wobbly goblet

[Dean Matthews]

So... The wife and kid were MIA today so I decided to go and goof off in the garage. For months I have been buying the stuff from the bargin bins over at Klingspore's for practice. When I bought my lathe one of the things I really wanted to do was/is goblets. I have done some VERY small ones as wine stoppers and today decided to give a full size one a shot.

It came out okay considering it was my first big one and it is from "cheap" wood (I think the 4"x4"x15" blank cost me like $1.50).

When I started making the goblet I rounded out the square blank with my gouge while the blank was between the spur center and the live center. Got it round, and then put a small tenon on one end to put it in my oneway chuck.

Brought the tailstock back up and made sure the blank still ran true. Everything seemed fine.

I formed the outside of the cup portion (without doing the stem) and then removed the tail stock and hollowed out the cup.

Now... when I did the outside I did not refine the whole shape. I wanted to get more of the inside cut out first. And everything seemed to be tracking just fine.

Somewhere along the line the piece must have moved. I noticed that the outside was kind of off center from the inside. I tried to correct, but nothing.

I had brought the tailstock back into play at one point. I put some t-shirt rag material in the bowl and brought the live center in on that so as not to damage the wood.

Everything else turned fine... it just got a little weird on the cup. Any thoughts?

here are "all" of the pix:

http://picasaweb.google.com/doctorew/FullSizeGoblet

(oh... it's "finished" with Tung Oil)

[Paul Engle]

Nice work Dean, first time anything is special and this one is no exception.Sometime things just do not work out and you may never figure out why, too many variables me thinks. Keep it up the nice work!

[Steve Schlumpf]

Good looking goblet Dean! Sounds like you did everything right to prevent the wood from moving. Could possibly be the stress within the wood being released once you had it thinned down. Form looks great - keep turning and have fun!

[ROY DICK]

Hello Dean,

I really do like your goblet. I had a friend tell me to double check the chuck for tightness prior to moving the tail stock back.

Keep up the good work,


Roy

[Mike A. Smith]

Looks like a great first effort Dean. I've only done a few of these but I have tried to get all of the inside done before starting on the outside and then 'stuffing the cup' like you did. I consider Curt Fuller to be the king of the goblets around here, maybe he'll chime in with some advice.

[Rich Souchek]

Dean,
Looks real good for first full size goblet and it is a keeper.
The wood movement happens to me often in bowls, particularly in wet woods. For me, the out-of round or slightly of center inside vs.outside is due to stresses in the wood acting out as wood is cut off, chucks not quite gripping the piece in the same turning center, the silly turner getting a catch that moves the wood slightly in the chuck while turning the inside. Sure there are other reason, but the catch moving the wood is my main reason. Got to take it easier and have some patience.
For a while, the tenions on bowls were cut with great care. A resting place for the jaws leveled, and fairly large tenions were sized. Used CA glue to harden the wet wood, to prevent the wood moving. These efforts really slowed the off-centering rechucking and turning, but did not eliminate then. It also made most of the catches minor, not moving the tood in the chuck.
Rich S.

[Ken Fitzgerald]

Dean....nice lookig first goblet.

One thing comes to mind. If you are using wet wood, and my first couple were wet wood, you might try turning a tenon on one end, chuck it up and rough it out ....don't try to finish it.

I successfully dried my roughed out wet ones frist by weighing them on a scale, then by placing them in a paper bag and microwaving them for a couple of minutes ........set them outside to cool for a couple of hours and then repeating the process. There is a website......woodturningonline IIRC that has an article on microwaving. I kept repeating the procedure until there was no change in the weight. Then I rechucked it and finish turned it. If the wood is wet, it can and mostly like will warp. The microwaving seemed to reduce the warping.

[Dean Matthews]

The wood was dry actually. But it looks like the place where it started to go out of round was at knot in the wood. I have seen some people chuck goblets just off center to avoid weirdness with the grain... perhaps I should have done that.

As for wet wood... Mr. Ron Kent hooked me up with that one. I was browsing the net one day trying to figure out how to deal with working with wet wood. I have no patience to sit around waiting for stuff to dry. I found an article about taking a solution of 50% dishwashing liquid and 50% water and soaking your rough turned vessel in it.

So... I rough turned some cocobolo blanks that I bought and then put them in the solution for about 24-48 hours. Then I took them out and wrapped them in several layers of newspaper. Once a week for about three weeks I would replace the paper. When the newspaper stopped being wet they were dry. The process worked great. Neither of the bowls seems to have "moved" any since they were finished.

[robert hainstock]

I DON'T REMEMBER EVER REVERSING SOMETHING, AND NOT HAVING TO RE TURN SOMEWHERE , OR SOMETHING THAT WAS SUDDENLY OUT OF ROUND. PSI MAY HAVE AN ANSWER, #2 MT FOR THE TAILSTOCK WITH A THREADED ADAPTER FOR A CHUCK. IGHT HELP, MIGHT NOT?
BOB