Tuesday, October 07, 2014

Hackberry Slab Bench

I found a lovely hackberry trunk slab at Owl Hardwoods a while back, and decided to make a bench for our front hall.  I fabricated the frame out of square steel tube at my metal sculpture class - all welded joints.  The slab top is very much as I bought it, although I radiused the ends (which had been square cut) and softened the front and back edges, which would have been fragile (and sharp!).   I couldn't find any more hackberry for the bottom shelf, so I used hickory, ripped into four strips and mounted it on steel rods with spacers to keep everything in line; I fabricated Z shaped tabs to suspend the shelf in the bottom of the frame.

Monday, September 01, 2014

Bernie's Birthday Bowl

This series of photos shows the process of turning a large box elder bowl I gave to my wife as a birthday present.  The photos are largely self-explanatory, but I'll add a few comments.

The blank is held between centers and the bark largely removed; the flats from sawing are still present:



The bark is now gone; you can see the three-point drive center I'm using on the headstock end. Since the side-mounted points are adjustable it's very handy for holding an uneven surface securely:


The blank is now nearly round. At this point I cut a recess (shown later in the series) in the base for expansion jaws to hold the blank for hollowing:



I've reversed the bowl blank so that it is now held in the chuck for hollowing, but before that I'll true up the rim and even up the top surface some - and then get rid of the tailstock support:


The following photo is of the same set up, but shows the chuck expanded to hold the blank in the recess:



Beginning to hollow out the inside:



Same stage, showing my lathe:


Lots of shavings, of course... 


Selfie! 


The bowl rough-hollowed, showing the heavy curly shavings from the hollowing process:


After rough turning the bowl I put it in a paper bag for a couple of weeks to dry some:


This photo shows the recess cut in the base for the expansion jaws:


The inside of the bowl is nearly fully turned:


And the outside is completed:


Ready to power sand and then remove for finish sanding and finishing: 


The final product. Finished with three coats of Danish oil and three coats of wipe-on poly:







Thursday, May 22, 2014

Steel Floor Lamp - Something Different

As mentioned in an earlier post, I've been taking some Metal Sculpture classes at the Evanston Art Center over the past few months - initially a course on welding mild steel, and more recently a course on oxy-acetylene welding of non-ferrous metals (copper, brass, bronze, aluminum, stainless steel). A couple weeks ago I finished a project I'd started in the first course, namely a floor lamp, pictured here.


The outside ring of the base is solid steel, heated and bent into a circle and welded closed.  The other metal parts are square steel tubing, welded to the outer ring and together. The cord runs through a hole drilled in the outer ring, through one of the spoke tubes and then up the main tube to the lamp part (a three-way fluorescent fixture).  For a finish the steel has been power sanded and then waxed.



Wednesday, May 07, 2014

More Parallam Scratch Awls

I did turn a few more scratch awls - Rockler had the kits on sale again.  The light colored ones in the photos are turned from Parallam (see January post). The green ones are turned from a dyed, laminated material - I don't know which brand.



Spice Storage Rack

I didn't do much wood turning over the winter, since a lot of my focus was on my new-found activity of rock wall climbing at the gym and my metals class - this semester we're doing oxy-acetylene welding of non-ferrous metals.  And for the last month I've been recuperating from a car vs. pedestrian collision in which I was the unfortunate pedestrian.  But I recently completed a project I'd had in mind for quite some time: creating a spice storage rack for our kitchen pantry shelves.  I wanted it to be as compact as possible while providing a lot of storage, and it obviously had to fit and function within the available space.  My final design included 8 spice "shelves," suspended at the ends on a rotating frame system, much like a wide, squat mini-version of a ferris wheel.  The individual shelves stay vertical as the system rotates.  The rack will hold 48 small spice jars.  The wood used is principally cherry.  The only turned parts are the knobs at the ends of the center shaft, which are held by grub screws so I can disassemble the unit if I need to at some point in the future (the cross-pieces at the bottom are likewise screwed in place rather than glued).







Thursday, January 09, 2014

Parallam Scratch Awls

For Christmas I turned four scratch awls from a material called Parallam, which is a composite wood/resin material used in manufactured construction beams.  A good friend of mine who builds houses (and whose shop space I am sharing) gave me some of his scrap to play with.  I turned one awl for him (not pictured) and then the three shown below as presents for my brothers and brother-in-law.  The metal parts came in kit form from Rockler and are also available from other turning vendors.  The wooden parts are turned on a pen mandrel, to whatever shape you like, the only physical limitation being the length of the brass tube (part of the kit) that is glued into the center of the wooden blank.  The hardest part is actually the surface finishing, because the Parallam has frequent surface defects that must be filled with a sawdust/glue slurry so that the outside is smooth.  I also coated these with epoxy, sanded some more, and finished with wipe-on poly.  Next project is to do one for myself.  (Need to order more kits!)







Saturday, November 09, 2013

Streptohedrons (Part II) - Here are 3 more

I have now turned three more streptohedrons, these based on some of the examples and plans in Woodturning Full Circle.

The first of these is a variation of a Four Branched Streptohedron, which has a kind of art deco shape.  It is turned as a series of right-angled "stairsteps" on each side, as indicated in the photos.  (Cherry, finished with Watco Danish Oil.)








The second streptohedron is a Twisted Pentagon.  Because of the additional side there is an additional axis available, giving the possibility of two variations in the final shape.  Here's what it looks like (Cherry; Watco Danish Oil finish):



The third streptohedron in this group is a Six Branched Streptohedron, with its center of rotation through the valleys.  The turning process here is rather more complex, and it is difficult (at my skill level, at least), to make the cuts precisely enough to get a perfect match-up when the two sections are rotated.  Here are some photos showing the overall approach:

Initially the blank (previously divided lengthwise and re-glued with a paper insert) is turned to the desired diameter; lines are drawn on the circumference to indicate the cutting locations;  and a tapered hole is turned in the end, using a template for size and shape:



Then the first of the shaped sections is turned; again a template is used to get the inside angle correct:



Here is the mostly turned blank.  The left (headstock) end is still fastened in the chuck.  The right end, where the tapered hole is shown in the first photo, is simply supported by the live center.



After the shaping is done, the piece is parted off at the headstock end.  It is then reversed into a jam chuck (a wooden block with a hole turned to hold the piece snugly), and a matching tapered hole turned in the other end.



The piece is then removed from the lathe, and re-split along the glue line into two halves.


The halves are then rotated so as to form the streptohedron and glued together.  The piece is then sanded and finished.  In this case I used several coats of black gesso as the finish - it is both dramatic and disguises minor defects pretty effectively.





The smooth outer rim of the resulting piece is continuous, having neither beginning nor end.  Pretty dramatic, I think.






Friday, November 08, 2013

Streptohedrons (Part I) - My first! And what in the world are they?

The cover article of the August 2013 issue of American Woodturner was titled "Behold, the Streptohedron" (by Bob Rollings, with David Heim), and had an elegant and intriguing photo:

 

I hadn't ever seen these forms before, and was fascinated.  I turned the form described in the article (shown below), and then acquired David Springett's amazing book, Woodturning Full Circle, which (among many things!) includes sections on how to turn a variety of streptohedrons of different configurations.

As defined by Springhett, who appears to have invented the term, a streptohedron is a "twisted polygon," that is, a polygon which has "rotational symmetry":  when split along an axis, rotated, and rejoined, it becomes a new shape with "compound-curved faces that seem to flow smoothly into each other." (Rollings)  The beginning polygon can have any number of sides.  To turn one you prepare a blank, split it down the middle, and then glue it back together with paper in the joint.  You then turn the specific shape you want, re-split the piece along the glue joint (and clean up the faces), rotate ("twist") one section in relation to the other, and then glue them back together.  If (!!) the turning has been done precisely, the edges will line up and the streptohedron emerges.  A little - or a lot - of careful sanding also can help.

This is the first streptohedron I turned, based on the AW article.  It has four "sides."  The wood is Claro walnut.

Here is the glued-up blank, turned to shape between centers on the lathe:


Then the turning is re-split along the glue line:



The two pieces are then turned 90 degrees and re-glued to create the new, complex form:



Once the glue is dry, the piece is completed - the extended ends removed, the piece sanded, and finish applied.  Here is the result (finished with Watco Danish Oil):



In the next entry I'll show you the others that I've done so far.