How To Remove The Piston Knob Of M800 ?

[Sunburst]

Does anyone know how to disassmble/remove piston knob (knob only) from the

piston assy of M800?

Does piston assy needs to come out from the pen to accomplish this?

Any info is truly appreciated.

Edited November 16, 2010 by Sunburst

[hari317]

 

Does piston assy needs to come put from the pen to accomplish this?

 

 

Yes, unless, the piston mechanism is broken.

 

after the filler is unscrewed from the barrel (using the spanner, LH threads), keep unscrewing the knob to extend the piston, the piston rod will separate from the filler unit and the knob will unscrew off.

Edited November 16, 2010 by hari317

[Sunburst]

Hari,

 

Piston mechanism is fully functional.

I just need to replace the piston knob to correct type for old-style M800 with gold disc.

[hari317]

Hari,

 

Piston mechanism is fully functional.

I just need to replace the piston knob to correct type for old-style M800 with gold disc.

 

It is very simple to do so. You will need a 7mm spanner ground down to 1mm thickness, I got this tool from Fountainbel. Also see following links for tools:

 

Link1

link2

 

Remember that the filler has LH threads, so insert the spanner, holding it by your hand, rotate the barrel counterclockwise to extract the filler.

 

once the filler threads are disengaged from the barrel, just pull the filler assy out. now rotate the knob in the motion used to extend the piston, the piston will extend and finally disengage, continue to rotate the knob, it will simply disengage from the brass connector. The knob's inside engages with the cylindrical nut that actually extends retracts the piston spindle. it is just a slide fit with the backlash mechanism.

Edited November 16, 2010 by hari317

[fabrimedeiros]

Most of the time, unscrew the nib and put a bit of silicon grease with a toothpick is all you need to.

 

If you need a better cleaning, you can unscrew the piston with a 7mm key (like a Diamond Key from TWSBI). You can remove & assemble M800 piston fill the same way as Diamond 530.

 

You can use a hard credit card as a 7mm key. It's easy to make it.

[Sunburst]

Hari,

 

Thanks again for the detail info.

I like the looks of Moody Tool.

[Sunburst]

You can use a hard credit card as a 7mm key. It's easy to make it.

 

Excellent idea - I may give that a try.

[hari317]

You can use a hard credit card as a 7mm key. It's easy to make it.

 

Excellent idea - I may give that a try.

 

I made myself a "credit card spanner" (link) and was using it till I finally recently got a professional spanner made by Fountainbel.

[Sunburst]

Strange coincidence as I've just received new Amex card in the mail. :hmm1:

And this is the first time that I'll be actually using Amex (as a spanner wrench). :roflmho:

Edited November 16, 2010 by Sunburst

[tdd]

Hari,

 

Piston mechanism is fully functional.

I just need to replace the piston knob to correct type for old-style M800 with gold disc.

 

It is very simple to do so. You will need a 7mm spanner ground down to 1mm thickness, I got this tool from Fountainbel. Also see following links for tools:

 

Link1

link2

 

Remember that the filler has LH threads, so insert the spanner, holding it by your hand, rotate the barrel counterclockwise to extract the filler.

 

once the filler threads are disengaged from the barrel, just pull the filler assy out. now rotate the knob in the motion used to extend the piston, the piston will extend and finally disengage, continue to rotate the knob, it will simply disengage from the brass connector. The knob's inside engages with the cylindrical nut that actually extends retracts the piston spindle. it is just a slide fit with the backlash mechanism.

[tdd]

I noticed this thread and have a M800 where the the knob has come lose and the brass connector also has come lose from the body. I have a spanner wrench but when I try to put it all together there is a small gap between the knob and the body of the pen. When I turn the knob it comes off, its not stopped when the piston reached the bottom near the nib.

 

How does one tighten down the brass connector and get the knob to seat properly with the pens body?

 

thanks in advance for your help....Tom

[hari317]

 

How does one tighten down the brass connector and get the knob to seat properly with the pens body?

 

 

It seems the piston stroke is not adjusted properly during re-assembly. Sorry, I have no pictures to help you understand more clearly...

• 
   
  
• Extract the filler assembly completely from the barrel.
  
• Unscrew the knob completely from the connector, There will be a hollow cylindrical nut inside the knob.
  
• Engage this cylindrical nut into the knob properly
  
• Now screw in the knob on the connector so that only 3-4mm remains from the end.
  
• At this point insert the piston rod from the bottom of the connector through the flat slot.
  
• Screw in the knob fully, it should shut tight and piston should get completely retracted.
  
• Repeat the procedure with minor adjustements to the point when you insert the piston rod, so that the knob screws down fully and full piston retraction is achieved, 2-3mm from the end slot of the connector.
  
• Now just unscrew the knob a few turns, insert the spanner on the slots, screw the knob in again to hold the spanner and now thread in the filler to the barrel snugly, LH Threads.
   
  

Edited December 11, 2010 by hari317