help, big bowls, big problems

allen levine

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new york city burbs
I turned one large bowl and I thought ok, I can do this stuff, easy enough.
I got a piece of Michigan walnut, fresh, cut as I waited, like coldcuts, I watched the guy cut it.
when I got it home, I cut it more circular on the bandsaw because its heavy.
I cant get my lathe much over 300-350 speed because with this heavy piece, the lathe shakes.
I managed to get it up a few notches as I turned more off and evened it out.
I got a catch,but I turned the speed too high witout realizing it when it was off, the thing flew off the lathe and took out a light.
I used machine screws on the face plate, hooked it up again, another catch, the screws broke again.
as one can see, the top and bottom of this piece is uneven.
I was going to rough it out, then leave it a while, but the only thing that is happening is that is roughing me up.
so what am I don't wrong and how should I approach this differently?
(I had almost no problems when I turned my first large bowl from glueup)

this one is tough, I don't want to launch it again, maybe 3 times wont be a charm and the bulk of this bowl could certainly leave a mark.

Im sorry for asking such amateur questions, Im headed back for some flatwork to relax a bit.

btw, Im using easy tools new carbide blade, so not a sharpness problem
 

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The blank doesn't look like it should cause any problems by looking at it. My guess is your being to aggressive possibly. What size are the screws you're using. They might be a bit small size wise, not length wise in the pic anyway. Right now I can't remember what size I use for sure, but I think it's #14 hex head sheat metal screws. I've had some BIG catches before, but never broke a screw. I'll verify the size today and get back to you soon.

BTW, that thing flying across the shop would send me to do some flat work for a bit too! Glad you're OK!!

Edit: I stoppped by lowes at lunch and I do use #14 screws. They are as big as the holes in my faceplates. Using your tailstock for more support is a great idea too...I usually forget that one.
 
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Two things come right to mind, Allen.

1. Flatten a face for the face plate. Saw or hand plane, but get it flat across the diameter of the face plate. You will want as much contact between the wood and the face plate as you can muster.

2. Bring up the tailstock to help 'pin' the piece between the two centers.

Additionally, the largest diameter screws that fit the holes of your faceplate and at the least the length should equal two to three times the thickness of the faceplate.

My mentor has been Wally Dickerman of Arizona. He has been turning longer than I am old and I am older than you! He was turning before chucks where used and before bowl gouges. He has embraced new things and tools as they come along (and has an awesome shop!) but still remembers, uses and teaches the basics from when he began. But all his rough turnings, small and large, begin with a face plate. As I recall, he also pre-drills the screw holes to get the best hold. Screws are #12's or 1/4" lag bolts from 1-1/2 to 2 or more inches long.

The two things I suggested come right from my notes from Wally. I have launched one bowl and it was a crushed tenon that was the weak spot. Reminded me of rule #2!

And taking out a light with a hunk that size is bad enough. Don't try to bounce one off your head, though. :bonkers: :chair: :eek:
 
Allen,
Follow Carol's advice, you do need as near a flat as possible for the face plate..
Use the largest sheet metal screws that will fit through the screw holes of your face plate... I use #12's x 1 1/2" in mine... that's the largest that will go through my face plate... if you feel you need longer screws, use them... remember you'll cut away that portion of the bowl so the screw holes will be gone....
keep your speed as low as possible until you get the piece rounded and running true... looks like you are jusing a 1642 Jet EVS... you could start at 200 and stay there until true...
make sure your tools are as sharp as possible, sharpen regularly when they feel like they're not cutting smoothly... My opinion for what it's worth, dull tools are more likely to catch than sharp ones.
Use the tail stock for extra support until you get to running true.... I usually keep the tail stock up until I reach a point that it's in the way... I even cut my tenons with the tail stock up, then when I pull back, I can cut away the little nub on the tenon where the tail stock sat.
The maximum speed I ever try to do a larger bowl at, after it's running true and has been reversed to the chuck is about 800 rpms... I know that Glenn Lucas says he runs large bowls at 1800 rpm, but I don't have the stones to do that.... I've already lost a light over the lathe, almost had an eye put out and sported a black and blue face for a few months...
don't be too aggressive with your cuts until you start to run true, then you can open up a little more and cut a little faster,

The most important thing is keep you mind in the process, stay in the moment and be safe... remember that chunk of wood is spinning towards you.
 
What the other said. I use #12 sheet metal hex head screws, just easier for me to install/remove with a power bit. Most of the time mine go about an inch into the wood unless it is a platter or some other slim item.

Do try to have a flat area to mount the faceplate to, it can even be a little concave but never convex. Even if you start between centers (spur drive) and only flatten an area big enough for your faceplate it will help a lot (You can remove the little nub with a chisel). My faceplate is 3" so a 3-1/8 forstner bit works fine, I think your faceplate is quite a bit larger.

Keep tailstock support until it is fully rounded as best you can.
 
I'll repeat Carol's advice, because she nailed it:

1. Make sure the faceplate is flat. I've used a handheld power planer to do that on some blanks. Other times, I've used a Forstner bit and drilled a series of shallow holes to the same depth until I had a flat spot big enough to accommodate the faceplate. If the faceplate can rock with no screws in it, you're bound to have problems once things start spinning.

2. Use the tailstock for additional support when roughing any time that it's possible, which is about 99.99% of the time. That way, if you do get a catch, the tensile forces on the screws are minimized. (Lighter cuts are also indicated, based on the picture of the bent screw.)

3. Bigger screws, for sure. From the look of the photo, those are very undersized for the task. Use as big as can fit through the holes of your faceplate, and long enough to penetrate 1" to 2" into the blank.

And as you have seen, it's a good idea to turn the speed way down whenever starting up an unbalanced piece. We tend to remember that advice after a time or two of chasing a hopping lathe down the driveway and into the street. :rofl: On a piece like that one, I might be running as slow as 200 - 300 rpm until I got the blank rounded and better balanced.

Take a break, catch your breath, and give it another shot. You've got this. ;)
 
I thought my machine screws were light, Im going to head over to the hardware store in the morning and get at least #12.

I know to have the face plate mounted as flush/flat as possible, but I was trying to save some depth on the piece.
The bottom side is off a lot and I figured once I got it rounded, I would flatten it a bit more and make a round mortice to fit the chuck.
Don't know why I didn't think to pull the tail stock up, guess I was looking at how uneven it was.
I also think while Im at hardware, Im going to build the shelf that jet gives a spot for in the base legs, and add some weight to it.
The lathe was moving across that hard plastic floor I have,(gladiator floor) but I cant bolt it to floor, I need it able to move a bit

I will continue tomorrow, I will use my hand held electric plane to smooth surface as much as I can, but I see its turning from a deep bowl into a high dish/platter

Ill put a post tomorrow after I give it shot number 2.
(btw, I wont give up either until it shoots off and knocks me out, or Im down to a spindle)
 
I'd ditch the carbide for regular gouges. Carbide will catch more than a traditional gouge IMHO. Carbide has its place...but I disagree for roughing a bowl blank. JMHO.
 
Here's another thought, Allen. From the looks of that blank you are trying to rough it out by standing in front of it and trying to take off the high spots with your bowl gouge. I find it a lot easier, after snugging up the tailstock, to start taking material off right next to the tailstock where the tennon/recess will be. Smooth out that area first and work your way out toward the rim, riding the bevel and shaping the bottom as you go. By doing it that way you will naturally eliminate those high spots that are beating you up now.
http://wonderfulwood.com/roughing-a-bowl-blank-on-the-lathe/
 
...The bottom side is off a lot and I figured once I got it rounded, I would flatten it a bit more and make a round mortice to fit the chuck...its turning from a deep bowl into a high dish/platter...

You still have lots of depth left, assuming the side with the faceplate on it now is the side that ends up being the top of the bowl. As Ted suggested, concentrate your cutting on the bottom of the bowl for now, and create the tenon (or recess, if you prefer) for your chuck. (You can do nearly all of that with the tailstock in place.) If I'm incorrect in my assumption about you wanting the bottom of the bowl to be the side where the bark currently is, now is the time to cut away the bark and make a flat spot for your faceplate.

Then work your way from the bottom of the bowl to the rim, creating the shape you want. After you have shaped the outside to your liking, remove the faceplate and turn the blank around so you're holding the tenon (or recess) with your chuck. In the process of hollowing out the bowl, you'll cut away all the screw holes in the blank. After the inside of the bowl is shaped to your liking, you'll turn the bowl back around so that the foot is pointed toward the tailstock. That's when you finish the bottom and remove the tenon (or clean up the recess). But we'll save the steps for doing that until later...don't want to overload you with suggestions. ;)

I'll also echo Jim and suggest trying a gouge instead of the Easy Rougher. I can see from the photos you posted that the carbide cutter is tearing the wet wood fibers instead of cutting them. You might be able to get cleaner cuts with the carbide once you've got things more rounded out, but for now, it's not only beating you up, but it's beating up the blank (and the faceplate screws) too.

And lastly, I'm sure you've thought of this, but if you use the handheld planer fo maks a flat spot for the faceplate, be sure you've removed any broken-off screws.
 
Im not a real club type of person, but Ive been giving some thought to joining the Long Island woodworkers and the turning club.
Its a bit over an hour drive for me if no traffic,for the monthly meetings, and it might prove to supply some valuable insight from experienced turners.
Just not sure if an inexperienced turner like me would fit in something like that.
 
Been to lots of turning club meetings all over the country. Never been to one that did not welcome a newbie with open arms. You'll have more help than you knew existed, all of it eager to help you. You may even find some one just down the street and around the corner from you! It will be the best hour getting there you ever spent!
 
Allen, based on what I've read and seen in person, pretty much every woodturning club has aat least a few guys who are more than happy to mentor new turners. A couple of hours with an experienced guys will save you weeks of frustration.

Have you checked out this AAW (American Association of Woodturners) chapter, or are the the same club that's an hour away from you?

http://liwoodturners.com/
 
Allen, Another thing to consider is how you are going to re-mount your blank in your chuck after you get the outside shaped. It's fine to just unscrew the faceplate from the headstock, mount your chuck and use the recess/tennon you have created, along with some light tailstock pressure, to center the blank in the chuck. It won't be perfectly centered and may still need to be re-trued and take some fiddling with. Or....Consider this way. One of the best investments I ever made was a Oneway multi-tip revolving center http://www.woodturnerscatalog.com/p/108/5487/Oneway-Multi-Tip-Revolving-Center-4-Piece-Set and a oneway chuck adapter http://www.woodturnerscatalog.com/p/108/5488/Oneway-Multi-Tip-Revolving-Center-Chuck-Adapter. There may be a similar adapter for the live center on your lathe. With this set up you put the chuck adapter onto the live center and re-mount the faceplate with the piece still attached onto the tailstock. The piece still spins freely and stays in line with the turning axis. You can then slide the reversed piece up to the chuck, clamp it in and get a near perfect alignment. Once its secured in the chuck, remove the faceplate and the adapter, bring up the tailstock and begin hollowing the inside of the bowl. This also works great if you ever decide to get a vacuum chuck (and you will :) )
 
Allen, based on what I've read and seen in person, pretty much every woodturning club has aat least a few guys who are more than happy to mentor new turners. A couple of hours with an experienced guys will save you weeks of frustration.

Have you checked out this AAW (American Association of Woodturners) chapter, or are the the same club that's an hour away from you?

http://liwoodturners.com/

that's another club I believe. Ill look into them after the new year.

ted, Im trying to be reasonable with the spending, seems there is no end to lathe accessories and different tools.
 
... One of the best investments I ever made was a Oneway multi-tip revolving center http://www.woodturnerscatalog.com/p/108/5487/Oneway-Multi-Tip-Revolving-Center-4-Piece-Set and a oneway chuck adapter http://www.woodturnerscatalog.com/p/108/5488/Oneway-Multi-Tip-Revolving-Center-Chuck-Adapter. There may be a similar adapter for the live center on your lathe...

I also have the Oneway live center (love it) and the chuck adaptor, but did you know the chuck adaptor will fit on the stock Powermatic live center too? I'm also pretty sure the live center that came with Allen's Jet is the same as the one shipped with our Powermatics, and they are clones of the Oneway.
 
All have given you great advise. I just want to say that Carol's advise to join or at least visit a woodturning club is very important. I learned to turn on my own and didn't fine a club for several years after I started turning. I had figgered out most of the basics but my turning has improved greatly since I started attending a monthly turning club meeting. I drive 65 miles one way to meetings but I look forward to that every month. Be careful and as much as possible stay out of the line of fire and have fun.
 
uh.........I know Im going to start sounding like wendy whiner,but Ill ask for a drop more help, then either it will be fire wood or Ill finish it in a few months.
I took advice naturally, moved the tailstock up, went out and got some thicker screws, all was going well.
there is a spot on the bottom, it seems almost as if its rot?...........I can pick the wood out with my fingernail, so I didn't want to continue on the outside figuring maybe Ill let it dry more for a few months. Not sure how to approach this bad spot.
I got a shape on the outside, cut out a mortise and chucked it up. Light passes, all was going well. all of the sudden that bad white spot, the rotted stuff, where the mortise was cut, gave way, chipped off and the piece again came off the chuck. It didn't fly, as I noticed it wobbling and stopped the lathe, I was only at 300 speed doing the inside.
not the chuck wont hold the piece, and this is where Im at.
suggestions on how to get the piece back onto the chuck? I was thinking I could turn a small tenon to fit the hole, glue it in, then chuck it up to finish the bowl, then cut the tenon off on the band saw and sand.
any better suggestions. I wanted to turn the piece down another inch inside and then let it dry up a bit.

pictures are rough, but you can look at the white and see how it just looks rotted.
I love the color in this piece, would love to save it.

right side of first pic you can see the botton where the side of the mortise hole cracked off. Second pic right, the rotted looking stuff
 

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Allen the white spongy wood is the sapwood. I usually try and turn most of it away as it doesn't hold very well as you now know. It's a bit late to turn that part away now that you have started the interior of the bowl. The mortise you chucked into looks bigger than it needs to be to me. I think I would try and use a large forstner bit and make a new smaller mortise and rechuck. Looks like it's smaller the sapwood won't be used. Not that big of deal if you can't get it centered perfectly as there is plenty of wood to take off and get it trued up, but remember it will probably be a little wobbly so slow down the lathe again.

Does that make sense? :huh: Hope you can get it back on the lathe...that MI chocolate looks real pretty!
 
Jeff's right about the sapwood. It can tend to be soft, especially when the wood is still green. (And you may be seeing some of the cambium layer too, which is even softer.)

I also agree that the recess (what you're calling the mortise) looks a bit large. Ideally, it should only be a little bit larger (1/8" to 1/4") than your chuck jaws when they are fully retracted (the smallest they can go). Anything bigger and you won't get as strong of a hold. I like Jeff's suggestion of drilling a smaller recess if possible. You should be able to get it fairly well centered by using the marks in the bottom of the existing recess. Personally, I'd probably wrap it up in paper as it is now to slow down the drying, then let it dry for a few weeks or more. That'll help firm the softer parts up a bit.

You could possibly glue a tenon into the recess, but you'll need to wait for the wood to dry before you can get a good glue joint, and even then, it might be difficult unless the bottom of your recess it good and flat. If you do go that route, I'll caution you about cutting the tenon off with your bandsaw. Unless you have a special jig to hold the bowl securely sideways, it's a very risky cut, both for your bandsaw blade and your fingers. If it was me, I'd just turn the tenon away on the lathe, using a jam (aka friction) chuck. There are pics of me turning the tenon off a bowl in this recent blog entry.
 
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