Help With Onoto Restoration. What Is The Problem Here?

[Greenie]

The pen is restored. New O ring on the barrel. New gasket. Great suction.

 

But now the rod seems 1 mm too long. i can't screw down the piston rod cap. Or, I can loosen the section 1 mm, and then screw down the piston rod cap.

The rod just seats into the section 1 mm too soon. The pins are all in the holes. The threaded part on the piston rod is pretty short and does not look like it can screw down another mm.

 

Has anyone had this problem? What do I think that I did right, but actually got wrong?

 

I can put the section end of the rod on the lathe and shave it down, but I hate to remove material when the thing fit together fine before I cleaned and restored it.

 

Edited May 14, 2017 by Greenie

[northlodge]

Couple of things spring to mind.

 

The coned part has raised slightly.

Is there an o ring fitted below it that can be removed?

or is the whole cone part a replacement that was slightly taller than the original?

 

Was the filling mechanism completely seized when you received it? If not it could be possible that someone replaced a part / parts, with the wrong seal seat being screwed to the piston rod.

 

There are various solutions that would address your problem, but bear in mind that the piston rod cannot be shortened beyond the point where the seal frees from the barrel. Therefore the three 'botches' (in descending order of desperation) might be

1. shorten the cone piece from the base before fitting it on the peg

2. remove the point (like on the minor) or re-sculpt the point, so as to allow closure - this may well negate the ink-lock design.

3. shave a piece off the feed - again the ink-lock might be compromised

Edited May 14, 2017 by northlodge

[Cob]

I think that the way to look at this one is to ask oneself "what has changed?"

 

You mention "O ring" What is this? I use cup seals from Custom Pen Parts and also their corks.

 

The only thing that could have changed to cause this problem, given that the pins are in their original places and of course on the original piston rod, is that the feed is further back in the section than it was beforehand.

 

Rgds

 

Cob

[Beechwood]

I have just completed a K3 and had the same issue although the system is probably simpler, there was no pinning, I just used trial and error for how the rod sat within the piston and the knob, minor adjustments and reassembly eventually produced the required result.

[Greenie]

I want to thank everyone for the advice! Simpler questions on other brand forums often fail to bring out anyone helpful.

 

Great advice all the way around.

 

In no particular order:

 

 

I have just completed a K3 and had the same issue although the system is probably simpler, there was no pinning, I just used trial and error for how the rod sat within the piston and the knob, minor adjustments and reassembly eventually produced the required result.

 

I certainly hope so! I have taken the entire thing apart again back to the individual pieces hoping I either see the problem or that it fixes itself with reassembly.

 

 

Couple of things spring to mind.

 

The coned part has raised slightly.

Is there an o ring fitted below it that can be removed?

or is the whole cone part a replacement that was slightly taller than the original?

 

Was the filling mechanism completely seized when you received it? If not it could be possible that someone replaced a part / parts, with the wrong seal seat being screwed to the piston rod.

 

There are various solutions that would address your problem, but bear in mind that the piston rod cannot be shortened beyond the point where the seal frees from the barrel. Therefore the three 'botches' (in descending order of desperation) might be

1. shorten the cone piece from the base before fitting it on the peg

2. remove the point (like on the minor) or re-sculpt the point, so as to allow closure - this may well negate the ink-lock design.

3. shave a piece off the feed - again the ink-lock might be compromised

 

The cup washer was brittle and only jiggled in the wider portion of the barrel - not entirely seized, but seemed original

 

****Is there something down inside the section normally that helps with the piston rod seal ???? I have to go look down in there! That would be a great explanation for this problem.

 

And as for the solutions, thank you for three good ones. If all else fails, I will gradually shave down the cone on the end of the piston rod until I have a good fit. I am a pretty good sculptor on the lathe. I would like to keep the pen working as intended, but with the ambering, and being a short model, I am not sure that it is such a prize. Probably no tragedy if I ruin the anti leak design accidentally by over shortening the cone.

 

 

I think that the way to look at this one is to ask oneself "what has changed?"

 

You mention "O ring" What is this? I use cup seals from Custom Pen Parts and also their corks.

 

The only thing that could have changed to cause this problem, given that the pins are in their original places and of course on the original piston rod, is that the feed is further back in the section than it was beforehand.

 

I used O rings in place of the cork seal.

 

I used a flat gasket and not a cup washer. It functioned great. The Oldfield book states that a flat washer is correct for this model pen. But I am very new to Onoto and could use some education. To trouble shoot this, I will take off the washer and reassemble to see if it somehow made a difference.

 

I had thought about the feed placement before reassembly. So the plan was to put the section on first and put the rod down all the way before fitting the feed. That way it would be in the right spot. But the problem came up before the feed was installed.

 

 

BACK TO THE WORKSHOP!!!!!!

[Vintagepens]

Did you remove the nib and feed?

If they were reset slightly deeper into the section, you'll have the problem you describe.

[Greenie]

Did you remove the nib and feed?

If they were reset slightly deeper into the section, you'll have the problem you describe.

 

I did remove the nib and feed. And the original plan was to put in the nib and feed with the pen piston screwed down, so as to prevent this problem. The problem persists even with the nib and feed removed. And I took a better look inside the section - no material there to cause the hang up.

 

Rather odd. If some disassembly and reassembly fails to work it out, I will shave a bit of the conical end piece until it has a proper fit to the section and feed.

[Greenie]

Well, while trying to shave it down on the lathe, I ended up breaking it.

 

So I ended up making a new one with the same diameter, angle of the end cone point, etc, but about 1 mm shorter.

 

Now all is well. Hard to say if there is a good ink shut off or not, but it must be close.

 

Thanks to all for the advice. It would have been more interesting had I solved the problem rather than breaking and remaking the piece.

[Vintagepens]

For future reference, it's best to reseat the nib and feed with the piston knob unscrewed slightly. That way you get a good firm seal when the knob is screwed in all the way.

 

 

I did remove the nib and feed. And the original plan was to put in the nib and feed with the pen piston screwed down, so as to prevent this problem. The problem persists even with the nib and feed removed. And I took a better look inside the section - no material there to cause the hang up.

 

Rather odd. If some disassembly and reassembly fails to work it out, I will shave a bit of the conical end piece until it has a proper fit to the section and feed.

[Greenie]

Thanks for the advice, David.