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Turning between centers and tools

Discussion in 'Woodturning Discussion Forum' started by John Torchick, Nov 25, 2017.

  1. John Torchick

    John Torchick

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    My grandson took a pen turning class at Woodcraft a few weeks ago. When we were working on a pen, he said that the instructor said to turn the ends of the blank to the proper diameter. OK, I thought about this yesterday while turning pens. I had a blank that I needed to salvage (see my thread on Almost Segmented) and I used a 1/4" parting tool to turn down the blank after rounding it with a roughing gouge. Now, my thought is this- I could use the parting tool on the end after turning to round to get close to the needed dimension of the pen and the components. Your thoughts?
    Showing a photo of my TBC setup.
    IMG_20171118_053144535.jpg
     
  2. hockenbery

    hockenbery AAW Advisor Staff Member

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    With pens I want the wood to be the same diameter as metal parts so that it feels smooth with no lip at the joint. some designs curve to the metal part where the parting tool would not be useful.

    A parting tool could be used to get close then a final cut from a skew or spindle gouge.

    I generally use bushings for the guide and turn the wood to the bushing diameter with a skew or spindle gouge.
    The parting tool would be an extra step that would not get me better results.

    However the parting tool might give you a better view.
    If using the parting tool - leave enough wood to cut a clean surface.
     
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  3. Gary Beasley

    Gary Beasley

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    I wouldnt use a parting tool, Id use a roughing gouge, detail gouge or skew used with a slicing cut and check the wood against the parts with a caliper. Remember to allow for the thickness of the finish if using something that builds thick like CA. Check penturners.org for more information on penturning.
     
  4. Hy Tran

    Hy Tran

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    Good morning, John,

    What they said--a parting tool, for the most part, will leave torn grain. Leave enough material behind for a final clean cut using a gouge or skew (depending on the grain orientation; I'm assuming these are spindle-oriented pen blanks).

    Or, you could use a bedan--using it as a parting tool to get near net-shape, and then, use as a skew to get the final cut with a clean finish! ;)
     
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  5. John Torchick

    John Torchick

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    I used the parting tool on a stabilized blank and it left a very smooth surface. Fortunately it did not leave any torn grain. Photo is the part I IMG_20171124_072021751.jpg turned with the PT. I guess grain tear would depend on the species of wood. I use digital calipers and measure the parts. I don't use bushings anymore as per recommendation from other experienced turners here. I am going to experiment on some hardwood dowels and square stock. Need to refine my techniques with the skew. I feel it is worthwhile to learn how to use it.
    Don't own a Bedan tool......yet.
    Hy Tran, was in ALB two years ago. My grandson played baseball for the Isotopes. Loved NM!
     
  6. Dennis J Gooding

    Dennis J Gooding

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    John, the result will depend very much on how you use the parting tool. Cutting straight in as one usually does for parting almost always leaves a bad surface. Much better results can be had by cutting at a skew angle (slicing cut). In this case, the tool is just a very narrow skew chisel that happens to be sharpened at a rather blunt angle. See my post below "Blunt but Sharp" for more details
     
  7. Bill Boehme

    Bill Boehme Administrator Staff Member

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    It seems like the "right" way to turn a pen blank has been continuously evolving ever since I started turning. To me, turning between centers makes more sense than using a rigid mandrel, but I still like bushings for precisely sizing the ends. As Dennis said, it depends on how you use the parting tool (or any other tool for that matter). I prefer the skew, but a bedan or any tool used so that it is slicing the wood rather than scraping would be fine. Besides matching the diameter, it is also important to match the flow. For example, there should be a smooth continuity at the nib rather than a corner.
     
  8. John Torchick

    John Torchick

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    This blank must not know it was to have a fuzzy surface.
    Edit: Bill, I aim to try to turn the blank down and leave enough to shape the blank to flow evenly with the nib. Will try to show some practice turnings later.
     
  9. Hy Tran

    Hy Tran

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    John,

    Stabilized wood (if well-stabilized) doesn't tear out; the resin has penetrated the fibers and helps them hold together even if cutting uphill. Stabilized burl pen blanks are a joy to turn; they don't misbehave (like regular burl would), and they sand and polish evenly (no sanding dips in the rings).

    Pine, now--that's a wood that will tear out if you just look at it uphill!

    Measuring with calipers vs with a bushing: When I make a pen, I like to curve the pen into the end fittings (think of the pen as a really overgrown bead). Calipers have a finite thickness, so I don't believe that I can get the pen to the fitting diameter as well as I can with a bushing.

    Next time you're in Albuquerque, stop by and say hello! We've got a really friendly turning club here!

    Hy
     
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  10. Jamie Straw

    Jamie Straw

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    I'll often use a parting tool to set rough (i.e., slightly big) diameter marks, but as stated above they're not a finishing tool. It's convenient to use one to get close to a the lowest point of coves, then use a spindle gouge to shape and get a clean cut for instance. (Not a pen-turner, so can't speak to that specifically)
     
  11. John Torchick

    John Torchick

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    Hy, thanks for the invitation. Grandson won't know where he will be playing after spring training. Right now, he is a free agent with the Mariners club.
    My first turning was with a piece of 2x4 and a wood chisel.
    Jamie, that is basically I am using the PT for right now. Rough shape and then finish with a gouge or skew.
     
  12. john lucas

    john lucas

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    For pens now days I just use one tool. A Hunter mini Hercules. You rough it out in scraping mode, then turn it on it's side and do a shear cut for the final clean up and sizing. It takes me about 3 minutes or less to do a slimline pen. Well that doesn't include sanding and finishing.
     
  13. John Torchick

    John Torchick

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    Thanks, John.
     
  14. Jamie Straw

    Jamie Straw

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    Cool!
     
  15. Mike Devers

    Mike Devers

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    Without a bushing is the live and dead centers put directly into the ends of the tube?
     
  16. Gary Beasley

    Gary Beasley

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    Thats right. However bushings made to fit the tubes and mount to the centers (tbc bushings) are available and are handy to quickly get in the ballpark. Once there the calipers take over.
    One thing to watch is overpressure on the ends, avoiding deforming the tube or causing the blank to crack. One reason I like tbc bushings, they protect against that. Actually any bushing setup will.
     
  17. John Torchick

    John Torchick

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    Let me clarify something- my TBC setup is on a mandrel. I don't use bushings and can sacrifice a bit of plastic to get the needed diameter.
     
  18. Derek Lane

    Derek Lane

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    When turning pens I use a 3/4" roughing gauge and a skew chisel no matter which material I am using. I do use bushes but only as a guide for the last little bit I always measure the component and match the blank to that as over Time the bushes can wear. I have also in the past used tappered bushes and just turned to size using callipers. I don't use any other tools for mine
     

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