Filamentalist FV3 o-ring and tensioner upgrade

[Alienbliep]

Goodday,

I have made an design change to the FV3 rewinder that i wanted to share.

1. I found that he original o-ring created alot of friction. (Found a fitting car part, since i was car mechanic i rembembered the part)
2. Also the tensioner arm was rubbing against the o-rings. (Designed an bigger arch around the CDR)
3. The tension spring was not always in the middle of the arm and bolt. (so i made the opening for the spring ~6.2mm and an bushing for the bolt to retain the spring)

The outcome is i only adjusted the FV3's once when i mounted them. With minimal spring force. The is almost no friction, but the grip on the filament is really really good.
I use 5 FV3's daily with an Prusa MMU3 since begin september 2025 with absolute 0 re-adjustments or failures. Around 2000

https://www.printables.com/model/1405103-filamentalist-fv3-upgrades-improved-tensioner-with

[Alienbliep]

Still not adjusted the spring or anything and it is running daily. 😁👍👌