Why Does The Twsbi...

[amberleadavis]

Thank you Speedy!

[Sasha Royale]

I loved my TWSBI 540...broad nib, great, smooth writer. BUT, it cracked... now it is in a pen pouch with others...I just don't use it anymore. I am disappointed, too, because it really was one of the best writing pens I owned. Oh well....

 

FPN members rerport that TWSBI will stand by the pen. I suggest

contacting TWSBI for remedy.

[amberleadavis]

I loved my TWSBI 540...broad nib, great, smooth writer. BUT, it cracked... now it is in a pen pouch with others...I just don't use it anymore. I am disappointed, too, because it really was one of the best writing pens I owned. Oh well....

 

FPN members rerport that TWSBI will stand by the pen. I suggest

contacting TWSBI for remedy.

 

I can tell you that TWSBI customer support has been great.

[Sasha Royale]

I ordered my Diamond 540 in advance from UK. It arrived in August that year.

After two months of continuous use, it was fine. I ordered ten

of them for Christmas giving, and ended up keeping one for myself.

No cracking after two years.

 

My mother inquired about the name. A letter arrived from Taiwan

with a handwritten calligraphy of the Chinese characters and the

name, and a very nice note of greeting for my mother. A few weeks

later, Mom received a gift TWSBI Diamond 540. It hasn't cracked

either.

 

From Beretta Pistols to I-phones to jet airliners, there are

faults in manufacturing. A good company strives to correct such

faults and stands by its warranty.

 

The TWSBI Diamond 540 was a great $50 fountain pen. I recently

bought my third one for $38. The TWSBI Diamond 540 was a great

$38 fountain pen. I hope to get one for $20 someday.

Edited March 8, 2013 by Sasha Royale

[amberleadavis]

Well, with that special buy a Vac 700 and a 540 for $100, the net cost of the 540 was $15. Impressive really!

[MartinCB]

I was very interested to learn that TWSBI opted for PC over PMMA for their pens. Both materials can be injection moulded so the option of using acrylic would have been available to them. Both materials are quite difficult to get right because of residual stresses, but if great care is taken in tool design, i.e. finely radiused corners, appropriate spruing etc. it should be possible to get a good component with both. One key point with both materials is don't go anywhere near them with solvents as it will cause cracking. Speedy has mentioned that they think the finishing laquer has been the cause of their problem. As acrylic produces a better, more resilient finish, thus negating the need of a finish coat, I wonder why that wasn't the first choice. I wonder, Speedy, if their was a particular reason for the choice of polycarbonate over acrylic. I am only interested as I once worked in the engineering plastics industry.

[imahawki]

Speedy has said there was a cracking problem and that the new method and design resolves it. To those who say there is not a cracking problem but merely vocal complainers, I'm not sure how you arrive at that conclusion.

[pokermind]

As acrylic produces a better, more resilient finish, thus negating the need of a finish coat, I wonder why that wasn't the first choice. I wonder, Speedy, if their was a particular reason for the choice of polycarbonate over acrylic. I am only interested as I once worked in the engineering plastics industry.

not that I can speak for Speedy, but I gathered the reason for using polycarbonate was, as UK Mike said:

Polycarbonate has a higher tensile and impact strength than acrylic when used under the correct conditions.

meaning, it can "take a beating" better (tolerate stronger forces without breaking, like when dropped on a tile floor).

 

I have a 540 that I'm (irrationally) fearful of using. By any chance, can polycarbonate be baked at low temperature to relieve the internal stresses (sort of like hardend steel can be tempered or annealed to be less brittle)?

[iamchum]

Either way Speedy and TWSBI are making the pens better Which can only be a good thing. Go speedy!

[MartinCB]

As acrylic produces a better, more resilient finish, thus negating the need of a finish coat, I wonder why that wasn't the first choice. I wonder, Speedy, if their was a particular reason for the choice of polycarbonate over acrylic. I am only interested as I once worked in the engineering plastics industry.

not that I can speak for Speedy, but I gathered the reason for using polycarbonate was, as UK Mike said:

Polycarbonate has a higher tensile and impact strength than acrylic when used under the correct conditions.

meaning, it can "take a beating" better (tolerate stronger forces without breaking, like when dropped on a tile floor).

 

I have a 540 that I'm (irrationally) fearful of using. By any chance, can polycarbonate be baked at low temperature to relieve the internal stresses (sort of like hardend steel can be tempered or annealed to be less brittle)?

 

UK Mike is correct that polycarbonate has much better impact resistance but it does mark very easily. Whilst PMMA is perhaps more brittle under fairly abusive conditions it does finish better and retains that finish. You don't subject either material solvent contact as it will cause cracking. Speedy has identified that their problem was caused by the finishing lacquer (probably the solvent in the lacquer) that was essential when using PC. I'm not sure that using additional metal rings to prevent possible cracks spreading is an ideal engineering solution. I am just curious why TWSBI have decided to persevere with PC when there is a clear problem with it in this application, and not look at using a different polymer.

 

By the way I am looking forward to the 580 coming out as I do want one and I don't think I'll be too concerned about the material used unless it develops a problem. just looking at things from an engineering point of view.