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

[truckerdave]

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!!!
:at-wits-end:

 

[maxwell_smart007]

the recess for the chuck to grip has to bevel 'in' if that makes sense - they sell a tool for that reason:

NOVA DOVETAIL CHISEL

 

[maxwell_smart007]

hey, that was post number 5000 - hope it was a good one! :biggrin:

 

[truckerdave]

the recess for the chuck to grip has to bevel 'in' if that makes sense - they sell a tool for that reason:

NOVA DOVETAIL CHISEL

I have that tool! and the damn bowl blank still flies off!

 

[jcm71]

At what speed are you turning?

 

[truckerdave]

At what speed are you turning?

The next to slowest speed on my Jet Mini-lathe, 840 rpms IIRC.

 

[juteck]

Your recess might be too deep depending on your jaws. You want it dovetailed slightly inwards, and only deep enough so the top face of the jaws bottom out in the recess. Another idea is to loosely put your bowl blank onto the chuck and bring up your tailstock into the screw chuck hole to help line it up, then tighten your jaws.

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[juteck]

Another thing to consider is to keep the diameter of your recess as close as possible to the closed diameter of your chuck, where you will get the most contact area.

If you still have problems with a recess, try chucking onto a tenon and see is that makes a difference.

Sent from my iPhone using Forum Runner

 

[truckerdave]

Your recess might be too deep depending on your jaws. You want it dovetailed slightly inwards, and only deep enough so the top face of the jaws bottom out in the recess. Another idea is to loosely put your bowl blank onto the chuck and bring up your tailstock into the screw chuck hole to help line it up, then tighten your jaws.

Sent from my iPhone using Forum Runner

I have not tried bringing up the tailstock yet. Maybe I should give it a shot. Afterall I am using FOG wood so it isn't like the wood cost me any money.

Another thing to consider is to keep the diameter of your recess as close as possible to the closed diameter of your chuck, where you will get the most contact area.

Sent from my iPhone using Forum Runner

I try to keep the recess as small as absolutely possible so there is the most surface area possible contacting the chuck. I do not make the recess too deep, maybe that is part of the problem???

 

[SC_Turner]

First off, hang in there Dave. I had the same problem when I first started turning bowls. I use a Nova chuck and I was putting a dovetail on the tenon because the man who taught me had a oneway chuck that requires a dovetail. The Nova should have a square shoulder when the jaws are compacting on the tenon. There is an excellent youtube video by Mike Peace of the Gwinnett woodworkers club that covers everything anyone would ever want to know about chucking wood. It is 90 minutes of excellent teaching. Search youtube for Mike Peace and it should come right up. You will get past this issue. I had so many blanks come flying off the lathe that I became afraid to turn. I always wear a face shield and would urge everyone to wear one at all times.
When you chuck wood in the expansion mode the integrity of the wood is critical. I started with found wood that was beautifully spalted but it lacked the strength required for expansion chucking. If your recess is splitting then the wood may not be strong enough. Maple is relatively cheap and strong. My earliest success was with maple blanks. When I first started I used a pretty deep recess but I am amazed at how little recess I am using now. I bought the Nova dovetail tool as you have and I used it when I first started. Now I use a skew chisel to create the dovetail and it seems to work better than the Nova tool. I would suggest leaving a good amount of wood outside of the recess for now just so you can get past this issue. One last thing I wonder is if you are working with endgrain as you are hollowing? I tend to use a scraper with endgrain with better results than with bowl gouges. My gouges work better for me on natural edge bowls which is facegrain I think. Keep us posted on your progress and don't give up.

Joe

 

[Holz Mechaniker]

you say your using a screw chuck, what size drill bit are you using to prep the hole for the screw chuck.

 

[Ed McDonnell]

An experienced turner could watch you and probably set you straight in a very short time. You are in Rochester and it looks like the Finger Lakes Woodturners meet in Rochester.

Finger Lakes Woodturners Association

Why not check out a meeting and see whether it's a group you would like to be part of. The resources that AAW clubs make available to new (and experienced) woodturners is priceless.

30 minutes of someone working with you could be worth hours / days / weeks of trying to figure it out yourself by asking questions, reading or watching videos on the web.

Just a thought.

Ed

 

[juteck]

Green wood will be easier to learn on as well, as compared to dry wood.

Keep with it though - bowls can be quite rewarding too!

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[stonepecker]

First......Don't give up. Everyone one here has felt the same way at one time or another.
Second.....Find that local club that will be a sorce of untapped information. Not everything is in the books.
Third......Find a mentor. That person you can ask any question of and they won't laugh in your face. They can help in ways nobody else can

My personal experience .... it sounds almost like you are not turning fast enough, I would also stop after a few minutes and retighting the chuck. You can't be to safe.

Hang in there.

 

[wolftat]

Are you trying to turn dry wood or is it green? I have learned from a good friend that trying to start out with dry wood was a big mistake on my part. I also was using the wrong tools and using way too much force on the tool for it to work properly.

 

[truckerdave]

Well, it was green wood when I found it on the ground this summer. It (along with alot of other wood) has been sitting in my garage for over 6 months now. I often find green wood. The hard part is finding the TIME to turn it while it isstill wet!!!

 

[monophoto]

A couple of years ago, I attended a bowl turning demonstration by Richard Raffen. Raffen is one of the leading authorities on bowl turning, and has written lots of books on the subject.

He mounted the walnut blank, and started the turning - - - and the blank flew off the chuck and bounced off the wall.

The point is that it happens to everyone. Just keep working at it.

It might be helpful to have someone looking over your shoulder to see what it is that you are doing when the blank flies.

 

[Bob Wemm]

Dave, There must be something wrong with the tenon to allow the blank to fly off. If you have a dovetail cut into the tenon, it rarely can come out, unless the tenon collapses.
I always make my tenon and dovetail shape so that when the jaws are closed TIGHT there is a gap of at least 1/8 inch between each jaw. That way I know the full clamping pressure is on the wood and not on the jaws.
I am very loathe to use the expansion mode unless it is absolutely essential to do so.
Don't give up, Bowls are so much fun.

Hope this helps,
Bob.

 

[mhbeauford]

The jaws must be TIGHT. I alternately tighten on opposite key holes until I can no longer tighten it by hand. I've turned 100's of bowls, some up to 20" and I very rarely have one come off. I use a Vicmarc 120 for large bowels and a Super Nova for the smaller ones. The dovetail angle must match the chuck jaw angle. I have homemade tool for inside and use a skew for out side dovetails. As others have pointed the dovetail either inside or outside should not be deep enough to bottom. You want the jaws to set well into the dovetail angle. On speed, a recommendation in that diameter in inches times speed in rpm should be between 6,000 and 10,000 of course that assumes the it is round and balanced.

 

[truckerdave]

Dave, There must be something wrong with the tenon to allow the blank to fly off. If you have a dovetail cut into the tenon, it rarely can come out, unless the tenon collapses.
I always make my tenon and dovetail shape so that when the jaws are closed TIGHT there is a gap of at least 1/8 inch between each jaw. That way I know the full clamping pressure is on the wood and not on the jaws.
I am very loathe to use the expansion mode unless it is absolutely essential to do so.
Don't give up, Bowls are so much fun.

Hope this helps,
Bob.

To be clear, I have not turned a bowl using a tenon yet. I am going to use my next opportunity in the shop to try that! It makes sense that the jaws on the chuck clamp better in the compression mode rather than the expansion mode.

But the next question I have is how to clean up the bottom of the bowl after hollowing? It isn't a finished project till the whole thing is perfect.

 

[alankulwicki7]

I actually prefer using a tenon when I turn bowls. There are a many ways to get rid of it:
1. Longworth chuck
http://www.mikes-woodwork.com/images/Turning/Longworth-chuck.jpg

2. Donut chuck
http://www.woodworkerssource.com/blog/wp-content/uploads/2010/01/donut-chuck-II.JPG

3. Flat jaws for your chuck -
http://www.woodcraft.com/product/2020042/18877/woodriver-large-flat-jaws-chuck.aspx

4. Use pressure from the tail stock to hold the bowl against the chuck and nibble away at the tenon until it is almost gone. Then remove the bowl from the lathe, cut the little nib off and hand sand the bottom of the bowl.

I made a donut chuck out of some scrap plywood and some long bolts. Then I took some rubber hose to wrap around the hole so it doesn't mar the bowl. Just take light cuts and it'll work like a charm....

Don't give up just yet!

 

[philipff]

Please find a place or a person who will sell you some lessons before you get really hurt! There is nothing intuitive about turning bowls, you need to be taught!! phil

 

[robutacion]

Yeah, I agree with a lot that has been said already and, the last thing you want is to start fearing when you have a bowl to make.

My first piece of advice is get a proper bowl jaws set for you nova chuck one of these heavy duty ones and plenty of gripping teeth NOVA 75mm (3") Bowl Jaw Set

Get some green lots to practice on, the the logs have been cut for as while and you want to make sure they are soft when you turn them, put then on a drum full of water for a few days, they will be the closest thing to freshly cut wood...!

Use low speed, the lowest possible until the blanks is balanced them go up a little but never over 800rpm, 600 is ideal for most bowls. Remember, centrifugal forces Called "G's" are capable to disintegrated a large blank of wood, all by itself in extremely high speeds, any line cracks or weaknesses in the wood, and it will blow to pieces, this is off-course with exaggerated high speeds so, keep it slow, the 15 minutes longer that will take you to turn it, are irrelevant for the extra safety and piece of mind however, do your bowl turning with a good full face shield, you will never regret it...!

Good luck...!

PS: If you were closer, I would take you through all the basics and some more advanced techniques all free of charge and I would even supply all the wood but, you are too far away so hopefully, you will find someone closer to you that can give you a few "pointers"

Cheers
George

 

[Bob Wemm]

Dave, There must be something wrong with the tenon to allow the blank to fly off. If you have a dovetail cut into the tenon, it rarely can come out, unless the tenon collapses.
I always make my tenon and dovetail shape so that when the jaws are closed TIGHT there is a gap of at least 1/8 inch between each jaw. That way I know the full clamping pressure is on the wood and not on the jaws.
I am very loathe to use the expansion mode unless it is absolutely essential to do so.
Don't give up, Bowls are so much fun.

Hope this helps,
Bob.

To be clear, I have not turned a bowl using a tenon yet. I am going to use my next opportunity in the shop to try that! It makes sense that the jaws on the chuck clamp better in the compression mode rather than the expansion mode.

But the next question I have is how to clean up the bottom of the bowl after hollowing? It isn't a finished project till the whole thing is perfect.

I use a set of jaws similar to the Woodchuck ones on the following post from your last one. As Quoted here. Mine are a different brand and can hold almost 11 inches. I made an extension set for bigger bowls.
Ideal to clean off the tenon and sand the base.
Bob.

 

[monophoto]

A point that I eventually learned the hard way is that the exact fit between the chuck jaws and the dovetail tenon is critical. Here's a sketch that illustrates what I mean.

It is important that the taper of the tenon (spigot) match the taper of the jaws, and that the exterior face of the jaw fit tight against the blank. But it is also very important that the tenon NOT bottom out in the jaws - there must be a gap between the bottom of the tenon and the interior face of the jaws.
the strength of the grip comes from having a tight fit in the corner between the side of the tenon and the back face of the blank.

 

[SC_Turner]

Some really good advice in this thread. Monophoto's post is excellent and should help you find the problem. I use the same approach you are trying Dave. I use a Nova screw chuck to turn the outside and bottom of my bowls and then flip the bowl using the jaws in expansion mode. One thing I have learned that you may or may not already do when flipping the bowl for hollowing. I mark the bowl with a pencil at the #1 jaw before flipping and leave the screw in the blank. I then loosen the jaws to flip the blank with the screw still in the wood. I do this in case I am not happy with my recess so I can flip the bowl back with perfect alignment to make adjustments to my bottom recess.

Joe

 

[nativewooder]

So why don't you turn a tenon and use the chuck to grip the tenon! As long as the tenon does not bottom out against the back of the jaws you should have no problem.

 

[louisbry]

To be clear, I have not turned a bowl using a tenon yet. I am going to use my next opportunity in the shop to try that! It makes sense that the jaws on the chuck clamp better in the compression mode rather than the expansion mode.

But the next question I have is how to clean up the bottom of the bowl after hollowing? It isn't a finished project till the whole thing is perfect.[/quote]


The following pdf file should answer your second question.

http://www.cumberlandwoodturners.com/Tips/Methods%20and%20Jigs%20for%20Reverse%20Turning%20Bowls.pdf

I found another pdf file that addresses both of your questions.

http://www.turnedtreasures.com/pdf_pages/bowl_pdf.pdf

Good luck. Hope this helps.

 

[sbwertz]

I'm pretty much a beginner at bowls, too, and also have had the problem with the bowl flying off. What works for me is to screw a waste block to my faceplate, then glue a piece of brown paper bag to the waste block and glue the bottom of the bowl to the brown paper. It holds the bowl securely while I turn the inside, and I can pop off the waste block with a tap of a chisel and mallet. Then I reverse the bowl and hold it with a set of cole jaws to clean up the bottom. So far, no more unidentified flying bowl close encounters.

 

[Phil Labowski]

Don't give up, bowls can be tricky. My first bowl was orbited by the guy showing me how to turn bowls and he has been turning for years and years. Bill Grumbine has a pair of bowl turning videos that are a good value. One of the things he says is that he uses a tenon because of how easy it can be for your blank to split with the recess.

 

[Deadhead]

I used to make a recess and chuck the inside (smaller projects I still do). I finally got tired of larger turnings flying off the lathe; I now use a tenon, and to finish the bottom with a Longworth chuck. It looks harder to make than it really is; this is the site I used to make the chuck. When you finish the bottom use the tail stock until there is about 1/4" x 1/4" left on the tenon, then remove the tail stock and finish the bottom off.

How To Make A Longworth Chuck | Woodworker's Guide

Good Luck
Ben

 

[randyrls]

An experienced turner could watch you and probably set you straight in a very short time. You are in Rochester and it looks like the Finger Lakes Woodturners meet in Rochester.

This is good advice always! Many members of turning clubs would be happy to mentor you. Some clubs have even developed learning programs. Our local club is having a wood collection this Saturday. (I will not be able to go :frown. The wood is almost always free and unlike other things, it does grow on trees! :biggrin:

Clubs also often have seminars or demonstrations by notable turners. Our own club has had demonstrations by David Ellsworth, Cindy Drozda, and others. This fall Liam O'neil (sp?) will demonstrate at our club.

I hope you are wearing a high rated face shield!

 

[greggas]

I turn many bowls and have learned to prefer spigots for holding with a check as opposed to recesses. I find the chuck holds the spigot much tighter than a recess which tends to let go with catches or aggressive turning.

You may find more success as you learn the ins and out ( no pun intended) of bowl turning and then can always circle back to recesses with experience. If you , as I did, use recessed to keep the bowl as deep as possible then add a glue block to act as the spigot.....that is now my preferred method.

good luck