Sierra problem

[Darley]

It's the first time I have a problem like this with the Sierra pen kit, I read that some of you have problem with mechanism but does any one have this happen to them.

So I decide to take some calibration

First inside of the Sierra nib I notice a ring who will stop the ink refill to go further out, ( please some one tell me if I'm right )

Now I see that the inside ring as been push to far down ( I mean toward the nib )nib B to compared to nib A

Does any one have any ideas to pull the ring out further to reach the measuring of the nib A? or do I have to use this kit as spare part

 

[1080Wayne]

Haven`t seen that problem Serge . It might be possible to remove the nib tip from the rest of the tip assembly with a 1/4 in transfer punch , and then use a 5/16 to tap the ring back to it`s proper position . Wayne

 

[Darley]

Wayne thanks for your reply look like lot of people didn't see this type of problem so will use the kit as spare

 

[Ligget]

Serge sorry you have not had more feedback, I have not had this problem either!

 

[Randy_]

Serge: I think you are barking up the wrong tree.

I'm not sure exactly what the "ring" is that you are seeing; but I don't think it has anything to do with your problem. The distance that the cartridge tip extends from the pen tip is controlled by the transmission and not by anything in the tip. You can prove this by removing the spring from the refill and putting it in the Sierra "nib." I think you will find that just like my Sierra, the tip of the refill extends from the tip of the pen by about 15mm....a much greater distance than shown in either of your pictures. Even with the spring on the refill, the refill tip extends about 10mm.

The information you have provided leads me to believe that the problem lies either with the refill or the transmission. First thing to do is make sure that both refills are the same length. It would be a rare occurrence if they were not the same length; but stranger things have happened.

My guess is that one of the transmissions is defective. Try switching the transmissions from one nib to the other and see if the problem is transferred from one nib to the other.

The other reason I don't think it is your "ring" is the following. The difference in the two measurements that you showed is 0.062". I can't be sure, but from your picture, it looks like the difference between the extension of the two refill tips is quite a bit more than that.

Another thing you might do is measure the total length of both nibs and be sure they are the same length. In the picture they look to be pretty close; but I can't be sure. The measured length of mine is 2.530".

Let me know what you find out. If this doesn't help, we'll will try something else until we get it figured out.

Added: While you are at it, measure the length of the transmissions. Mine measures about 2.365".

 

[Rmartin]

Sorry, I haven't had that problem either. Try switching the refills and trans around. As a last resort (sings in Elvis voice) "Return to sender".

 

[Darley]

Originally posted by Randy_
<br />Serge: I think you are barking up the wrong tree.

I'm not sure exactly what the "ring" is that you are seeing; but I don't think it has anything to do with your problem. The distance that the cartridge tip extends from the pen tip is controlled by the transmission and not by anything in the tip. You can prove this by removing the spring from the refill and putting it in the Sierra "nib." I think you will find that just like my Sierra, the tip of the refill extends from the tip of the pen by about 15mm....a much greater distance than shown in either of your pictures. Even with the spring on the refill, the refill tip extends about 10mm.

The information you have provided leads me to believe that the problem lies either with the refill or the transmission. First thing to do is make sure that both refills are the same length. It would be a rare occurrence if they were not the same length; but stranger things have happened.

My guess is that one of the transmissions is defective. Try switching the transmissions from one nib to the other and see if the problem is transferred from one nib to the other.

The other reason I don't think it is your "ring" is the following. The difference in the two measurements that you showed is 0.062". I can't be sure, but from your picture, it looks like the difference between the extension of the two refill tips is quite a bit more than that.

Another thing you might do is measure the total length of both nibs and be sure they are the same length. In the picture they look to be pretty close; but I can't be sure. The measured length of mine is 2.530".

Let me know what you find out. If this doesn't help, we'll will try something else until we get it figured out.

Added: While you are at it, measure the length of the transmissions. Mine measures about 2.365".

Ligget and Martin thanks will try to solve the matter.

Randy I do have 14 sierra pen kits and I try all parts switching refill and mechanism around only this nib ( B ) is faulty, now Randy if you can take 1 of your sierra pen kit and with the depth gauge of your caliper read the measument then tell me what is the reading, I think that if the refill tip goes out of the pen nib 10m/m to 15 m/m you're talking about dart [] never see a refill goin out so much, no offence here, my reading are correct. Can someone take a photo of is Sierra with the nib out ready for writing and post here would like to see if I'm right or Randy is right, Thanks

 

[Randy_]

Serge: I think you may have missed my point. In my assembled pen, the tip configuration looks exactly like your nib "A". Just the cone shaped tip of the refill extends from the pen.

When I talked about the refill tip sticking out 10mm+, that was by pushing on the end of the refill with a finger without the the transmission being in place. To me the fact that the refill will extend so far shows that the transmission controls the extension of the refill and not something inside the nib.

As I recall, there is a little step or shoulder inside the nib; but I think it is the end of the tip that has been pressed into the nib and not some sort of separate movable "ring".

I'll run out to the shop in a few minutes and measure the distance to that shoulder to see how it compares with the measurements you posted.

Since you are still of the opinion that the problem is with nib "B", would you measure the length of your nib and see how it compares with the length that I mentioned for mine.

Thanks

 

[Randy_]

I selected three kits at random from my Sierra inventory and measured each. They measured:

1.557"
1.565"
1.560"

Not that I think it is a consideration; but each kit was a different plating.

 

[pssherman]

Serge,
I measured the length of one of my Sierra nibs and it was between 2 1/2 and 2 9/16 inches long. This is in agreement with Randy's measurement. Check the length of nib "B". I believe you will find that it is shorter. You can compensate for this difference by pushing the transmission back out of the housing by an amount equal to the difference. This will result in a "matched" nib/transmission combination providing for the correct amount of tip exposure. Of course these parts WILL NOT be interchangeable with any of your other kits. If you are not sure how to push the transmission back out, PM me and I will try to give you some detailed instructions that should work.

Paul in AR

 

[Randy_]

Originally posted by pssherman
<br />...If you are not sure how to push the transmission back out, PM me and I will try to give you some detailed instructions that should work.

Paul: Why don't you just post them here? I suspect there are others who would like to have that information, myself included.

 

[Darley]

Paul Thanks,
Randy spot on, did again another reading for the out side nib look like the measurment are different

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Randy you got your 0.062" + will have to figure out how I can save this faulty nib,, Thanks for your help Randy and everyone

 

[Randy_]

Serge:

Glad to see we are making progress!!

I can think of six different ways to attack this problem and there are probably one or two others that I have missed. A couple are easy fixes and a couple are sort of complicated and I really don't like any of them except number 1. (see below)

I'm going to hang onto five of the six for a day or two so my thinking won't influence yours and see what ideas you come up with. Then we can compare ideas and see which one you like best.

What I would do in the meantime is email your vendor and test their customer service. I know you are a long way from your point of purchase; but the best solution I see to your problem is a replacement by the vendor of the defective kit. You might even send them a link to this thread so they can understand exactly what is going on and, in any event, they certainly need to be notified that they may have a problem with thier quality control. Who knows, perhaps they have a whole group of kits sitting in their inventory with the same problem?

Did you order the kits directly from Berea or from one of their resellers?

After you have had a day or two to think about a possible method of repair, let's chat again. Maybe Paul has some other ideas, too. I'm not too crazy about disassembling the transmission unless this is something he has already done and knows, from experience, is a workable solution.

 

[Rifleman1776]

Good thread. Highlights the fact that there is often inconsistency with the products they ship. Shouldn't be but it is a fact that we must check, measure and re-check everything if we are to produce a quality pen and not waste money by throwing away expensive kits that are not usable. The only kit (that I'm aware of) that has the transmission seated by a given measurement is the Cigar. For all others the try and check, then seat some more and check some more method is the only safe way.

 

[Mudder]

Originally posted by Rifleman1776
<br />The only kit (that I'm aware of) that has the transmission seated by a given measurement is the Cigar.

How about the perfect fit?
And the designer series from Penn state? PKMONT-PAR for example?
I'm quite sure there is many others.

 

[pssherman]

Originally posted by Randy_
<br />

Originally posted by pssherman
<br />...If you are not sure how to push the transmission back out, PM me and I will try to give you some detailed instructions that should work.

Paul: Why don't you just post them here? I suspect there are others who would like to have that information, myself included.

No problem.

I have never encountered this problem before, so, I have not tried any of these suggestions yet. But, being a mechanical engineering professor, one of my 'best' talents is problem-solving. Here are the possible solutions to this problem if you can't resolve this with the supplier/manufacturer.

1) Trim the length of the refill at the area circled. This will need to be repeated every time the refill is changed. Therefor, it is not a good idea if you are selling or giving away this pen. You don't want to have the customer doing this every time they change the refill.

<br />

2) Make a small ring the same diameter as the nib at end of the threads and glue it to the nib at the point indicated. This will correct the length of the nib, which will make it interchangeable with the other kits, but, the attached ring may not be very secure and can be knocked off.

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3) Make a small ring that fits over the threads on the transmision assembly at point A and glue it in place at point A. This will correct for the shortened nib and be much more secure, but the parts will not be interchangeable with the other kits.

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4) Push the transmission back out of the assembly to compensate for the shortened nib. To do this, make a hollow tube that fits snug against the assembly and rests against the shoulder at point B and extends beyond the transmission. Insert a transfer punch inside the threaded tube and use a press to push the transmission back out a little ways. If you push it too far, it can always be pushed back in the same way we install transmissions in other pens. As mentioned before, I have not tried this, but the brass portion of the transmission appears to be press-fit into the stepped, threaded tube and should be able to be corrected in this manner. But I am not able to confirm this at this time.

Hope these suggestions help.

Paul in AR

 

[Randy_]

Paul:

All good suggestions......but each has a wart or two!!

Your #1 is probably the easiest solution; but, as you point out, would not be appropriate for a pen that you wanted to sell.

Your #2 is on my list; but in a slightly different configuration. I think a better location for the "ring" would be glued to the shoulder on the transmission (location A in your third picture). There would be a larger gluing surface available and I think the ring would be less likely to be dislodged from that position.

Difficulty with this alternative is that making the ring might require more skill and tooling than some/most pencrafters possess and it would reduce the length of transmission threads engaging the nib. There is not much thread length engaging the nib even in a normal pen and while there is not a great deal of stress on this joint, reducing the thread engagement would weaken the connection at this joint.

Your number 3 was mentioned in an earlier post and I have a concern about it as well. According to my measurements, the transmission is only seated into the threaded coupling to a depth of about 0.15". According to Serge's measurements (which I think are correct), he needs an addition 0.07" to make the tip extend properly which means the seating depth would have to be reduced to 0.08". I don't think that is deep enough to give a solid connection. Additionally, in looking closely at my transmissions, it appears that there is a roll crimp to keep the transmission in place. If you back the transmission out a little or remove it entirely from the coupler and then reseat it, I'm afraid you might reduce/eliminate the effectiveness of the crimp.

 

[pssherman]

Randy,
If you look at the transmission, there is a portion that is brass that is press-fit into the stepped tube. The rotating portion does have a roll crimp on it which holds the lower and upper portions together. If you use a transfer punch that just fits inside the stepped tube you will be pushing on the brass portion not the rotating portion. This will prevent damage to the rolled crimp.

The layout of the transmission is the same as for the slimline transmission but the brass portion is much longer. Pushing the transmission out would be the same as disassembling a slimline except that you support the shoulder of the stepped tube instead of the blank.

Paul in AR

 

[Randy_]

Paul; That is not the crimp I am talking about. Take a very careful look at the threaded coupling about 0.08" from the end where the brass of the transmission is pressed into it. You may need to rotate it a bit to get the light just right. Good eyes and a magnifying glass are a help, too. There is a very faint impressed ring in the coupling that I take to be a crimp. I suppose it could just be a tooling mark; but I see it on all of my kits and think it is there by design. It is just a little too much of a coincidence that the "crimp" falls exactly in the middle of the brass section of the transmission that is inside of the coupling!!

 

[pssherman]

Randy,
The one that I have been looking at (shown in the photo of a previous post) does not seem to have a crimp where you mention. I received this pen in a pen swap about a year ago and wonder if there could be slight differences between manufacturers and/or year of production.

Anyway, a crimp in the location you describe would serve to increase the clamping force of the press fit. Unless you push the brass portion past this crimp, there should be little or no effect on clamping force. If there is any doubt as to the strength of the press fit after moving the transmission one could: a) apply a drop of CA to reinforce the press fit or b) use a small tubing cutter with a little pressure on the cutting wheel to put an indentation (crimp) near the point where the brass enters the stepped tube.

By small tubing cutter, I mean the kind that is intended to be used for small tubes, not copper piping and use only enough pressure to indent the surface, not cut though it.

Also, the chamfer on the transfer punch probably should be ground down so that you have a completely square end to push against the brass.

Paul in AR

 

[Randy_]

Originally posted by pssherman
<br />Randy,
The one that I have been looking at (shown in the photo of a previous post) does not seem to have a crimp where you mention. I received this pen in a pen swap about a year ago and wonder if there could be slight differences between manufacturers and/or year of production.
<b>Certainly a possibility.</b>

Anyway, a crimp in the location you describe would serve to increase the clamping force of the press fit. <b>Unless you push the brass portion past this crimp, there should be little or no effect on clamping force. </b>If there is any doubt as to the strength of the press fit after moving the transmission one could: a) apply a drop of CA to reinforce the press fit or b) use a small tubing cutter with a little pressure on the cutting wheel to put an indentation (crimp) near the point where the brass enters the stepped tube.
<b>Exactly. With the measurements Serge has provided, the transmission would have to be pushed out to the point where the brass would no longer be engaged by the crimp if that is what it is. I agree that CA might help; but the brass would still only be inserted to a depth of about 0.08†which I don’t think is deep enough to give a very secure connection. Given that the brass is only seated to a depth of 0.08â€, a new crimp would only be about 0.04†from the end of the threaded coupler. That might be a little tricky to do. </b>

By small tubing cutter, I mean the kind that is intended to be used for small tubes, not copper piping and use only enough pressure to indent the surface, not cut though it.
<b>I do know the type of cutter you are talking about. I have the smallest cutter that is available for plumbers and that appears to be too big for this task. Someone may make a mini cutter for model makers; but buying one of those might be more costly than just buying a new kit??</b>

Also, the chamfer on the transfer punch probably should be ground down so that you have a completely square end to push against the brass.
<b>Good point!!</b>

Paul: I don't mean to be argumentative here. Just trying to throw out some ideas and see what you think. Certainly, your training as an engineer gives you a totally different perspective and knowledge base on this type of problem from most of us here at IAP. It is always good to hear from technically trained folks. Sometimes the musings of we amateur garage-shop tinkerers can get us in trouble.

 

[workinforwood]

Tie the nib end to a sturdy tree. Get some sturdy ropes and pullies and 2 Clydesdale horses. Hang the pullies from a metal A-frame assembly. String ropes through pullies and tie to threaded end of pen with a slip knot. Use a double underbelly hook knot to attach ropes to horses. Crack a 32" whip on the horses behinds and stand back. This will stretch the kit to the proper length. If you had read the instructions that come with the kit, you clearly would have known this.

 

[bitshird]

It is possible to cut thin brass, copper or aluminum tubing with a sharp utility knife, use a flat surface and roll the tubing under the blade while exerting a slight downward pressure on the knife, this has the same effect as a tubing cutter, and if done right is more precise, and leaves a cleaner edge, be careful as the knife blade starts to go through the tubing, this will actually leave a cleaner cut than a tubing cutter, provided you roll it back and forth slowly, and keep the blade straight.
This might allow you to make the needed spacers[]

 

[Ron Mc]

And we are having to fix a faulty Sierra kit....why?

It looks like everyone has found good ways to make something that is not properly manufactured work.

 

[Randy_]

Main reason, Ron, is because Serge wants to. But the other consideration is that the kit is in Australia and getting a replacement may take a while. And learning how we can manipulate the kit may benefit those who want to modify the design at some future time.

And for me personally, it is just fun to see if we can solve a mechanical problem......sort of like solving a Rubik cube.[][]

 

[Randy_]

Ken: That is a handy tip which I will definitely file away for future use; but I wonder if it would work in this particular situation? The spacer we need is only 2mm long and would need to come out of a 9mm tube. It is such a tiny little spacer, I would be worried about it collapsing under the pressure of the knife. Might work if a wood or metal rod was inside the tube to keep it from collapsing? What do you think??

 

[pssherman]

OK, back online again.
The following is fairly long.

Randy, I did not, and do not, think that you are being argumentative. Discussing ideas back and forth is an effective way to solve a problem.

Lets summarize where we stand at his time. Hopefully I've got things straigthened out in my mind.

1) Getting a replacement from the supplier is the best choice. Unfortunately, for our international members and those who are in a hurry, this may not be practical. It is for these people that we are trying to help.

2) Cut the refill to compensate for the error in the nib. If you are going to use the pen for yourself or as a demo (where you are the one replacing the refill) then this is an eaasy fix. However, if someone else is going to be using this pen, and changing the refill, then this might hurt your reputation for doing quality work.

3) Attaching a ring either to the nib (very weak) or to the threaded tube (stonger) may be doable if you can make the ring. Per Ken's and Randy's suggestions, a ring could be made from a brass tube using a utility knife and a dowel for suppport. The amount of threads that are engaged will be reduced and may be easily loosened. Perhaps applying a coat of CA to the threads and allowing it to fully cure will tighten the connection enough to prevent it from coming loose during use. How well this will work is unknown until someone actually tries it and reports the results.

Randy reports that the length of the ring would need to be about 0.07 inch. This could be reduced if it is acceptable to allow the refill tip to extend slightly farther than normal but less than what Serge's photo shows. Maybe 0.04 inch would be enough. That would allow more of the thread to be engaged.

4) Push the transmission back to compensate for the nib length. This is where most of our discussion has been. Basic instruction on how to push the transmission has been presented. Randy indicates that on his assembly there is a rolled crimp to help hold the transmission in the stepped tube and moving the transmission by 0.07 inch would push it past this crimp. So, how do we make sure that the clamping force between the stepped tube and the brass portion?

The location of the brass/stepped tube interface is such that the only stresses that it will see is when a) the upper and lower portions of the pen are pulled apart or b) trying to twist the mechanism farther than the normal range of motion. Again if a little excess extension of the tip can be tolerated then the amount of correction can be reduced and the amount of contact area is increased. Ken's idea of using a utility knife can be used to produce a new rolled crimp on the stepped tube in a more easily controlled manner than using hobby sized tubeing cutter. CA can also be used to reinforce the press-fit.

Another idea I came up with is to produce an inside-out crimp at the end of the brass portion. This can be done by using a tapered end on a transfer punch. You want the tapered portion to make contact with the inside edge of the brass simmilar to using a tube insertion tool for gluing a tube in a blank. Place the end of the transmission on a hard but resilient surface, put the tapered tool in contact with the brass (inside edge) inside the stepped tube and gently tap the tool with a hammer. This will cause the end of the brass to be pushed outward against the stepped tube resulting in a greater clamping force.

I believe that the solutions presented above have now evolved to the point that most of us could make them work.

Any other ideas, comments, suggestion, or concerns?

Paul in AR

 

[Randy_]

OK, Paul, I think you have done a thorough job of stating the current status of the situation.

My only reservation in what you have stated is the suggestion to put a new crimp in the "stepped tube". According to my measurements, the wall thickness of the stepped tube is about twice that of the brass tubes in our pen kits. I'm not so sure you could make an effective crimp in the thicker material by just rolling a utility knife. It might be possible by using a snug fitting mandrel inside of the tube to prevent deformation and tapping the back of the knife blade with a small brass hammer to get a little more force to the tube. In fact you could probably accomplish the same thing by making a series of dimples in the tube using a punch. It would actually be a little more complicated than that; but it doesn't really matter as I think Paul's idea of an inside-out crimp on the brass section of the transmission is a much nicer solution.

Another way to go would to be to make an "oops" ring for the nib. I'm surprised someone hasn't suggested that already......maybe because it would be a little tricky to get right. I'm reasonably certain the nib end is nothing more than a tapered chunk of plated or powder coated brass with a tip pressed in one end and a threaded coupling pressed into the other. Disassemble the nib and add an oops ring at one end or the other or both and the problem would be resolved. Making an oops ring would require some fine work; but would not be outside the ability of many IAP pencrafters.

I've got one more solution; but I'm going to hang onto it for another day or so and see if anyone else comes up with it. I'll give you a hint. It is a derivative of an idea originally suggested by Mudder. It is my favorite of all of the solutions; but I have to admit that I am not completely sure it will work. The cool thing about it is it will take about 30 seconds to complete!!

 

[Darley]

Originally posted by workinforwood
<br />Tie the nib end to a sturdy tree. Get some sturdy ropes and pullies and 2 Clydesdale horses. Hang the pullies from a metal A-frame assembly. String ropes through pullies and tie to threaded end of pen with a slip knot. Use a double underbelly hook knot to attach ropes to horses. Crack a 32" whip on the horses behinds and stand back. This will stretch the kit to the proper length. If you had read the instructions that come with the kit, you clearly would have known this.

[][] LOL you're funny, who need to read the instructions?? Sierra is the most easy pen kit to assemble, I did contact BB and pin point this link to him about this matter,at this stage I'm not worries to munch and would like to thanks every one for they input

 

[Randy_]

Oops!! Got distracted and forgot to post this last suggestion. Inside the Sierra transmission is a little blue(in my kits) piece of plastic that actually bears on the end of the refill and pushes it into the writing position when the mechanism is twisted. I don't guarantee that this will work; but it seems to me that if this piece were shortened slightly, the extension of the refill tip could be reduced. This would be a sensitive, fit & try operation and if you took off too much material the mistake would not be easily reversible.

I have never disassembled one of those transmissions so I don't know exactly what the "guts" look like; but it might be possible to modify the transmission as follows. Mount a 1/4" drill bit in something that will allow you to hold the bit securely; but still twist it by hand......vice grips, small machinists vice, c-clamp, Jacobs chuck or whatever. Twist the mechanism so the refill would be in a fully extended position if it were in place. Insert the drill bit into the transmission "WITH THE TIP UP" to allow any drilling residue to fall out of the transmission and reduce the possibility of jamming up the mechanism in the future. Now gently rotate the drill bit or the transmission, depending on your set-up, and try to remove some material from the end of the little blue part. After you remove some material, reassemble the pen and see if you have removed enough or if more needs to be removed. Go slow as you can't put it back in if you remove too much material. If you have confidence in your "mechanical touch" you could use a cordless drill and "bounce" the transmission down on the spinning drill bit; but, again, the most extreme care would be necessary so as to not remove too much material.

I know these pieces can be drilled successfully as I have done it in using Mudder's method for converting a cigar pen to a pencil. However, there is always some possibility that the twisting force exerted by the drill bit could cause damage to the transmission. The twisting force will be much greater in this exercise using a 1/4" drill bit than was generated in the pencil conversion where only a 3/32" drill bit was used.

If someone has an extra twist mechanism laying around that they could fully disassemble and photograph, that would be be a great help.

 

[Charlie in Garfield]

Hi Darley,
You definitely have a bad nib as you can see by your own measurement.
Now you can do 2 things. 1 get a hold of your supplier if local and
ask them for a new nib and explain why you want a new one.2 And I have done this so I know it will work,unscrew the transmission,VERY
carefully put it in a metal vice,DO NOT Squeeze brass part down,
make sure the shoulder on the shiny part sets on the jaws.Take a punch
or Drill that will JUST fit in the shiny part and very carefully
bump out the transmission out a LITTLE. Now put it back together
and see where you are. If it is not enough do it again.If too much
just press it back in a little. Must just keep fiddling with it till
you get it right. Patience is a virtue, LOL [)] Best of luck
Merry Christmas
Just Charlie & Betsy

 

[Darley]

Randy and Charles thanks for this input but I think my Sierra problem is not finished, [] will talk soon abour it []