Twsbi Diamond 530 Piston Seal Leakage Report 2010/07/20
The Fountain Pen Network: Twsbi Diamond 530 Piston Seal Leakage Report 2010/07/20 - The Fountain Pen Network
Posted Today, 07:57 AM
TWSBI Diamond 530 Piston Seal Leakage Report 2010/07/20As you may have known that from the first 300 FPN pre-sale pens we found certain pen has seal leaking issue. Here in short are the explanations and solutions.
PISTON VERSION
Piston version 1.3 : The final version before mass production. The design of this version works fine without problem providing the parts dimension is within the spec. All of the early day samples were made by this version.Piston version 1.3b1 : First mass production batch of version 1.3, but being found some parts are out of spec on sealing ring size.
Piston version 1.3g1 : version 1.3 piston made by harder material to enhance the contact force to the barrel inner wall.
Piston version 1.5 : new version design, sealing rings outer diameter and wall thickness be increased to enhance the contact force to the barrel inner wall. Aiming to eliminate 100% water test procedure during production.
BARREL VERSION
Barrel version 1 : Current version with large inner wall tapering angle to facilitate ejection of core pin during injection molding, so not to leave scratch mark on inner barrel wall.Barrel version 2 : Future version with reduced inner wall tapering angle, if successful, will made piston design easier and even harder material can be used, this will make piston design and manufacturing easier.
STATUS
Phase 1 : Pen made with piston version 1.3b1 without water leak test.
Minor leak: small sign of ink pass through seal 1, no ink reaches seal 2
Medium leak: larger amount of ink pass through seal 1, did not break through seal 2
Major leak: ink passes through seal 1 and seal 2
Number of pen sold: 300 FPN pre-sale plus roughly 50 others, total around 350 pens. From customers' feedback around 110 leak pen, most of them are minor to medium leak, only 2 or 3 major leak. Twsbi will send replacement parts for repair.Phase 2 : Pen made with piston version 1.3b1, but with water leak test, without pen tapping against desk top. A few feedback came in reporting still some leakage. Immediately we made house check on 10 completed pen (same batch from 160 speedy carry to LA) ink filled, drop test from 20cm high to desk top(blind cap head down), 1 out of 10 pen has minor leak, I estimate the leak rate can be 10%. If sold pen still found leakage, Twsbi will send replacement part for repair.
Number of pen: 160 pens speedy hand carry to USA plus roughly 20 pens sold by Taipei office. Total around 180 pens.Phase 3 : Piston version 1.3b1, water leak test, pen tapping against desk top. Few pen left house already. These few days we are still confirming the result.
Phase 4 : Piston version 1.3g1, water leak test, pen tapping against desk top. We anticipate will have no leak issue.
Phase 5 : Piston version 1.5 + barrel version 1. I strongly believe this will permanently prevent seal leaking problem.
Phase 6 : Piston version 1.5 + barrel version 2. We will enter the real test soon, as I heard the barrel version 2 sample came out already. This will be the ultimate solution I wish to see it success.
I feel really sorry for the inconvenience that bring you and hope the solutions will bring back your trust to the TWSBI brand we try to establish.
Sincerely Yours
speedy
Twsbi Diamond 530 Piston Seal Leakage Report 2010/07/20