Mb149 Repair

[Sagar_C]

I have a MB149 from mid 1980s. The pen is in good condition except for what you are seeing in the picture: filling system doesn't work. Any idea about the charges for repair from MB service center? I have to find out the charges in Denmark and also if a service center exists.

 

I may also send it to Eric (eckiethump on FPN) who has done wonderful work on 4 of my other pens (non-MB) earlier.

Edited March 8, 2012 by Sagar_C

[fountainbel]

Hi Sagar,

The locking ring - securing the screw spindle axially in the filling knob - is simply detached.

This can happen when the piston moves very thight , and when turning the piston up ( during filling)

Nothing seems to be broken, so the repair is rather simple.

Francis

[Rowbo]

I had a similar problem My link - if you want to try DIY. Note well - the tube must be small enough to fit into the hole in the cap. Good luck.

[Sagar_C]

I had a similar problem My link - if you want to try DIY. Note well - the tube must be small enough to fit into the hole in the cap. Good luck.

 

So I have to push the C-ring in the piston-cap and then force the spindle into it? A little more algorithmic description will be very helpful.

[Dr. Eriko]

I had a similar problem My link - if you want to try DIY. Note well - the tube must be small enough to fit into the hole in the cap. Good luck.

 

So I have to push the C-ring in the piston-cap and then force the spindle into it? A little more algorithmic description will be very helpful.

 

 

Hello.

Rowbo had a similar problem thatn yours. Rowbo helped me a lot when I had a problem with my piston form one 146. Hary has a lot of experience with this matter too. You can send a Private Mesage to Rowbo and ask for more details, Rowbo is a very nice person, and I am agree that you can fix that pen by yourself, maybe you are going to need the tool to disengage the piston system. Nothing broken appears.

Good Luck

Regards.

[Rowbo]

Sorry for not being more precise in my suggestion or responding sooner - I have just acquired new PC.

 

If you want to try DIY, then I shall tell you what I did.

 

Find a metal tube that has an internal diameter that permits it to fit over the spindle as far as the thick end that fits into the knob. I measured my spindle at 3.5mm. The outside diameter of the tube should be no more than is a good fit into the recess in the knob where the thick end of the spindle sits. I measured mine by trying different sized drills - 5mm was the best fit. This means the wall thickness of the tube is only 0.75mm. The tube should have a nice square end without rounded edges and without burrs or any roughness. It needs to be longer than the spindle and long enough to be able to get a firm grip - best if it has some sort of handle, say a 5mm hole drilled into a piece of wood.

 

Do NOT put the C-ring in first!!

 

Offer the thick end of the spindle into the knob and confirm that it is properly seated by gently rotating it. It should stop after less than half a turn in both directions. If you examine the end of the spindle and the inside of the knob, then you will see why this is - there are 'cheese-shaped' features on both parts.

 

It may be that the C-ring has become slightly distorted from the trauma of being forcibly extracted from its groove in the first place so it is best to check that it is nice and flat and not twisted or stretched open. Two small pairs of pliers might be needed to adjust it. Do not close it into a circle because it will not work and will just fall out again.

 

Put the C-ring onto the spindle followed by the tube. The C-ring should not fall over the thick end.

 

Now for the make or break (!) part.

 

Whilst holding the knob in one hand, push the tube carefully but firmly, without letting it stray 'off axis' i.e. straight and without twisting it, so that the C-ring snaps into the undercut groove in the knob. This can be a bit of a fiddle. I had to have several attempts until I succeeded.

 

When it snaps into the groove it makes an audible click sound and you can then smile and congratulate yourself.

 

If you are not confident or do not feel competent then please take the safe option. I am engineer and consider myself to be 'good with my hands' and, it has to be said, willing to 'have a go' - but not a 'risk-taker'.

 

Do let us know if it turns out well. If it does not, please forgive me for even suggesting DIY.

 

If there is anyone who wishes to intervene and offer advice as to how to improve my method - a method that I have only used once - please do so now.

 

Best regards

Rowbo.

 

p.s. You will also need a peg spanner to unscrew the piston mechanism from the barrel. Putting it back together is intuitive, not difficult, nor too risky, but trial and error is needed to get full travel on the piston. There is a thread somewhere that describes how to do it.

Edited March 9, 2012 by Rowbo

[stevlight]

Rowbo--Pics of this procedure would be very valuable --for us visual learners!

[Rowbo]

Sorry, I did not record the event! and it was a one off (I hope), but I shall do a sketch.

[Rowbo]

Sorry, I did not record the event! and it was a one off (I hope), but I shall do a sketch.

 

Website error caused double post.

 

Edited March 9, 2012 by Rowbo

[Sagar_C]

I bow to thee for being so helpful and clear! The sketch is ice on the cake. Let's see if I can find a tube — I am thinking hard and recalling about all the tubes in my memory. :hmm1:. This thread has been of great educative value. Thanks again.

[Chrissy]

I thought the procedure all sounded more or less possible until I got to:

 

"p.s. You will also need a peg spanner to unscrew the piston mechanism from the barrel. Putting it back together is intuitive, not difficult, nor too risky, but trial and error is needed to get full travel on the piston. There is a thread somewhere that describes how to do it."

 

Then it became really difficult

[Rowbo]

Please do not rush into anything. I have sent a PM to a very respected pen tooling expert (fountainbel) to ask him if he would review this.

[stevlight]

The sketch is much appreciated--thank you

[Rowbo]

Oops! just noticed that 'fountainbel' (Francis) was the first to respond to the OP.

 

The expression 'leave it to the experts' springs to mind. :embarrassed_smile:

[hari317]

I thought the procedure all sounded more or less possible until I got to:

 

"p.s. You will also need a peg spanner to unscrew the piston mechanism from the barrel. Putting it back together is intuitive, not difficult, nor too risky, but trial and error is needed to get full travel on the piston. There is a thread somewhere that describes how to do it."

 

Then it became really difficult

 

It is quite easy.

 

https://www.fountainpennetwork.com/forum/index.php?/topic/125061-lubing-the-piston-of-my-149/page__view__findpost__p__1837161

[fountainbel]

Sorry, I did not record the event! and it was a one off (I hope), but I shall do a sketch.

 

Website error caused double post.

 

 

Perfect explanation and sketch Rowbo, that's the way to go !

Complementary would suggest to seat the filling knob in a 10mm hole made in a wooden or plastic block when knocking the C -ring in.

When supporting the filling knob on its convex end, there arre some risk for cracking the filling knob end.

Francis

Edited March 10, 2012 by fountainbel

[hari317]

Francis, what is the best way to remove the C ring? Have you made a tool for this yet? I have several knobs with broken spindles.

[Rowbo]

Now that really is a challenge!

[fountainbel]

Francis, what is the best way to remove the C ring? Have you made a tool for this yet? I have several knobs with broken spindles.

 

Removing the C ring when the spindle is sheared is nearly impossible.

I've tried this several times but never suceeded.

In the end I decided to drill a 1.0mm central hole in the cap top, just going through the cap top material.

Doing so one can knock the broken spindle end and the C ring easily through using a 1mm driver pin ( made form a 1 mm drill)

The hole is then filled with a 1.05 mm diameter HR plug .

Benefit being one can knock the spindle./C ring out whenever needed.

Francis

Edited March 10, 2012 by fountainbel

[hari317]

Thank you Francis, I also failed in my attempts to get the C-ring out. Is it practical to remanufacture the spindle using a stronger material like brass? The relatively weak spindle is the Achilles heel of the otherwise perfect MB piston design.