threading

[Pblot]

Hello
I already make pens for a few years.
I would like to make kitless fountain pens.
I have a threading problem on epoxy resin. With the dies, the nets are crushed.
Can you tell me why ????
Is there a particular way to proceed ?

I'm waiting for your advice
Thank you

 

[lorbay]

What are the nets???
Lin

 

[Pblot]

Sorry. Google translate...!
Thread maybe ????
Pat

 

[Fred Bruche]

Where did you get your epoxy resin blanks? Is it really epoxy? Some "plastics" are really easy to thread, others are pretty much impossible to thread (like bakelite) and could correspond to what you describe.

 

[Pblot]

I cast the resin blank myself. this problem also occurs with alumunium.

 

[Pblot]

but actually with some resins the threading is good

 

[magpens]

There are some materials that do not thread well.
You just have to work around that problem by substituting material that does thread well.
You can glue in a small piece of material that does thread well and try to make a feature of that material.

For example, if you are making the barrel of a fountain pen and the barrel material does not thread well to accept the nib assembly, then you could glue a ring of different material into the end of the barrel so that the nib assembly will screw into that.

You have to try to match up the materials so that the result looks nice.

In general, I would say that most epoxy materials do not thread well .... that is a known fact.

And, yes, aluminum is also difficult to thread if you are trying to cut fine threads. . There are different "grades" and alloys of aluminum which might overcome this problem but you will have to research the subject to fine out. . Some people on this forum might have enough experience with doing this that they could advise you what to do.

When you are trying to thread some awkward materials, your problems can be reduced by using the right lubricant.

 

[Curly]

You might try to make the sizes a little more loose. Instead of 12mm outside diameter make it 11.8mm. Instead of 11.3mm inside diameter try 11.4mm. You can play with the sizing 0.1mm at a time to see what works best. Also be sure you lubricate with an oil (grape seed oil or any cooking oil work well just clean the lathe well after) when cutting the threads.

 

[Pblot]

thank you for these tips that I will put into practice soon

 

[lorbay]

Another thing you can do if your dies are adjustable like this one is open it up and work it back down to correct size.

 

[Ed McDonnell]

Also, make sure you have a good set of dies intended for cutting threads. Some less expensive dies are only intended for thread chasing (cleaning up existing threads) and won't cleanly cut new threads in many materials.

Ed

 

[More4dan]

For Aluminum use a good tap oil like Tap Magic, actually WD40 works good for aluminum too. If you tendon is too large, it want thread, the die will just shear off the threads as the6 form. Experiment on some cutoffs. Having die and tap guides are also critical for kitless pens to get everything to line up straight. Check out www.littlemachineshop.com for theses.


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[More4dan]

Also, make sure you have a good set of dies intended for cutting threads. Some less expensive dies are only intended for thread chasing (cleaning up existing threads) and won't cleanly cut new threads in many materials.

Ed

The hex shaped dies are only good for chasing threads instead of cutting new ones.


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[frank123]

If you aren't lubricating it then that is the most likely cause of your problem. At least the first thing to check.

What kind of aluminum are you using? Some of the aluminum alloys do not machine well, try 6061 if you're not already using it now and see if that threads better for you.

 

[Jonathansmith]

If u re using the adjustable die, make sure your screws are on the dimple found on the side of the die...just thought