Let's cook them with hot water :) Idea is to wrap a piece of PLA filament around a spring maker, slide everything in the spring maker sleeve (or holder) to hold the filament in place and stir everything in hot water for a few minutes. Create a thermal shock by throwing everything in cold water.
Three spring sizes (diameter) have been created and uploaded here. These are 8, 12 and 16mm diameter springs allowing you to use the three sizes in series (coaxial) in order to increase spring stiffness as per your requirements. It will need some sort of case to hold them coaxially. Different pitch and number of coils are available. Here is how I named them:
Material memory form shall keep the spring in shape but best is to put these compression springs within a housing as they won't have any structural rigidity.
Edit Dec. 5th 2017: I am pleased to do a final release of the design. The latest design revision fulfills all my expectations. The spring shape is very consistent, dimensions are very stable after "cooking". I will try to do a short video showing how to use the spring maker, in the meantime, I will upload various design variants but a scale is always possible to accomodate different pitch and/or diameter. A scale will not help to increase number of turns, if you require longer spring, please post a comment and I will upload a tailor made design.
Edit Dec. 4th 2017: after the experience collected with 2nd prototype, I upgraded the tool to guide the filament during turning. I also modified how the filament is maintained within the core to avoid the 90° bend which may cause the filament to snap off, the angle is now 45° only. To improve ergonomics, I also made handles longer and added 2 more on the nut. As soon as the design is validated, I can generate different variations of the spring maker to serve many applications and upload them here. Make it customizable looks complicated.
Edit Dec. 1st 2017: after my first prototype test, I decided to do a major revision. The struggle was to turn the core and at the same time hold the filament in the groove. Being almost impossible to hold everything tight, the filament was getting off the spiral groove resulting to an irregular spring. Therefore, I created a turning tool consisting of a nut using the filament as thread. By doing so, a regular spring shape can be achieved with the coil maintained tight enough against the spring core tool. I'll put pictures of the updated tool asap. Top start with, I kept only the 18mm diameter spring along with 2 different pitch 4 & 8mm. Have fun!
I uploaded 3 different spring makers: diameter 10mm, 14mm and 18mm. Using 1.75mm filament it is possible to use the 3 different sizes to make one more rigid spring.
Each spring maker has 2 different pitch:
You can also select the length with the multiple radial through holes.
As example, I made a 10mm diameter spring having 4mm pitch and a second having 6mm pitch. The 4mm pitch produces 150g of force when fully compressed, the 6mm produces 300g of force when fully compressed. Works like a charm :)
I identified some improvement potential to ease the process. Let's draw and update!
Please share your experience !
SpringMaker_Core_d12p4x10.stl | 3.5MB | |
SpringMaker_Core_d12p6x10.stl | 3.4MB | |
SpringMaker_Core_d12p8x7.stl | 3.3MB | |
SpringMaker_Core_d16p10x7.stl | 3.7MB | |
SpringMaker_Core_d16p6x10.stl | 3.6MB | |
SpringMaker_Core_d16p8x7.stl | 3.7MB | |
SpringMaker_Core_d8p4x10.stl | 3.3MB | |
SpringMaker_Core_d8p6x10.stl | 3.3MB | |
SpringMaker_Core_d8p8x7.stl | 2.1MB | |
SpringMaker_Nut_d12p4.stl | 536.2KB | |
SpringMaker_Nut_d12p6.stl | 547.2KB | |
SpringMaker_Nut_d12p8.stl | 561.6KB | |
SpringMaker_Nut_d16p10.stl | 704.2KB | |
SpringMaker_Nut_d16p6.stl | 679.5KB | |
SpringMaker_Nut_d16p8.stl | 645.7KB | |
SpringMaker_Nut_d8p4.stl | 601.4KB | |
SpringMaker_Nut_d8p6.stl | 537.7KB | |
SpringMaker_Nut_d8p8.stl | 537.0KB |