predicting tip extension

[sorcerertd]

I run into this now and then and am wondering if anyone knows a relatively easy way to predict if an ink cartridge tip will extend properly. Case in point, I just made this SPW clicker. Nice little pen, but I'm really unhappy that the tip doesn't extend a bit further. I did not alter the kit in any way, but now that it's assembled wish I would have taken a little less than a mm off the tube. Some pens can be disassembled and adjusted, but click pens, not so much. Is trial and error, discovering the perfect tube length for each style, the only way to really know?

 

[magpens]

" Is trial and error, discovering the perfect tube length for each style, the only way to really know? "

With twist ballpoints and click ballpoints I have the feeling that "trial and error" may be the only way.

The " purists " and " determinists " among us might advise us to just ... " measure and calculate " !

I have had several experiences of trying to do just that, but my efforts have never been fully successful . . . always some discrepancy occurred.

With the variety of pen refills that exist there definitely are length discrepancies .... not large but definitely significant .

And even if you " measure and calculate ", you potentially may have to then " compensate " to get what you want for your ideal pen format.

And there may be more than one way to " compensate ".

Do you shorten/lengthen the barrel ? . Do you grind a little off the Parker-style refill's plastic stub ?

And if you do " compensate " in such a way, what if you later replace the refill with another brand, say, of slightly different length ?

Personal preferences of customers and giftees come into it as well.

And, oh, by the way, Todd @sorcerertd , the tip extension that you show in your photo above is " IDEAL ", ..... in MY opinion !! . . LOL

 

[Ironwood]

I prefer to have my pens with the exact amount of refill protruding as your pen there shows.

I make some pens using a commercially available twist mechanism, because I am restrained by the length of the other components I use, the twist mechanisms extend the refill a millimeter or two, too much. I overcome this by running a drill bit into the mechanism and drilling out the plastic bit inside, so that the refill will sit in a bit further. Once I get the refill protrusion I am happy with, I assemble the pen, and sell it, the only problem is, if the mechanism fails, and the customer brings it back ( which has happened a couple of times, out of a couple of hundred pens sold ) it's not a simple matter of just putting a new mechanism in to replace the old one, I have to take the pen home and drill out a new mechanism to suit . No 2 pens are exactly the same length, so each one has to be done to suit that particular pen.
It's fairly easy to get it right, as one turn of my tailstock = .75mm, I just measure how far the refill is extending, and work out how many turns it will take. I have marked the handwheel on the tailstock to make it easier.

 

[RichAldrich]

I like mine out a hair more. I would not adjust the fit on the one shown.

 

[randyrls]

I have a method for determining the correct length. I've had several pens where the brass tube was too short and the point didn't retract completely!

Before assembly, place the ink fill in the cap end and set the clicker to the extended position. Place the nib over the point and the blank beside the ink fill against the fitting ends. The amount of point exposure is shown. Now you can set the amount of exposure you want. It is difficult to say, easy to do.

Hope this helps.

 

[sorcerertd]

I have a method for determining the correct length. I've had several pens where the brass tube was too short and the point didn't retract completely!

Before assembly, place the ink fill in the cap end and set the clicker to the extended position. Place the nib over the point and the blank beside the ink fill against the fitting ends. The amount of point exposure is shown. Now you can set the amount of exposure you want. It is difficult to say, easy to do.

Hope this helps.

I think I'll have to try this to get what you mean. Sounds like one of those things you have to do to understand, but I think I can picture it.

Not retracting is definitely much worse.

I usually want it to look like, if you were to draw a line at the angle of the nib, the angle of the cartridge tip appears to line up with it, or somewhere close to that. I just prefer a more flowing line instead of angles. I would not want it extended too much further. Maybe just a half mm. The crude scribbling here shows what I mean.

Thanks for the "ideal" vote of confidence, Mal. I suppose that it is ultimately up to the customer to decide if they like it or not. I show pictures of the tip extension on all my pens in the Etsy store so people know before they make a purchase. I definitely don't want to make it necessary for the end user to alter anything to make a refill fit.

 

[randyrls]

Ok; I took a staged photo of how I do this. Normally I hold the pen upright to judge the extension, but I laid this one down (cause I don't have a third hand to hold the camera). I think it is a bit short.

 

[sorcerertd]

Ok; I took a staged photo of how I do this.

Thanks. That's what I had pictured. I guess you described it well enough for me to get it, but now I know for sure.