DaveM
Member
I am looking at the way our pens are built, and the way the larger companies do it. One of the big differences is that most of them have the threading right on the body of the pen, as opposed to little push in threaded couplers. Same for the caps on several of them. I would like to make some acrylics, and later some ebonite and cumberland pens with this design feature. I have access to a metal lathe with threading capabilities.
Would I be better off doing this directly on the lathe, or could I create a tap and die with the threads I want, and use them to make the pen's threads? It seems like the tap and die would be more foolproof, since I would only have to get them just right once. To cut a four start thread in both the cap and body of a pen would require eight separate threads to be cut, and I am not that accurate with a lathe. (Four of them would be inside of the cap too!) I was thinking of threading a slightly tapered rod, and then grinding slits into it to make a tap for the insides of the cap. Any real machinists have a better idea? I could just pull the tail stock slightly off center to get the taper.
To cut multistart threads, I would just need to adjust the cross feed between each course of threads, or use the compound, and calculate the amount using trig. (I think) I was just reading about multi start threads being cut using a thread chaser at twice the TPI of the setting on the lathe to make a two start thread. I was wondering if this would be feasible for a four point start, or if that is even necessary?
Has anybody gone down this road before, or am I losing it in my addiction to pens. (I spent a whole day on the 'net looking at Bill's fountain pen page, and every other site on the old pens)
Thanks,
Dave
p.s. Is there a really easy out for this, like a pre made tap and die set for these threads? I have been known to re invent the wheel forno particular reason before.
Would I be better off doing this directly on the lathe, or could I create a tap and die with the threads I want, and use them to make the pen's threads? It seems like the tap and die would be more foolproof, since I would only have to get them just right once. To cut a four start thread in both the cap and body of a pen would require eight separate threads to be cut, and I am not that accurate with a lathe. (Four of them would be inside of the cap too!) I was thinking of threading a slightly tapered rod, and then grinding slits into it to make a tap for the insides of the cap. Any real machinists have a better idea? I could just pull the tail stock slightly off center to get the taper.
To cut multistart threads, I would just need to adjust the cross feed between each course of threads, or use the compound, and calculate the amount using trig. (I think) I was just reading about multi start threads being cut using a thread chaser at twice the TPI of the setting on the lathe to make a two start thread. I was wondering if this would be feasible for a four point start, or if that is even necessary?
Has anybody gone down this road before, or am I losing it in my addiction to pens. (I spent a whole day on the 'net looking at Bill's fountain pen page, and every other site on the old pens)
Thanks,
Dave
p.s. Is there a really easy out for this, like a pre made tap and die set for these threads? I have been known to re invent the wheel forno particular reason before.
