drilling for #5 bock nib units

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watch_art

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Okay - I'm having a pain in the butt time making a section for a #5 nib unit. Actually wasted a bit of material which bugs the heck out of me.

So to start with...

- turn down and cut the section threads (10mm)
....then what??

I've made one section but I keep ruining the threads that hold the unit in. It seems like there's only a very tiny margin of error and then you ruin the threads - which I've done about 5 times. Either I'm not measuring something right or I'm just being an idiot. Either way I'm getting really ****ed off at the whole situation.

Should I just drill and tap the whole length of the section and then flip the piece around, put it in a holder thingy in a round collet, drill out to hold the nib unit, then turn down the section to shape?

I don't know why I'm having so much trouble with this.
Maybe I need more sleep.

Ugh...
 
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I'd love to help but some detail, please. Assuming the 10mm threads are the external threads (if this is wrong then forget the rest of this reply) then I guess you're having trouble with the internal threads that hold the nib assembly in.

What hole diameter are you drilling/boring?
What tap size are you using. (I believe you're not single-pointing the threads)
Are you holding the tap in your tailstock - same as what gave you the earlier external thread problems?
How deep are you trying to thread?
What kind of tap is it? taper, plug, or bottoming.
What material are you tapping?

Cheers,
Rich
 
Just a thought --

The internal threads are really fine so if you are tapping acrylic or something soft like that you shouldn't be holding the tap in anything that gives the least resistance to allowing the tap to feed as it needs to. (Like a heavy tailstock)

Cheers,
Rich
 
So is this right?

Turn a tenon - 16mm

cut 10mm threads

drill the length of the section 43mm (for this particular section) going a little farther so when I part it off the hole goes through the entire piece

tap 19mm in for the nib unit threads

drill with an L bit in 16mm for the converter

Turn the section down to shape (mostly)

Part it off and hold it in a threaded holder

Drill in 24mm for nib housing, hopefully not trashing the threads, w/ 19/64 bit
Then in about 3.5mm with L bit for housing lip.

Finish turning down and finish to shine


I'm sure I missed something, my notes are out in the shop.
 
watch_art said:
So is this right?

Turn a tenon - 16mm

cut 10mm threads

drill the length of the section 43mm (for this particular section) going a little farther so when I part it off the hole goes through the entire piece

tap 19mm in for the nib unit threads

drill with an L bit in 16mm for the converter

Turn the section down to shape (mostly)

Part it off and hold it in a threaded holder

Drill in 24mm for nib housing, hopefully not trashing the threads, w/ 19/64 bit
Then in about 3.5mm with L bit for housing lip.

Finish turning down and finish to shine


I'm sure I missed something, my notes are out in the shop.
Click to expand...

Why are you turning a 16mm tenon to cut 10mm threads:confused: You tenon for a 10mm threads should be around 9.8mm. Where are you getting your dimensions from?
 
watch_art said:
So is this right?

Turn a tenon - 16mm

cut 10mm threads (You have got to be turning this down some more from 16mm for 10mm thread pitch, right?)

drill the length of the section 43mm (for this particular section) going a little farther so when I part it off the hole goes through the entire piece (what size drill?)

tap 19mm in for the nib unit threads (size of tap? length of thread? Is 19mm the last thread?)

drill with an L bit in 16mm for the converter (.290" bit. No problems with these threads?)

Turn the section down to shape (mostly)

Part it off and hold it in a threaded holder (the 10mm threads being held?)

Drill in 24mm for nib housing, hopefully not trashing the threads, w/ 19/64 bit (since you've reversed the unit you seem to be only going in exactly as far as the last thread you made from the other side - and that's a partial and shallow thread. The tap has a taper on it so you will not be drilling in as far as you need to in order to drill into the full thread profile. My guess is that here's your problem. You need to tap further than 19mm)

Then in about 3.5mm with L bit for housing lip.

Finish turning down and finish to shine


I'm sure I missed something, my notes are out in the shop.
Click to expand...

Cheers,
Rich
 
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Rich L said:
Just a thought --

The internal threads are really fine so if you are tapping acrylic or something soft like that you shouldn't be holding the tap in anything that gives the least resistance to allowing the tap to feed as it needs to. (Like a heavy tailstock)

Cheers,
Rich
Click to expand...

Really? How would I hold the tap then? I haven't had any trouble tapping like this before.

And I'm tapping into acrylic.

The tap is the one that you can get at classicnib for the #5 nib bock units.
 
Sorry - misunderstanding.
The tenon is 9.8 or so thick, but it's 16mm wide. It's the width of my penpro tool. Otherwise I can't get in there to cut it b/c of the live center getting in the way.

Hope that makes sense.
 
drill the length of the section 43mm (for this particular section) going a little farther so when I part it off the hole goes through the entire piece (what size drill?)

tap 19mm in for the nib unit threads (size of tap? length of thread? Is 19mm the last thread?)

drill with an L bit in 16mm for the converter (.290" bit. No problems with these threads?)
Click to expand...

#2

I could go farther in than 19, 22 or just the entire length of the tap. I just wrote 19 b/c that's about where the last thread would need to be.

.290 bit. What do you mean no problems?

I've made one good section for the #5, with just enough threads to hold all of the threads on the unit housing. THe problem comes when I try to make the back of the section big enough for a converter to fit in there AND touch the back of the feed nipple. With the #6 Meister nib units it's no problem b/c the J bit used before threading makes a big enough hole for the converters. If I use the pen as an eyedropper it won't matter, but not everybody likes to do that - and for my kids it would just be a big mess.

Thanks!
 
Shawn, the threads for the Bock feed is very fine and as you can see on the feed there is only a small portion of threads at the bottom of the feed. This means that you have to be very gentle when you cut these threads. If you over tighten it when you get to the bottom of the hole, you will strip the threads. I also do things backwards form you. I tun my tenon for my outer threads, cut my tenon, drill my letter A hole for my threads all the way through, and drill a fraction of an inch with a 1/4" bit for the end of the converter. Then i flip it around in my collet, drill the letter L hole 1.1" deep and tap with the Bock tap, very gently. Then i use the edge of my Woodchuck Penpro to chamfer the front edge for the front lip on the Bock feed, and im done. I dont turn it to shape until im have all the pieces for my pen ready to turn to finial shape. PS: I also hold the tap in my tailstock, no problems here.

Hope this helps
 
#2 is way to small. Why are you using such a small bit? This is why your threads are tearing out. Do you know how to size your bit for your tap?
 
I'm using a #2 b/c of this:
http://www.penturners.org/forum/f56/feed-hole-size-91422/

OKLAHOMAN said:
This is what Justin Short (Timebandit) uses :

For the threads for the #6 use a Letter L drill bit and for the #5 use a #2 drill bit. For the housingsi use a Letter P for the #6 and a Letter L for the #5
Click to expand...

Timebandit said:
#2 is way to small. Why are you using such a small bit? This is why your threads are tearing out. Do you know how to size your bit for your tap?
Click to expand...

And no - I only use the bits that I read as recommended for each size tap. #2 for the #5 bock, and J for the 6 Meister.
 
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Theoretically you should use a #1 bit, but you should give it a little clearance so that its not to tight, which is why i went with the letter A. Im not sure why i told Roy a #2.....does anyone else use the #2 with success?
 
ok thanks. i'll go w/ A.

#2 does work fine, though, until I ruin my threads - but w/ my one that worked it worked just fine.
 
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To find out your tap drill size for a metric tap( this is only with metric) you take the 2nd number on the tap(which in this case is .6) and subtract it from the first number( in this case its 6.4) which gives you a 5.8mm drill bit. 5.8mm in inches is .228" which is #1 drill, so just up size to the next closest drill size. If you would like to know how to figure out an imperial tap just let me know :)
 
Glad you guys that have actually made these sections are weighing in. It generally comes down to some fundamentals.

Cheers,
Rich
 
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