Having a hard time turning bowls! NEED HELP B4 I SELL MY TOOLS!!!

[David Seward]

I am extremely frustrated by my results with bowl turning!!!

If one more bowl blank flies off my chuck, I will get rid of ALL my tools!!!

I have started with round bowl blanks of about 6" in diameter. I have tried using a screw chuck and also a blank screwed to a faceplate. I seem to be able to shape the outside profile to my liking, I turn a 2" recess about 1/4" to 3/8" deep with dovetail shape to match the jaws to grip better. Then using a Nova chuck, I mount the blank on the bottom. It doesn't take long for the blank to come flying off the chuck.

I have sharpened my bowl gouge satisfactorily. I can tell by the shavings coming off the wood. I use a VERY light touch, rubbing the bevel, everything I have been taught. Then without warning, the damn thing goes flying!


I have had the wood spilt along the grain or just plain fly off the chuck.

Please let me know what I am doing wrong before I sell all my tools and find an easier hobby!!!
:mad:

 

[Owen Lowe]

You could try a tenon on the wood instead of a recess. Either way, the depth should be just shy of the total depth of the jaws. You want the face of the jaws to seat against a flat shoulder on the wood as well.

How wet is the wood? If very wet, it could be compressing in the jaws and then coming loose. Even when dry check the tightness of the chuck as you turn the inside.

Does the chuck let loose during a similar cut or place in the profile on all of your experiences?

How fast are you turning? A 6" bowl should likely be in the 800-1200 rpm range.

 

[David Seward]

You could try a tenon on the wood instead of a recess. Either way, the depth should be just shy of the total depth of the jaws. You want the face of the jaws to seat against a flat shoulder on the wood as well.

How wet is the wood? If very wet, it could be compressing in the jaws and then coming loose. Even when dry check the tightness of the chuck as you turn the inside.

Does the chuck let loose during a similar cut or place in the profile on all of your experiences?

How fast are you turning? A 6" bowl should likely be in the 800-1200 rpm range.

Never thought of a tenon, good idea! The chuck lets go anytime I try to start digging to deep.

I turned my lathe down to about 840 rpm, IIRC. (2nd gear on the Jet Mini-lathe)

 

[john lucas]

Sounds like you don't haven enough wood outside the recess. The jaws apply quite a bit of force in expansion mode. I try to have at least 3/4" of wood outside the jaws in expansion mode.
If you use a tenon it will usually be stronger. Of course you do have to remove the tenon afterwords but that gives you a chance to really refine the foot of your bowl.
If you go to our club website under the tips section and look up my article on reverse turning methods you may find a way to do the bottom.
http://www.cumberlandwoodturners.com/htm/tips.htm

 

[John Giem]

It sounds like you are getting a significant catch to pop the bowl off so frequently. Try using a tenon, it is much more reliable. The most common mistake my new students make involves tool control. With bowl turning the grain of the wood runs perpendicular to the axis of rotation. If one uses spindle turning techniques (the grain is parallel to the axis of rotation) on bowls then it an almost guaranteed catch due to digging into the end grain. The tool should be applied to the wood so that it is cutting a cross the grain. There are a few good You Tube videos showing this. Maybe one of the other readers can suggest a good one.
Second, always use the tailstock to support the turning blank. Only remove it when it prevents you from making your cut, typically this is when hollowing out the inside of the bowl.
Early on, I was taught that after I mounted my blank on the lathe to grab hold of it and try to rip it off. If I can pull it off by hand then I'm not doing something right. If it stays on, then there is a good chance of success, assuming no catches.
Another consideration, use the biggest recess or tenon the project will allow. Too small a tenon or recess is often not strong enough to hold the blank securely.
What is the condition of the wood where you are trying to cut your recess or tenon? I recall once cutting a tenon into green sap wood. The bowl did not stay on the lathe. I actually tore it off. So, be sure that the bowl mounting is in sound wood.

Let us know how you are doing.
John Giem

 

[John Giem]

David,
After rereading your post another idea(s) came up.
Get one of the bowl blanks that came off of the lathe, take it to the bandsaw and cut it in half through the center of the recess. This will expose the profile of the recess you cut. Now fit this onto one of the jaws of the chuck you were using. You are looking for how good a match you have between your wood and the jaw.
A good recess will have a sharp angle at the perimeter allowing the jaw to touch the bottom of the bowl with no gaps. Also, the dovetail of the jaw should be a good fit against the sidewall of the recess. If you do not have these conditions, then it will have difficulty in supporting the stresses of turning.
The diameter of the recess is also important. When the jaws are mounted into the recess and tightened, the gap between the jaws will be about 1/8 inch for the best fit.
Now taking one more step back, are the jaws on your chuck properly mounted onto the body? If you close your jaws on the chuck, there should no gap between the jaws. The proper way to mount the jaws on a Nova chuck is: match the number on the jaw to the number on the sliding jaw in the base, mount the jaw and only finger tighten the screws, tighten the jaws forcing the jaws to align, no gaps, then fully tighten the screws.

Since I am not standing by your side, I cannot see what is causing the difficulty. Consequently, I am trying to point to all the 'little things' that may be causing your problems

The good news is that after some success then woodturning becomes addictive.

Good luck,
John Giem

 

[MichaelMouse]

I turn a 2" recess about 1/4" to 3/8" deep with dovetail shape to match the jaws to grip better. Then using a Nova chuck, I mount the blank on the bottom. It doesn't take long for the blank to come flying off the chuck.

Lots of misconceptions flying around.

Two things to begin with. First, the mortise is too deep. You want the front of the jaws to bottom on the wood. You'll notice the step on the jaws is ~1/4. Go less. Your jaws should not exceed the step portion in depth. Img 1040 shows the step with the bowl tilted somewhat out of the way. If they go into the non-dovetail portion of the step, they will never hold properly.

Second, you don't "grip" the piece from the inside. Cranking after you meet resistance is liable to lift up the wood being wedged, weakening it even if you don't see the crack you've made. Snug is good, and if the piece doesn't rotate true, release and clean it out. Since you just turned it true, it must have no runout - assuming your chuck has none.

The dovetail is a wedge, and if we forget it, we can be reminded what a wedge does to wood when it's overdriven - it splits it. You don't need a lot of wood around it (see waitsand), you just need to bottom the nose. You don't need complete contact around the circumference, though the better the fit the more effective. And you don't need the mortice exactly the same as the angle of the dovetail. You need it a degree or two less so it will draw as you press and snug. Remember, it's a wedge. Look at Img 1045 to see the shadows of corrosion left by the jaws. That's a pretty good fit for flinging 15" of WET hard maple at 680rpm.

Same wedge concept goes for a tenon, though a tenon steals a bit of depth (see the illustration), and can be trouble for folks like me who have difficulty visualizing and cutting a fair curve with the tenon in place. To be most effective, it should be close to the diameter of the jaws at their first point of circularity, but since the wood will shrink, it must be about 1/4 over to re-turn. A compromise. There must be a shoulder for the nose of the jaws to meet, and a space for the wedge to seat. The first defends against racking and other alignment problems, the second against flyaway.

NB The Nova 2" jaws are a lousy choice for a tenon, and they admit it. If you're going to use one, don't make a dovetailed slot for something that's not there inside. I just take my 1/16 parting tool and use it to cut both shoulder and about a 16th beyond for the lip to wedge into.

Oh yes, lower you turn, more control you use, better off you are. Take a few rpm off that 840.

 

[robo hippy]

No substitute for a 1 on 1 mentoring session. Find the nearest club.

Mortice or tenon hold equally well when properly made. For a 6 inch bowl blank, your recess can be 3/16 deep. 3/8 in over kill and does not give a better grip. You want 1/2 inch of shoulder width outside that. You can get away with less, but more is better to start.

You can over tighten. At worst, you blow your recess apart before you start turning. You can tighten to the point where it is so tight that any excess pressure from cutting can make it blow up.

Go to You Tube and type in robo hippy. I have a couple of bowl turning clips up. They may help. Other than that, a mentor, which most clubs have.

robo hippy

 

[hockenbery]

I recommend the tenon over the mortise.
Simple reason is you can over tighten a Mortise and split the wood or under tighten and have the piece breakout.
You can't over tighten a tenon.

I second. "get some quality mentoring"
One observation built over hundreds of students is that students occasionally internalize a small misconception that block their progress.
A good teacher will quickly spot what you are doing wrong.

It could be you have your gouge ground with a dip somewhere on the profile. Or you turn the gouge up too much.
or you have wood mounted in spindle grain direction or your tool rest is too low or your tool rest is slipping too low.


If you hollow the bowl with the gouge in the 3 o'clock position, tool parallel to the floor, with the tool rest set to cut at center, and stop cutting at bottom center, you cannot get a catch. That said it takes some practice, and learning.

For hollowing there are sweet spots on the gouge at around 1:30 and another 12 that cut more efficiently. Cutting at 12 is an advanced cut.
Stay between 1:30 and 3. Always enter at 3 with the bevel pointed down the side of the bowl.


Have fun,
Al

 

[Alan Trout]

I am going to suggest as Reed has find a club or take a lesson. It will pay huge dividends and eliminate frustration. Hard to say what you are doing wrong without seeing exactly what you are doing.

Alan

 

[Patrick Miller]

No substitute for a 1 on 1 mentoring session. Find the nearest club.

No better advise here than this. Several years back when I first started to turn I posted a nearly identical message of frustration on another forum. This led me to the AAW, a chapter 90 miles away and a local mentor. I learned enough in an hour for me to take back the "I'm putting all this stuff on Craigslist" threat. I'm so glad I stuck it out. Let us know about your progress.

 

[bowlman]

Others have already posted some great tips. However, it may be that you are having problems with the entry point where the tool first meets the wood. If that is the case, here is what I was taught some 30 years ago ... use the corner of the skew or a small parting tool to give you a starting point for the bowl gouge. Once this is established (and it doesn't have to be very deep, say 1/8 inch), switch back to the bowl gouge and since you now have a "ledge" you can proceed from there. Also, don't try to "hog off" the wood. speed of making is no substitue for good tool control and good form.

If this solves part of the problem, get some hands on instruction from a good bowl turner. Have him explain in detail how to get the gouge started on the inside without using the method I describe above. And be sure to try it with him watching ... try it several times. Nothing beats practice!

 

[MichaelMouse]

I recommend the tenon over the mortise.
Simple reason is you can over tighten a Mortise and split the wood or under tighten and have the piece breakout.
You can't over tighten a tenon.

I second. "get some quality mentoring"

If you hollow the bowl with the gouge in the 3 o'clock position, tool parallel to the floor, with the tool rest set to cut at center, and stop cutting at bottom center, you cannot get a catch. That said it takes some practice, and learning.

Of course you can overtighten a tenon. Two ways I know of are to split it off entirely by wedging it up with a dovetail, and crushing enough long grain to lose hold in that direction with other kinds of jaws designed with teeth. When making any tenon, pays to get the annual ring in the center, not up near the nose of the jaws. The easy split is along the ring.

No assurance of quality no matter whom you visit. Get some varied mentoring. As you can see by the replies, there are alternatives. Learning how one turner works is learning one person's prejudices. Learning principles and seeing them applied by many is a lot different.

Not sure about the clock in Al's house, or maybe he's turning outboard. Most of us find that cutting close to 9:00 hollowing a bowl is best. I favor air over the tool, so I'll put the rest down around 8:30/8:45.

Though you didn't indicate any special problem with entry cuts, you've had two pieces of advice already. Here's number three. Anchor the gouge to the toolrest with an overhand grip in a position where you can pivot it around that fulcrum, aiming to shave the shadow by an angled eighth of an inch. Go right on through, and you'll find that the tool is supported by where it's been almost instantly.

You said you were taking shavings. That's what you want. Not chips. But don't "ride" the bevel. That will put a lot of lateral strain on your mortise or tenon. Probably worse overall than a quick catch and throw out while entering at the rim.

 

[hockenbery]

No assurance of quality no matter whom you visit. Get some varied mentoring.

Not sure about the clock in Al's house, or maybe he's turning outboard. Most of us find that cutting close to 9:00 hollowing a bowl is best. I favor air over the tool, so I'll put the rest down around 8:30/8:45.

.

MM ,
Confusion may be in regard to flute position versus where you cut on the bowl.

Entry position for hollowing a bowl has the flute position at 3 o'clock and the cut is begun at 9 o'clock on the rim of the bowl.
Flute position at 9 o'clock is for the outside of the bowl.


Al

 

[odie]

Hard to second guess your troubles.......but, my first thought is a catch of some kind. Others have mentioned flute position, and that could do it. Even if your tool flute is correctly positioned, if you dip the gouge below centerline of the bowl, that could do it too.

I sometimes start at the rim of the bowl interior well above centerline......1/2", or so. Then gradually drop the tool rest as I work closer to the axis of rotation. I also change gouges and bevel angles as I work to the center.

Getting help from someone else is a good suggestion.......but, I have never had a single minute of 1 on 1 instruction. You can do it the hard way, like I did, but developing a personal style and tool usage on your own can be done.......by learning what doesn't work! You already have something going on that doesn't work, and once you find out what it is........you aren't likely to EVER forget it! (Personally, I believe knowledge that is acquired by finding out first hand what doesn't work, might be a better teacher than having someone tell you outright what does work......)

I did purchase books and professionally produced videos early on......and, this is also a good instructional resource. If you do this, try to stay away from Youtube, and the like.......get the pros advice first......then check out all the free resources. This isn't to say that all the free advice is bad. Some of it is good, but you'll have a better grasp of the basics if you stick with information available with a price tag first.

ooc

 

[Mark Mandell]

David,

You're lucky that you're in Rochester as it's a nice 4-hour drive down to Quakertown, near Allentown, PA where you can spend an entire weekend in David Ellsworth's studio class and learn from the true master, 1-on-1. Just leave all the preconceived notions and self-induced bad technique at home, listen carefully and do exactly as he tells and shows you.

Turning is fun and David will show you how to keep it that way.

Google him and you'll find the links to his school

 

[Bill Boehme]

David, hold onto your turning tools. The things that you have experienced are very normal for a beginner, especially if self taught and trying to remember all the "rules" encountered in reading how-to-turn instructions and simultaneously wound up tighter than a $3 pocket watch in anticipation of the next nerve wrecking catch-from-hell.

There are more catches in your future, but their frequency and severity will greatly diminish if you remain persistent in developing your skills. I agree with all the suggestions about hooking up with a mentor. If you can't locate one then a good video is much better than reading about turning. I recommend Bill Grumbine's video on bowl turning basics as a very good starting point.

There have also been numerous very good suggestions about improving the way that you are using the chuck to hold the bowl blank. I agree that getting a proper mount is essential, however I suspect that the real problem is the way that you are using the gouge on the interior of the bowl. Specificially, make that you are cutting above centerline when doing the interior.

 

[Richard Jones]

Ditto Mr. Boehme's recommendation re: Bill Grumbine's "Turned Bowls Made Easy." A great video, for sure. As I am one that has not been able to attend "local" club events, this video was a huge help. Well worth the $$.

There is also an excellent photo essay on Mr. Grumbine's site, http://wonderfulwood.com/roughing-a-bowl-blank-on-the-lathe/

Rich

 

[john lucas]

And don't be afraid to really tighten up on a tenon. I hog down on mine all the time and have never broken one off by over tightening. And that's with dovetail jaws. I also recommend stopping the lathe frequently and retighten the jaws because the vibrations and force from cutting will cause the wood to compress and the jaws get slightly loose. having the wood sit on tip of the jaws as well as inside of them helps with this because it keeps the wood from rocking but it's always a good idea to snug the jaws up. Especially on green wood.

 

[hockenbery]

I was a self taught turner. Had a bad teacher who didn't know much at the time.
In the early 90s I joined AAW and a club in 1993. Our club had classes about once a year.
I took a class with Liam O'niell and later with David Ellsworth.
Liam had me spend a half day turning the outside of bowls with one hand. I was holding tool to tightly get decent curves.
When I had a class with David, a year later, he had me turn the inside of bowls with one hand. He noticed I would tense up on the inside hollowing.

Learning to let the tools do the work, changed my whole approach to turning and made it so much more enjoyable.
The front hand doesn't need to do much.

I see lots of students leave a class with skills it took me years to master including unlearning the death grip.

Consider the advice to take a class with David Ellsworth.

Have fun,
Al

 

[MichaelMouse]

MM ,
Confusion may be in regard to flute position versus where you cut on the bowl.

Entry position for hollowing a bowl has the flute position at 3 o'clock and the cut is begun at 9 o'clock on the rim of the bowl.
Flute position at 9 o'clock is for the outside of the bowl.

Ah, cut at the bottom of the flute, which I've always considered 6:00, like the lowest point on the clock. Pretty good advice, and can be made even more effective if you choose a tool that doesn't have that pesky thick heel in the way, forcing a high pitch angle. High pitch angles require more effort to roll up the shaving than low ones.

Since everyone else has deviated a long way from the original question, I'd like to remind David and everyone else that the technique of cutting between centers until things are at their lightest and most balanced, as seen in the clip here, is a great way to avoid a total dismount. Even if you just put a 60 live center in the woodworm hole, you gain a lot.

http://s35.beta.photobucket.com/user/GoodOnesGone/media/Inside.mp4.html

Basic poke and roll. I rotate the flute counterclockwise on the center out so I don't get shavings in my face. Also helps maybe a little in getting some wear on the left side of the flute, rather than the right.

 

[hockenbery]

Ah, cut at the bottom of the flute, which I've always considered 6:00, like the lowest point on the clock.

MM,
Now you are confusing the face of the gouge with the flute position.

Most turners use the clock position for the roll of the gouge. Maybe you don't get to see the diagrams on you computer.
In hollowing, Rolling to 3 o'clock to enter the bowl at the rim is the safest way to begin the cut.

Flute straight up is 12 o'clock. Flute a 6 o'clock is flute straight down.
This is useful in the Raffan back hollowing but the flute is more at 5 o'clock.

One of the problems in the woodturning community is the lack of a common language.
Some folks talk about open flute for 12 and closed flute for 3 and 9


Have fun
Al

 

[KellyDunn]

Most of us started out by ourselves and had major problems cause no one showed us any different.
I am a mentor in our local club. Many clubs have them. I will spend anywhere from a couple hours to half a day with someone. I ask they bring their tools and an idea of what they want to know and what they are having problems with.
A couple things stand out. proper sharpening and how to apply the particular tool grind they have to the wood.
You can keep flubbering around or hunt up someone near you known to be a good turner and ask if they would not mind helping you out. From what you are saying, an hour with a good turner will get you light years beyond where you are now. A good turner will take a look at your tools and what you are doing and have it sized up in a few minutes.
That said most of us go about what we do a bit differently. So with time you will pickup what works best for you. But spending a bit of one on one is the best advise folks here are giving you.
Ellsworth is one of the best. I suggest seeing him when you got the basics down so you can really learn what he has to offer. If he taught you the basics you would not have time or the experience to truly soak in what he can offer. David mentored me. Slowly teaching me to be able to see.
But in 1985 Richard Raffan and Nick Cook spent some hands on time with me. Even though I was actually making money from turning then I was a crappy turner. In a brief time they taught me to sharpen my tools and how to put them to the wood. When I had a bowl finished Richard held it, looked at me and said, now all you need is practice.

 

[MichaelMouse]

MM,
Now you are confusing the face of the gouge with the flute position.

Most turners use the clock position for the roll of the gouge. Maybe you don't get to see the diagrams on you computer.
In hollowing, Rolling to 3 o'clock to enter the bowl at the rim is the safest way to begin the cut.

Digital watch?

If the open part of the gouge faces 3, you're cutting with the bottom of the flute. Even in your diagram. Which is a fine way to enter because the nose is normally round or pointed to reduce contact area. Problem is the high pitch angle you must maintain to try and shave further on. The heel forces you to that on a conventional grind, therefore you want to roll the gouge slightly to begin cutting where you have some clearance angle. When I roll roughing L to R (rim to center) it's slightly counterclockwise, so the material being removed is being done from the right side of the flute, nose stabilizing. http://i35.photobucket.com/albums/d160/GoodOnesGone/GreenStart.jpg This is not a cylindrical gouge, but there's no extra distractions, so you can see how the tool is rolled to mostly shear, with little skew. http://i35.photobucket.com/albums/d160/GoodOnesGone/BroadInStaging.jpg A bit less aggressive on this cured piece, but cutting in the same place to the bottom right. You can see in this one how the skew begins.

 

[Glenn McCullough]

frustrated

David,
I was like you...very frustrated at my lack of improvement, kept making the same mistakes I didn't know were mistakes. If you join a club or are in a club, ask for individual "lessons". Most clubs have a mentoring program, free. I have been turning for 8 years, now and still go to more experienced members shops to learn. I still have a way to go , but hang in there! It is so worth it.