Monday, November 5, 2012

Sourcing RepRap extruder springs in South Africa

Several RepRap extruders use compression coil springs to provide tension on the idler. While some companies exist that manufacture springs locally, they are not really conveniently located and might charge a lot if you are only interested in small quantities.

After search the internet and fastener / hardware stores unsuccessfully, I happened to notice that certain clothes-pegs have springs that seem perfect for the job.

Sourcing the clothes-pegs turned out to be relatively easy....

The ones that I found are:
Barcode: 6009695720525
Branded as: "You Save"
Pack size: 48 pegs (with one spring each) (Can't find it on their online shopping page)
Sources: Pick 'n Pay (~R26 per pack of 48)
Free length: 16mm
Wire thickness: 0.9mm
Turns: 9 (first and last one flattened)
Outside diameter: ~6.4mm (Fits M4 / M3 screws)
Turn "pitch" (relaxed): ~ 1.9mm (including 1 wire thickness)
Spring coefficient: Unknown
Material: Unknown ("rust free", looks like it might be zinc coated steel)

The pegs themselves seem to be made from PE and might be recyclable into filament with a filament extruder.

This thread on the RepRap forums seem to mention the same springs.