Hi I made this instructable to help people who would like a flexible drinking straw that stays in the same position so that they can take a drink whenever they want knowing that it won't move from the position they or the caregivers placed it in without paying extra because of the accessibility or disability tag.

This idea should cost less than £15 about $19.90 usd not including a 3d printer, pliers, digital calipers or cup.

Supplies

2mm ID Silicone Tube £4.29 (easier)

4mm ID Silicone Tube £4.59

Coolant Pipe £5.89

Any cup with lid that uses a straw

3d printer

pliers and digital calipers optional but is helpful

Step 1: Step 1: Modifying the Coolant Pipe

The whole Coolant Pipe is adjustable not only can it bend you can pop off at any joint to change its length to what ever length you want for now you need to pop off the cone bit you can use your hand or pliers. the reason for removing it is the tube won't fit.

Step 2: Step 2: Putting the Silicone Tube in Place

This step will be quite awkward if you went with the larger Silicone Tubing I recommend straightening out the coolant pipe as much as possible before attempting to put the Silicone Tubing inside the coolant pipe. You will want to put the tube thorough the side where the thread is on because its easier as the tube is less likely to catch on the inside from that direction.

Step 3: Step 4: Design the Holder

First make a polygon with 6 sides aka a hexagon slightly bigger than the hexagon on the coolant pipe I used 13mm by 15mm then change it to a hole, next create a cylinder size doesn't really matter here just as long as it's strong enough to support the weight, I went with 40mm by 40mm.

When you have those shapes made you will want to align them so the hexagon is in the centre, you can do so by selecting both shapes and then clicking the handy button on the top right (it looks like two rectangles beside a line) 9 dots will appear around your selection looking from the top angle click the middle dot on both sides and you shapes are aligned. While you have the shapes selected change the height slightly higher than threaded and hexagon part of the coolant pipe originally I used 17mm but in end I went with 19mm and after doing that click group (Ctrl + G) this will put the hole in the cylinder.

Next we will make the threaded parts this will prevent the holder from falling off the cup. Making the bolt and nut is very easy with Thinkercad's featured shape generator ISO metric thread generator, to get to this generator above the box and cylinder a drop down button with "basic shapes" if you click it you should see shape generator > featured > ISO metric thread generator. Click and drag the ISO metric thread generator icon the settings I used are Diameter of 13mm, 32 segments and 19mm height, you will need two of these so copy and paste it and set the copied shape to hole.

Create a cylinder hole width smaller than the centre of the first bolt but higher than it, I found that 6mmx6mm it needs to be slightly bigger than the silicon tubing and a height of 20mm work well with the 13mm diameter of the bolt, check if the cylinder leaves a wall connecting the threads together by selecting the bolt and cylinder align them like the hexagon and cylinder from earlier and group them together if it looks like a pipe with threads on it thats exactly what it should.

We will need something that will allow the threaded pipe to connect to the rest. We can use the tube shape with a radius of 8mm and wall thickness of 5mm, the wall thickness needs to only touch the inside of the threaded pipe any more and it will interfere with the silicon tubing. align the threaded pipe and tube so that it's centred and group them it should now look like screw with a hole going through it.

Its time to combine the screw with a hole going through it and the cylinder with hexagon hole together, the screw with a hole going through it needs to be on top of the hexagon hole so we need to change the plane we are working on to do this clicking on the workplane icon and click one of the sides while in front view and raise the screw with a hole going through it so the that the flat side closest to the threaded pipe is the same height as the cylinder with hexagon hole (I didn't do a good job at that) once you've done that return to the top plane by clicking on the workplane icon and click one of the tops of shapes while in top view again align both shapes so that they are centredto each other and combine them.

Lastly the nut to stop the holder from falling off, create a hexagon any size but probably smaller than the cylinder with hexagon hole it but not smaller than the threaded pipe, when you have that made click on the ISO metric thread generator shape we copied earlier and change the diameter to 14mm needs to slightly bigger than the first one we made for tolerance otherwise it won't fit. select the hexagon and iso hole and align them to the centre then combine them should look like a normal bolt.

The holder is now designed all that is left is exporting it to .stl or whatever your preferred format is and print it

Settings I used are 15% infill, brim, .20mm layer height and pla filament.

Step 4: Step 5: Putting It Together

Before putting the tube in the 3d object check if the threaded part fits through the hole for the straw on the cup if it doesn't you can resize the 3d printed parts, try different cups or make the hole bigger with a drill or something like that. Next put the tube into the 3d printed part with the hexagon hole so that the yellow bit is in that hole, its a bit tricky to get it in but if cut the tube so it's pointed it's much easier to do.

finally put the 3d printed parts on the cup the threaded bit goes in facing down thorough the hole in the lid and the 3d printed nut goes on from the bottom wedging the lid between the 3d printed parts.

Step 5: Step 5: Final Adjustments and Some Notes

If the straw isn't long enough you can add more coolant pipe all you need to do is pop off the threaded yellow bit of the part you want to add and pop it on to the straw if you need long than two together it will need a longer silicon tubing and something to support it.

The tubing I bought is washable over 100 celsius/373.15 kelvin I would recommend washing it regularly.

A possible upgrade to this is a cup holder as its likely to fall if near empty and a no return valve for those who can't suck very well.

Hopefully this was understandable and useful for everyone interested.