Live Edge Goblets

[Kirk Amidon]

Been wanting to try my hand at live edge goblets for a year or so after seeing work by @Don Wattenhofer posted here. Don was kind enough to give me a gentle push last spring with some .pdf presentations.

Fast forward to present. I've now turned two of them, and between them would have something worth keeping!

Top

First effort ended up thicker than desired, but otherwise things worked out fine. The rim is about 5/32" thick and was cut perpendicular to the lathe. The rest of it ended up fine.

My goals for the second one were to ensure that the cup and edge were thinner than 1/8" and had a more gentle curve to the profile. Pleased to see the rim is already bending and undulating. Here is what ended up:

The rim ended up where I wanted it from a thinness perspective, but unfortunately half the bark came unglued. I did notice that the bark on this piece was much thicker than the first one, which probably played into that. Is it normal for the bark to feel spongy when cutting into it at something other than a 90* angle? Or is that a function of it being thick.


The outside ended up getting some vibration waves in it, which I'll have to work on, but have ideas on what to do differently - mainly be more aggressive with the second bevel on the gouges.

Part of that may be due to hidden cracking along the pith, which nearly caused complete disaster on the stem as a chunk sheared off. This crack also was in the transition from cup to stem, and caused a bit of instability.

Comparison of both. In a perfect world, I'd take the rim and stem of left one, combined with thinness of right one, and it would be stellar. As is, it just gives me more incentive to get back to the lathe and take another spin.


TLDR questions:
What is best angle to approach cutting into the rim, and assuming it is ok to do this at something other than 90, is there any suggestion on technique to follow?

Hollowing - using a 3/8" spindle gouge, was getting a lot of vibration, in two scenarios. On the wider, flatter part along the rim, and deeper at the bottom of the cup, as the tool was 2" or more off the rest. Could a bowl gouge be used for the hollowing, and if so what is preferred grind, I have both fingernail and 40-40 gouges.

Turning the stem. Always nerve wracking, partially due to having relatively long overhang, due to not getting tool rest close due to the differences in diameter between cup and stem- my shortest rest is 6", not opposed to getting a 4" if this would help. But if it is technique, that is fine too.

Open to any other critiques of form and process.

 

[hockenbery]

Looks like you succeeded! Mostly practice and experimentation will guide you.

@Don Wattenhofer does these quite well. Jimmy Clewes does these as large vases with short stems in demos and workshops.
Rudy Lopez does these with longer stems.

Rudy does a great demo. One at Sarasota woodturners is on line.
Now that you’ve done a couple of nice ones you can view Rudy’s demo with an eye towards examining the subtlies.

View: https://www.youtube.com/watch?v=X7se6hIfivA

 

[Don Wattenhofer]

The rim ended up where I wanted it from a thinness perspective, but unfortunately half the bark came unglued. I did notice that the bark on this piece was much thicker than the first one, which probably played into that. Is it normal for the bark to feel spongy when cutting into it at something other than a 90* angle? Or is that a function of it being thick.

Note in the top of the picture there is a slight darkening of the sap wood which could indicate that the tree was dead on that side and the result of dead is a deterioration of the bark in that area. The angle cutting into the bark is not the problem rather it is the direction of the cut as there needs to be a shear angle so inside start in the center and work out to the edge/bark and on the outside start at the edge/ bark.
The first one with the 90 degree edge is a surprise that it does not have radial checks.

 

[Kirk Amidon]

Don,

That is the sort of attention to detail that always impresses me. Not sure I'd have put those two things together on my own. Thanks!

Al,

Thanks for the video link, I'll take a gander later.

 

[Marc Banka]

My 2 cents:
I learned for Rudy Lopez, then went my own way, a bit.
If the blank is too long you’ll have problems with whipping, making the interior of the cup challenging. You can’t have chattering. I cut away wood from the outside, only near the mouth, and cut the entry through the bark. The do the inside. I drill a depth hole and use a spindle gouge for hollowing. I use a very sharp 3/8 bowl gouge for cutting the inside of the rim. Fully shape the interior before doing the outside of the cup. With a bright light shinning into cup, you’ll be able to accurately see the thickness .
After hollowing, use the tail stock for steady. Fashion something , like soft rubber to keep the cup from moving as you cut further down the stem.
Take it in small bites working toward the base, remembering that you can’t go back.
Its hard to have a tool rest close enough for most of our comfort. I tried a short, 6 inch rest, but found the stem gets in my way too much. I like to be away from the tool post so I can have my thumb on the gouge, a finger feeling the back of the toolrest, and a finger supporting the back of the stem.
Regarding the entry angle, for natural edge, I don’t understand the horizontal cut. I don’t care for the look and have not found it necessary. I enter at maybe 30 degrees, and transition to something sharper, maybe 15 or 20. I’ve made 20 or so this way and have never had bark separate. The two things that make this work are to make it thin - mine are not more than 1mm, and very importantly, don’t bump the piece with the bevel when cutting, especially that bark edge.

These are fun, and a terrific training excersize.

 

[John Hicks]

If you watch youtube. This guy does some really neat stuff....

View: https://www.youtube.com/watch?v=7A62Gt86Xdc

 

[Don Wattenhofer]

The featured videos both parted off the base using a parting tool, which to my way of thinking is a poor idea.
They are too thick so they will likely get radial cracks and the base with bark on are out of proportion, they should be about 2/3rds or less the diameter of the cup.
The following pictures demonstrates a method to get a thin base that will distort rather then crack plus when the wood is dried and distorted it can be easily flattened by rubbing on sand paper. The rounded tool in the 2nd picture has bur formed so when held at an angle as shown will make the under cut. The 3rd picture shows continuing to under cut the base using a detail gouge. Note undercut in stages to the final thickness to the cut is complete avoid vibration plus the thin wood will begin drying and distorting before the final cut off. The first picture is what is left when turning is complete.