Archive for the ‘Projects’ Category
The best looking were cocobolo pieces with amazing figure, but they all had significant cracks, checks or other defects.
At that price I could pass up a few and figured I would at least get some nice pen blanks out of them.
But as I examined the flaws I realized I could get some nice pendant rounds out of the undamaged areas and so cut out about a half-dozen and worked them today with my Ruth Niles off-center turning jig.
I took the time to shoot about 40 process photos and will turn this into a teaching document for anyone interested.
The main thing to note here is that the flat stock meant I had to use a bowl gouge for most of this work as the wood was in face-grain orientation as opposed to spindle work.
The key to making these is finding a way to safely mount and turn them off-center. I’ve used wooden holdings, where you create multiple mountings on a block and affix your piece with glue or double-sided tape. They work, but are limiting in that you can only cut so many different mounting points in the wood before threatening the integrity of the holding.
A few years ago I picked up this jig from Ruth Niles at a Woodturning symposium. It’s cast aluminum with 8 different off-center mounting holes and a separate holding disk that can be rotated on a 24-point index. The combination of these two features provides for hundreds of possible variations.
The mounting plate further has inset holes so you can screw in a waste block for easier surface cleanup.
The approach here is to turn a simple round disk on center, then change the center to drill and form a hanging hole that doesn’t look like you went at it with a hand drill and a bad attitude. Next you have the option of several more off-center mountings to carve interesting partial curves across the surface.
With Ruth’s jig, you do all of this by simply unscrewing and moving parts of her jig. The glue or tape holding of the piece stays untouched and uncompromised. What’s more, the definitive screw holes means you can go back and repeat any mounting without risking the slightest shift in the work area.
I’ve been teaching how to make end-grain boxes at TechShop for a few months now. I documented the full process in an older blog post but something was missing — a simple overview.
So the other day I used Google’s free SketchUp design tool to show all stages of the process in a three-dimensional drawing.
In this one image/handout I tilted each piece to show the relevant area being worked.
1. Simply round the blank between centers.
2. Cut a tenon on both ends to fit your chuck jaws.
3. Separate the lid from the body with a parting tool (thin).
4. Put the lid in the chuck, square the face and cut a straight shoulder/lip for the box.
5. Hollow out the inner lid beyond the shoulder and sand/finish the inside.
6. Mount the base in the chuck and cut a tenon to fit the lid shoulder — carefully and tightly.
7. Hollow out the box body then sand and finish it.
8. Pressure fit the lid — use tailstock if it’s loose — to shape the outer box and remove the tenon.
9. Sand and finish as much of the outer box and lid as you can reach.
10. Mount the boxy body backward in your jaws or a jam chuck to shape and finish the bottom.
Of course there are many details on each step in the process, but this is the procedure in a nut shell. For beginners it is very easy to mix up the steps and doing so can wreck your chances of success.
This 13″ spalted-maple bowl sat rough-turned in my garage for about 6 months and I finally got a chance to finish it when I noticed the moisture was down to just about 10%.
In the roughing I left the central cone as I had only turned it between centers so far. As I worked on completing it I decided to try keeping the cone as a feature. The tip stands about 1/2″ proud of the rim.
I just liked how the spalting figure continued into the cone. I thought about attempting to reshape it into some kind of finial but then decided to just let the figure do the talking.