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tenon removal problems

1800 Views 29 Replies 10 Participants Last post by  Woodmaster1
2
why is this happening. when I scrape the bottom of the bowl where I took off the tenon this happens, it is a gouge in one side some time it is deeper

Brown Table Wood Varnish Hardwood

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I assume that you reversed it to turn off the tenon and smooth it? How did you mount it? It seems to indicate that you didn't get it quite flat.
I used a jamb chuck treaded on to the spindle
I used a jamb chuck treaded on to the spindle

- Karda
Yep, You are not getting it perfectly lined up. So it is off center just ever so slightly.
If you have enough bowl thickness. You can keep going till you get a good foot under it.
Of course if you are way off, your bowl would look to sit crooked. But it looks to be off just a little bit.
Probably not notice it at all.
Cole jaws help to reduce the guess work.
Yep, cole Jaws or a Longworth chuck will help a lot with that. One other option is to mount a plywood disk that you can use for your jam chuck. That will give you a flat surface to press against instead of trying to get it perfectly centered and flat on a domed one. You can mount the disk on a faceplate but if you have a chuck, you can mount a attach a round block, glued and screwed to the disk, that you can mount in your scroll chuck. It sound like you may have have a 1" 8TPI tap so you can instead tap treads in the block so that you can mount the disk directly to your spindle. Glue some rubber to the face to help prevent the bowl from slipping. You can use sandpaper instead of rubber but rubber will better protect the rim better.

BTW, there are some free instructions/plans out there for making your own Longworth chuck if you have a router.
I rough turn bowls wet. And finish turning them dry. The bowl and it's tenon dry, are out of round. Getting them to sit flat in the chuck is rare. After I finish turning the dry bowl, I remove bowl and chuck together, screw the chuck into a tail stock adapter, mount a home brew vacuum chuck, bring the bowl up to the vacuum chuck, and then remove the regular chuck from the tenon.

Now the tenon and the base of the bowl below the tenon in most cases is no longer flat to the bottom of the bowl. Like an off center turning.

So I leave plenty of wood to make the bottom flat. Or slightly con cave.
Mike, show us all how you set up to remove the tenon. After that is shown, maybe you can get better answers. You have the tools necessary to do an excellent job on removing tenons.

What i see is the bowl rim might be warped a little and not sitting flat on whatever device you are using, causing the bottom to not be square to the spindle. Like Bigjohn stated, if you have the thickness, go ahead and finish it because from what I see there isn't enough distortion to cause it to look tilted when sitting on a surface…........ Jerry (in Tucson)
I found a couple things wrong, the jam chuck threads are crooked but t it straighted as tightened down The wood is pine so might have moved some. Also i had padding a little on the face but it didn't cove the whole face so the bowl could rock a little. I tossed that one, I also found that some of the gouging is cause by the corner of the bowl gouge wing. knowing that helps some but I still have a hard time with bottoms, I can't cut smooth close to the center. What kind of picture do you want. I use what work for a jam chuck with tail stock. and tail stock stready when I get that far
I have a video for tenon removal. I couldn't bring myself to watch it, it's about four years ago and I've come a long way since, but you might get something out of it.
Phil thats not a bad video. I don't have the guts to remove a tenon as you do, besides minimum on my lath is 750 RPMs. I think a lot of my problem is bevel control, if I take care of that i won't need to scrape away from the center. still working on the off center issue. thanks for the video
Pretty much the way I do most of mine as well, except I will only go to the point right before 'separation' - that is, I will leave the smallest V shaped wedge possible, and then remove it off the lathe with a chisel or sometimes it will just snap off. Speed shouldn't be much of a concern either. That was how I did it using my old Delta which had a minimum speed of 900 rpm.

Trick is getting it well centered, so you need to leave the initial center point on the tenon, and align with the jam chuck as shown in the video. As long as it's balanced, it will be just fine and you can get down to a pretty small nub without much fear.

Cheers,
Brad
I'll try that next time
Another thought: You might switch to using a recess (mortise) for holding bowls in your chuck. I turned the recess on this walnut bowl while holding the blank between centers. After turning the bowl, I turned a plug (base) to fill the recess.

https://www.lumberjocks.com/projects/408564
Mike, why is this starting to be a problem for you? You have the Tail Stock Steady and you have gotten instruction from me on tenon removal. The only thing I can think of is you don't have enough bottom thickness and you are worried about punching through.

I'm going to head up to massatwoshiets in mid September. If you're up for a meet up, I would gladly go out of my way a little bit to help you out some. After all, the best instruction is personal instruction rather than reading a bunch of words and then trying to do what the words say. Are you up for that????? ........... Jerry (in Tucson)
I have a video for tenon removal. I couldn t bring myself to watch it, it s about four years ago and I ve come a long way since, but you might get something out of it.

- Phil Anderson - Shady Acres Woodshop
Phil, I watched your video. I commented also. I also left a link you could go to and watch.
Try it and let me know what you think through private message. ......... Jerry (in Tucson)
Definitely Jerry I am up for a visit
I know Jerry i have received a lot of instruction and watched a lot of utube videos but when I am at the lathe I can't do what they do. I can turn so I must be doing something right just no well. I have the tools just not the talent. I usually have to much bottom thickness started watching turn a wood bowl and I think my biggest problem is tool control. I was have the problems pictured from the begging I just couldn't figure ii out so asked for help. I have never ever turned with somebody watching me to criticize and thats what i need, somebody to tell what I am doing wrong when I am doing it and how to correct it. I got a n email from my turning club about what can be done to make it more interesting. one of the items on the list of thing the club does is help beginners but after club hours, it moot I can't go anymore my ride moved to the Carolinas.
I have a video for tenon removal. I couldn t bring myself to watch it, it s about four years ago and I ve come a long way since, but you might get something out of it.

- Phil Anderson - Shady Acres Woodshop

Phil, I watched your video. I commented also. I also left a link you could go to and watch.
Try it and let me know what you think through private message. ......... Jerry (in Tucson)

- Nubsnstubs
No need for private message just as there was no need to promote your overly complicated contraption on my video, Jerry.
I watched your video long time ago. My way doesn't call for anything other than what a woodturner already has on hand and has worked for me for years.
I'm all for the "you use what works for you and I'll use what works for me" school of thought.
No need for private message just as there was no need to promote your overly complicated contraption on my video, Jerry.
I watched your video long time ago. My way doesn' t call for anything other than what a woodturner already has on hand and has worked for me for years.
I m all for the "you use what works for you and I ll use what works for me" school of thought.

- Phil Anderson - Shady Acres Woodshop
[/QUOTE]

Overly complicated contraption??? Boy, you don't have a clue. The reason that O. C .C. was invented was because I used to remove my tenons exactly the same way you are promoting removing them. After 3 losses in every 10 pieces, I decided there had to be something more overly complicated, so I decided to go ahead and waste my time inventing and patenting it.

I'm sorry I didn't make myself clear when I said "Try it" after my link. That was supposed to be "Watch it", not try it. I don't need your endorsement or promotions. All I was looking for is an opinion and it looks like I got it. Thanks…....... Jerry (in Tucson)
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