Making your own threads

[rtjw]

I am looking to try and figure out how to make my own threads on a pen. Dont know if i can explain it right. You know the threaded part of the cap that you screw the bottom barrel into? I want to make the threaded end for the cap and the threaded end for the lower barrel. I would like to do it on acrylic.

here is a pic of what I am talking about.

Money is not a problem. I am going to let Griz and Coach buy it for me for Christmas!!!

 

[Dario]

Originally posted by rtjw
<br />
Money is not a problem. I am going to let Griz and Coach buy it for me for Christmas!!!
[/img]<br />

LOL..you obviously don't know Tom that well yet!!! I am not sure about Coach. [][}][]

 

[Old Griz]

Actually, I am going to buy the tap and die set up for Johnny to do his pens....

AND... he is going to fly me and my family down to Texas over Christmas so I can give them to him [][]

 

[Dario]

LOL...now that's something I can comprehend LOL. []

 

[DCBluesman]

This is a fairly straight forward question, Johnny, with a simple answer, a complex fix and a fair amount of money to do.

The simple answer is you need a tap and die. The tap cuts the inside threads and the die cuts the outside thread. There are a large number of suppliers of these parts including MSC.

The complexity begins here.

You will need to know what size or sizes you want for each. You have the nib assembly to consider first (nib, feed mechanism and housing). If the housing is already threaded, you need to match the threading with the appropriate tap. If not, you will need to determine what size tap and die can be used and still support and not interfere with the nib assembly.

Next, you will need to decide whether you want single start or multiple starts for the cap. Up to four starts are used in fountain pens, although beyond three starts on a standard sized fountain pen and you might have a problem with the thread pitch.

Next, you will need to drive both the tap and the die on the same plane. Single start tap a dn die in normal sizes are not very expensive and the process sounds easy, but it's not. Ask Anthony. [] A better solution is a metal lathe which can do both threads. Of course, that runs into money and a little time to learn the lathe, thus my comment about running into some money. Of course, when you run a business whose service people are just dying to use, that's a small obstacle. [] (Sorry, blame my macabre sense of humor on Wilma.)

 

[rtjw]

Okay Lou, what would be the best tap and die set to use for a pen the size of a gentlemen and where do i find it.

 

[DCBluesman]

You've just reached the limits of my knowledge. Hopefully Rich (Scubaman) will look at this thread tonight. He may be able to make some suggestions and, in all likelihood, can expand upon my limited experience. (He's probably even got a correction or two he can make.) My only experience thus far is with a Baron and until I get one that works correctly and a process which is reproducible I don't want to lead you astray.

 

[lkorn]

Johnny,
First you need to KNOW what the finished diameter of the threaded part of the pen will be. Then you select a die to cut the make threads on the nib section. After that, you need to drill the cap to the proper size for the matching tap for the complementary female threads. Simple! See you on Friday.

 

[Mudder]

I could be wrong but I have never seen a tap that will cut 3-start threads....

Depending on the diameter you are looking for I would think the easiest is a regular single start thread, but the threads are usually pretty deep. An alternative that might be worth looking into is a pipe thread. A word of caution though, pipe threads are tapered.

 

[coach]

I guess I'll be seeing you at Christmas now too![]

 

[btboone]

Those threads are all super fine, and usually dual or triple lead. You likely won't find a tap in that size. The best bet, and a good long term investment, is to get one of those tiny metal lathes from Harbor Freight or others for around $375. That's a great price for a real working metal lathe that can do threads. Going to a lathe just a big bigger jumps the price to a couple thousand dollars. You can actually make your own taps from drill rod that will work in acrylic or brass. They can have fine threads and triple lead if you want. Sure, there's a little learning curve, but it does greatly expand your capabilities to make pens in the several hundred dollar range, so it can easily pay for itself, and can be written off as a business expense.

 

[scubaman]

You can certainly get taps and dies custom-made to your specs. You will not find them in a 'set' off the shelf anywhere... Since you make both male and female threads, you are not limited by anything but your design abilities. There's definitely not a simple solution out there that you can just read a catalog description, plop down some green stuff, and go... you'll have to invest some time (and money) and learn... As Bruce and Lou pointed out (maybe others, I just glanced through quickly) a metal lathe may be your best solution. Cetainly has the most flexibility. You don't HAVE to use multiple entry threads. The Havana/El Presidente/El Toro pens have single entry threads, e.g.. It just takes more turns to open and close. Personally I prefer triple entry threads, but they are not an absolute necessity

 

[Brent]

Speedway mini lathe, The last time I looked it has more features than the Harbor freight, and a little less money. mine works great for small jobs. You may find it very useful for alot of things. I have an old odd ball wood lathe with a 3/4 x 10 tpi on head stock I made my own adaptor for it to bring up to the more used 3/4 x 16 tpi. all kind of uses, I use mine a lot more than I thought I would

 

[Darley]

Originally posted by Old Griz
<br />Actually, I am going to buy the tap and die set up for Johnny to do his pens....

AND... he is going to fly me and my family down to Texas over Christmas so I can give them to him [][]

That is what I call a good trade Tom,[]

Johnny ask Anthony I think a while back he ask the same question or he did some of is own threading

 

[Mudder]

Originally posted by Brent
<br />Speedway mini lathe, The last time I looked it has more features than the Harbor freight, and a little less money. mine works great for small jobs. You may find it very useful for alot of things. I have an old odd ball wood lathe with a 3/4 x 10 tpi on head stock I made my own adaptor for it to bring up to the more used 3/4 x 16 tpi. all kind of uses, I use mine a lot more than I thought I would

There are several places that sell that same lathe (with different paint). I gor mine from Cummins tools and it is basically the same as the speedway with the $99.00 accessory kit included. The price is the same (within a penny)

Speedway lathe $299.99 + accessory kit $99.99

Cummins lathe $399.99


Links to look at:

http://www.homier.com/detail.asp?dpt=&cat=&sku=03911 Lathe

http://www.homier.com/detail.asp?dpt=&cat=&sku=04705 Accessory kit

http://www.cumminstools.com/browse.cfm/4,876.htm

 

[Fred in NC]

I have the same metal lathe.

However, I will not attempt to cut threads on a pen barrel or cap, it is too easy to ruin the barrel, especially if you have threads with multiple starts.

Best use for the metal lathe would be to make taps and dies, and then use these to cut the actual threads. For threading plastics you don't need a very hard metal, just a fine grained metal will do.

 

[Mudder]

I stand corrected.

I had originally thought a triple thread tap and die could not be made until I talked to the salesmen at e-taps..... they can make taps and dies up to 12 starts for a price..........

So, you tell them what you need, give them somewhere between $300-$1200 and they would be happy to help you out.

You might be able to make a tap and die in a mini lathe but I have never attempted it.

Hope this helps.

 

[Fred in NC]

One of my projects for when I retire (in December) is to make some taps and dies for fountain pens.

There is quite a bit of work involved in making these fine thread taps and dies. For one thing, they have to be tested on an actual barrel. However, after one is successfully completed it is relatively easy to make a few more. Also, one has to buy the materials, and as you all know, you have to buy the whole piece and pay shipping, etc. So there is an initial investment whether you make one or a bunch.

I am sure I can beat the commercial prices down to a level that will be affordable for us.

 

[JimGo]

December!?!? I gotta wait 'till December!?!? What is this world coming to? []

I look forward to 'em Fred!

 

[Rifleman1776]

You're trying a "Boonie". Can't be easy. Just reading his descriptions of his design process earns one a PhD in engineering. []

 

[rtjw]

Not trying to build a boonie, but I do like the designs alot. I am wanting to work with acrylics more and get out of the mainstream pen kits.

 

[btboone]

It's a noble cause, Dr. Frank and Dr. Johnny. [] Being able to make your own threads and centerbands and other parts does free you up considerably on design. You could always pay to have someone (like me or Fred) make you some taps or other parts, but learning a metal lathe will buy freedom from the kits, and design freedom in general. It's funny how people at pen shows just hone in on if something is made from a kit. They have radar for such a thing. I think most of it is perceived rather than reality, but they are perceived to be lower value. This hurts sellability.

As I told Johnny this morning on the phone, I think the challenge with acrylics will be doing the threads inside the cap. The material is thin there, and most attempts at tapping the threads will probably result in the part splitting. It will take making the hole and threads in a thicker part first, then taking the outside down later. You need to come up with special mandrels and ways of doing things, but again, if you have a metal lathe, those things are easily possible.

 

[rtjw]

Originally posted by btboone
<br /> You could always pay to have someone (like me or Fred) make you some taps or other parts

So boone what are you saying. That for a price you will make mine for me. I need them in gentlemen size. Just the threads for the cap and the nib.

When will you be shipping to me?[]

 

[btboone]

Johnny, I've offered in the past to make any tap for $50 plus shipping. They're not quite the quality of real taps, but seem to work OK. I've never made a Gentleman pen, but if you send me parts that should fit, I should be able to do it.

 

[tnilmerl]

Ok, an appropriate time has expired. Any decision on the tap design/manufacturing? And what about a corresponding die? Still interested in manufacturing tap-die sets? I imagine you can tap &lt;pun intended&gt; into a huge market for these specialized sets, similar to the pin chucks mentioned elsewhere.

Now, additionally I would like to know &lt;turn on moron switch here [)] &gt; where can I get detailed, no nonsense instructions for the proper use of a tap-n-die set. Specifically, I want to know the exact drill bit to use with which tap, and the shaft diameter for the pen barrel for the matching die. Short of a full machinist course, I have not found a good, straight forward tutorial. I have found short articles that reference certain drill bits and tap sets, but that state that the corresponding drill bit is usually not a standard sized bit.

The store front book stores are slim to none on books containing this information, and the internet is vast, deep, and lean. I have picked up tidbits here and there.

On a final note, does anyone have the thread specifications on any of the fountain pen nib kits out on the market? I imagine this would be the only purchased part you would need.

 

[vick]

Travis,
If no one else posts on this send me a message and I will tell you what I know. I am fairly inexperienced at using taps and dies but I have done it (not on pens though). We have some very knowledgeabe people in the forum about this kind of thing that could speak more intelligently than me and I hope they will see your post. If no one else post I do not want to leave you hanging though.

 

[scubaman]

Originally posted by tnilmerl
<br />OI imagine you can tap &lt;pun intended&gt; into a huge market for these specialized sets, similar to the pin chucks mentioned elsewhere.

Somehow I doubt that there is a huge market. Maybe you are looking too much for a turn-key system? For a certain price? You can get any tap and die made, for a price, at e-taps.com e.g. And if you get a few people together you get a price break. But it's still more money than most folks want to spend. I wonder how many people took up Bruce's offer for a $50 tap? It's a decent price!

Now, additionally I would like to know &lt;turn on moron switch here [)] &gt; where can I get detailed, no nonsense instructions for the proper use of a tap-n-die set. Specifically, I want to know the exact drill bit to use with which tap, and the shaft diameter for the pen barrel for the matching die. Short of a full machinist course, I have not found a good, straight forward tutorial. I have found short articles that reference certain drill bits and tap sets, but that state that the corresponding drill bit is usually not a standard sized bit.

Standard sized bit? That should not stop you! ;-) You can get drill bits ground back to any size you want. If you go to the e-taps site and download their catalog, you'll get a ton of info. Once you select the type and dimension you want, if you can't figure out the drill diameter, write to their tech support folks and ask. I don't know about that particular outfit, maybe they even offer properly sized drill bits. This may sound smug, but it's not meant to be: this will not come to you as a simple click-on-this button... I know you're probably just wondering if someone else has done the work for you, and that's perfectly OK - why waste effort if someone is willing to share? All I mean to say is if you don't get answers, it's not that hard to roll your own

The store front book stores are slim to none on books containing this information, and the internet is vast, deep, and lean. I have picked up tidbits here and there.

I was on a site a few days ago and found very nice drawings of all the dimensions and tolerances for the varioius class fits. I just looked and can't find the site again. (but it's out there ;-) I would suggest to pick up an old secondhand copy of Machinery's Handbook - this info has not changed over the years. It's an invaluable reference, you don't need the latest copy

On a final note, does anyone have the thread specifications on any of the fountain pen nib kits out on the market? I imagine this would be the only purchased part you would need.

Don't have it handy, but again, if you want to go down this road, you need to be able to figure this yourself. Get a metric thread pitch gauge, it's just a couple of bucks, and a pair of calipers, and you should be able to figure it out.

Good luck, and be sure to let everyone know how you make out ;-)

 

[btboone]

On the last pen I did and on my next pen, I made up my own size of threads to utilize a particular 1/2" drill I always have in the lathe. The outside diameter of the threads is something weird like .553". I didn't have any charts to come up with the stuff, so I just drew it all in CAD. I nipped off the tops of the internal and external threads, and had a few thousandths of an inch clearance. The inside of the nipped off internal threads used the 1/2" dimension. I used a thread mill (which is normally used in a milling machine) for the internal threads and it saved a lot of money over buying a carbide insert internal threading tool. The triple lead threads worked dead nuts the first time! It's not quite that easy with a manual metal cutting lathe, but it should be doable.

 

[TomServo]

One of those "Pocket Ref" books (little black books, like $13 or free from kb electronics website!) should have a chart - there's all kinds of great stuff in there...