A foot in the door.

I had an idea a couple of nights ago and had to try it out. This was the first opportunity to give it a shot. I started by cutting a piece of Birdseye maple from the veneer log core I got a couple weeks ago. It's only 6" diameter so I was very limited in size but the quality of the wood made up for the lack of size. The piece was ripped in half to give me 2 blanks 6" diameter, 6 1/2" long, and 3" deep.












I marked the center on both sides and mounted it between centers. The drive center is a 1" diameter Woodriver multi tooth drive center (stebcenter). The live center the Jet live center that came with my lathe.  It's nearly identical to the Oneway live center.













The outside shaped and a tenon turned so the inside can be hollowed. I have not sanded yet, the finish is straight off the gouge. I love the look of the Birdseye, unfortunately it doesn't show up very well on what will become the rim or on the end grain.












The bowl was flipped around and mounted in the chuck.  The rim was shaped, and the center is now ready to be hollowed out. The blank wasn't quite big enough to core, and even if it was a little bigger the Birdseye is much less pronounced as the diameter gets smaller.











After hollowing the inside of the bowl was sanded before flipped around again and mounted on my vacuum chuck. The tenon was removed, a small recess turned, and the outside sanded smooth. The vacuum drum I'm using here is a 3" PVC pipe coupler.












The inside of the finished bowl. The rim is under cut significantly so it's not as heavy as it appears. The under cut rim made sanding difficult so the interior isn't as smooth as I would like. Such is life.

Bottom view, this is where my idea came to fruition. Turning the collar for my recent hollow form gave me the idea that I could do the same thing for a foot. I followed the same process as I did for the collar, except instead of fitting it for the opening in the hollow form I fit it for the recess I turned in the bottom. The wood for the ring is Desert Ironwood.

Profile view. The foot gives it lift, the color gives it contrast, and it's a nice surprise for the buyer when they flip it over to see the extra effort put into making the piece special.

Here's my sketch from this evening, before I headed out to the shop.  The shape is different on the outside than what I had drawn but the overall effect is exactly what I had envisioned when I thought of using the collar as a foot. 

Yea or Nay?

 I talked to a few club members on Saturday about my latest hollow form.  Consensus was that an Ebony or African Blackwood collar would probably highlight the black line spalting better than the Desert Ironwood collar I originally had in place.  With that in mind I headed out to the shop last night to give it a go.  Here a blank approximately 2" square and 3/8" thick is secured between the live center and the front face of the spindle.  This is a trick I picked up from Mark St. Leger back in 2009.  There's plenty of friction to drive the blank and the flat face of the spindle ensures that the blank is square to the lathe.

 The blank is turned round and a tenon is formed that matches the diameter of the opening that it is to fit.  Using this method the blank can usually be removed from the lathe for test fittings and be placed back with a high degree of accuracy.  I also faced off the bottom of the tenon and under cut the shoulder on the tenon so the area near the tenon doesn't bottom out before the outer rim does.  I use a 1/2" bowl gouge to turn it round, and a 3/8" diamond shaped parting tool and 3/8" spindle gouge to shape the tenon.

 I also took the time to shape part of the upper profile and to start to contour the under side of the tenon.  I won't have access to it any other time and when people try to feel the inside of the vessel (and they will, other turners in particular) I don't want them to feel a sharp corner.  I also prefer the depth of the tenon to match the thickness of the vessel at the opening.

A quick sketch illustrating the cross section of the finished collar.  The tenon matches the thickness of the wall and the under side of the tenon is contoured so the transition is as seamless as possible.  I like to get the cross section as close to round as possible and there should not be a gap between the vessel and the collar at any point.  The collar should look like it belongs on the piece and was not an after thought.

To turn the top and inside of the collar I use a shop made jig based on a jig used by Mark St. Leger.  It's scrap end grain maple.  A groove is cut on one side to allow the wood to expand and contract as the jaws of the chuck are opened and closed.  The face of the jig is turned flat and a recess is turned in the face so that the tenon of the collar fits inside snugly.  The recess should be deeper than the length of the tenon so to outside lip of the collar rests on the face of the jig.  The jaws of the chuck are then snugged tight and the collar is held securely by the jig, not the jaws of the chuck.

The collar is placed in the jig so the top and inside of the collar can be turned.  You can see ring where the end of the spindle compressed the wax sealant on the outside of the blank.  If you look carefully and compare with the photo above you can see how the gap in the is narrower in this photo, the wood is flexible enough to move and compress as the jaws are tightened.

And now the face and inside of the collar have been turned and sanded.  The back side of the ring is relieved and the contour matched to give me the cross section I want.  The collar can be removed, test fit, and then placed back in the chuck for any additional turning with very good accuracy.  All of this shaping work is done with a 3/8" spindle gouge with a fingernail grind.

The finished rings side by side.  Desert Ironwood on the left and Ebony on the right.  The light ring on the Ebony is light reflecting off the highly polished surface.  The color of the collar is almost pure jet black, unless you look closely for the grain some might assume it's plastic, not wood.  One strike against the Ebony.

The Ebony collar set in place.  I think the black color brings out the black line spalting in the piece.

The original Desert Ironwood collar.  I think the Desert Ironwood looks more natural (less like plastic) but it doesn't work as well with the spalt lines.  I do prefer the shape of this collar better, the one above is a little flat so if I decide to go with the Ebony I will probably turn a new one anyway.

Should I go with the Ebony or with the Desert Ironwood?

Demo prep II

A few more sample jigs for my demo this weekend.

These jigs both thread onto the lathe.  The one on the left threads directly onto the spindle (1 1/4" X  8 TPI in my case)  I only threaded part way through this blank to make it "closed ended" as the drive portion in this case is the same diameter as the spindle.  The tailstock adapter was threaded and turned the other night.  The shoulder on the end was turned down to the same 1 1/4" diameter as the blank on the headstock.


These centers can be used to drive peppermill blanks, kaleidescope blanks, and similar objects.  The shoulders on each end are really to center the piece, the drive actually comes from the pressure between both ends.  The other advantage to using wood for the drive centers is that not only can they be custom fitted for a particular diameter but you can also turn right down and into the jig without damaging your tools.

Next up was another live center jig.  The blank was drilled, tapped and then the outside was turned as a reverse cone.











The inside was removed and the jig can now be used to drive spheres and help center and drive hollow forms.

Tailstock tap

I received a package on my front porch this afternoon.  I ordered a new 3/4"-10 tap from Enco late last week for my upcoming demo.  I now have all 3 of the most common sizes that I will need. 1" X 8 TPI, 1 1/4" X 8 TPI, and 3/4" X 10 TPI.  There are other thread sizes and pitches out there (3/4" X 16 TPI, 1 1/2" X 8 TPI, 33mm X 3.5) but these 3 should be all I need. 
 

This tap is used to tap small blanks to be used on my live center in the tailstock. The blanks are secured in my chuck, drilled, and then tapped with the thread that matches the thread on the nose of the live center.  The outside of the blank can then be turned to any shape needed. 





The trick for turning the outside is to lock the live center so that it doesn't turn.  A small screw inserted into the locking hole (which can be seen at the rear of the cylinder) and then secured with a couple of wraps of tape will prohibit the bearings from spinning, allowing you to shape the outside.  It's a right hand thread so it actually tightens as it spins. 

This one will be used to center the tailstock ends of peppermills.  Other shapes can be used to drive spheres, kalidescope blanks, and anything else that you don't want to mar the surface of.  It's also useful for preventing Turner's Elbow.

Demo prep

2 weeks until my Prescott demo.  This one snuck up on me a bit with everything going on surrounding the DWR so I'm scrambling to get everything lined up and get my handout done.

I've chosen to do a demo on shop made jigs.  More specifically turning related jigs that you can make with stuff you probably already have laying around in your shop.  I'm planning to do 4 or 5 different jigs, 2 of which are similar to the jig at the left.  I call this a Mark St. Leger style compression jig.  A recess is turned on the face of the jig and a cut is made on the side so that as the jaws of the chuck are closed the wood will flex and compress and grip the piece to be turned.  In this case the recess has a slight concave shape to grip the outside of the ring and prevent it from coming out of the jig unexpectedly.