I was actually drilling for the nib unit threads too deeply getting into the tenon. And the tap wS entering the tenon. When the tap got close to the tenon it broke. I like your suggestions.I couldn't work out exactly what's happening to cause this, so forgive me if I'm wrong, but my guess is you're adding a rebate/undercutting at the back end of the threads on the section to allow it to screw into the barrel smoothly. (I see this a lot). If you are then it creates a point of weakness which may cause the threaded tenon to come away when drilling the wider diameter needed for the Bock nib unit. (Again I'm guessing your order of events).
If so I would suggest adding a small rebate inside the barrel if needed, rather than adding an undercut to the tenon.
Or alternatively make the visible part of the section long enough to entirely envelope the nib unit so you don't come close to the threaded tenon when drilling for the nib unit.
Hope this makes sense.
Cheers
Ash
Sure, stopping drilling before the tenon is the safest and my comment about the undercut becomes redundant in that case.I was actually drilling for the nib unit threads too deeply getting into the tenon. And the tap wS entering the tenon. When the tap got close to the tenon it broke. I like your suggestions.
Thanks. There seemed to be some change in the housing. Not sure when. I have several Bock nib units and a couple of them do not screw in as far as they should. The tap I have from one of the group buys was not working. It was marked with D4 next to the M7.9x.6. I was advised to get a different tap and it worked fine. I can let you know where I got it if you encounter the same problems. I can also tell you my drilling sequence if you want.Great looking pen, Don.
I'm about to make some Bock #6 sections. Like you, I've been making JoWo sections without too many problems ... that is, once I got the turning, drilling and threading in the correct sequenceI'll pay extra attention to the depth I drill & tap for the housing.
Thanks; I don't remember what the coding on my tap is, but I have a matching die so I can chase the threads on the housing before fitting it into the section. I've found that helps with JoWo units too - they are sometimes a little out of round and get stuck in the section.Thanks. There seemed to be some change in the housing. Not sure when. I have several Bock nib units and a couple of them do not screw in as far as they should. The tap I have from one of the group buys was not working. It was marked with D4 next to the M7.9x.6. I was advised to get a different tap and it worked fine. I can let you know where I got it if you encounter the same problems. I can also tell you my drilling sequence if you want.
Do a good turn daily!
Don
Charles,Hi Don,
I have been working with Bock nibs also. Where did you get your m13-.8 tap and die? Is it a single start? I have been using a triple start and want to switch to a single.
Thanks,
Charles