Modern Montblanc's- Weak Piston Lead Screw?

[vates]

Francis, please, don't worry! The lead spindle on my pen was already broken. My problems have nothing to do with your advises; rather with my anxiety Thank you for all valuable information provided in this and other FPN threads!

[fountainbel]

Francis, please, don't worry! The lead spindle on my pen was already broken. My problems have nothing to do with your advises; rather with my anxiety

Oefff….. that's a relief !

Francis

[vates]

First things first: thank you all, dear forumites, for sharing you highly valuable knowledge on pens' costruction, repair and maintenance! This is what makes FPN such an exceptional resource.

 

So, here's the story. The spindle of my MB149 was broken: it had only a tiny part of it left in the piston knob (/blind cap). This was caused obviously by the serious clogging of the piston inside the barrel so that the previous owner forced the piston knob too much. So I tried to take the remains of the spindle out from the knob. Ouch! The knob cracked in half.

 

Luckily, a fellow professional chemist (from the local factory of hi-tech products) was able to glue the knob and then polish it so that it looks almost as new. While being glued, a new washer was inserted in place of the C-ring and also the spindle was replaced with presumably more durable purchased from (earlier mentioned) Custom Pen Parts.

 

For those who always wondered, according to the conclusion of the chemist, the so called "precious resin" of my '85-'90 MB is actually phenoplast based on phenol-formaldehyde: it is a carbolite resin with certain filler (which may be even wood chips).

 

While the cap was glued, I (upon extensive examination of this wonderful vault of knowledge) made my own MB tools both for nib and piston sides. Fully disassembled and cleaned the pen. I've also got some 100% silicone grease.

 

So the pen is now fully assembled and inked with MB Irish Green.

 

It is a smooth writer, the nib is great. However, it has an uneven flow: the line varies from wet to dry in the same word with no change in pressure and writing angle.

 

Did someone encountered similar problem? What it may be caused with? Thank you!

[MBFan]

 

It is a smooth writer, the nib is great. However, it has an uneven flow: the line varies from wet to dry in the same word with no change in pressure and writing angle.

 

Did someone encountered similar problem? What it may be caused with? Thank you!

I have this problem. I haven't the foggiest as to the cause or the solution.

 

Any suggestions?

[CS388]

 

 

It is a smooth writer, the nib is great. However, it has an uneven flow: the line varies from wet to dry in the same word with no change in pressure and writing angle.

 

Was it an even writer, before disassembly? Could you have accidentally got some silicone grease on/in the feed during assembly?

(You may be better off starting a new thread on this topic, as it is currently buried in the topic of Francis' new spindle and may not be seen.Maybe even in the Repairs Q&A sub-forum?)

 

Francis: excellent work on the new spindle.

Last time I bought a 146, I was surpised by how many were for sale with broken spindles. Obviously a common fault.

I'm sure your work will grow in demand!

 

Thanks

[vates]

I have this problem. I haven't the foggiest as to the cause or the solution.

 

Any suggestions?

 

 

 

 

Was it an even writer, before disassembly? Could you have accidentally got some silicone grease on/in the feed during assembly?

(You may be better off starting a new thread on this topic, as it is currently buried in the topic of Francis' new spindle and may not be seen.Maybe even in the Repairs Q&A sub-forum?)

 

 

 

 

Opened a new thread on the problem HERE

[macball]

There is another option that I would like to share. I purchased a MB149 off of ebay for a very good price. However, the original owner left ink in the pen that completely dried. At one point someone tried to move the piston and severely twisted the lead screw. When I received it I soaked the pen in water/dish soap/ammonia (as described here) for several days and successfully removed all the dried ink. But, the lead screw damage had been done. There are two options described in this thread: 1) send it back to MB for professional installation of a new lead screw or 2) obtain a new lead screw (from the sources listed in this thread) and struggle with the problem of the metal c ring that holds it in place. At least one reply to this thread asked if there was a drop in solution that did not require prying, pushing, drilling, tapping, threading, etc. All these methods come with great caution. I used a simpler approach. I removed the bent, weakened lead screw and purchased a new, stronger one from the UK (as described in this thread. An amazing product with fast reliable delivery). I just dropped (screwed) it in. Whenever I need to fill I unscrew the back cap (which now acts as a blind cap), unscrew the lead screw a bit, and manually depress the piston to empty and pull back the piston to refill. Afterwards I just drop (screw) the lead screw back into the piston thread and screw the back cap on. At some point I might find someone to attach the lead screw to the back cap properly with a c ring, but in the meantime the pen works perfectly as is and did not require any of the delicate alterations.

[vates]

That's an interesting solution But how did you remove the remains of the original lead screw out from the piston knob?

[macball]

I didn't know how the lead screw was attached to the end cap, so I just pulled it off. As usual, I wasn't doing this on a proper workbench and "ping" the C ring flew across the room and was never recovered. The original lead screw was pretty gnarled and could shear off in the middle at any time. It wouldn't fit easily inside the piston so I just kept it in my ink box and used it to manually move the piston for refilling. I used the pen for many months without any lead screw in the pen. It did bother me that if I needed to refill anywhere else I wouldn't have the lead screw to work the piston. But, that was kind of dumb because I wouldn't have the bottle of ink either! I was also worried about losing it so I put it in a larger tube marked "pen" in case the lead screw and the C ring were reunited in the land of odd socks. Once the new lead screw arrived I just dropped it in the piston, covered with the end cap, and the pen is now self-contained. Everything is normal except that I use the lead screw to work the piston manually and separately from the end cap.

[Inkling13]

Let me get this straight, as I am unfamiliar with MB. The brass piston is currently in the new 146/149's? or am I mistaken?

[macball]

Some parts are made of brass such as the back cap threads but the piston is made from a white plastic (precious teflon?) which you can see inside the ink window as it moves up and down. The piston is moved by a plastic threaded sleeve and screw rod (that has a number of names including lead screw). The end of the black plastic lead screw is attached to the back cap by a metal c ring. Normally, you don't see any of this because you move the piston by screwing the back cap that internally moves the lead screw against the threaded piston sleeve. As shown in the pictures in this thread the stock lead screw is made of an oval profile rod that does not tolerate much force to move a stuck piston. There are three non-stock replacements shown, including brass, each of which are stronger due to a round profile and improved materials. In my opinion the stock lead screw is appropriate but it is the weakest part and can bend when excess force is put on the mechanism to move a neglected stuck piston. In my case the pen was sold by an antique/estate sale dealer and at some point in time a novice tried to move the piston with dried ink in it. It is a wonder the cap/barrel threads aren't seen to be damaged more often in pre-owned pens. On the few regrettable occasions when I loaned my FPs for someone to make a quick note or sign a paper, the issue was not so much the novice putting too much force on the nib, writing on side or back of the nib (which has happened), but trying with all their might to pull the cap off rather than unscrewing it and then screwing it back on so tight that you can't get it off again.

[vates]

I didn't know how the lead screw was attached to the end cap, so I just pulled it off. As usual, I wasn't doing this on a proper workbench and "ping" the C ring flew across the room and was never recovered. The original lead screw was pretty gnarled and could shear off in the middle at any time. It wouldn't fit easily inside the piston so I just kept it in my ink box and used it to manually move the piston for refilling. I used the pen for many months without any lead screw in the pen. It did bother me that if I needed to refill anywhere else I wouldn't have the lead screw to work the piston. But, that was kind of dumb because I wouldn't have the bottle of ink either! I was also worried about losing it so I put it in a larger tube marked "pen" in case the lead screw and the C ring were reunited in the land of odd socks. Once the new lead screw arrived I just dropped it in the piston, covered with the end cap, and the pen is now self-contained. Everything is normal except that I use the lead screw to work the piston manually and separately from the end cap.

 

 

 

 

Brilliant

[GTOZack]

I always unscrew the cap off for them and said 'shiny part up 45 degrees angle, light as feather, and Have fun' most of the time they just slide across paper with no problem I just dont trust strangers, I do sometimes.. read, SOMETIMES lend to friends.

 

They would comment on how smooth MB's/Pelikans are, and sometimes theyd ask me where they could buy, I pointed FPN address and classified out for them, I told them that they would save SO MUCH buying here!

 

 

anyways, I noticed that there is many sheared or twisted plastic screws. is there a shop or even an individual that mass produces these screws for sale? I am tempted to just get on 3D printer and create these screws

( tempered plastic of course) It wont get me back in black but for sure there will be many functioning 1970s and 1980s MB's out there.