Twist pen mechanism turning in tube

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Woodpecker26

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Jan 27, 2013
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Fresno, CA
Hello All,

For a twist pen, when you turn it to expose the writing tip, it hits a 'stop' so you know when to stop twisting, and really should not turn beyond that. I have quite a few where the tube basically 'slips' and turns around the twist mechanism and you can keep twisting past the maximum open point. I don't know if these are manufacturing issues or slight variances in tube sizes, or maybe inside tube material honed out when trimming the barrel? I see these as defective pens, and you don't know if it's going to happen until the pen is done and assembled, then the beautiful pen you just made is useless. I've only used Penn State kits, and it has happened on different types of kits. Has anyone else that's run into this have any suggestions for how to fix, or even better, identify when it might happen?

Thanks in advance for your comments
 
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It has happened to me when using PSI Designer pen kits. No longer use them. Try using some Modge Podge on the exposed area of the transmission before assembly. I had some success doing that, but have no idea how long that "fix" will work. I definitely wouldn't sell them.
 
I've had it happen ...

on kits from 3 different suppliers. In one case, when retracting it also happened.

I still wonder if it is not something I am doing that is allowing this to happen.
 
This happens more on slimlines than others but it can happen with almost any twist pen. It usually is not a defective transmission. I suspect it typically is a small variation it tube size with a small variation in the grip nipple(s) on the transmissions.

The gripping surface on slimline transmissions is usually not the whole surface area but a couple (mostly three I believe) small ridges in the chrome area. If the tube is a little oversized where the ridges don't make tight contact you can get the symptom you describe. It might well be caused by reaming to clean the tubes or when squaring the blank with a pen mill. Replacing the transmission will not necessarily fix it.

You can probably avoid it by trying the tube with the transmission prior to installing the transmission. There are a number of things that could be easily done to fix it - none of which would last forever in my opinion. I might try using very course sand paper and roughing the inside of the tube a bit and the transmission first.
 
Smitty37 said:
You can probably avoid it by trying the tube with the transmission prior to installing the transmission. There are a number of things that could be easily done to fix it - none of which would last forever in my opinion. I might try using very course sand paper and roughing the inside of the tube a bit and the transmission first.
Click to expand...

Of course , the pen might not last forever , either !

Sandpaper might worsen the problem by removing more of the tube . I would try using a dental pick in a fairly tight spiral motion over the full tube length . The object is to create a groove with raised edges which can hold onto the transmission ridges . This is a theoretical solution , not one which I have tried .
 
Thanks to everyone for the fantastic feedback and advice. This happened on both PSI slimlines and Designer pens. I have not tried to sell pens yet though might some day and mainly give them as gifts to the kid's teachers and friends. Even so, I still want them to be professional, so end up keeping the 'slippers' around the house. I hate the idea of getting a pen perfect then rolling the dice at the end to see if it's a keeper. Thanks again to all.
 
You CAN slightly bend the transmission, using a vice-grip.

Grip the top half and squeeze it ever-so-slightly. This makes the "small ridges" (Smitty referred to) more prominent. I don't see any reason this would not "last forever".
 
I have used a automatic prick punch from the inside out. I advance the transmission first, place the end of the transmission on a piece of wood and and put the prick punch just inside the end and punch down. This will leave a small prick going out of the casing of the transmission. If it is to much adjust the spring on the punch until it is right. Also if it is to much at first I file off the dimple a little. I usually put two or four on a transmission. I do this on slimline pens but if you can get into the end of the transmission on other pens a little it should work on any transmission. I have also used a little ca in the tube, using a q-tip, and sanded it out until it fit.
 
ed4copies said:
You CAN slightly bend the transmission, using a vice-grip.

Grip the top half and squeeze it ever-so-slightly. This makes the "small ridges" (Smitty referred to) more prominent. I don't see any reason this would not "last forever".
Click to expand...
Good idea, I never tried it but I don't see any reason it won't work so long as you tighten the vice grip slowly. I think I'll use that from now on.
 
I have made a tool for this. I put a 10p nail into a small handle I ground the nail head to a sharp point and insert the nail into the transmission and give it a good push down on the chrome part and make dimples. hasn't failed me yet
 
Ed's earlier vice grip solution is so, so much better than the Modge Podge one I posted. I just took a pair a pliers to two transmissions, lightly scoring them around the circumference. The pens work like a charm. I'll try a dimple maker next.
 
I've had this happen a few times. Coat the inside of the slipping tube with a layer of thin CA. MAKE SURE IT IS FULLY CURED BEFORE INSERTING (damhikt). If you put too much, file it down with a mini rat tail. Not enough? Do a 2nd coat.
 
I've solved this problem on a few Slimlines by putting a layer of medium CA on the exposed part of the transmission AND LETTING IT DRY COMPLETELY before assembling the pen.

(Don't be impatient, I've glued a couple of them together!)

This makes for a more snug fit but you can still take the pen apart to refill.
 
I have this problen to. I narrowed it down to the "upper" tube. For a long while I was champhering the leading edges of both the upper and lower tube for easy insertion. Bt NOT champhering the lower part of the upper tube I now have "Great Grab".
 
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