parker 75 cap clutch - again

[gregglee]

There are other threads on this but I figured better to start a new one than revive an old one.

 

I know there are older threads but none recent found by search.  I attached a diagram snipped from parker75.com. 

Most of this is what I tried without success. 

 

I have a parker sterling crosshatch with a damaged clutch.  one finger bent backward.  Old threads here suggest:  grip the clip screw (aka tassie) with padded pliers while also gripping outer cap in hand, then turn the clip screw to unscrew it.  The clip screw threads into the inner cap so this depends on the inner cap holding to the barrel.  I succeeded with this method in disassembling one pen, bought in mid 1990's.  From this I know what the parts look like and how they fit together.   

 

But the method failed on the the cap on the one I am trying to fix, which is about 30 years older, based on design details.  On that one using the same method the clip screw turns in the cap but the clip screw does not loosen.   It seems the inner cap is turning inside the outer cap.  The screw threads are stuck too tight in the inner cap.   

 

There is a second method, listed on the snip from parker75.  It uses an "arbor" to turn the inner cap inside the barrel, depending on the outer cap and clip to hold the screw in place relative to the inner cap.  I haven't seen the arbor listed anywhere, nor found a picture.  Looking down the cap with a flashlight I don't see anything obvious to suggest its shape.  However it works, it must grip the inner cap but not the end of the screw, which I can see. 

  

I thought maybe the arbor grips by friction so I tried a large diameter pencil with soft eraser that does not reach the screw when it grounds in the inner cap.   I did this both while holding the cap in hand and then with padded pliers on the screw.  The eraser gripped a lot but eventually slipped before the screw turned.  At the same point I was getting concerned about gripping the screw too tightly.   I was also concerned about damaging the inner cap,       

 

Nevertheless I tried the blunt end of a fat plastic pen as the arbor, pushed tightly into the inner cap.  pen was smooth but not soft.  That held more than the pencil eraser, but I reached the point of fear of damage before any movement of the screw. 

 

So the screw is stuck.  I tried soaking.  I would not try heat because of damage risk to the inner cap, and since the metal screw would expand more than the plastic inner cap it would become tighter. 

 

I did try soaking in benign solution.  I didn't try soaking in koh-i-noor rapido-eze pen cleaner (intended for rapidograph type pens), because I don't know if it is sufficiently benign for the inner cap. 

   

I though about using something like wd 40 or penetrating oil, or  but I won't unless I know it won't damage the inner cap. 

 

Any  insights or suggestions?              

         

[Ron Z]

All of the rollerball and fountain pen caps have a threaded tassie on top.  The inner cap may be the short one shown, or may be a long one with the clutch bumps molded into the inner cap.   It should come loose. You may need to use heat as well.  Inner caps are available, and not all that expensive should you need to replace it.   Parker75.com has both the tool and replacement inner caps ($15) and clutch fingers ($10). 

 

The tools to grip the inner cap are knurled at the top so that they can bite into the plastic of the inner cap to keep it from turning. 

[gregglee]

thanks.  sorry for the delay.  I thought email notifications for replies was on, but it was off.  

[gregglee]

The tool looks more like spines than knurling.    About 40 splines.  tapered. 

But overall it looks al lot like a torx  wrench.  Only 6 points on a torx driver,  but I might try that first.  I already have them.          

 

photos snipped from the internet.  parker tool then torx.