How much weight can the DF700 connectors hold?

[aaduranh]

Hi,

I need to attach heavy legs to a table top.  Each leg is 28" x 28 3/4, 3" 1/8 thick. It is in hard maple. Each leg is around 80 pounds. The top is 72" x 36" 1" 1/4 thick in maple too.
If i use around 6 DF700 connectors in each leg, would the connectors be strong enough to hold the legs to that top?

Thanks
Alex

 

[tjbnwi]

I can't answer the question directly, but....

When I first got the 700 kit we did a few test mock ups, we could not pull the expanding piece out of the mock up after removeing the center post, we had to cut the wood away from it so we could reuse the insert (I'm to cheep to waste the pieces).

If you're wondering if 6 of the connectors in the leg will hold it to the top it when the table is lifted----my guess is yes they will.

Tom

 

[aaduranh]

I would have done the same thing

Let's hope someone put the df700 connectors to the extreme.

 

[mwolczko]

A while ago I looked but could not find any published specs on the strength of the connectors.  If anyone has a source I’d love to see it too.
In any case I went ahead and built an outdoor sofa using connectors and it feels solid to me (and has stayed solid for the ~2years it has been used).

For your table, are the connectors carrying the weight of the top, or is that being transferred directly to the material of the legs?  If they’re not carrying the weight, but being used to prevent racking, then I would think they will suffice. For my sofa I recessed the seat members into the armrests so that the connectors were not carrying the weight, just providing tension.

Also, be sure to consider any cross-grain wood movement that may occur.

 

[aaduranh]

The top would be seating on the end grain of the leg.

Let's say i would have to move table. The connectors would have to carry the weight of the legs attached to the top.

I know some people do beds with the connectors. They have to take the weight of two people. I imagine they are good enough. Does it make sense?

 

[mwolczko]

Should work fine — I would guess the pulling force needed to remove one of these connectors is measured in hundreds of pounds.

 

[Cheese]

They always use wood Dominos along with the removable ones. Here's a photo from the printed Festool connector catalog. Read the TIP in the lower RH corner of the page. 

If you're going with 6 for each leg I'd probably do 4 wood versions and 2 removable versions.

Let us know how that works. [smile]

[attachimg=1]

 

[tjbnwi]

They always use wood Dominos along with the removable ones. Here's a photo from the printed Festool connector catalog. Read the TIP in the lower RH corner of the page. 

If you're going with 6 for each leg I'd probably do 4 wood versions and 2 removable versions.

Let us know how that works. [smile]

[attachimg=1]

Their examples are in shear, the question posed here is for pullout.

I do agree, six is probaly over kill, I'd start with 2 connectors, one on each "inside face", 2 normal Dominos on the "visible faces".

Tom

 

[aaduranh]

I need to attach those legs to the table top. This not exactly my table. My table is in maple.

I am sorry i should have started with the picture ;D

 

[tjbnwi]

I need to attach those legs to the table top. This not exactly my table. My table is in maple.

Are the legs solid or hollow?

Tom

 

[aaduranh]

super solid hard maple!

 

[tjbnwi]

super solid hard maple!

Each leg weighs ~65-1/2 pounds (using the dimensions you posted).

I'd put 2 connectors on the long sides of each leg (4 per leg), about 3" in for the sides. Centered I'd place 2 Dominos, these will aid in alignment.

I suggested inside only in a previous post due to the covers for the set screw access mortices, there are covers that are very close to maple color. You could fabricate your own plugs for the visible side.

Tom

 

[aaduranh]

Thanks a lot for your help.

Just to make sure that I understood. you would install the connectors only in the inside of the leg, nothing on the outside?
Creating my own maple plugs is a great idea!

Thanks a lot

 

[tjbnwi]

Thanks a lot for your help.

Just to make sure that I understood. you would install the connectors only in the inside of the leg, nothing on the outside?
Creating my own maple plugs is a great idea!

Thanks a lot

For even load lift, install 2 inside, 2 outside.

Tom

 

[Jim_in_PA]

As in Cheese's reply in post #6, I used them for a Twin-XL over Queen heavy bunk bed setup recently and I have no concerns about strength. The connector plus two 14mm Dominos can support a whole bunch of weight and the design of the connector brings the joint in very tight. If the materials are cut true, that fully engaged surface to surface touch adds to the stability of the joint, too. Most of the weight of the joint is borne by the adjacent 14mm dominos...you don't often use "just" the connector in the joint.

 

[tjbnwi]

Now I'm wordering if one on each end would suffice??? Regular Dominos on the long sides?????

The connectors are only there for when the table is lifted.....hummmm.

Tom

 

[Cheese]

Ya, my thought was that any lateral loading to the table and consequently through the legs, would be transferred to and carried by the wood Dominos, while the D14 removable Dominos would maintain the tightness of the joint and facilitate lifting the table and moving it.

 

[Michael Kellough]

Straight withdrawal resistance is not the concern. A couple fittings per leg are sufficient for that.

The powerful leverage the non-aproned legs possess is what you have to resist. What happens when someone leans into the end of the table or the movers set one end down too abruptly?

I’d use a minimum of four per leg but probably twice that, placed close to the long faces of the legs.

If the mechanical fittings weren’t available your best joining method would be wedged through tenons (3 or 4 per leg) the full thickness of the leg (3 or 4 inches?).

This merits full scale testing. The mechanical replacement should be equally strong but I don’t know how many fittings that would require.

 

[Birdhunter]

I’d worry a lot more about the table racking and snapping off the legs.

 

[Bob D.]

I’d worry a lot more about the table racking and snapping off the legs.

A single stretcher up high, maybe 5 or 6 inches tall, and down the center of the table
would mitigate that concern, and not detract from the look of the table, at least for me.