# Twist mechanism and how to install



## PhotonFanatic

I am attempting to make a pen, using as few parts that I can not make myself. However, I have zilch experience making pens, so I am quite unfamiliar with many of the components and how they might actually be installed in a pen. 

Like this twist mechanism from Richard Greenwald:







I will be using a Schmidt 9000 EasyFlo cartridge, and I think I have figured out how the cartridge inserts into the mechanism, i.e., from the left in the photo above.

So, threading the mechanism into the main body of the pen isn't a problem, that I can do. But, what is the function of the widest part of the mechanism, just to the right of the threads? Should that be recessed into the body, or allowed to just sit on the top edge of the pen's body?

And the top of the mechanism--what are those three ridges called? Now I can see that the very top of the mechanism turns clockwise to advance the pen. The pen that I am trying to complete would basically have four pieces--the tip, the body, the cap and an integrated clip that is attached to the cap. Question is, what is the best way to insert the very top of the mechanism into the cap?

Should I just bore out a hole and then perhaps mill three grooves for the ridges to fit into? Or is there a better way that I really have no clue about? :biggrin:


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## workinforwood

If you don't want to be able to see widest part of the transmission, you will need to grind it off or recess it.  It isn't much bigger than the mechanism and I would prefer to keep that and simply recess it into the body.  The purpose is simply to stop the transmission from being screwed in to the body of the pen too far.  Because that is a stop so that a customer can't screw the transmission in too far, and I don't know what to call it, I"ll just call it the flare.
Lets say you are going to recess that flare. You need to turn the transmission there to the closed position.  Install your cartridge and measure from the right side of the flare to the tip of ink cartridge. Add 1/16 to this measurement and that is how long the lower part of  your pen will be. So if the measurement is 2"...just using an easy number..then the overall length will be 2 1/16.  The 1/16 is so that when the pen is closed, the ink is inside the nib.  Now...I don't know how long your nib is, so I'll say it is 1/2" long.  You deduct that measurement from your 2 1/16 and that is how long the body of the pen is.

Now you have the top end of the pen to deal with.  This is not a cap.  A transmission is not used in a pen that will be capped.  If you put a cap on a pen with a transmission in it, that would be counter productive.  The transmission pulls the refill inside the nib so that the ink is safe and not touching anything.  Your refill will have to have a spring on the end of it.  When you retract the transmission, the spring is what pushes the ink up into the nib. Wen you detract the transmission, the refill is pushed down and the spring simply compresses while it wait for you to retract the transmission.  The "ridges" in the top of the transmission are nothing for you to concern yourself with.  They are for holding the inner workings of the tranny together.  The top of the transmission is still important though.  The top section of the pen needs to be a tight fit to the outer diameter of the tranny. If the hole is too large, the pen won't work.  The tight fitting hole is what grabs the tranny so when you twist the pen, it operates.  So when you want to refill the pen, you simply pull on it until it comes apart in the center.  Then you unscrew the tranny, grab out the refill, grab the spring, put the spring on to the new refill, and so on.

To thoroughly understand how a pen like what you have there works, I would suggest you purchase a mandrel, a cigar pen kit and bushings.  It will come with instructions.  Build a cigar pen and then just by building it you will have some understanding, and then you can disect that pen to guide you through your new pen.


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## PhotonFanatic

Jeff,

Thanks for the response. As it turns out, I've done most of what you suggested, but I just wasn't sure that I was doing things right. I did decide to recess the flare, as you called it, since I couldn't think of anything else to do with it. :biggrin:






I got the length of the tube pretty close to perfect, through careful measuring and modeling the pen in SolidWorks:






And the tip of the pen, with a landing for the spring, came out fine, too:






The top of the pen, however, left me wondering what to do, as the twist mechanism came with a sleeve that looked as though it just belonged on the top of the twist mechanism. So I planned the top with the idea of inserting that sleeve inside the top and then friction fitting the combo to the top of the mechanism. 

But I found that while I bored the top out enough to hold the sleeve, it was still a very tight fit to get it onto the top of the twist mechanism. And, at times the sleeve wants to pull out of the top, when I try to remove the top of the pen. I suppose I could epoxy it in place, but I don't care for that technique.

I think the best solution would be to bore the top to fit the top of the twist mechanism without any sleeve involved at all. As this is a Ti pen, I think the top could withstand the wear and tear of repeated on and offs over the years.


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## workinforwood

You can do that with the top of the pen, but if the fit is too tight it will crush the mechanism.  If you have a sleeve that is a perfect snug fit, I would epoxy it in.  Great thing about a brass tube is that it has the ability to expand a bit, assuming the area outside the tube has some breathing room as well.
  Because you are using a screw in nib, you could have made this pen just one long piece if you had wanted to.  The transmission would still be in the same position.  The tube that grabs the transmission would extend all the way to the top of the pen, where you would make a knob to attach to that tube and the knob is what you would turn to activate the pen.  I really like it that way because it looks like a click pen, but is still the more reliable twist pen.  Either way..the pen is looking pretty good to me.


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## PhotonFanatic

This was my original top for the pen, but it has some problems, i.e., the clip is way too close to the body of the pen, and the press fit pins weren't all the same height.






So I will make a revised version and for that I will just bore the cap to fit the top of the twist mechanism directly, with no sleeve involved.


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## workinforwood

That clip is certainly on the right track.  The end of the clip should not be out in the middle of the air.  So the end of the clip can't extend into the lower barrel of the pen.  If this was to happen, when you twist the pen, the clip can rub on the lower barrel and create a scratch.  I understand what you are saying..it's too close to the body..I'll take your word on the spacing issue, but I also have to recommend that if you are using a straight clip like that, then you should have a bump under the end of the clip so that if someone clips it in their shirt, when they bend over the pen doesn't slide out and hit the floor.  I don't know how springy your clip is.  The bump should be touching or almost touching the upper body of the pen.  The clip will have to be able to spring back a bit for a shirt to slide under the bump.  Usually people will use or make a clip that is more of an S type shape.  But a straight clip would make the pen much more streamlined, and that's great too!


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## PhotonFanatic

Jeff,

Well, actually there is a little bump under the straight clip--there is a ceramic ball bearing inserted there:






But it was a problem--exactly as you described--it was so close that it could rub against the long part of the pen. And, you know what? A *ceramic* ball bearing is much harder than Titanium! Made some really fine lines in the polished Ti. :redface:

The pen body itself is so long, that not having that clip come down onto the pen body would mean that I'd have to make a very long cap to contain the length of the clip, if I am understanding you correctly. 

That would make the pen completely unwieldy, in my opnion.

I'm going to redesign the clip/cap and make sure that the tip which will extend onto the pen's long tube will be far enough away so that it will fit over a shirt pocket and not scratch the tube either. 

I was just trying hard to get away from a 'regular' clip that slips over the pen and then is bent down. I know that there are some nice clips out there and coming up with something different isn't easy.


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## skiprat

Wow!!! I've just been browsing your site:biggrin: Beautiful little torches!!

What if you fix the clip to the body and have the 'cap' do the twist still?

I'd love to see a pic of your Swiss lathe too:biggrin:


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## workinforwood

I didn't see the ball bearing..that's a cool idea.  I think part of your problem is that you are using a rollerball refill in a twist pen that is traditionally a parker refill.  If you use my other suggestion, then you end up with what Steve is talking about.  Then there really is no "Cap" at all.  One long tube.  The transmission inserted down in.  Another short tube reaches down and grabs the tranny to activate it.  A little button is attached to the short tube, sticking out the top of the pen.  You turn the button to activate. The clip is on the body, the body does not twist.  I'll have to check out your site myself.


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## PhotonFanatic

skiprat said:


> Wow!!! I've just been browsing your site:biggrin: Beautiful little torches!!
> 
> What if you fix the clip to the body and have the 'cap' do the twist still?
> 
> I'd love to see a pic of your Swiss lathe too:biggrin:



Steve,

Not a bad idea, except that the threads to hold the twist mechanism are fairly close to where I would want to attach the clip. I may explore that option though.

Here's a full shot of the lathe that I have, a Wahli:






However, mine isn't the same color, nor as clean:






What makes this lathe so versatile is the sliding headstock--it can move up and down. Admitedly, that make tailstock alignment a bit more of a chore, but the benefit of the headstock is that it allows me to do some milling on the lathe. Made before VFD motors were readily available, the Wahli has variable speeds, which one can change while the machine is running. Just crank the dial up. :biggrin:

Max RPMs tops out at 3K, not bad for most of the milling that I do, which are usually just shallow grooves, dimples, etc.

The lathe has change gears, so I can do both Imperial and metric threads, although I primarily do metric. No cross feed power--that's manual.


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## cnirenberg

Dang Fred, Keep on posting.  I followed up on what Steve said, your site and the flashlights are extremely interesting.  I can't wait to see the final version of your pen.


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## PhotonFanatic

workinforwood said:


> I didn't see the ball bearing..that's a cool idea.  I think part of your problem is that you are using a rollerball refill in a twist pen that is traditionally a parker refill.  If you use my other suggestion, then you end up with what Steve is talking about.  Then there really is no "Cap" at all.  One long tube.  The transmission inserted down in.  Another short tube reaches down and grabs the tranny to activate it.  A little button is attached to the short tube, sticking out the top of the pen.  You turn the button to activate. The clip is on the body, the body does not twist.  I'll have to check out your site myself.



Jeff,

What twist mechanism specifically would be good for the rollerball refill?

And do you have any photo, schematic of the design you are suggesting? 

Seems to me I'd need some texture on the short tube, if I did not attach the clip to it, so that one could turn the mechanism easily. Right now, the design I have is very slippery, but with the clip on it, there is some leverage obtained by putting ones fingers next to the clip to turn the cap.


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## workinforwood

It would involve me grabbing my camera and uploading a pic, so I just did a quick search here and came up with one of Butch's pens.  The area above the clip on a pen, ie the very tip top of a pen, is called a finial.  In this pen that Butch made, the area above the clip is what you turn to activate the pen.  It can be as long as his or shorter.  The fact that it is very smooth to the touch will not stop it from activating pretty easily. 
http://www.penturners.org/forum/showthread.php?t=48345&highlight=finial+twist
As he says in his post, he used a parker refill.  A typical rollerball refill is very long and usually used in a pen that uses a cap.  The refill always sticks out the end, the cap screws on to the end to protect the refill while not in use.  This is why a rollerball is not any longer than a twist pen, because there is no tranny in a rollerball pen.  You can find shorty rollerball refills, but you would have to check that they will fit into your transmission, or you can simply purchase a parker gel refill, which is a rollerball cartridge but parker size and style.  You can still use your refill and system, but the pen is sure to end up a bit longer than typical.  If you use the finial twist idea, that allows you to shorten the top of the pen a little at least.  You are not going to do anything much different than you already have done. You will need a longer pen body.  You will drill the hole that fits the tranny all the way through.  You will come back and drill a larger hole to fit the shoulder on the refill, but that hole will stop in the postition where it currently is on this pen..so it's just a way deeper recess in a longer body.  You then make a tube that can grab the tranny top.  You make a knob that will fit into, or over that tube..secured to the tube, the nob sticks out the top of the pen..the knob is the finial.  Twist the finial, the pen opens.  The clip is on the body of the pen and never moves.


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## skiprat

I just knocked up a quick and crude modded slimline. I used the stock mech but reversed it and pressed it into the finial. I used the Cross style refill, the clip and nib from the kit. Black Ti on aluminium. 
Because the mech doesn't hold the refill, I had to rig up a couple of small sleeves and a return spring. Could probably do it without the sleeves but I forgot that the slim refill doesn't have a nib return spring.
The clip is recessed and pressed into the body.


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## workinforwood

skiprat said:


> I just knocked up a quick and crude modded slimline.



That's a shocker Steve!   Great looking slim too. Why am I surprised???:biggrin:

Just keep in mind that Steve used a cross transmission instead of your parker style transmission, but the theory is the same.  With your transmission, the tranny will stay inside the pen, and with his reverse one, the tranny can be pulled out..different style tranny.  But you will still have the button and sleeve that grabs down in to turn your tranny.  Now I am inspired and wish I had time to run down to the shop and whip one up! Those home made jobs are too fun.

BTW..you won't find anyone more helpful and go more out of his way to help a person than Steve Jackson, AKA Skiprat.


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## ldb2000

Great to see some one playing with some of Richard's pen parts . 
You could also make a "Cap Operated" pen like this one ,



 

Here's the thread http://www.penturners.org/forum/showthread.php?t=52551

This is a click pen but you could do the same thing with a twist pen . Just make the cap as long as the clip and fit it to go over the pen body . This way the clip turns with the cap and don't scratch the pen body .


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## PhotonFanatic

Thanks everyone for the tips and feedback.

Some more questions:

Where can I buy the Cross transmission?

Butch: How long is that click pen?

Steve: Nice improvisation on the spring.  That's my kind of machining. Now, can you knurl Ti like that? :wink:

Jeff: Thanks for the link. 

Since I've invested so much time in this pen, I intend to finish it with a clip attached to the finial, but I will surely be looking at the options that everyone has proposed for any future builds.


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## skiprat

Fred, although it's not a Cross product, these mechs can be purchased seperately. I can't remember which of the USA pen vendors stock them in bulk though. There are shorter versions available too.

I'd love to get my hands on some Ti rod and tube but have searched UK sites without luck for years. I  did put knurls on some stainless steel once but the knurls wheels were only fit for the bin afterwards.
I know that titanium is lighter than stainless but I don't know how tough it is.   Maybe one day I'll find some.

Your moving head lathe is fascinating, I have never seen anything like it before. I use a vertical slide vise when I do milling on the lathe. Can you alter the head while it's running?


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## ldb2000

The click pen is about 5 1/2" long and the cap end is 1/2" diameter . The transmission I used on the Telesto pen Is a regular cigar transmission that I buy in bulk from www.woodpenpro.com . I use them in most of my twist pens , they work with a Parker style refill and I press fit them into the aluminum core tube I use and I use an 8mm tube to couple them to the cap or finial . 
When you design a finial operated pen , like yours , you have to attach the clip to the body of the pen some how . I do this by using a clip that fits over the core tube and gets held in place by the finial ring . You have to size the body and finial ring to the outer dimensions of the clip ring , or larger if you want a hidden clip design .


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## workinforwood

http://www.penmakers.com/used.html

Try that for some springs and cross transmissions for only a buck a piece.

You know that the idea of a finial operated twist pen can also be used exactly the reverse way too.  You can make it so the nib is what you twist to operate the pen. That is a very simple procedure.  Your nib would not be a threaded nib.  You would have the nib, a tube, and the transmission, all pressed together. The pen body would be drilled larger at the bottom and thinner at the top, so the top squeezes the transmission.  You simply push the parts up into the pen.  Twisting the nib would operate the ink.  To refill you pull the pen apart, unscrew the top of the transmission and pull out the ink....that's for the parker style transmission.  For a cross transmission, you can't unscrew it.  It is a press fit only.  If you use a cross transmission for a parker refill, that is fine, but you may have to shave a little plastic off the top of the refill for it to fit in the hole.  If you were to do a nib twist with a cross refill, you would have to press the transmission in to the top of the pen upside down, otherwise you would never be able to access the refill.

I have to throw that in there as an idea, because I saw your website and saw what you are capable of, so I know that you can make any and all of these ideas work for you!


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## PhotonFanatic

skiprat said:


> Fred, although it's not a Cross product, these mechs can be purchased seperately. I can't remember which of the USA pen vendors stock them in bulk though. There are shorter versions available too.
> 
> I'd love to get my hands on some Ti rod and tube but have searched UK sites without luck for years. I  did put knurls on some stainless steel once but the knurls wheels were only fit for the bin afterwards.
> I know that titanium is lighter than stainless but I don't know how tough it is.   Maybe one day I'll find some.
> 
> Your moving head lathe is fascinating, I have never seen anything like it before. I use a vertical slide vise when I do milling on the lathe. Can you alter the head while it's running?



That was a rhetorical question about knurling Ti--it can be done on strong machines with scissor-style knurlers, but the home shop machinist, unless they are really rich, is unlikely to have a machine to handle the job. Or, if we try, then we do what you did--ruin the knurling cutter in one use. :-(

As for Ti tubing and rod, send me an e-mail with what you'd like, I can probably find something for you. And I regularly mail stuff out to the UK all the time, so that's not a problem. It is hard to find the right diameter and wall thickness in Ti tubing though. I did get some recently that was .55" in diameter with a .16" wall thickness. Wish I had bought all the guy had--he's now out of stock, but he gets more in from time to time.

As for the lathe--I'm not sure what you mean by alter while running, but I can certainly move the head up and down, while the spindle is running, and I can change the spindle speed up or down at will, too, while it is running. Since I usually hold the workpiece on the cross slide, that lets me move perpendicularly to the spindle, or allows me to rotate the piece while machining it.


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## PhotonFanatic

Butch and Jeff--thanks for the links--I've spent a little more money. :biggrin:

You've given me a lot of advice, and I'll need to spend some time with all the pieces and then re-read all the suggestions. Maybe then, I'll understand precisely what you've written.


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## ldb2000

Fred , glad to help . If you need any further explanations please feel free to ask , either here or by PM .
I think what you are trying to do is great . If you haven't built any kit pens yet , you should . It would give you a better understanding how they are designed and what the different parts are and how they can be used .


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