Closed end Cuban Cigar Pen, custom pin chuck

[RobS]

Hi Guys

This is a work in progress, more pictures to come.

*****The information in this posting is intended for member use, if you find a flaw in the design or an improvement, please let me know and I will update the model and print and re-post. This was done in Solidworks2014, if you'd like the native file PM me with an email address.*****

So I've been dying to make a Closed end Cuban Cigar Pen. However I could not find a pin chuck that would work for what I wanted. So I drew up the attached drawing and Rick (rherrell) was kind enough to custom make this for me at a nominal fee (well worth it).
Please note it was designed to be used with a Beal Chuck with a 0.625 collet.

The one thing to note, is that the chuck has been designed with the bushing built in, so you would turn your blank down to the shoulder which has already been machined to the correct diameter. I'm sure one day I'll beat it up too badly to use, then I would have the shoulder turned down and another separate collar bushing turned and installed. However, I like not having more parts to lose, so I went with the permanent shoulder.

This baby just came in, so I have not had a chance to make anything yet.
However, the fit and finish is awesome.


View in Gallery

View in Gallery

Thanks

 

[SteveG]

This pin chuck is in the "beautiful" category, as it is so well made, and especially with the concept of "Form follows function." There is one design aspect of a pin chuck that I believe could be an improvement. I have never used one of these, but a discussion point I have read is that because the chuck works on the principle of wedging the pin between the chuck body and the tube, it can distort the tube/blank a small amount. If that is so, you would want that distortion to be located along the blank where it would have the least undesirable effect. I expect that would be a little away from the open end (thus no OOR at the point where this end of the pen meets the opposite end). But also, one would want it far away from the closed end, as that is where the blank is typically going to be turned to the thinnest diameter for most pen designs. This would put the optimum pin location at about .5 inch from the open end point of the barrel.

Anyone have differing views on this comment? Perhaps the "distortion effect" is not significant, in practice?

 

[RobS]

works great. tight fit, but it hold like a rock.:biggrin:


View in Gallery

 

[MDWine]

I assume you're using a cigar kit for that build?
Could you post a picture? I'd love to see the finished product!

Nice turn, BTW.

 

[KenV]

Steve --- you are over thinking and under measuring with the pin style, or for that matter, the compression style blind chucks.

While I can measure a small amount of distortion on the outside of a bare tube, it is minimal. With epoxy and blank on the tube, I could not measure a difference. After turning measuring over the pin before and after dismounting, there was no difference given 0.001 measurement tolerance.

The captured pin design pretty much avoids the ends and my process of lightly reaming the ends removes distortion if there was any.

There is always a gorilla factor but with reasonable use, minimal secondary problems.

 

[RobS]

Hi Gents, this is a work in progress. I will gladly keep posting pictures on this thread as it moves forward. Note, I do most of my turning Saturday and Sunday 5-9am to beat the heat. So likely no new pictures till Next Monday, I do need to swing by the cigar shop and hit them up for some bands.

Since this is not a comissioned piece, I'm sneaking it in just to see how it all is coming together.

Thank yous:
This is a simple piece of Koa wood from a lot purchased from @danroggensee as a bulk assortment of blanks. They are getting put to use. I stabilized it in Cactus Juice just for kicks.

Thanks to who ever posted the Big Ben/Cuban Cigar- modified closed ends on the net, that is what drove me to have Rick turn a custom pin chuck with bushing built in.

Thanks to Rick for making a $150 custom pin chuck for <$20. The fruit of your labor is being put to use.

Cheers:biggrin:

 

[duncsuss]

... one would want it far away from the closed end, as that is where the blank is typically going to be turned to the thinnest diameter for most pen designs ...

I don't see any reason why the blank is going to be thinnest at the end of the brass tube.

I know exactly how long the tube is inside the blank, because that's how deep I drilled the hole before gluing the tube into it. Beyond that point, I drill with a smaller diameter bit (just large enough to receive the twisty end of a fountain pen ink converter), again for a precisely measured depth.

There's no need to make the taper into the butt-end of the barrel such that you run the risk of breaking through to the brass tube.

 

[RobS]

The progress so far. I do not have the skills needed yet to CA finish, decal mount and clear coat yet.

I will note that i had to use the lathe to press the components into the closed end, I did not realize I would still need the end cap hardware without the clip press all the way in. I thought I could forgo it completely, but you can't you need it to actuate the mechanism.


View in Gallery

 

[KenV]

Rob, the tube that drives the transmission is an 8 mm tube.

You can modify the insert and tube to slip inside the tube and hold it in place with a bit of epoxy. You have a good bit of tolerance on length of the 8 mm tube .

 

[RobS]

Gotcha, I didn't think of that. I just turned off the threads on a metal lathe and pressed it all the way in.

Your idea would really help when it comes to materials that crack easily like ebony. Since there would be no hoop stress.

Thanks for the idea.

Rob, the tube that drives the transmission is an 8 mm tube.

You can modify the insert and tube to slip inside the tube and hold it in place with a bit of epoxy. You have a good bit of tolerance on length of the 8 mm tube .