Dining table design

[gasman]

A friend has asked me to copy this table for them

They want me to alter the sizes etc of a design from an italian company called casamiliano http://www.casamilanohome.com/home/index.php?mod=20_fncommerce/00_Prodotti&op=view&pid=113
I have produced a version on sketchup which they approved - it is 1900 x 900.

The casamiliano table top is 50mm thick and is a manmade board veneered board. My friend only wants the top to be 32mm tapered at the edges (as shown this is tapered to 16mm - it will probably be more like 24mm) and want the whole thing to be solid wood (actually beech).
The 2 pairs of legs are attached with M8 bolts I imagine into some kind of metal frame within the table top - which I will not be able to do - but I was thinking I need to get some metal plates maybe 10mm thick which I would then use to screw up into the table top to minimise the chance of the table racking under pressure. Any one any better ideas? Is there a metal female part I can embed very robustly into the bottom of the table somehow to receive a bolt?
Thanks for any help
Cheers mark

 

[gasman]

Major blank in my head this morning - couldn't think of the name of the product - what I am talking about is a threaded insert I think?? So I guess my question is whether 25mm M10 threaded inserts would be strong enough when in solid beech to prevent my table design from racking sideways??
Thanks for the advice
Mark

 

[Racers]

I think what ever you do you will have problems, its not a stable design.

Looks like the legs are connected to a metal plate which is bolted to inserts in the top, which is probably the best way.
The problems I can see is bolting the legs to the plate and then bolting the plate to the top, the screw in inserts should be o/k in a solid top.
You might be able to use the same ones to connect the legs to the plate if you can get 3 in each leg top or 2 diagonally to help the stability .

Pete

 

[Random Orbital Bob]

T-nuts is the name of a threaded insert you hammer into a slightly smaller hole than its diameter. It has hook type things on the outside to help it get purchase in the hole. Used for casters a lot. I don't know if they do those big enough for serious bolts though. If they do I would resin it in and not just rely on a friction fit.

 

[Racers]

These are what I am talking about, 25mm long so if you can get them in they should hold.

http://www.ebay.co.uk/itm/Pack-of-20-M8 ... 4897.l4276

Pete

 

[Sheffield Tony]

Does not look like a stable table at all to me.

I'm guessing that the original design either has some sturdy metal bracketry concealed under that black paint, or it is a style over substance type design that will fall to bits quickly. You need a fitting that will not easily pull out with a 70cm crowbar, which is effectively what the legs will act as when someone leans on one end of the table.

You might use quite large plates let into the top, with the screw holes as far as possible apart so that they wouldn't pull out of the top. But how to fix it to the leg ? I can only think of industrial looking solutions, kind of thing used to marry together timber frame and stainless steel construction on Grand Designs !

 

[Racers]

A diagonal brace from the middle of the X up to the table top would cure 99% of your problems.

Pete

 

[gasman]

Thanks Pete - I also arrived at that conclusion today after thinking about how much leverage there is - the crowbar concept was quite a vivid one. I thought a pair of braces meeting halfway along the table underneath - one from each X. Thank you very much indeed for all suggestions
Regards
Mark

 

[gasman]

Just thought I would add a photo showing this finished - well it needs another 3 coats of hardwaxoil but otherwise finished
It went quite well - tried to match the grain and alternate the boards for the top - which is 32mm tapered to 25 all round the edge
The legs are 90mm square - at an angle of 53 degrees. The top is 1900 x 900 and 725 high
To secure them to the top, I got 2 mild steel plates, 8 x 100 x 700 and had them drilled and countersunk appropriately
Then attached them to the legs with 3 x 140mm coach bolts on each of the 4 legs
Then, after marking carefully the location of all the bolt holes on the underside of the top, I drilled 5/8" fortsner holes to a depth of 25mm - actually put a depth collar round the forester bit which worked well
Then I used a 3/4" wood thread tap to cut the thread and put 10mm threaded inserts in each hole. Then 6 countersunk 10mm diameter 30mm long bolts were used for each pair of legs. It is absolutely bombproof - very solid and I am pleased it all worked out OK in the end

Cheers
Mark