Table frame how long can i go?

[mastercabman]

I have a job that calls for a table frame to be attached to an island in the kitchen(this is new construction)
I have allready put the island together and built the table frame with 4 turn legs 3"thick x 29" tall
I used 3/4" material to make up the skirt.(witch is furniture kick plate used upside down)
The table frame is about 32"w X 78" long including the legs.So the long skirts are 72".
Now the homeowner wants to increase the size to 96" + the legs  so the table frame would be 102" long.
The 3/4" material that i used is 3.5" wide.
My question is,do you think it would be ok to have that long of a run for a table frame?
I am worry about sagging.The top will be wood but don't about thickness yet.
Do you think i should add 2 more legs in the middle of the run?

 

[jmbfestool]

Why not just screw a steel plate on the inside back of the frame full length. This will allow you to keep your frame as is but increases the strength 10fold.

Jmb

 

[tiralie]

Use the Sagulator to measure the beam deflection. This should give you a good idea how much sag or flex there will be in the top. The table I am sitting at is approx. 96" long (oval) and the frame on the outside is a good 2 1/4" thick x 3" in height. It is expandable so there is some sliding steel runners under it to allow for two sections to be added. The steel runners add to the strength.

 

[Theshipstore]

Tim  And I thought I was one of the few who used sagulator for my shelves and table tops. I think this program has saved me alot of time and money particularly with my cabinet shelving  [big grin]

Sal

 

[tiralie]

Tim   And I thought I was one of the few who used sagulator for my shelves and table tops. I think this program has saved me alot of time and money particularly with my cabinet shelving  [big grin]

Sal

Sal:
Agreed.
Great time saver! Works for almost everything I need except torsion box/hollow core shelf construction. For that I use my "saggy backside" and test with a mockup.
Tim

 

[mastercabman]

Why not just screw a steel plate on the inside back of the frame full length. This will allow you to keep your frame as is but increases the strength 10fold.

Jmb

I might take on your idea.But i'm also thinking about using a thick piece of wood in the same way.

 

[Tim Morris]

I've gone over 120" on conference tables with the same leg arrangement and 3 1/2" high but I usually use 6/4 for the aprons. Just my  [2cents].

TIM