Getting sides square to each other

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knowltoh

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I know that when a finished pen has segments that are not symmetrical, it is probably due to the blank not being perfectly square. I know I have the sides equal in length, but how can I get the four sides to be at 90°? Evidently I have the rhombus, but not the square. A joiner works on larger pieces, but I am having a hard time with the 6" pen blank.
 
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mark true center of the blank based on the segments and not the end dimensions. mount between centers and turn round, place in chuck and drill on lathe.

hopefully this helps
 
If you get one side flat, a table saw can quickly make the adjacent sides 90 degree to it and parallel to each other.

Some do it another way. They turn the piece round to begin with, then cut and segment, then return to round. Then next cut and segment, then return to round. Makes for more work, but the results are 100% each time.

Eagle did most of his blanks as Hexagons.

There are many ways.
 
If I glue in the segments for, lets say a celtic knot, how do I find the true center based on those glued in segments? If I understand correctly that is what is being suggested.

Thanks
 
Centerdrill the ends, turn it round. make a template to show the radial directions you need and adhere it to the end. Make your cuts using a v grooved sled using the template to align the cuts.

Never cut through fully. Use a hold down to make sure the piece doesn't move as you cut. After the glue dries, return it round for the next cut.
 
I am very interested in this particular discussion, as I have been wondering about safe ways to get segmented blanks square as well. I am also interested in the suggestions about turning round during the process as well, so I hope this thread goes to 6 pages with good suggestions for various different methods. Pictures and diagrams are always helpful. . . :)

Sandy.
 
Square the blank on the table saw as explained above. Then keep the blank the same size and do not sand it down into another smaller size while working. That is the real trick. I do mine by not cutting 100% through the blank for the segments. Then I make sure my insert material exactly matches the saw kerf width. This prevents distortion of the segments when the insert is glued into the kerf. I also make my insert so it is not proud when glued in place. By keeping it just slightly below the surface I do not need to constantly sand the surface flat again. Do not be sloppy in too much glue or epoxy when gluing the segments. The neater you work the better your product will be in the end.

When finished the blank is center marked on both ends. I then drill one half the way from each end on the lathe. Most times the hole exactly matches in the center. Sometimes there is a little difference that must be adjusted or blended to make the blank centered for turning. If you drill from only one end if you drift off by the other end the drift will be so much that the blank will look off center because it will be. Easier to keep it centered if you are drilling very short distances.

If you do not make the insert the exact width of the saw kerf the final segments will not line up as the blank get shorter as you work. Worse you see wide glue lines where glue is used a filler to fill in the gaps. Or they seem to jump back and forth. Too often you see inserts that are too thin for the saw kerf and the blank gets shorter as you work.

The real challenge is in the fine details, keeping the precision fit and alignment of the segments. The number of segments is not the real challenge. A well made segmented blank with three inserts will look better than a poorly done blank with 20 inserts. Look at the blanks posted here and see how the inserts line up. When well done the inserts are in perfect lines. Not as a series of close Z's moving back and forth.

Another problem is working time of the glue or epoxy letting it cure and long set times. Five minute set is too short working time for me. I want to adjust items as nneded before they start to set up. I find that by making multiple blanks at the same time I get better outcomes. I will do say five or more blanks at once. Cut one insert kerf, trim the inserts to exact fit, dry fit, then using epoxy place and clamp one insert in each. Set aside for a day to let the epoxy cure. Then do another cut, repeat over and over until all five are done. By keeping everything the same I keep the blanks all the same.

When done I place the extra segmented blanks into stock. Often I have people see one pen made with a segmented blanks and they want it in another kit form. Rather than starting over again and trying to duplicate the segmented blank I just go into my stock and pull out a ready made blank. They think it is great when they get what they want in a few days instead of a few weeks. Also you never seem to get blowups when you have backups sitting on the shelf for some reason.
 
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