Turning Archive 2008

Concept + Wood + Time + Skill = THE Piece?------We *PIC*

charlie belden
>Michaelangelo was said to have described his approach to sculpting in marble as "seeing the piece in the block of marble and merely freeing it from the surrounding stone".

A while back Gary Knox Bennett / Bennet / Benett (I've seen his last name spelled various ways) submitted a cube of wood, with the largest circle which could be inscribed within each of the six square sides, with centers, to a woodturning competition. His "piece" won the competition. The judges' explanation - the sphere is the perfect 3 dimensional form and the piece submitted had all the information needed to create it - the rest was merely wood removal.

Before "post lathe" work began its dominance of woodturning, it was The Perfect Shape, either in itself, or for a given piece of wood, that was the Holy Grail of woodturning. And short of making The Perfect Shape in ceramics, on a potter's wheel, creating The Perfect Shape involved a lot of time and skill hogging off, and then carefully removing 90 to 95 percent of the wood. OK - so you only needed the outside of The Perfect Shape, the inside was most of the grunt work, some of it butt cheek clenching, teeth grinding grunt work. The point is that to really "see" the piece you had to physically remove everything that didn't look like The Perfect Shape.

Then CAD came along - 3-D CAD specifically. But the learning curve was far steeper than the turning learning curve, and just as fraught with lurking disasters, without the potential broken bones and blood - though heart attacks and migraine headaches rank up there with turning accidents. And when it came to modeling curvilinear surfaces - well the slope of the learning curve was like climbing Everest.

Now along comes Google's SketchUp. SketchUp has taken a new approach to the user interface for 3-D computer modeling, making much of the mental grunt work a LOT easier, but by no means easy.

One of the neat, though not obvious, features of SketchUp is the use of a "tool" called "follow me". Here's how it's used for virtual "turning":

1. using "line" and "curve" tools, create the cross section of your shape in the XZ plane, with the centerline about which you'll later rotate on the X-axis.
2. on the YZ plane, using the X-axis as the center, create a circle.

You now have two virtual "objects" in your computer model
- a flat disk square to your "cross section", centered on the "bottom" of your "cross section"
- your shape's cross section, the bottom of which falls on the centerline of the disk

Think of the disk as your headstock / chuck / headstock drive center.

Using the "select tool", select the disk to tell the program what path you will later want it to follow as it "extrudes" your profile.
Switch to the "follow me" tool and click inside your cross section to select it for "extrusion"

Now move the "follow me" cursor around the perimeter of the "chuck" disk - all the way around if you want a complete shape or as far around as you want if you want a "cut open" part of the shape.

Ta-Da you've got a 3-D model of the shape which you can rotate about to change your view - in real time. Want to add color, using the "select" tool, select a surface on your shape then pick the "paint bucket" tool, pick a color, and "paint" the selected surface with that color. Repeat until all the surfaces are "painted". Now rotate around, changing the view of the piece 'til you see an orientation you like. "Grab" the area of the screen you want, or do a "screenshot" of the screen to create a PhotoShop readable file and then edit that file in PhotoShop (or Adobe Elements 6) to tweek it to the way you like it, then save THAT image to a JPEG or PNG file format for uploading or viewing later.

Attached is an image, the top two items are the SketchUp versions of the shape, the bottom two are Adobe Elements 6 "tweeked" versions. Though I used a simple cylinder to "hollow" the "piece", there's an "offset" tool that yo can use to create the wall thickness in order to create a true (though only virtual) hollow form.

Oh - and you can use a digital image of a piece of wood and use it to "skin" the virtual turning. Haven't tried THAT - yet - but it seems like it'd let you get closer to the look of a real turning.

(This SketchUp "turning" thing has no doubt been posted here before - but it's new to me, and perhaps others in the group).

Back to the reason for this post - my question:

Given that many turners aspire to turn The Perfect Form for a given size blank
Given that SketchUp makes it quicker and easier (after a learning curve that's a LOT shallower than that of a turning tool and technique) to create a virtual shape/form

Is creating the "virtual" form the IT for turning, eliminating, or leaving the Wood + Time + Skill for others, along with any post lathe "enhancments", or merely another tool in a turner's bag of tricks?

(I'll leave the "Which is the more important part of the finished piece - the turned piece or the finished (read post lathe "enhancements"/ modifications)- to another time) piece"?

charlie belden


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