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Vibration Troubles turning 4x4x11 Vase

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I've been working on learning how to turn vases recently. I've turned a few, smaller ones around 4x4xY or just some small logs turned into twig vases.

I'm trying to turn a 4x4x11 piece of Sycamore right now. The outside is shaped, and now I've turned my attention to the inside. I've been working my way from the center out, but so far I've barely been able to get about half an inch deep to constant vibrations. Just barely enough pressure on the spindle gouge tip to start cutting the wood starts vibrations, and they don't stop until the tool is removed from the wood. I've made a few exceptionally fine cuts to get as deep as I have, but it would take me a week or so to turn this thing at this rate.

I did not experience this turning previous vases. There were some vibrations occasionally, but nothing continuous like this. I've tried a few different tools even...a normal spindle gouge, detail gouge, larger spindle gouge, even an EWT strait hollowing tool, and they all seem to be having the same problem. I've verified that the chuck is tight without any play, and the piece is firmly clamped in the chuck.

Kind of at a loss as to how to proceed here... Any ideas would be greatly appreciated.
 

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A picture would help so we could see how it is mounted. Also, remove the vase from the chuck so that we can see the tenon. The problem you described sounds like a holding issue. Make sure that your tool is sharp and presented slightly above the centerline.
 
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I also wonder if there might be a defect in the wood. Perhaps a crack you can’t see when the piece is at rest, but opens a bit when it turns?
 
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When I get vibrations I start a mental list, it goes something like this. Tool position, lathe speed, sharp tool, width of cut, mounting. I'm sure there are a few more, and not necessarily in that order. Changing the tool position and lathe speed can sometimes help with harmonics, a sharp tool always helps. Width of cut, a narrower width of cut equals less resistance, Cutting far from the headstock, the stress is on the wood, cutting deep into a vessel, the stress is on the tool shaft. As for the mounting, If I get vibrations from the start, the mounting would probably end up being the culprit. A right sized, well made tendon is a must. Right diameter, and no gap where the shoulder meets the top of the jaws.
All that being said, the tools you mentioned using would be a challenge. If you haven't checked out Lyles website, it is a wealth of information, so is he for that matter, and he doesn't mind a call, just don't mention you are using s chuck...o_O

 
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Really need to see pics. Could be a tenon issue as mentioned, or it is very easy to cut too much away at the chuck end, leaving the upper end without enough support, easily leading to vibration. 2 options available in that case 1) steady rest, 2) cut the piece down in stages, OD and ID, so there is enough material to support the cut.
 
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When I do some hollowing, which isn't often, I want the biggest tenon possible from the chunk of wood that I am using. I don't hollow with gouges. They can be used, but are limited. Biggest problem, which is worse the farther out you are off the tool rest is that you have too much metal in the wood at one time. This is when you need the hollowing tools with the small tips, generally not more than 1/4 inch wide.

robo hippy
 

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I agree with Bill. Sounds like a mounting problem. One trick I find when hollowing vases is to cut at a 45° angle to the wood instead of straight across the grain. This way you're cutting downhill with bbn the grain and it chatters a lot less.
 
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Hey all! Thank you for your replies, I appreciate it. Apologies for the late reply, had a long work day...

I seem to have made my problems worse, as after starting a bore, which had some vibration issues itself, I then tried to clean up the surface of the top of the vase before moving up to the next bit size. That vibrated a ton, instantly...and I seem to have shifted the vase in the chuck. I could have sworn it was seated as flat as possible before, but now its tilted and I have as of yet been unable to get it back to true.

Anyway, here are some pictures:

Vibration Vase Photos-1.jpg

Vibration Vase Photos-2.jpg

Vibration Vase Photos-3.jpg

With the original forstner back in, you can see how much the end of the base has become uncentered now:

Vibration Vase Photos-4.jpg

So I'm trying to fix that ATM. It looks like you can even see the ripples in the cut as well, from the vibration. I only cut for a couple of seconds, but the vibration was suddenly extreme. I've never encountered this issue before...I've turned a few vases, and always have some vibration problems when hollowing the inside, but never just trying to surface the top like this.
I have a bunch of tools for hollowing. I have the entire set of EWT hollowers and standard EWT tools, with normal and negative rake tips. I also just purchased this a couple of weeks ago for doing larger vases (I have five 6x6x12+ vase blanks that I am hoping to turn soon):

Hollow Master-1.jpg

Not sure that this will work with this small vase I have here...I don't know if I'll be able to get that curve through the neck here...but, if it does go through, I'm hoping to hollow this out with the hollow master.
 
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I think this piece may be a dud...

It appears that it got knocked out of true when I was turning the outside. If I adjust the seat in the chuck so that the outside turns true, I cannot bore a hole into the inside properly...the forstner sits off to one side, and carves a larger hole than the size of the bit that extends beyond the opposite side of the forstner that is actually cutting the wood. If I try to true it up so that the forstner cuts properly, the outside is out of true enough that there is too much vibration just from spinning.

I wonder if that is what is why I've been having trouble cutting the inside? It got knocked out of true before I even finished turning the outside? I thought originally that the wood was moving due to some release of tension...but, I must have bumped it or something at some point, I guess...
 

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It's hard to tell from the picture, but it looks like the chuck jaws aren't solidly seated against the shoulder. This could be the result of not having a sharp corner between the tenon and shoulder. For the distance that this piece extends, a much larger diameter tenon (and chuck jaws) would help immensely. Strive to make the tenon exactly match the perfect circle diameter of the jaws. It looks like the tenon might be slightly larger than the perfect circle diameter.

And the small diameter neck reduces stiffness considerably.


Vibration Vase Photos-2.jpg


There is no reason to have the bottom of the vase such a long distance from the chuck jaws. Excuse my sloppy editing in the picture below, but leave the bottom third of the vase at the larger diameter so that the bottom of the vase will be very close to the tenon. When the inside hollowing gets to the unfinished exterior alternately work the inside and outside together.


Vibration Vase Photos-1.jpg
 
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It's hard to tell from the picture, but it looks like the chuck jaws aren't solidly seated against the shoulder. This could be the result of not having a sharp corner between the tenon and shoulder. For the distance that this piece extends, a much larger diameter tenon (and chuck jaws) would help immensely. Strive to make the tenon exactly match the perfect circle diameter of the jaws. It looks like the tenon might be slightly larger than the perfect circle diameter.

And the small diameter neck reduces stiffness considerably.


View attachment 40236


There is no reason to have the bottom of the vase such a long distance from the chuck jaws. Excuse my sloppy editing in the picture below, but leave the bottom third of the vase at the larger diameter so that the bottom of the vase will be very close to the tenon. When the inside hollowing gets to the unfinished exterior alternately work the inside and outside together.


View attachment 40235
When I tightly seat the tenon in the chuck, there is no gap anywhere. I think what you see in the photo is just a shadow. Now, to get the vase to turn true on the outside, I actually have to adjust it so that it is not properly seated in the chuck... When I was originally turning the outside, it kept getting a little out of true, so I kept turning it till it was true again. I thought it was a tension thing, I get that with boxes, once you start releasing tension in the wood it moves. I think I must have chucked it wrong in this case, though.

When I reseat it properly so that I can bore a hole with a forstner, then the outside is out of true, and it gets worse the farther from the chuck, so the outside was turned with it at a slight angle in the chuck, I guess.

I understand what you are saying about the base being too small in diameter...I noticed that a bit too late. I'm wondering if it is also the type of wood I'm turning as well? This is sycamore, IIRC. I've turned bowls and a platter from sycamore, but never a spindle or vase. I wonder if the type of grain is problematic on the endgrain with a spindle gouge?

I think the only way I;m going to make anything out of this particular piece now, is if I narrow the neck considerably to get it back into true while it is properly seated in the chuck. Then see if I have much room left to hollow, or maybe I just bore a hole as large as I can, and leave it at that. :p

I have another piece of this wood, and a bunch of other 4x4x10-14" spindles, so I can try again for sure. I was mostly just experimenting with different vase shapes. This one was interesting, but something is not quite right about it. I guess I'll see how it looks once the neck is fixed, and then try again on the next spindle.
 

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On the next one - @Bill Boehme diagram. You can leave a mass of wood until you hollow to the depth. Then turn the outside.
also if the tool rest is too low the vibration increases a lot When hollowing.
cutting a little above center will make a huge difference from citing a little below center.
 
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Well, I would try to form another tenon and use larger chuck jaws. Like some one said, use a cone center, if you have one to kind of get the piece running true, form a new tenon, and then start again. It does look like where the chuck jaws meet the bottom of the form, the surface is slightly convex rather than dead flat or even slightly concave.

If I am using a forstner bit, I like to turn a hole for it to fit into first, then drill out. It seems that whenever I start a hole with just the bit, it gets off center. If you turn a recess for the bit to fit into, it stays a little bit more true.

robo hippy
 
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There is a partial black mark on the tenon that appears to be a chemical reaction with the steel. It appears to show only a partial contact with the dovetail jaw. That won't help the cause.
 
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I'm learning some good tidbits from this thread. I want to ask about 'shark jaws', such as 68mm (2-5/8") and similar style Vicmarc shark jaws. I've seen people use these in situations like this and for hollow forms but can't figure out how the tenons are made. Some jaw types seem to have a dovetail and straight section for the tenon. Do you make both straight tenon with a dovetail at the top like it appears or am I confused about this?

Would a vase this size benefit from these types of jaws because you can use a longer tenon?
 
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I think this piece may be a dud...

It appears that it got knocked out of true when I was turning the outside. If I adjust the seat in the chuck so that the outside turns true, I cannot bore a hole into the inside properly...the forstner sits off to one side, and carves a larger hole than the size of the bit that extends beyond the opposite side of the forstner that is actually cutting the wood. If I try to true it up so that the forstner cuts properly, the outside is out of true enough that there is too much vibration just from spinning.

I wonder if that is what is why I've been having trouble cutting the inside? It got knocked out of true before I even finished turning the outside? I thought originally that the wood was moving due to some release of tension...but, I must have bumped it or something at some point, I guess...
Bill Boehme got it right on all counts, especially the narrow neck below the foot of the vase.
You're probably right.....this may be a dud! You may not want to waste any more time on it.

BUT, if you want to try and play with it maybe this will work - 1). Mount so the hole runs true. 2) Slightly true up the bottom area of the vase. 3) Turn a shallow tenon on the bottom area of the vase (the bottom of the vase will be inside the chuck) which will now run true with the hole. 4). Part off or cut off the narrow neck area. 5). Remount on the chuck and continue to hollow and true-up the exterior. 6). Figure out a method to reverse mount (between centers) to deal with the tenon or turn it into a feature groove or carve it away.
I'm just going by what I can see from the photos. This may not work and may not be worth the effort. :rolleyes:
 
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With seeing the pics, it's as I surmised previously - you cut the bottom of the vase down way too far. Also the 2-3" below the vase bottom hurts the situation by increasing the distance the mass is from the chuck/support. You could save it as is with a steady rest, but it doesn't sound like you have one. While a larger tenon would help, I suspect the 50mm jaws are ok, provided the OD is not necked down toward the bottom until the upper 1/2 or more had been completely turned - ID and OD. I don't think the wood type is the issue.

Best opportunity to make something from this is to part off the entire bottom end below the vase bottom, turn a new tenon into the existing bottom, and go from there. Do not turn the bottom OD down any until you have hollowed at least 1/2 the depth.

For HF's, I prefer to use a forstner the dia of the hollowing hole to 1-2" depth, then use an auger bit the same size to go to ~1/4" of desired total depth. I then hollow out with various tools. I do think you are being pretty ambitious to hollow 12" depth or so with the tools listed. You need at least a 3/4" dia bar to get that deep, with a 3/16" to 1/4" size cutter, and a 3-4 ft long handle. You may want to look at captive/articulating hollowing systems vs beefing up for hand held hollowing, I suggest this from experience. Doing more than 5-6" deep hand held is not fun. It requires constant concentration, one "ah sh*t" will blow up hours of work. My preference is Lyle Jamieson's system but there are other capable systems available.
 
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There is a partial black mark on the tenon that appears to be a chemical reaction with the steel. It appears to show only a partial contact with the dovetail jaw. That won't help the cause.

That's magic marker. :p I always mark the chucks #1 jaw with marker on the tenon on either side of that jaw, so that if for any reason I do have to rechuck without turning a new tenon, I can chuck it in exactly the same orientation.
 
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Well, I would try to form another tenon and use larger chuck jaws. Like some one said, use a cone center, if you have one to kind of get the piece running true, form a new tenon, and then start again. It does look like where the chuck jaws meet the bottom of the form, the surface is slightly convex rather than dead flat or even slightly concave.

If I am using a forstner bit, I like to turn a hole for it to fit into first, then drill out. It seems that whenever I start a hole with just the bit, it gets off center. If you turn a recess for the bit to fit into, it stays a little bit more true.

robo hippy

So, these are the largest size of jaws I have. Its just the standard Nova G3. I'll have to check the buttom, and see if it is convex... I usually test with a square or level to make sure it is flat.

I think the off-centering in this case, is just because the outside is turned off-center. I don't know when or how that happened, but its pretty clear as day if I center the piece do that I can actually drill out the center of the piece inside, then the outside is definitely out of true.

I'm not really sure how I re-turn the tenon. At this point, the hole drilled by the forstner is not centered, the depression I've started to turn into the top of the vase is not centered, and the outside is definitely not centered... I am not sure how to reverse it so I can turn off the existing tenon, in order to turn a new tenon. Unless anyone has any ideas there, I think the only thing I could do with it is narrow the neck and get it all true, turn off the top of the neck, and start completely fresh with a flat top so I can pilot a small hole, and bore it out with the forstner properly centered in the rotation of the piece.

I have never messed up a piece this bad before. :p I've turned, yeesh, many dozens of things since I first started. I had catches very early on, but thats a thing of the past now... Somehow I just totally bombed on this one...
 
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With seeing the pics, it's as I surmised previously - you cut the bottom of the vase down way too far. Also the 2-3" below the vase bottom hurts the situation by increasing the distance the mass is from the chuck/support. You could save it as is with a steady rest, but it doesn't sound like you have one. While a larger tenon would help, I suspect the 50mm jaws are ok, provided the OD is not necked down toward the bottom until the upper 1/2 or more had been completely turned - ID and OD. I don't think the wood type is the issue.

Best opportunity to make something from this is to part off the entire bottom end below the vase bottom, turn a new tenon into the existing bottom, and go from there. Do not turn the bottom OD down any until you have hollowed at least 1/2 the depth.

For HF's, I prefer to use a forstner the dia of the hollowing hole to 1-2" depth, then use an auger bit the same size to go to ~1/4" of desired total depth. I then hollow out with various tools. I do think you are being pretty ambitious to hollow 12" depth or so with the tools listed. You need at least a 3/4" dia bar to get that deep, with a 3/16" to 1/4" size cutter, and a 3-4 ft long handle. You may want to look at captive/articulating hollowing systems vs beefing up for hand held hollowing, I suggest this from experience. Doing more than 5-6" deep hand held is not fun. It requires constant concentration, one "ah sh*t" will blow up hours of work. My preference is Lyle Jamieson's system but there are other capable systems available.

Doug, thank you for your careful analysis.

I suspected turning down the base like that was part of the problem. I wasn't thinking, and kept working on it, then it hit me that I hadn't started the inside. I wondered if that would be contributing to the vibrations...sounds like it is.

Regarding depth of this particular vase, the entire blank was 12" (or maybe 11"...) The vase itself, which starts above that chunk that the tenon is turned into, above that part at the bottom that I turned too narrow, is 7 1/2" by my measurement. So I would probably be hollowing a little over 7" deep. That may be the deepest I've gone, not sure, I've turned some other vases about the same size (although out of slightly shorter blanks, so I didn't end up with a waste block on the tenon end like I did in this case.) I do remember the EWT hollowers getting a bit grabby near the bottom of the prior vases...but, if there is anything this hobby teaches you, its patience.

FWIW, the hollow master is 1/4" cutter, and the bar is 3/4" wide with a flat bottom so it won't twist when cutting. I haven't used it yet, just bought it, but I picked that one up because it seemed large enough to handle a vase this size and a bit larger. I am not not sure if it will actually fit a small vase with a small neck like this... I do have some ~6x6x12" vase blanks to turn, and one is actually 5x5x16", and I think I have another that is a bit longer than 12". The latter I will need bigger tools, for sure. For the 12" blanks, with a bigger chuck, I figured there would be a 1" or so loss just to truing the top and bottom and cutting the tenon, and maybe a bit more once I've fully shaped the neck. Then depending on the thickness of the walls, I think the Hollow Master will do the job, although I may have to leave the base a little thick. I guess it may not be optimal...but I'm still a beginner and this stuff is mostly just learning ATM. ;)

I do have some longer blanks, and I will probably need a better cutting system for hollowing those. I checked out the Lyle Jamieson system...very intriguing! The laser system sounds...well, kind of sounds essential. I've never quite been able to get calipers to give me a useful reading, and a lot of the time with these smaller vases I haven't been able to get the ones I have to even fit through the neck properly. A laser system would be so useful. He also has a DVD that covers hollowing techniques, and I may just get that to start. I've been sitting on these bigger blank for months and months now, as I haven't had the nerve to try and turn any of them yet. The Sorby Hollow Master was my first foray into a tool big enough that I thought I could actually turn one of them. I think I'll give it a try on the smallest blank, just to see if I can start developing some proper hollowing technique with that style of cutter. The EWT hollowers are fine for more small bowl-sized hollow forms or small vases like the one here (that I've totally botched!!), but they do get a bit grabby 5-6" or so in.
 
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On the next one - @Bill Boehme diagram. You can leave a mass of wood until you hollow to the depth. Then turn the outside.
also if the tool rest is too low the vibration increases a lot When hollowing.
cutting a little above center will make a huge difference from citing a little below center.

Thanks for the tip! I will give it a try once I get things going again.
 
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To salvage the project, I would flip the piece and locate the top OD in a chuck, or locate the center with a cone drive center, just a choice depending how it looks. Turn off the bottom part and cut a new tenon. There will be enough material to support hollowing the vase and finishing it I think.

unfortunately I dont think the Hollow Master will provide much depth capability due to it being a 1/2 shaft. That cuts the bending strength in 1/2. It might be good out to 4-5” depending on the material. As mentioned a full 3/4” dia can go 10 maybe 12” depending on material.

Lyle’s videos are very good and helpful. He doesnt like chucks, they have worked fine for me. He provides a lot of important info without getting technical.
 
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To salvage the project, I would flip the piece and locate the top OD in a chuck, or locate the center with a cone drive center, just a choice depending how it looks. Turn off the bottom part and cut a new tenon. There will be enough material to support hollowing the vase and finishing it I think.

unfortunately I dont think the Hollow Master will provide much depth capability due to it being a 1/2 shaft. That cuts the bending strength in 1/2. It might be good out to 4-5” depending on the material. As mentioned a full 3/4” dia can go 10 maybe 12” depending on material.

Lyle’s videos are very good and helpful. He doesnt like chucks, they have worked fine for me. He provides a lot of important info without getting technical.

Hmm, it looks to be 3/4" to me, or about 1/32nd short:

Hollow Master Dimensions-1.jpg

Its only got ~8" of reach anyway, though, and the total length is about 23-24"...so, it wouldn't get any deeper than 8" tops even if I wanted it to.

Hollow Master Dimensions-2.jpg

Hollow Master Dimensions-3.jpg
 
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To salvage the project, I would flip the piece and locate the top OD in a chuck, or locate the center with a cone drive center, just a choice depending how it looks. Turn off the bottom part and cut a new tenon. There will be enough material to support hollowing the vase and finishing it I think.

So, the outer diameter of the top is definitely not true...and the center that I could locate isn't true either... Wouldn't both of those issues make using these approaches ineffective? I don't think I could turn a tenon that was true to the current shape of the vase right now...and if I just turn some new tenon on, I'm gonna have to turn down the vase a good deal to get the whole thing true again to the new tenon...
 
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To salvage the project, I would flip the piece and locate the top OD in a chuck, or locate the center with a cone drive center, just a choice depending how it looks. Turn off the bottom part and cut a new tenon. There will be enough material to support hollowing the vase and finishing it I think.

unfortunately I dont think the Hollow Master will provide much depth capability due to it being a 1/2 shaft. That cuts the bending strength in 1/2. It might be good out to 4-5” depending on the material. As mentioned a full 3/4” dia can go 10 maybe 12” depending on material.

Lyle’s videos are very good and helpful. He doesnt like chucks, they have worked fine for me. He provides a lot of important info without getting technical.
I just found Carter's Hollow Roller system as well...also looks pretty nice. They say up to 12" hollowing with their normal bar, 18" with their large bar.

Looks like these systems are between $400-500, and I am sure I'll need a steady-rest as well once I start trying to hollow things that large. I was looking at Ron Brown's Steady Rest 2, as I have his longworth chuck. I noticed Carter has one as well, but its over twice as much, even though it looks like it may technically be more flexible/versatile.
 

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Hmm, it looks to be 3/4" to me, or about 1/32nd short:

It's 18 mm, but everybody on this side of the pond calls it ¾ inch.

Its only got ~8" of reach anyway, though, and the total length is about 23-24"...so, it wouldn't get any deeper than 8" tops even if I wanted it to.

You wouldn't want any additional overhang for hand hollowing unless you're really experienced because the mechanical advantage is in the wood's favor if you go much deeper with hand hollowing. Don't ever let the cutter drop below center or you'll lose control.

There aren't any "failures" if you turn them into learning experiences. It may be purely academic at this point, but you could put the piece between centers to create a new tenon. If you have a live center with a large cone, put the cone on "backward" so that it goes over the exterior of the top of the vase.
 
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Agree with @Bill Boehme , its a learning experience. Try things. Those that dont work provide valuable knowledge.

The much more important dimension of the shaft is the vertical dimension, 90 deg from your measurement, as it is the axis force is applied. That shaft is only ~ 3/8” thick in that axis. It would be much stiffer rolled 90 deg, tho its not designed for that orientation.

Your tenon will be centered by your choice of live center positioning. Yes the piece will need to be trued the entire length, not much at the tenon end, and the top depending on whether you choose ID or OD to center. I would center the top on the OD possibly as Bill suggests. The offcenter ID can then be cut out. The piece will be more rigid allowing the middle to be cut out.
 
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If you really don't want to abandon this piece of wood, I would do as others have suggested. Use tail support and cut a new tendon in the waste area. Then remount, true things up and cut off some of the top. How were you planning to get the hollow master to the bottom of the vase? G3 chuck? I would buy a larger chuck with at least 100mm jaws for your future projects.
 
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I agree, at this point you could give up on making a vase and experiment on how to solve the re-centering problem.

Also, there have to be at least 6 or 8 steady rests on the market and at least that many hollowing rigs. So make sure you've had a good look around before you pull out the credit card :) . And there's build your own options as well.
 
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If you really don't want to abandon this piece of wood, I would do as others have suggested. Use tail support and cut a new tendon in the waste area. Then remount, true things up and cut off some of the top. How were you planning to get the hollow master to the bottom of the vase? G3 chuck? I would buy a larger chuck with at least 100mm jaws for your future projects.

If I can salvage it, I'd like to. As Mark mentioned, though, even if I can't, its good practice with recentering a piece.

A larger set of jaws is planned. I do have a larger Record Power chuck (bigger than the G3, maybe not quite as large as the Nova Titan, but definitely bigger than the G3), but it still has 50mm jaws. It looks like they have something they call 100mm deep gripper jaws. They also have 75mm heavy bowl jaws. The 100mm can range from 94-114mm internal grip around a Tenon...and I'm guessing that a 100mm tenon would be optimally sized for maximum contact with the jaws.

As for hollowing this particular piece...I was going to experiment with the Sorby hollower, but the main plan was to use the EWT hollowing tools, which I've used several times before on similar vases. Based on my research, I am quite sure the cutter design on the Sorby hollower will be superior at cutting wood out of a hollow form, but for smaller vases like this I've been using the EWT tools and they work well enough.

Don't worry, though. You guys have convinced me I need a better hollowing system. ;) I need to do some research before I buy one, but I'll have a proper hollowing system before I try to turn any of the larger vases.
 
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It's 18 mm, but everybody on this side of the pond calls it ¾ inch.



You wouldn't want any additional overhang for hand hollowing unless you're really experienced because the mechanical advantage is in the wood's favor if you go much deeper with hand hollowing. Don't ever let the cutter drop below center or you'll lose control.

There aren't any "failures" if you turn them into learning experiences. It may be purely academic at this point, but you could put the piece between centers to create a new tenon. If you have a live center with a large cone, put the cone on "backward" so that it goes over the exterior of the top of the vase.

Thanks for the encouragement. I do want to try to salvage it... I don't think I have a live center like you are talking about. I do have one of those standard 60 degree live centers, but I don't think that is what you are referring to. If I understand correctly, you are talking about one of these:


I was looking at these before, and I had some people warn me off of both the OneWay and the ... Savannah I think it was? The EWT is a lot more expensive, but they all seem to be exactly the same design, so I'm not really sure which one to get. Seems like these are much more versatile centers, for sure, but the warn off of OneWay was pretty hard (which surprised me, as I've heard great things about their lathes).
 
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So, the outer diameter of the top is definitely not true...and the center that I could locate isn't true either... Wouldn't both of those issues make using these approaches ineffective? I don't think I could turn a tenon that was true to the current shape of the vase right now...and if I just turn some new tenon on, I'm gonna have to turn down the vase a good deal to get the whole thing true again to the new tenon...
Jon, I probably wasn't very clear in my comment, but this is what I thought I said. Center on the drilled hole. You can do this one of two ways. 1) A cone center in the tailstock will center the hole and then tighten your chuck (it won't match your tenon) and use it to drive your piece to form a new tenon (on the vase portion)..... or, 2) Reverse mount by centering the hole at the headstock (with a dead center, a turned plug or tenon, etc., to drive it) and center it at the tailstock. You do always have a center divot don't you?....or you can get very close by eyeballing it. Form your new tenon, etc., .......

YES, you will have to turn down your form a bit to true it up! You may not like the end result or even survive your repair attempts, but as others have said - think of this as a learning experience. ;)
 
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Jon, I probably wasn't very clear in my comment, but this is what I thought I said. Center on the drilled hole. You can do this one of two ways. 1) A cone center in the tailstock will center the hole and then tighten your chuck (it won't match your tenon) and use it to drive your piece to form a new tenon (on the vase portion)..... or, 2) Reverse mount by centering the hole at the headstock (with a dead center, a turned plug or tenon, etc., to drive it) and center it at the tailstock. You do always have a center divot don't you?....or you can get very close by eyeballing it. Form your new tenon, etc., .......

YES, you will have to turn down your form a bit to true it up! You may not like the end result or even survive your repair attempts, but as others have said - think of this as a learning experience. ;)
Ah, I see. I can give that a try...but, I think the drilled hole is also off-centered, as when I first started it, I did not realize at the time that the whole thing had already been thrown off center (at the time, the piece was spinning true...or, at least, I thought it was). I drilled a couple of inches, then was switching to a larger bit. Couldn't get it to bite properly, so I was going to try and clean up the surface of the top, and that's when it vibrated like crazy and shifted in the chuck.

So if I use the currently drilled hole, I think its off-center enough that I might not really have any neck left once I get everything trued up... I wonder if it may just be best to chop off the top of the neck entirely, before I try to do any of this...
 
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