closed end question

[spnemo]

I just finished my first closed end pen. It is curly spalted maple using a tycoon pen kit from PSI. It looks really good but I think I need to work on my process.

Everything went smoothly until I parted off the end. From that point on I had a wobble at the end of the mandrel. Is there a way to eliminate that wobble without buying a collet chuck or special tool?

Here is my process:

1. Cut and drilled blanks then glued in tubes.
2. Mounted blank for closed end on lathe.

a. Used a rod from my center punch kit as the mandrel. It was mounted in my drill chuck.
b. Put blue tape on the mandrel to make sure the bushing and barrel trimming sleeve would fit snug and support the entire tube.
c. Mounted the blank on the mandrel and brought up the live center (with just enough pressure to turn the blank)
​

3. Turned the blank and sanded.

4. Parted off the end (wobble begins) and sanded the end

5. Applied CA Finish , sanded, buffed, and waxed.

What did I do wrong?

 

[gwilki]

Sean

I'm not sure what you are referring to as the "barrel trimming sleeve". I suggest that the problem is that, using tape, the punch is not properly centred. You could make a pin chuck using the punch for better results.

 

[hewunch]

Not having done a closed ended tycoon, but several other kits, I would say use the punch that is either a perfect match or slightly bigger and sand it down. Do not use the trimming sleeves or the bushing at all. Mount it all in your drill chuck.

 

[gr8danish]

I just got finished making my first "good" closed-end pen this week...

I ended up making my own pinchucks. While it takes a while to figure out how to make your first one work properly, you'll never look back. I've already made myself a full set of pinchucks for every tube size I use...

A properly sized pinchuck, is steady enough to turn the pen blank, sand, and finish with almost no support on the opposite side. I did still make the blank over length, and c/d the end supporting it in the live center. This just lets you rough out the shape quickly. Then part-off the end with the c/d, final light passes, and cut the end shape.

 

[jskeen]

Actually, if you have an adjustable mandrel, you don't need any of that. Just drill your blank first with a drill bit that will allow the threads on the end of the mandrel to bite into them a little. Use that to drill your blank first to about 1/2 inch deeper than the depth for the tube (allow more if using a kit like a euro screw cap rb or something that needs an endcap for proper refill clearance). Then drill the blank with the usual bit for the tube to the normal depth. Glue in tube. Slide the proper bushing onto the mandrel, and slip the blank onto the bushing. Then thread the small diameter hole at the end of the blank onto the end of the mandrel. Then adjust the mandrel so that the bushing is snug to the face of the collet. Turn as any other closed end. The threads on the end will be centered to the tube since they were drilled from the same setup. The bushing centers the open end, and the collet keeps everything tight. No tape needed.

 

[spnemo]

I tried another pen. Again, good results but the wobble is still there. So, I investigated further. It turns out that the wobble is caused by a slight deflection in the rod. I checked it before mounting the blank and it was fine but after turning the blank it was wobbling. The deflection is either a slipage at the chuck end or a bend in the rod itself. I think it was a slipage because I took the rod out and re-chucked it and it ran true. Then when the pen was added, the wobble returned and the rod had slipped again.

Oh, well. Back to the drawing board. At least the pens look good. They don't look out of round and the finish is good. So, for now this is just a minor annoyance that needs to be corrected.

 

[spnemo]

I have looked at a couple of tutorials on making pin chucks but I don't really understand them. For some reason, I am not getting the concept of how they work. Usually, I like to have a good understanding of the concept before proceeding. However, I suppose I will have to give them a try and just learn as I go.

 

[its_virgil]

Take a look at the closed end articles at
http://www.RedRiverPens.com/articles

Do a good turn daily!
Don

 

[PaulSF]

I use the closed end mandrel from Arizona Silhouette, and I secure it using a collet chuck. This has worked pretty well on the two closed end pens I've done. I haven't had any wobble problems at all.

 

[spnemo]

Don,
Thanks for the link. I really enjoy your articles. Does using a pin chuck create pressure points in the brass tube? I don't want to stretch the tube out of round or crack the wood. How precise does the fit have to be?
Thanks,
Sean

 

[ssajn]

I just turn a dowel rod down to fit snug in the tube and use it as you would a jam chuck.

 

[ldb2000]

I just turn a dowel rod down to fit snug in the tube and use it as you would a jam chuck.

This is my method as well . Never have to worry about it holding tightly or being off center . I use a new jam chuck for each pen so I also don't have to worry about errors creaping in from not having the jam chuck inserted the same exact way in the collet everytime .

 

[its_virgil]

Sean,
I only have a couple of pin chucks. The fit has to be a snug, but not tight. slip of the rod inside the tube. The problem with pin chucks and other closed end pen mandrels is the need of a closed end mandrel or pin chuck for each size of pen kit tube. I have not noticed any deforming of the tube or problems with cracking using pin chucks.

I use the "alternative" closed end pen method discussed in my articles. I have done demonstrations on closed end pens at 3 symposiums this year using that method. I do show the other methods of making closed end pens but use the standard mandrel alternative way.

Using a jam chuck as mentioned by Butch and ssajn is also an excellent way to make closed end pens.

Do a good turn daily!
Don

Don,
Thanks for the link. I really enjoy your articles. Does using a pin chuck create pressure points in the brass tube? I don't want to stretch the tube out of round or crack the wood. How precise does the fit have to be?
Thanks,
Sean

 

[spnemo]

Thanks for all the help guys!