Metallic Copper Fountain Pen

[ValleyBoy]

i
Thanks for the info. That is gold dust!
The chipping im getting is all when i'm threading. Very little chipping whith M10x1 or M10x.75 Mostly with the Beaufort Ink supplied three start cap threading die. I don't believe the die is blunt or defective. I've got some indeterminate black resin which i use for insert tenons etc and they chip far worse than the alumilite. When you say applying too much pressure are you talking about sideways pressure on the die to keep it cutting (i've managed to strip a tenon entirely when not applying enough sideways pressure so i could be going too far the other way i guess).
Do you have a go to youtube video guide person who gives good tutorials i could have a look at? Might save you being endlessly brain picked
.
Once again, thank you for your patience.

Pleasure!

You will tend to find that threading with a triple lead die is more difficult than the single lead type and is more prone to chipping. Even though, for example, a 13mm die has a pitch of .75mm the fact that there are three helixes running alongside each other means that there’s quite a lot of torque being applied when you’re twisting the die on the workpiece, and as such any small inaccuracies with the tenon diameter will likely be exaggerated much more than with a single lead thread.

However you’re probably closer than you think and what I would do, first of all, is make sure your tailstock is perfectly aligned to your headstock. This is critical because if it’s slightly off then you’ll end up threading at an angle which will cause too deep threads on one side (and hence chipping). I can’t stress this enough and concentricity is critical.

Then it’s a case of practice. Make a cap and tap it. If you’re using acrylic it should feel firm when your applying the tap but not so tight it makes your hand turn blue, not so loose that it slides threads it very easily. Once you’ve made it set it to one side, you may need to make more once you get the make threads sorted.

Then just turn a tenon in the right ball park and thread it. If it chips then turn another a little smaller (I’m talking about 0.1mm increments) and keep doing it until it taps without chipping. You’re sneaking up on it. This diameter may be different for acrylic compared to, say, cellulose. So keep a note!

Then screw it into the cap. If it’s too loose you need to make a cap with a slightly narrower hole, and if too tight then try making one with a wider hole. Again I’d go up or down in 0.1mm increments.

The reason I can’t tell you exactly what size to drill or turn is because my tools will be marginally different to yours so could be 0.1 or 0.2mm different. It does sound like you’re not too far away, but it does take a bit of patience. However once you get the perfect fit you’ll be enjoy that Primitovo a lot more!

Cheers
Ash

 

[sutdm]

I turn the tenons to the stated diameter minus a bit by .1 or.2 mm. They aren't the issue though, it's the bigger diameter ones i'm getting the chipping with. After some more experimentation today i think perhaps i was going too fast. The smaller ones didn't have the same peripheral speed at the rate i was going. The latest one went peachy thanks. And after some inspection i discovered a massive burr on one of the flutes of the 10mm tap which was stripping my thread. Dremels are great aren't they? I 'sharpened' the flute with the burr and it's cutting clean threads. So, until it's not, the problems sorted. Thanks for your time.

Mark

 

[sutdm]

Pleasure!

You will tend to find that threading with a triple lead die is more difficult than the single lead type and is more prone to chipping. Even though, for example, a 13mm die has a pitch of .75mm the fact that there are three helixes running alongside each other means that there’s quite a lot of torque being applied when you’re twisting the die on the workpiece, and as such any small inaccuracies with the tenon diameter will likely be exaggerated much more than with a single lead thread.

However you’re probably closer than you think and what I would do, first of all, is make sure your tailstock is perfectly aligned to your headstock. This is critical because if it’s slightly off then you’ll end up threading at an angle which will cause too deep threads on one side (and hence chipping). I can’t stress this enough and concentricity is critical.

Then it’s a case of practice. Make a cap and tap it. If you’re using acrylic it should feel firm when your applying the tap but not so tight it makes your hand turn blue, not so loose that it slides threads it very easily. Once you’ve made it set it to one side, you may need to make more once you get the make threads sorted.

Then just turn a tenon in the right ball park and thread it. If it chips then turn another a little smaller (I’m talking about 0.1mm increments) and keep doing it until it taps without chipping. You’re sneaking up on it. This diameter may be different for acrylic compared to, say, cellulose. So keep a note!

Then screw it into the cap. If it’s too loose you need to make a cap with a slightly narrower hole, and if too tight then try making one with a wider hole. Again I’d go up or down in 0.1mm increments.

The reason I can’t tell you exactly what size to drill or turn is because my tools will be marginally different to yours so could be 0.1 or 0.2mm different. It does sound like you’re not too far away, but it does take a bit of patience. However once you get the perfect fit you’ll be enjoy that Primitovo a lot more!

Cheers
Ash

That's brilliant again Ash, thank you so much. Thinking about the triple start thread, not only the issues you mention but also i guess each single thread is 'travelling' sideways at three times the rate of a single thread so the cutting forces are more sideways than rotational.

I've found 'Blondihacks' on youtube who seems to be a no nonsense tutor on lathes, she's done one on head/tailstock alignment so i'll follow her lesson and see how i get on.
And back to the vino!

 

[ValleyBoy]

That's brilliant again Ash, thank you so much. Thinking about the triple start thread, not only the issues you mention but also i guess each single thread is 'travelling' sideways at three times the rate of a single thread so the cutting forces are more sideways than rotational.

I've found 'Blondihacks' on youtube who seems to be a no nonsense tutor on lathes, she's done one on head/tailstock alignment so i'll follow her lesson and see how i get on.
And back to the vino!

Blondihacks is the best resource for metal lathes/mills I’ve found. I think she should be made the patron saint of machinists. A real modern day Joan of Arc in what is still a very male oriented discipline.

Cheers
Ash

 

[alpha1]

I am a fan of Blondihacs I have learnt bucket loads of stuff regarding Metal lathes and Mills. Not so mutch wood turning stuff.
To be honest Ash has learnt me a lot about pen turning as I tend to lean to wards kitless pens now a days. His input has been invalubale.
One of my freinds at my new Woodturning club took home one of my kitless pens for his Wife. She is over the moon with it.
He showed it to the Wood turning group and considering most of these Guys could be classed as professional wood turners I could of sold a bunch of them they could not get over how I had cut the threads etc. Bottom line is Ash told me how to cut triple lead threads etc.

 

[sutdm]

It looks as if two deifications are in the offing. The pope is going to have a busy year. Maybe he needs to take up lathe work in his spare time. I wonder if the historically verified Jesus was into turned work or stuck with mortice and tenons in their rightangularity
Either way, you are very generous with your Knowledge Ash and will, in time save huge quantities of variousl plastic blanks ending up in landfill! Go and drink red wine!