cast and stamp the other end close to where you started.
take some bandage or somthing and stretch it around it all tight.
then let it dry on a warm place for some days.
take out the stamps and take out the cast, then trim the ends.
glue on mechanism with epoxy, and then covered it in horse leather
or any stretchy material of choice with some contact glue.
sew on some Velcro for fastening, with a shoelace hook for easy detaching
Runner Up in the
3D Printing Contest 2016