Why true a tenon??

[Denis Puland]

Hi all
I see quite often comments made about truing the tenons before remounting roughed out pieces that are warped and dry.

I use a Oneway Tallon chuck and never true the tenons on my roughed out pieces.
I have absolutely no problems with the holding power or the ability to adjust the position of the piece in the chuck to achieve a reasonable trueness of the warped piece.

In my opinion it seems like a lot of wasted work to fiddle with truing a tenon.

I interested in the reasons why and how many of you do or do not true the tenons.

Denis

[Ron Drew]

Well, the reason for truing the tenon is that it is likely no longer round. And while the chuck may hold an out of round tenon OK, it surely would be more secure when trued. As far as being a lot of work, it takes me maybe two minutes to place the inside of the bowl against the chuck jaws, bring up the tailstock to the center mark left when roughing out, and true the tenon. Just makes sense to me.

[George Guadiane]

Well, the reason for truing the tenon is that it is likely no longer round. And while the chuck may hold an out of round tenon OK, it surely would be more secure when trued. As far as being a lot of work, it takes me maybe two minutes to place the inside of the bowl against the chuck jaws, bring up the tailstock to the center mark left when roughing out, and true the tenon. Just makes sense to me.
I would agree, another point is if you take the out of round tenon out of the chuck again, before being finished, it will be MUCH harder to get the piece trued up if the tenon isn't true (IMHO).

[Steve Schlumpf]

Denis - I also have the Talon chuck and know that while I can crank it down on a roughed out tenon it is only really grabbing on 2 sides! Truing up the tenon allows the jaws to grab all of it - not just the warped edges. Also, during the time that I true up the tenon I also re-work the bottom and outside of the bowl or hollow form so I have the final form to work with. Hope that helps.

[Barry Elder]

My 2 cents is that if the roughed out bowl has warped, the tenon has warped. I like to work with a round tenon like I started with.

[Dennis Peacock]

IMHO??? Try turning a 20" blank with only 2 jaws holding it in place.!! :eek:
Talking about "pucker factor"!!!

Safety, for me any way, make the tenon round, mount securely, and have fun turning. ;)

[Nathan Hawkes]

Well, I don't have a talon, I (embarassingly) have a barracuda 3 chuck, and it does NOT hold well when you don't true the tenon of a warped dry rough out. Learned that the hard way last night. using the 3.5" or so large jaws on a 14" x5" cherry bowl. I thought it was on there really good, and had it all finished, just using a scraper, then I had one not even all that bad catch, and off it went, splitting into four or five big, and a dozen or so small pieces as it went. I didn't find all of them. Oh well. Was supposed to get a good penny for that bowl and others for a set....I'll be truing them on either a jam chuck or the longworth one I made.

[Alan Tolchinsky]

I wondered about out of round tenons also but didn't have a clue as to how to correct. Now I have an idea but still don't know exactly how to. I don't see how the chuck inside the bowl can rotate it. From past experience I feel I must be missing something here. :rolleyes: Can somebody clarify this some more?

[Bernie Weishapl]

I just put the inside of the bowl against the chuck jaws, bring up the tailstock to the mark from the roughing out session and true up the tenon. Don't worry about the inside of the bowl because it isn't finish yet anyway. Once the tenon is round plus the outside curve is true turn the bowl around and finish turning. I want my tenon trued up so my bowl will be true and the main thing is that all of the chuck jaws make contact with the tenon. I don't like pucker factors at all. :eek:

Alan the pressure from the tailstock holding the bowl against the chuck will be enough to true up the tenon. Just take light cuts and don't try to hog off to much at a time.

[Steve Schlumpf]

Alan - example of what I do is: Talon chuck with #2 jaws, open the jaws out to almost max, place bowl over the jaws and snug in place using the tailstock. There is enough friction there to turn the bowl and allow you to true up the tenon and re-shape the outside curve of the bowl. Try it - it works!

[Alan Tolchinsky]

I get it and will try it with the next bowl. These chucks are even more versatile than I ever thought. Thanks again for opening my eyes. Alan

[Tom Sherman]

Alan it works on the friction principle, if you are concerned about marring the inside you could always turn a soft radius on a piece of waste wood put that in your chuck and pad it with something soft then use the same process, it works like a charm. As has been mentioned don't try to take too heavy a cut.

[Alan Tolchinsky]

Hi Tom, Thanks for the tip; that makes sense. Alan

[robert hainstock]

Another thing to equate is that not all woods dry the same and some will be more out of round than others. The more oval they are the better your chances of getting bonked. :eek::eek::eek:
Bob

[Matt Hutchinson]

I use a lightly different method. If, for some reason, the chuck jaws create dents a little deeper than you prefer, make a "reverse bowl". I have a dedicated faceplate which holds a rounded, hemispherical piece of wood with T-shirt material stretched over it. It was originally designed for reversing nearly finished bowls, but I use it for truing tenons as well.

And another thing: Sometimes, if a bowl is REALLY out of round, I chuck the oval tenon, cut the inner bottom of the bowl so it is a circle again, then reverse it to true the tenon and foot. This helps immensely! It is much easier to true a large bowl's outside form all the way to the rim. When I haven't done this on large work, the bowl sometimes moves slightly, even with light pressure near the rim. Then I chuck it using the newly turned tenon and finish the inside.

It's still basically the same process. Yes, I too have found truing tenons to be essential.

Hutch

[Denis Puland]

Thanks for all the in put.
I have listened but I am still not sure I will do.

I have turned hundreds of bowls etc and have yet to get bonked.
So according to odds perhaps I should buy some medical insurance.

I thought perhaps I was not alone on this but It sounds like I is a black sheep::)))

Thxs again, Denis
PS: Perhaps my experience would be good advertising material for the Tallon chuck::))

[David Wilhelm]

I also NOW true my tenons I may not cut them very deep but i true them Up. I ONLY use ONEWAY chucks it's all I own. I have a talon and a strong hold. I've launch two bowls because of small untrue tenons and not at all the fault of my chuck. When i made my first bowls I didn't turn them around I started them on a face plate and parted them off and i was done EOS. I've grown very picky now. Not only do I true my tenon but i also recut/shape my foot. I'm very picky about how my foot looks on each bowl I make more so than the bowl itself. Point being if they like the bowl enough to pick it up and look at the bottom they then will see my name. I want the foot perfect. I do most my work with friction have yet to built the do-nut that i keep putting off and the jumbo jaws get on my last nerve. They are your bowls Denis you do what ever makes you feel happy and proud of your work. We all see people doing things and wonder why. Now you know. Keep cranking them out!!!