Following on from Part 1.
I needed three small compression springs to replace the missing ones from the chuck.
The holes in the chuck jaws are just over 4mm in diameter, but I wasn’t sure how long or springy the springs need to be.
Halfords sell a large selection pack of springs, which I bought on the off-chance there would be a small enough spring.
There wasn’t, but it’s a useful set, which will no doubt come in handy at some point.
My Dad and someone on UKWorkshop both suggested using springs from ballpoint pens, so I dug out a selection of pens from trade shows I’ve been to.
There seems to be quite a variety of springs in the pens, as can be seen above photo.
There’s a great deal of variety in terms of strength and length, but also pattern, with some springs having one or two tightly coiled sections in the middle.
In order to fully close the jaws, the springs need to compress into the holes, so I knew I would need either quite a “coarse” spring with few coils, or I’d have to cut one of the finer ones down, as otherwise when compressed they would not allow the jaws to meet.
The springs with two tightly wound sections looked like they could be cut in the tight sections to form 3 springs with ready made end sections:
This seemed to work quite well and the springs fit nicely into the holes in the jaws:
The jaws now open and close reasonably freely.
I think the springs are slightly too short, but they seem to do the trick and will no doubt improve once I’ve cleaned up the chuck and jaws a bit more and covered everything in grease.
First I need to get the pillar separated from the base and crank assembly, so I’ve soaked it in WD40 and left it for a bit while I watch some F1 qualifying.