18" Hollow Form

 

Home
Up

 

Large Hollow form tool

I have wanted to get a large hollow form tool since I saw one at the AAW convention in Richmond VA.  I saw Steve Sinner turn with a tool much like the one I made.  I created my own drawings from a sketch that I made at the convention and from memory.  The next step was to find a welder and machinist to make it.  After 3 months the first place I took the drawings had not produced anything.  I ended up using a machinist my friend Chuck knows.  The results were very good.  I am planning on tweaking the design a little by adding ribs to the secondary tool rest, as well as ribs to the base plate of the banjo.

 

Click on the pictures to enlarge.  

The first step in making the hollow form is to pick a block of wood from the wood pile.

The Chunk I selected was 40" x 15" x 15" piece of Sycamore. Unfortunately it was cut over a year ago. Consequently I had to trim quite a bit off the ends to get rid of the cracks.

This is another view of the wood being hoisted onto the lathe.

I mounted the wood to the face plate before hoisting it. When the wood is in place I could turn the spindle to thread the face plate to the lathe. In the end I needed my wife to turn the spindle by hand while I moved the block of wood around so the threads would mate up.

I cut the corners of the blank off while it was on the lathe with the circular saw set to 45 degrees and with the spindle locked.

This is another view of the blank mounted to the lathe.

This is one view of me turning the blank into a cylinder.

This is another view of me turning the blank into a cylinder

Unfortunately I had to do quite a bit of turning to get rid of the cracks in the blank. I ended up with a 9" cylinder 30" long. Closer inspection showed a very large punkie knot hole in the top section of the blank. I ended up parting this section off to remove the defect. Note the shavings on the floor are up to my knees.

After seeing a picture of hollow form at the AAW convention last year I was determined not to make a large hollow form that had being large as its only asset. To achieve that goal I did some reading on the internet about the Fibonacci sequence, also known as the golden rule. This drawing represents the first time I have ever drawn a form before turning it. I followed the rules of maintaining a ratio of heights and widths that factor to 1.618. The efferent was well worth it.

I cleaned up the shavings on the floor before turning the profile on the hollow form.

This is one view of the hollow form before it is drilled out.

This is another view of the hollowform before it is drilled out.

This is a third view of the hollowform before it is drilled out.

This is fourth view of the hollowform before it is drilled out.

This is a photo of the hollower, secondary banjo, secondary tool rest and laser pointer.

This is another photo of the hollower, secondary banjo, secondary tool rest and laser pointer.

Close up of the monroe hollower on a tool holder that I desinged to mount into the 5'6" tool holder.

18" Spalted sycamore Hollow form finished in wiping poly

first view

2012

18" Spalted sycamore Hollow form finished in wiping poly

second view

2012

18" Spalted sycamore Hollow form finished in wiping poly

third view

2012

18" Spalted sycamore Hollow form finished in wiping poly

fourth view

2012

Home | 18" Hollow Form | 36" Hollow Form | 30"  Hollow Form