kojent rollerball spring

[conandy]

I have made 2 kojent rollerballs from Woodcraft. I love the pen design, but just realized that on both of them, the rollerball refill has some play, in that it retracts a smidge as you apply pressure to write. It is like the spring isn't stiff enough or long enough to hold the refill tightly against the inside of the nose cone.

I have not noticed this with any other rollerball kit I have made. It is actually really annoying to try to write with.

Has anyone else experienced this? I have both of these pens up for sale, so I am glad I started using one, otherwise I would not have known.

Thanks for any comments or solutions.

Andy

 

[SteveG]

Three solutions:
1. (Most common) Simply stretch the spring. Once the slack is gone, you will likely find the spring to be strong enough.
2. Replace spring with longer/stronger spring. Many available from IAP vendors.
3. Glue in a spacer behind the spring.

All of these solutions are permanent fixes, i.e. do not require any mod to the refill itself, which goes away when refill is replaced.

Happyturning and writing! A little lesson learned...perform a functional test of every pen prior to moving on to the next one! :wink:

 

[conandy]

Three solutions:
1. (Most common) Simply stretch the spring. Once the slack is gone, you will likely find the spring to be strong enough.
2. Replace spring with longer/stronger spring. Many available from IAP vendors.
3. Glue in a spacer behind the spring.

All of these solutions are permanent fixes, i.e. do not require any mod to the refill itself, which goes away when refill is replaced.

Stretching the spring does help, but the spring on these is exceptionally weak. it stops the small initial clicky movement when putting pen to paper, but it still doesn't have enough resistance to push back if you apply more than a hair of pressure, in my opinion.

I tried dropping a little plug of dowel behind the spring. Same thing. Helps stop that initial click, but I still don't feel like the spring has enough oomph.

Think I'll try to find some better, stiffer, springs (in addition to the spacer if need be). I really like the stiffness of the spring in the PSI magnetic vertex, but that particular spring is way too short.

 

[SteveG]

You are welcome.

 

[conandy]

If anyone is following, this part # from McMaster-Carr is the PERFECT spring to use instead of the kit spring on a Kojent rollerball: 9434K164. 0.75" length, .24" OD, 0.38" wire, pack of 5:
https://www.mcmaster.com/#catalog/122/1275/=14vs1oj