Chair tenons

[bill howes]

A recent post on measuring chair tenons suggested the need for digital calipers. Subsequent discussion of calipers with accuracy to 1/128 inch or less would be warranted.
Seems to me that unless one was looking for an excuse to buy a new tool that this is a bit excessive.
In fact if one were to amortise the cost of the caliper over the number of chairs that most of us are likely to make allowing for average age and productivity its a bit over the top.

A suggested alternative
Drill a mortise in two halves and with an an appropriate reamer make two halves of the mortise. Subsequently cut one of the halves to an appropriate length ( making sure you cut off the correct end)
As you turn the tenon this piece can be used to test fit.
For compulsive turners rubbing the inside of the test piece with a pencil can be used for fine tuning but with the tapered tenons its probably excessive.
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Best wishes,
Bill Howes

[Mike Holbrook]

The more popular iGaging digital calipers cost $20 to $45 on Amazon, which does not seem excessive to me. From what I have read on the subject there are quite a few uses for digital or dial calipers other than making chairs so I doubt anyone buying one would use it just for chairs. In my experience turning tenons for the chair I made recently, a digital caliper would have been more helpful for me. I found it hard to tell how much more I needed to take off using a device that would only slip over the tenon when the exact size was reached. With a digital or dial caliper the actual diameter can be measured as the work progresses, providing an exact amount that still needs to be removed. The standard method for making a tapered tenon involves using a parting tool to make two different 1/8+" grooves to the depth required on each end of the tenon, leaving only the waste between the two grooves to be removed. The jig mentioned, wrenches etc. do not fit in a 1/8" groove, a digital caliper does.

[bill howes]

Hi Mike
I had no intent to offend. I meant to offer an alternative that I have found to be more useful for sizing the tapered leg tenons.
Similarly for spindles or splats I use a scrap with appropriate sized holes to size the tenon ends on these.
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As long as the parts all fit together I guess that's what counts
Bill

[Bob Glenn]

Bill, instead of throwing that nice spoke shave out with the shavings, send it to me! I'll even pay for the shipping. BTW, did a motorcycle tour of Nova Scotia last fall, and was in Halifax. Beautiful up there. Didn't like some of the prices though, 24 dollars for 12 PBRs at the package store? Cheers! Bob

[Winton Applegate]

amortise
. . . ohhhhhh man . . .
that is one of those take the fun out of it words or phrases. For sure.
Like "speed limit" , "bed time", "income tax form", "light beer"

I wonder if the last guy who bought a Ferrari 250 GTO amortized the cost against his work commuting budget ?
Let your pants down and live a little . . . er . . . I mean let your hair down . . .
. . . well you know what I mean.

[Jim Koepke]

The jig mentioned, wrenches etc. do not fit in a 1/8" groove, a digital caliper does.

Some wrenches will fit:

310716

Cone wrenches are thin wrenches used in working on bicycles.

Hilton will love that they are mostly available in metric. I haven't seen them in inch sizes.

These are a little less than 3/32" thick. The 13/14mm is from my bicycling/mechanic days of 40 years ago. The 16mm was bought at a bicycle shop while employed at a public transportation system for a specific purpose and one end was cut off and the ends ground to fit into a tight place. When it was shown to my supervisor whom I had been pestering to purchase such a thing he casually commented that he had gotten some and just hadn't gotten around to handing them out.

Sometimes creativity has to step "outside the box" and look in places we may not have looked in the past.

jtk

[Winton Applegate]

Campagnolo
OHHH YAHHH !
Campannellie :D

Good point.


he had gotten some and just hadn't gotten around to handing them out.
Special breed aren't they ?

[Jim Koepke]

Campagnolo
OHHH YAHHH !
Campannellie :D

Good point.


Special breed aren't they ?

At one time there were quite a few Campagnolo tools in my bag. Now just a few that were saved for their usefulness, my 6mm hex/8mm socket Tee wrench still gets a lot of use. A friend of mine who was more of a tool pig than me at the time got most of them.

Though this was at a time before plastic jars made it practical to carry a jar of peanut butter in ones saddle bag and gave the crank bolt wrench the "peanut butter wrench" moniker.

Yes, too many of the folks in charge are of the same breed. We would have machines out of service all over the place because some boss was sitting on replacement parts or paperwork.

Knowing about a slack attitude toward paperwork by one of my bosses saved my bacon big time when it was most needed.

My ambitions never turned toward management. I hate paperwork and bean counting which seems to be all management is about other than a bigger paycheck.

jtk

[bill howes]

Bill, instead of throwing that nice spoke shave out with the shavings, send it to me! I'll even pay for the shipping. BTW, did a motorcycle tour of Nova Scotia last fall, and was in Halifax. Beautiful up there. Didn't like some of the prices though, 24 dollars for 12 PBRs at the package store? Cheers! Bob

Bob,that's why we make our own jigs!Bill

[bill howes]

. . . ohhhhhh man . . .
that is one of those take the fun out of it words or phrases. For sure.
Like "speed limit" , "bed time", "income tax form", "light beer"

I wonder if the last guy who bought a Ferrari 250 GTO amortized the cost against his work commuting budget ?
Let your pants down and live a little . . . er . . . I mean let your hair down . . .
. . . well you know what I mean.

Winton-amortise is where you put atenon,
Bill

[Winton Applegate]

Though this was at a time before plastic jars made it practical to carry a jar of peanut butter in ones saddle bag and gave the crank bolt wrench the "peanut butter wrench" moniker.

If you ever had a team/repair shop size campy grease bucket sitting in front of you and an empty bench size/home size grease pot sitting next to it . . . . that paddle handle is a natural for digging out grease and transferring it to the little empty pot. Much better than a spoon or what ever else one might have tried in the past. Dhosguyeyes always thinkin'.

My mentor had a full on Campy tool chest (all the frame machining tools) and had the handles cut off and machined to screw into the drive shafts so he could fit everything into a Gerstner chest. When he was killed too early in life his widow gave it to one of his other best friends though I would have put it to more use. Loosing his companionship was probably the worst thing that ever happened to me.


machines out of service all over the place because some boss was sitting on replacement parts or paperwork.

You left out the classic gambit : While banging heads and saying we need to be more efficient and do more and to stop working so slowly.

PS: Ha, ha, ha, Queenmasteroftheuniverseandbabybunnytrainer just said something to me (I haven't had the courage to ask what she means but I am already considering having a T-shirt printed with it on it and or changing my slogan below) . . . she said "Don't be alarmed . . . it's just the snow peas". :confused: :eek:

[Winton Applegate]

Winton-amortise is where you put atenon,

"atenon"
That's that new particle they are working with at CERN . . . right ? :confused:
Probably be a while before Queenmasteroftheuniverseandbabybunnytrainer lets me have one to play with. Still clearing the debris from the last particle collider anomaly. I could have swore I had the vectorial pornoscoptics spot on . . . must have been a problem with the canoooter valve regulator calibration . . . that's always a tricky bit.

Anyway . . . thanks for telling me where to put it.

PS: ha, ha, ha duh . . . I just got it . . . :o:D;)