# I turn to the hive mind



## MikeinSC (Aug 8, 2016)

To thee, I must go to for answers because I have none. 

I am not sure what material this is but I presume it is similar to a plexiglass. And I believe it is the same material used on the mesh and water clear acrylics. It has a unique smell to it. 

I can not get it to take the threads for a Jowo nib section. My process is good and tools are as well. I made a two sections with my cast acrylic after wasting four sections with this material. I had good threads when using acrylics. 

Thanks for any help.


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## duncsuss (Aug 8, 2016)

MikeinSC said:


> I can not get it to take the threads for a Jowo nib section.



In what way "take the threads"? Do you mean it stripped the threads at the same time as it cut them? Or it wouldn't cut at all?

Were you able to successfully thread the tenon that screws into the barrel? (That's a good test because the threads are visible, so you can see if the material is crumbling away instead of holding threads.)


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## duncsuss (Aug 8, 2016)

btw, if it's "Inlace Acrylester" I gave up; the threads crumbled and shattered. I contacted Woodturningz and talked with somebody there who clearly had made pens, he said the material isn't really intended for threading.


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## MikeinSC (Aug 8, 2016)

It's not Inlace, this can actually be worked, although delicate is the key. I got it from Richard Greenwald. 
It does thread very easily for the larger threads but for the finer stuff, I'm not having any luck. The tap will screw in and pull itself in and out easily. I can't feel the thread stripping out either. 
I know it will take fine threads because Edison uses blanks made from the same material for #5 and $6 nibs.


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## KenV (Aug 8, 2016)

Mike

Does Edison use taps or do they use a thread mill to cut the threads?

CNC mill has way different set of abilities and challenges.


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## duncsuss (Aug 8, 2016)

I use a very simple set-up for tapping (no matter what gauge/threadcount).

I put the tap into a Jacobs chuck (the same one I use for drill bits) and put it loosely into the tailstock.

The workpiece is in a collet chuck on the headstock, which is locked (using the index pin) so it cannot rotate.

I slide the tailstock forward until the front of the tap just touches the entry hole, then spritz a little lubricant onto the tap (I used to use spray cooking oil, recently switched to use automatic transmission fluid).

By hand I turn the chuck gently pressing it into the material. One full turn, then back a half turn. The chuck is loose in the tailstock, so no resistance from that, and as the tap cuts into the material the Morse taper of the chuck begins to slide out of the tailstock. I don't care -- cutting a quarter inch of threads, it isn't going off-axis in that short distance. If I was tapping a deeper thread, I'd slide the tailstock forward a bit when it seemed it needed it. Gently, this isn't a ram (which is why I never touch the quill handle.)

Also, you might try drilling a smaller diameter hole to start with.


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## MikeinSC (Aug 9, 2016)

I'm using a 7mm bit for the #6 Jowo. I don't know that I could go any smaller and have it still work. It will cut good threads in the PR that I make but doesn't seem to make a good thread in this material for me. 

KenV, I believe Edison uses CNC for all of their operations so I'm sure they have a cutter programmed to make the threads. It'd be much easier that way, I would think.


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## ZbR (Aug 9, 2016)

I had similar problem with some materials even when I tried method described by Duncsuss. The final solution which works for me is chuck in chuck devise (please see pictures). 
There is PE tube in the chuck sitting in tailstock which serves as a bearing for the chuck with tap. This allows very delicate and smooth operation when threading.


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## duncsuss (Aug 9, 2016)

MikeinSC said:


> I'm using a 7mm bit for the #6 Jowo. I don't know that I could go any smaller and have it still work. It will cut good threads in the PR that I make but doesn't seem to make a good thread in this material for me.



JoWo #6 tap is M7.4 x 0.5. Minor diameter is therefore 6.9mm, so a perfectly drilled 7mm hole has removed 20% of the thread depth.

My notes say Letter Drill "I" for the threaded portion -- 0.272" compared to 0.2756" (7mm). Only 5.5 thousandths smaller, but the thread depth is only 20 thousandths so it could be significant.

Another question: how are you physically holding the section during the tapping process?

I've discovered I get better results when I sink all the material into a collet chuck and tighten it up. It prevents the material from deforming as the cutting edges of the tap bite. This is more significant the thinner the material, so I tap the internals before turning down the section. (Typically leave it around 15mm - 16mm diameter until after I've tapped for the nib housing.)


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## bmachin (Aug 9, 2016)

Mike: it kind of looks like Richard's Flexigran Autumn.  However that is a polyurethane material and should thread easily.

Ken:  Edison cuts all of its threads by single pointing on a CNC lathe.  There is some good video taken with Brian's GoPro inside the machine on HIS WEBSITE

BILL

SORRY:  CAPS LOCK SEEMS TO BE STUCK


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## duncsuss (Aug 9, 2016)

duncsuss said:


> 0.272" compared to 0.2756" (7mm). Only 5.5 thousandths smaller


My arithmetic isn't so good before my third cup of coffee ... 3.6 thou difference, it's still a chunk out of the thread depth


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