Breadboard Ends Oak Cutting Board

[hbmcc]

Correct, regarding the through tenons. I am hard on wood anyway via dishwashers, so have gone to plastic.

[Strokes77]

Well I can't take credit for the design, it's a Paul Sellers project.


That should help get this party started...

[Derek Cohen]

Did you execute his design exactly? I pointed out earlier that the tenons would need to be closer to the centre and leave the outer thirds free to move.

Regards from Perth

Derek

[DarrenBrewster]

They were closer to the centre in the board that PS made, based on a cutting board from the kitchen at the castle where his shop used to be located.

[Strokes77]

Same distance from center.  His board was overall larger.

And for the record. I'm not trying to be argumentative, and I don't know one way or another if this cutting board will last 1 season or a lifetime.

I'm just trying to add some content to this site. There hasn't been much activity lately.

thanks for all your thoughts.

[Derek Cohen]

Same distance from center.  His board was overall larger.

This is an educational thread. Please do not take it as a criticism. Your breadboard was beautifully crafted.

Here is the breadboard end of Paul Sellers ..

<img src="http://i13.photobucket.com/albums/a262/Derek50/Joints/Breadboard%20end/breadboard%20end_zpstjgwlet4.jpg" border="0" alt=" photo breadboard end_zpstjgwlet4.jpg"/>

I would argue that he has left at least 30% at each side of the tenon. This is different from your own dimensions, where there is no more than 20%.

Here is the most recent breadboard end I built ...

<img src="http://i13.photobucket.com/albums/a262/Derek50/Joints/Breadboard%20end/TopOfTheWorldToYou_html_m48dfe2d4_zpsx3y9dnpt.jpg" border="0" alt=" photo TopOfTheWorldToYou_html_m48dfe2d4_zpsx3y9dnpt.jpg"/>

The tenon is captured by a drawbore pin in the centre only. All the other tenons are captured by pins (not drawbore pins) in slots to permit movement.

Regards from Perth

Derek

[Rob Young]

Same distance from center.  His board was overall larger.

And for the record.  I'm not trying to be argumentative, and I don't know one way or another if this cutting board will last 1 season or a lifetime.

I'm just trying to add some content to this site.  There hasn't been much activity lately.

thanks for all your thoughts.

The red oak will be just fine for cutting up "dry" things.  Maybe not the best choice if you plan on butchering hogs on the kitchen counter, but bread and cheese and the like is fine. Keep it clean and oiled and it will work.

I'd also be willing to bet it lasts a long time if not submerged. Sure it is generally preferred to have bereadboard joints move out from the center. But yours is close enough for such a small joint. 

Just watch what it does with time and go make more stuff, learning each time.

[Paul-in-Plymouth]

This is a nice thread with very interesting comments about your very nice cutting board.  Thank you for starting it.  

If I understand you correctly, you are saying the dimensions of the central tenoned-and-pinned part of your board are the same as the corresponding part of Sellars’ board, but that Sellars’ board happens to be wider outside this constrained portion.   Seems to me, then, that your design should be about the same as Sellars’ with respect to seasonal stresses on the central board.  

The dimensions of the constrained part should determine the stresses for given seasonal variation, not the dimensions of the unconstrained part, assuming the “unconstrained” part is truly unconstrained and free to expand and contract.

In a way Derek is saying the same thing, but his focus on the relative sizes of constrained and unconstrained parts seems a bit misleading.  The actual size of the constrained part is what’s most important.

I share concerns voiced by some about the big pores of red oak retaining water and food scraps, especially of things that can spoil, but I suspect it will work just fine and last a long time if used carefully.  

The wood working is very nicely done!  Thank you for posting it.

[Derek Cohen]

In a way Derek is saying the same thing, but his focus on the relative sizes of constrained and unconstrained parts seems a bit misleading.  The actual size of the constrained part is what’s most important.

No, that's incorrect Paul. What is relevant is the ratio of the contrained and unconstrained sections. The complete section must be free to expand. It is the size of the unconstrained areas that permit this.

Regards from Perth

Derek

[Paul-in-Plymouth]

Derek,
Sorry, but I don’t quite see it.  I’m not a mechanical engineer, and my view of things may be too simple-minded.   But it seems to me in this Sellars-Strokes77 design  the mismatch from seasonal expansion and contraction is confined to a central “rectangle” of sorts defined roughly by the 4 tenons and 4 pins that attach the ends to the main body.  

Seasonal mismatch is a given of the design.  If the constraining rectangle is small, the stresses may be small enough to be tolerated.  If not, then the constrained piece may crack.

Outside that constrained area, the “wings” are free to expand and contract unconstrained by hard attachment to the grooves they ride in.  In that case, I don’t see how the size of the wings, absolute or relative, matters at all.  The wings move to accommodate expansion and the stress in the wings remains zero.

This neglects stray glue, friction and other secondary interactions that might arise, but as I said, my view is pretty simple-minded.

In your nice cabinet top, the hard constraining attachment you describe is 2-point, not a rectangle.  As a result, you accommodate the mismatch entirely, again neglecting friction etc. associated with your slots.  Essentially your top is all “wings,” as I see it, pinned in the middle.  

But you know that; that's why you made it that way.  I doubt we disagree about anything here except maybe how to describe it.  That said, I do not understand why you say the ratio is important.

Paul