This should keep me busy for a while!

[eyekode]

I finally finished making turning blanks out of the maple I picked up here.


Those blanks on the right are 12" diameter! That is the max my Jet 1236 can handle. And honestly it does not handle them very well .

Here is one of the bowls roughed out:


Now I just have to wait a year to see the final result .
Salem

[William Roscoe]

Nice flame! It will be a nice surprise in a year after you have forgotten how this looked and you put it back on the lathe. Looks like you'll have several nice surprises.

[Roy G]

Another aspect of all those blanks is that you would have spent maybe $30 each if you bought them. Good score.

Roy G

[eyekode]

There is some really nice wood in these! But they are the biggest I have ever turned. Any recommendations on how to chuck them? On smaller bowls I use a tenon. But the chuck manual says these are too big for a tenon and I should use a recess.

I plan on rough turning them to a thick inch, anchorseal, pack them in a bag with their shavings, and finish turning them in a year.

The first one I used a screw chuck on the top to make the a tenon on the foot. But then I chickened out, reversed the bowl, turned a tenon on the top, reversed the bowl and turned a recess on the bottom. After that I simply roughed it out. This is obviously NOT how I want to do the rest of the bowls.

I was thinking for the next I will: mount between centers, true the blank, turn a tenon on the top, reverse the bowl and turn a recess on the foot. Then reverse the bowl and use the recess to finish roughing it out. I can even leave the tenon on the top for truing after it dries.
Any alternate suggestions?
Thanks!
Salem

[eyekode]

I probably have more surprises then I can handle! Anyone want to trade bowl blanks?
Salem

[Timmy]

Very nice. I'm sure there will be some great bowls turned out of those blanks.

[caskey]

Depends on the chuck and jaws... i use tenons on stuff in the 24inch range

[eyekode]

Wow, that is huge! I have a supernova chuck with 50mm jaws. The manual lists 4" diameter x 6" length as the max sized blank when using a tenon. I have exceeded this on multiple occasions. It also says up to 12" diameter for recesses.

Maybe I should invest in larger jaws for these blanks? Or are they just in CYA mode in the manual?
Thanks!
Salem

[Gunslinger]

I think it is a bit of CYA with Nova, however, if you read instructions carefully a spigot to them is endgrain mount. Bowls are normally mounted face grain. A main consideration is the length, not the diameter; there are large leverage factors trying to tear the item out of the jaws the longer the item is.

For recess vs spigot it depends a lot on your design. I tend to stay with the 30-40% base guideline for bowls and use a recess about 90% of the time. If you want an artsy 12” bowl with a small base you will be forced to a spigot mount.
If you do the calculations (pi r squared) you will find the amount of wood which has to be broken off (dismount) is vastly different. A 2” recess with one inch of wood surrounding it has three times the area as a 2” spigot. Your 50mm jaws should be fine for anything up to your 12” diameter, be careful when you go wide and deep.

It may be the camera angle, but the Nova 50mm jaws do not use a dovetail in spigot use as shows in your pic. Spigots are cut completely straight with the standard jaws. Look for the one or two lines in your instructions which are all in capital letters.

[eyekode]

Oh my, you are right! I have been using a dovetail with these jaws for over a year. Doh! Only the very edge has a dovetail and that is probably just to bite in.
thanks!
Salem

[Gunslinger]

Eyekode said..
The first one I used a screw chuck on the top to make the a tenon on the foot. But then I chickened out, reversed the bowl, turned a tenon on the top, reversed the bowl and turned a recess on the bottom. After that I simply roughed it out. This is obviously NOT how I want to do the rest of the bowls.

I was thinking for the next I will: mount between centers, true the blank, turn a tenon on the top, reverse the bowl and turn a recess on the foot. Then reverse the bowl and use the reess to finish roughing it out. I can even leave the tenon on the top for truing after it dries.

I am making the assumption that by top you are referring to the pith side.
Although I don’t use them a lot, your wormwood screw in your chuck should hold it very very securely. Especially with tailstock support until it is rounded. I have a large forstner bit (3-1/4”) to flatten a shallow area to insure the top of the jaws seat firmly (I also use it for a base for my 3” faceplate). JMHO but I think the wormwood will hold much better than a tenon for roughing out. It also allows you to remove tailstock support for forming a recess or spigot.

In your last paragraph…I don’t understand the tenon on the top. Just turn a recess or spigot and reverse it to hollow out. A tenon on top would be turned away during hollowing?

[eyekode]

Have turned bowls both ways: pith at th bottom of the bowl and pith at the top. When I said top I meant the top of the bowl not the foot.

I like your idea of using a forstner for flattening. I may have to try that.

I do like using a wormwood screw and tailstock for truing the outside. But I didn't feel comfortable using the screw without the tailstock to form the recess. One issue is the minimum speed of my lathe is ~500 rpm.

About forming a tenon on the top of the bowl: I have heard of people doing this and then leaving a pillar of wood when they rough turn them. It can be handy to help true the blank after it dries.
Thanks for all the ideas!
Salem

[JRD]

Why wait a year?

I've had very good results after rough turning with DNA drying. Soak a blank in DNA for a day, let it air dry, then wrap in a paper bag with the interior of the bowl exposed to the environment. Sit it upside down on a wire rack so air can get to the interior surfaces. After about a month the blank will be at equilibrium with its environment.

This really works.

[eyekode]

I have been meaning to try this. Where do you buy DNA? How do you store it safely? Pour it back into the original container(s)?
Thanks
Salem

[kooshball]

Salem, I have bought DNA from the Sherwn Williams store on 64 by the High School.

I have been meaning to try this. Where do you buy DNA? How do you store it safely? Pour it back into the original container(s)?
Thanks
Salem