Help with a joint please

[Aragorn]

Hello!!
Hope you're all well.


Please could I cheekily ask for a little help with a problem...

Here's a project I'm working on. A kitchen table that needs a knock down stretcher. This is an image of part of the leg assembly:

I hope you can make that out.

See the blue stretcher?? That needs to fix into the green rail easily and very securely, but also be removeable, so that it can be knocked down.

Any ideas what kind of joint to use?? Or ideas for some other way of attaching it??

 

[Paul Chapman]

Could you use a metal cross dowel and some 6mm threaded rod of the type sold by Woodfit? http://www.woodfit.com/product_info.php ... +20mm+long. They are very strong and easy to knock down. Woodfit also do various heads to go on the threaded rod, so they look quite neat.

Hope this helps

Paul

 

[tim]

Glad to see you are still around!

Whats at the other end of the stretcher - ie which way can it move - its not clear from the pic whether it goes up to meet the apron frame or whether it curves to to the other leg assembly. Does that make sense?

Cheers

Tim

 

[Aragorn]

Hi Tim

Yeah that makes sense!
The stretcher will be completely loose initially.
At the other end, it will actually attach to the underside of the table top itself, probably locking in place with a pivot/pin mechanism.

Don't know if you can make it out from this: (sorry - it's a mirror image of the previous one).

Hi Paul
The metal cross dowel is a solution, but it would be great to avoid a mechanical fixing if poss.

 

[Adam]

Could it be notched somehow? (The piece coming down at 45 degrees) such that it hooks over the horizontal piece?

Good to see you back with us.

Adam

 

[tim]

Quite tricky really esp since it has to rotate into position. You could do something very similar at both ends. ie put a backing block on the horizontal rail that is notched to take the stretcher and then use a wedged tenon or dowel to hold it in place:

Cheers

Tim

 

[Keith Smith]

This doesn't have to be held too securely, just as long as it can't pull out should be enough, I would have thought.

In which case I would use a loose wedged mortise and tenon, pretty simple and looks neat. May need to beef up the cross rail though?

Keith

 

[Aragorn]

Nice one Tim - I like that!

Maybe I'll combine this idea with a bit of Adam's: the stretcher piece could notch into the rail, and be pinned with a dowel as in your picture. That might help reduce any play in the dowel fitting.

Good picture, BTW. Is that Sketchup??

Thanks fellas!

 

[SketchUp Guru]

What about using a sliding dovetail? Seems to me that the table legs have a very light feel to them and it would be a shame mess that up.

 

[tim]

Dave:

I thought that too, which is why I asked about the other end of the stretcher. Could that still work with a sliding DT? I've assumed that the DT doesn't run all the way through the rail and would start at the top. I couldn't see how that would then go together but maybe I'm coming at it all wrong.

Aragorn:

Yes its Sketchup.

Cheers
Tim

 

[Aragorn]

I had thought about a sliding DT, but was a bit concerned about keeping any strength in the joint, as the DT would be in the endgrain. Seems like it could easily tear out under higher pressures.

This joint effectively supports the whole table from collapsing, so it would need to be able to take a battering!

I think the sliding tail might not last long. What do you reckon?

 

[SketchUp Guru]

I guess it depends upon how often the table would need to be knocked down and reassembled. I doubt there'd be much problem with it pulling out. consider all those pedestal tables with the three legs. Those things are assembled with sliding DTs. Granted they don't generally get taken apart very many times in their lives.

I think if you use a 14° DT bit you'd be fine. Make it stopped and haunch the tenon to fit. That would add more holding power.

 

[engineer one]

why not use an upgraded card table catch

old fashioned card tables either have a spring clip to hold the dowel,
or slid into a box shaped mortise, then you should not need a mechanical extra fixing.
another paul :wink:

 

[Aragorn]

I'm not familiar with that Paul - Got any links to let me know what you have in mind??

 

[lugo35]

hi why not run a tenon through the rail and then wedge it verticaly,pulling it tight . like you see on pine benches. obviously more ornate. not worked out how to post pics yet hope this makes sense.
andy

 

[engineer one]

not sure how i can do that will search and or draw something
quick thought however.

put a thick dowel, say 3/4 inch dowel in the support arm.
mark where it hits the table with same slightly below horizontal. then build a three sided box, two cheeks and a back. mark the mid point of the box, then route a slightly curved slot on both cheeks, the top of it should be where the table becomes horizontal.
then when you erect table you slide dowel into cheek holes, and as it goes up it makes table flat and level.
to remove, lift table top slightly and pull back strut. needs some little slack,but mechanically this will work.

next time will try with better words.
paul :wink:

 

[Aragorn]

Hi Paul
:shock: Might be a bit early in the morning for me to get my head round that Sounds ingenious, so I'll try again later..!


Hi Andy
I think the problem with a through wedged tenon is the angle of the stretcher. The grain will be running at about 45º across the cheek, and I think it would just sheer off under the stresses involved.

If it met the rail at 90º your suggestion would be my first choice for sure.

Thanks again everyone!