Got my Cuda II today, trouble cutting tenon

[Nicholas Briggs]

Got a chunk of pine to practice on for my new Barracuda II. I cut a tenon way to big, then trimmed it down. The chuck went on great but when I put it on the lathe it was way off center, the whole stock wobbling and spinning about an inch off axis at he tail stock.

Anyone have a tutorial page or anything on how to use this thing?

[Ken Fitzgerald]

Nicholas,

Typically when I turn a tenon for my chuck, I turn the blank round between centers or turn the tenon on say a bowl blank. You don't want the tenon to bottom out in the chuck. Be sure to turn a good shoulder area where the tenon meets the rest of the project. Then when you place your piece in the chuck, the project rests on the shoulder where it touches the jaws of the chuck and NOT on the bottom of the tenon. The shoulder area and tenon I typically turn using either a parting tool or my skew but you can also gouges.

In short, while the jaws of the chuck clamp down on the tenon, the end of the tenon should not bottom out or touch the inner part of the chuck. It's important the shoulder where the tenon attaches to the project be flat or rather perependicular to the plane of the the tenon.

I hope this makes sense.

[Nicholas Briggs]

That helps a bit Ken, but now I have more questions :). What is the shoulder you are referring to? And how do I level the chuck over the tenon if the tenon is not to touch the depth of the chuck?

[Lee DeRaud]

That helps a bit Ken, but now I have more questions :). What is the shoulder you are referring to? And how do I level the chuck over the tenon if the tenon is not to touch the depth of the chuck?Let me give it a try: the installed (#2?) jaws on that chuck are about 1/2" deep...your tenon should not be more than 1/4"-3/8" long. The "shoulder" is the area where the tenon meets the main body of the piece: the edge of the circle formed by the chuck jaws should be in solid contact with it. And those jaws are ridged, not dovetail, so the tenon should be straight.

(If I can figure out how the stupid macro function on my camera works, I'll post a picture later. :p )

[Nicholas Briggs]

That makes sense Lee, thank you.&nbsp; I just didn't know what a shoulder was.&nbsp; My tenon is WAY to long.&nbsp; I'll trim it up and see if I can get this right.<br>

[Ken Fitzgerald]

Nicholas,

Here's a drawing. Your tenon has to be long enough for the jaws to grasp but not so long as they bottom out in the body of the chuck. The jaws grasp the tenon but the shoulder rests on the jaws. I hope this makes sense. When you apply force with a turning tool, the shoulder touching the jaws prevents the piece from moving within the jaws.

59529

[Neal Addy]

One other suggestion, Nicholas...

If that's just regular ol' Pine it's probably pretty soft. You might find you have to tighten the chuck every so often just to keep it on. Especially during hollowing.

[Nicholas Briggs]

K, I got the tenon thing down pretty well now. But now I'm having a hard time keeping the chuck tight while hollowing not using the tail stock. The stock is about 7" long, so I'm kida weary about hollowing using just the chuck. Any suggestions? And does anyone have a link to a tutorial or How To site?

http://i70.photobucket.com/albums/i95/nethowler/vase.jpg

http://i70.photobucket.com/albums/i95/nethowler/vase2.jpg

[Ken Fitzgerald]

Nicholas,

I just started turning a year ago. There are no clubs in my immediate area so I had to learn from books and videos. I'd suggest a book "Woodturning - A Foundation Course" by Keith Rowley. It cost about $20 IIRC. It's written for the beginner and is well written and illustrated. Another suggestion is videos by our own Bill Grumbine "Turned Bowls Made Easy" and "Turning Wood" by Richard Raffan.

Here's a site that is good for beginners. Check out the "challenges" area

http://www.aroundthewoods.com/index.shtml

Good luck!

[Bernie Weishapl]

Nicholas sometimes with different woods I have found you really and I mean really have to crank down when tightening the chuck on the tenon. Also when you do crank down and tighten the chuck hard make sure you tighten one hole then turn the chuck 180 deg and tighten down the other hole. Hope that makes sense. You have holes on the chuck 180 deg apart for your wrench to tighten with. So tighten one then the other.

[Ken Fitzgerald]

Nicholas.....As stated by Neal, if you are turning pine, it's a soft wood and will probably require that you retighten the chuck periodically as the wood compresses.

[Brian Myers]

Also make the diameter of the tenon closer to the the min size the jaws will hold. Don`t make the tenon the max diameter for the jaw, as you tighten the jaws you will see that they cup the tenon. You want to get the most surface area contact you can . That said , when roughing green wood you will need to cut the tenon back some after the wood dries due to distortion and you need to allow for that so cut the tenon a bit larger at first. The PSI Cuda2 will loosen up on you when you get a catch. After a catch stop the lathe and retighten the chuck. If given the chance it will throw wood at you , DAMHIK.:eek: I`ve found on larger , heavy , wet peices of wood that the #3 jaws hold better. You should also make a steadyrest from rollerblade wheels to use when hollowing. Just take a look around here as there are a number of good examples that have been shop built. Hope this makes some sense as I am not good with words, but atleast I know what I mean.:o

[Brian Myers]

Keep the chuck clean (blow it out when done using it on a peice) it gets stiff/ harder to tighten as it fills up with dust. Lubricate it from the back with graphite powder (it helps keep it free and doesn`t spray oil all over). Put a washer cut from a milk or water bottle behind it so it does not jam on the spindle. They are cheap and need to be replaced often as they distort from installing and removing the chuck. If you don`t they bunch up behind the chuck or get caught in the spindles threads and cause it to wobble (so will dust/shavings if it gets between the spindle and chuck). Cut out a few at a time and keep them on hand. ALWAYS stand off to the side when starting up your lathe to make sure everything is in solidly. ;)

[George Tokarev]

Strength of wood is measured as ability to resist a force/unit of area. Obvious that increasing the area of contact means that you will be more able to distribute that force and still remain below the threshhold where the wood will distort. Smooth jaws give you an opportunity to get more metal in contact with the wood. Dovetail jaws draw as they snug and wedge you up against that shoulder which resists pressure 90 degrees to the axis of rotation better than a deeper tenon will.

Wet wood is not as hard as dry, which means it will distort with less force per unit of area, which helps you a bit when you have the tenon a tad oversize by compressing within the elastic limit. Start a tad over minimum size for circularity.

Then there's the natural shrinkage of the wood to consider. It'll shrink more perpendicular to the annual rings than parallel, and harly at all along the grain. Means drying will give you a smaller and oval tenon, so you really want to have a larger one when starting a piece wet. Keeps you from finding that circularity is below the size of your jaws. One more reason why I like recesses for faceplate work. Though I sacrifice a bit of leverage by narrowing the breadth of my "shoulder" bearing surface, the dry wood will present me with pretty much the same dimension along the grain, closing in across it. Easier to take away wood for circularity once dry and preserve a broad contact area that way.

[Joe Melton]

One thing you can do is drill a large hole in the piece before you start the hollowing process. A 2" forstner bit will remove a lot of material.
This means you have a lot less material to remove, and this lessens the amount of sideways stress you will be putting on the tenon.
Another idea is to buy a steady rest such as this:http://tinyurl.com/2xouo8
It is fully adjustable, and will probably fit your lathe. When you use your gouge or scraper, this device will keep the bowl from flexing, thus putting less stress on the tenon.
Hope that makes sense.
Joe