Yes...a new guy...

[Walt Helms]

I'm relatively new to turning...done quite a few spindles, etc., so I'm pretty comfortable here.

Now I've "graduated" to hollowing. My first several attempts have involved "Goblets 101".

Here are my questions:

1) Since the goblet blank is approx 3" in diameter, what is a "good" turning speed (after roughing)?
2) I'm using a Termite to hollow. On some cuts, I get a nice ribbon of wood coming off of the cutter. Other times, I get a nasty vibration with lots of saw dust...no ribbons. Any suggestions here? More speed, less speed, sharper tool? Currently, I've had the lathe speed at 850 & 1250 RPM, and experienced the vibration / chatter at both speeds.
3) As I transistion from the goblet to the stem, I seem to get a "spiral" cut on the stem itself. Is this an indication of the lathe speed being too slow, too fast, dull tool, or a "burr / point" on the tool? :) It would take a heck of a lot of sanding to remove this spiral! :)
4) What is the "best" tool to do make a smooth transistion from say the goblet to the stem? What tool(s) do you recommend?

I defer to the experts (as I, at this point, certainly are not one! :)

Thanks for any and all assistance you can provide.

[Christopher Hunter]

First quesion I have is how long are the goblets or blanks? you may be getting vibration because the length is too long -- for this I would add a steady rest -- if the length is under 6" I would quess that your angle of attack is slightly off...
hope this helps
--Chris

[Ken Fitzgerald]

Walt.......Welcome to the Creek!

IF you have fast internet service you might want to go to the Woodcraft website and watch the Sorby video on turning a goblet.

When you turn a goblet they recommend you turn the interior of the bowl first...then shape the exterior of the bowl....then work on the base and stem. This is all done with a spindle gouge. I'm not familiar with the tool you are using.....Using the sequence they show reduces the whip that can happen if you turn the stem first.....

Good luck!

[Gary DeWitt]

Did you mean the kind of spiral you get from a catch, or the kind you get from vibration? If you're hearing a whining noise you don't hear at other times, it's vibration. Can be caused by trying to turn an area that's not supported by enough wood at the headstock end. Best way to get a thin stem is, only turn the stem after the bowl is completely finished inside and out, and only turn down to finished size in stages from the tailstock toward the headstock.
You may also need to support the bowl with the tailstock, using a piece of wood you have turned to fit over the end of it, with a curved face that aproximates the curve on the inside of the goblet. You can put a pad of something between to protect the goblets finish, and don't apply too much pressure, you'll bend the stem and create even more vibration.
Hope this makes sense.

[Walt Helms]

Gary - I'm pretty sure it's not a catch...I've experienced one or two of those (over the last week or so :)).

This spiral is more like a burr or point in the cutting tool, that cuts a sprial in the wood. If I move the tool along the rest quicker, the spiral spacing gets wider. If I move the tool slower, the space between the spirals gets smaller.

Here's where I've been thus far:

1) Dimension of blank - 3" diameter X 9" long - chuck mounted
2) Cut basic shape of the top of the goblet
3) Hollow with a Termite tool
3a) Sometimes get vibration, sometimes don't
3b) heavy or light cuts, same result
3c) 850 & 1250 RPM - doesn;t seem to matter
4) Refine shape of goblet seems to go OK - using spindle gouge
5) Begin transition of goblet to spindle
5a) This is where the "spirals" begin

I believe tonight, I will snug up the tailstock to provide a little more support and see if the spirals disappear.

[Ron Ainge]

Walt

I don't know how much of the stem that you are trying to turn down at one time. If you are ding more than an inch at a time you may be getting some vibration in the stem that would cause the spiral on it. I did a tutorial for a goblet contest that we had on this site, if you do a search for my posting or fot the goblet contest you may be able to get some information there.

Best of luck and keep it spinning

[Andy Hoyt]

Sounds an awful lot like chatter to me. And at 9" long there are two elements I'd want to employ.

First is a Steady Rest to be used while hollowing the vessel portion.

Second is that the tailstock really needs to come back in play once you're done with the hollowing.

[George Tokarev]

I believe tonight, I will snug up the tailstock to provide a little more support and see if the spirals disappear.

Snugging up can cause your problem once the stem gets thin. It'll put some static flex into it like it does on longer spindles. If you can do a bit of planning ahead, make a sort of half egg tapered to go into the goblet as hollowed, complete with a good center impression for the tailstock. Snug then take out about a quarter turn, lock and see how it goes. I've got a NOVA live center, so I can use a hanger bolt to put mine in place, but you can get by without anything that firm.

Best answer is to stay a bit thicker, especially with soft green wood, which is more prone to flex. Inside, it's tough to beat a good fingernail gouge. Even a termite doesn't do as well once you get off the absolute end grain.

[Walt Helms]

First - Thanks for all your ideas and suggestions. What a great bunch of folks! :)

I have resolved my issues using several of the suggestions provided.

I believe that the "spiraling" effect I was getting was caused by lack of support of the piece. As soon as I snugged up the tailstock , the spiraling effect went away. So there must have been enough flex in the piece to cause the spiral.

I also found that the gouge I was using had a small burr that made the spiral much more noticeable. After a quick trip to the grinder, that issue was resolved.

I'll post pics of my first two "junk wood" goblets in a bit.

Like most folks, I DO learn from my mistakes!;)

Thanks again for the help!

[Walt Helms]

After employing several of your suggestions, here's what I turned out! Not sure what kind of wood it is. It was the support pallet for a bunch of oak, walnut, white oak and cherry I had ordered.

So it's "imported" something or other!:D

[Tom Sherman]

Walt those are some great looking goblets and nice looking Dunnowood too.

[Steve Schlumpf]

Walt, Welcome to the Creek!

Nice looking goblets! I seriously like the form on the one on the left!

Looking forward to seeing some more of your work!