How to cut threads on wood lathe

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Gilrock

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So I've dug through several threads and articles on the forum and bought some taps, dies, delrin, nibs, feed housings, etc. I was planning trying to make a die holder similar to the one shown in George's article.

I've never tried to cut threads on my lathe before and I have a wood lathe so I was looking for pointers. So for a wood lathe is the basic technique to rotate the lathe by hand and the tailstock is supposed to be left loose and get pulled in? I'm a little worried about my tailstock sliding smoothly if thats the case. I have the Rikon 70-100. My handle that tightens the tailstock is famous for falling too far down with gravity and causing the tailstock to not slide easily...I'm always having to lift it a little to get it to slide. Plus that seems like a ton a weight to move. I was thinking I'd need to try to be helping it along by pushing with my right hand as I turn the other side with my left.

For the die holder I was brainstorming why not manufacture a shaft with a groove in it that would allow the die holder to freely slide as the threads are cut and the groove would prevent the die holder from rotating? Set screws could be adjusted into the groove.

Thanks in advance for any help,
Gil
 
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Gilrock

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Try this thread http://www.penturners.org/forum/f56/1-1-2-die-holder-3-4-chuck-91835/
Starting around post 12. I made my own die holder using some maple stock I had on hand and it works great.

Terry

Yeah I've seen that thread but I think I missed that embedded video the first time. I've already got 2" Delrin on the way so I was going to make one very similar to his. I can't watcht he video yet but from his description it sounds like the set screws would prevent the holder from sliding and rotating. I was dreaming of a setup where it could slide but not rotate.

Edit: Well it just hit me...I guess the material could just be locked in place on the left side and then rotate the die holder by hand...duh...

Gil
 
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TerryDowning

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I turn both the chuck (Left hand) and the die holder (right hand). I'm just impatient that way.

Post pics when done and show us how it turned out.
 

Gilrock

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Thanks to some fast shipping from Enco I almost completed my die holder yesterday. Still waiting for the other die to put on the other side but I've got the triple die installed. Only thing I want to add is I left no space behind the die in case I cut threads on something longer than the die. I need to decided how deep to go...I'd like to keep as much of the 1/4" hole as possible for support and I'll be housing dies on both sides.



Thanks,
Gil
 

Russianwolf

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You Die holder will slide, but when you need to tap you will want the tailstock loose. Just reach under the tailstock and loosen the nut on the clamp, then retighten once you want the lever to work again.
 

BRobbins629

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If you ned to cut threads longer than the die, just remove the die from the delrin holder and use a regular handled die holder. The reason for starting the threads on the lathe is to make sure they are straignt. Once you have a full dies worth of threads, it will stay straight regardless of how you hold it.
 

glycerine

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BRobbins629 said:
If you ned to cut threads longer than the die, just remove the die from the delrin holder and use a regular handled die holder. The reason for starting the threads on the lathe is to make sure they are straignt. Once you have a full dies worth of threads, it will stay straight regardless of how you hold it.

What he said... Once you get them started good, you're golden.
 

Gilrock

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Thanks for the tips....hopefully I'll get to try to make something soon. It doesn't look like my order from Victor Machinery has even shipped yet and I've received everything else I ordered that day. Waiting on another tap/die and drill bits from them.

Thanks,
Gil
 

Gilrock

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So I tried to practice making the triple start threads on a piece of Delrin and it didn't come out as anything I would consider usable. The weird thing I don't get is how the die seems to thread onto the male piece just fine and the tap threads into the female part just fine... But put those two pieces together and one moves inside the other without screwin it. If the tap and die are really matched for the same threads I don't see how this is possible.

I'm using the triple tap from SilverPenParts....the 12mm x .8 x 3. I used a 12mm tenon and a 7/16 drill bit for the hole.
 

randyrls

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So I tried to practice making the triple start threads on a piece of Delrin and it didn't come out as anything I would consider usable.


Gil; Delrin is too soft to take good threads. It deforms under pressure far too much. Acrylic acetate, nylon, or PVC rod will work.

I liked the photo of the die holder. Is it Delrin??
 
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Gilrock

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So I tried to practice making the triple start threads on a piece of Delrin and it didn't come out as anything I would consider usable.


Gil; Delrin is too soft to take good threads. It deforms under pressure far too much. Acrylic acetate, nylon, or PVC rod will work.

I liked the photo of the die holder. Is it Delrin??

Yes the die holder is Delrin...I started out with a 2" piece but turned it down to a size that would work with a 1" die plus set screws to be just below the surface.

Delrin might be too soft to take good threads but I saw George using it to make holders for his sections...that's what I was going to do I just didn't have the other tap/die yet so I was practicing with the triple tap.

What I was really curious to hear from anyone using the 12mm x 0.8 triple tap/die is what size tenon do you like for you're die and what size drill bit do you use for you're tap?

Thanks,
Gil
 

bluwolf

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I use a 7/16 drill for the tap and a .465 tenon for the die. But you still have something wrong. Your 12mm tenon works out to .472 which is bigger. Yet you say the tenon slides inside of the tapped 7/16 hole.

What do your tenoned threads look like after using the die, are they okay? Are you sure it's not an 11mm tenon? Are you sure you're getting good threads with the tap and it's not stripped out?


These may sound like stupid questions but I ask because I've used a .465 tenon and a 7/16 drill bit on aluminum, acrylic, ebonite, pretty much everything and it always works...always.

Mike
 

Dalecamino

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I use a 7/16 drill for the tap and a .465 tenon for the die. But you still have something wrong. Your 12mm tenon works out to .472 which is bigger. Yet you say the tenon slides inside of the tapped 7/16 hole.

What do your tenoned threads look like after using the die, are they okay? Are you sure it's not an 11mm tenon? Are you sure you're getting good threads with the tap and it's not stripped out?


These may sound like stupid questions but I ask because I've used a .465 tenon and a 7/16 drill bit on aluminum, acrylic, ebonite, pretty much everything and it always works...always.

Mike
I'm going to back Mike up on these sizes. They work for me too. Thanks for the education Mike.
 

cnirenberg

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I use a 7/16 drill for the tap and a .465 tenon for the die. But you still have something wrong. Your 12mm tenon works out to .472 which is bigger. Yet you say the tenon slides inside of the tapped 7/16 hole.

What do your tenoned threads look like after using the die, are they okay? Are you sure it's not an 11mm tenon? Are you sure you're getting good threads with the tap and it's not stripped out?


These may sound like stupid questions but I ask because I've used a .465 tenon and a 7/16 drill bit on aluminum, acrylic, ebonite, pretty much everything and it always works...always.

Mike
I'm going to back Mike up on these sizes. They work for me too. Thanks for the education Mike.
I second that.
 

Gilrock

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Ok thanks for the responses. I used a digital caliper to measure the tenon and I thought I had it right at 12mm. The threads on the tenon looked pretty good to me but up till now my experience has only been tapping 1/4-20 holes for machine screws. I'm more inclined to suspect the hole being too large due to a poor quality drill bit or maybe the bit not being perfectly aligned to the hole. But I wouldn't think the tap would feel like it's threading in ok if the hole was so large that the tenon threads don't even grab. I think I'm going to get a better drill bit set and try again.

Darn and I was hoping for perfection first try...lol.
 

Gilrock

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Well I haven't tried the 12mm tap / die again but my 9mm x 0.75 tap and die arrived so I tried it out a couple times. I've gained a ton of respect for everyone that's making the kitless pens. I'm usually pretty good at doing new things like this but I've gotten frustrated and been ready to just sell all the taps and dies to someone else...lol. I tapped a 9mm hole in a piece of delrin that seemed to come out ok. Then I tried putting male threads on a piece of black ebonite. I failed twice. For the third try I used delrin and finally got a part that threaded nicely into the female threads I had made. So at least now I see what the threads should be looking like and I have a master to check out other parts. I used the same tenon size 0.366" for the ebonite and the delrin it just seemed like the ebonite was really soft and must have stripped out easily. Guess I'll have to try again and be more careful.

Thanks,
Gil
 
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bluwolf

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Are you using anything as a lubricant when you're cutting the threads? A lot of people use Pam spray. I Just use soapy water unless it's aluminum. Then I use regular cutting oil.

Mike
 

Gilrock

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Are you using anything as a lubricant when you're cutting the threads? A lot of people use Pam spray. I Just use soapy water unless it's aluminum. Then I use regular cutting oil.

Mike

Yeah I was going to use Pam like others mentioned but not having any yet I sprayed WD-40 on it...not sure if that's a bad thing to use but I was anxious to try something.

Gil
 

Gilrock

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As a follow-up I just wanted to say I finally figured out the problem with my M12 triple threads was with the female part I had made. I made a new one last night and all the male parts I had made are working with it. I changed several things in my process so hard to say exactly what fixed things.

- First time I had used a 7/16" bit so I grabbed the next one down...don't remember but I assume its a 1/64th smaller.
- I used water in a syringe to keep everything cool...pulling the bit out every 1/8" and squirting water in the hole and on the bit.
- I used my new tap holder if you saw the pic in the other thread. It was a lot easier to "feel" the cutting without the weight of the tailstock.
- And I switched from Liquid Wrench to Olive Oil for cutting fluid cause the Liquid Wrench was leaving a smell that doesn't seem to go away.

So I was able to make a pen body that I'm pleased with for my first one. Just need to make a section and cap to have my first kitless done.

Oh and for any other beginners out there...don't do like I did and order just 3 or 4 drill bits you think you will need. I placed my order today for a 115 bit set.

Thanks,
Gil
 
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