Needed a larger dining room table - Hallucinations

[oliver2-44 10,778]

We have 7 grandkids, so my wife "Nanny" declared we need a larger dining room table so everyone could sit together.

 

So now you know what I've been working on for the last month!

 

I did some measuring and determined a 10 ft table would fill our space.

We did some looking, but really didn't find anything we liked, and the prices were high.

she asked if we could build a granite table for less that the store bought one.

I had suggested I have some heavy antique cast iron legs and could build a metal frame for the granite.

When I calculated that a 42" x 120" granite slab   would weigh 1225 I knew this frame needed some engineering.

I had a "strength of Materials" class back in collage 50 years ago. I remembered the basis, but never used the calculations part of it. 

It occurred to me that maybe AI could help me with the calculations.  So I dug out my old textbook.

So I use the free version of CHATGPT and asked if it could do steel design calculations. Of course it answered.

I gave it the granite size and weight, the cast iron legs size and weight and asked it to design a frame using rectangular tubing.

I went through several calculation iterations, giving it more information as I remembered various inputs it needed.  I also asked it to include a safety factor in the design,

Then even asked it to do a tipping analysis of what it would take to tip it over.

 

During this process it told me it could make a drawing, build me a metal cut list, specify the welding requirements and even suggested designing some under table LED lights.

First it told me I could download this design package at a "link" that didn't work

Then it told me it could put it all on a USB and mail it to me and I pay for the USB and shipping using PayPal

I asked it for its PayPal address and it gave me a copy of the instructions of how to set up a PayPal account.

I again asked it for "its PayPal address and it finally told me it couldn't have a PayPal account because it was a computer.

 It did make a a simple sketch of the frame using  "dash" lines to draw the frame and a material cut list.

As this point I texted my techie son and he said it was having "AI Hallucinations" telling me it could do the mailing when in reality it couldn't

 

A friend from when our sons were in Scouts together has a metal roofing and light fabrication business.

I cut out the parts and laid it out on his large long flat fab table. 

I started to tack it together, but his guys are such better welders that me and they just took over.

I payed him for a days work by one welder, a great deal. 

I had access to some leftover (low cost to me)  1-1/2 x 2-1/2 11ga steel tubing. so I asked AI to use this for the design.

Cast leg  set weigh 70lb each.  its solid and heavy.

 The legs set have a 4" wide top that already had bolt holes in them.

The legs bolt onto this flat plate. I welded the nuts since you can't get to them once the granites in place.

After Sunday evening dinner with my sons and families, I had them help me haul the steel frame inside and bolt it together.  

Granite delivered and set in place by 6 guys yesterday.

After they set the granite in place, my wife exclaimed "it's Huge"

So I think I did good!

 

  I briefly wondered if I mad enough brownie points to buy another tractor- Not

 

My existing 8 ft table and chairs are going to one of my sons.   The granite guys were great, and carried it out and put it on my trailer.

 

 

New chairs are expensive these days #200 - $300 each and up.

 I came across well build commercial used chairs at Restaurant Supply Businesses.

We found a simple design we liked advertised on Facebook Marketplace and I bought 14 for $20 each.

So my next project is to sand and paint the chairs a medium gray to match the colors in the granite,

 

 

[ri702bill 9,528]

Wow - too much like work. My "solution" would have been a second fold up table for the young'uns.... and kept the 8 footer.

In hindsight (which is always 20/20)... would it not have been easier to add a third leaf????

[Handy Don 14,129]

Wow. Just WOW. That was a humdinger of a project and what a good outcome.

Our kitchen table extends (with nine leaves) to 12’ 8”. Just barely fits in the room. Like you, we are just so tickled to have everyone at the same table on special occasions!

Edited Thursday at 07:48 PM by Handy Don

[ebinmaine 72,965]

3 hours ago, oliver2-44 said:

dining room table

 

BEAUTIFUL!!

 

Absolutely fantastic project! 

 

 

[oliver2-44 10,778]

On 8/14/2025 at 2:46 PM, ri702bill said:

 My "solution" would have been a second fold up table for the young'uns....

In hindsight (which is always 20/20)... would it not have been easier to add a third leaf????

The young'uns had a fold up tape, but that didn't pass "Nanny's" muster

 

I looked into adding a 3rd leaf. I would have had to replace the whole sliding mechanism. 

Then grind a custom router/shaper bit to match the edge of the existing table.

 

Then again i think she had her mind made up to replace the wooden table......I like wood....but!

Edited Friday at 11:52 PM by oliver2-44

[953 nut 60,339]

17 hours ago, oliver2-44 said:

42" x 120" granite slab   would weigh 1225

Nice job.         I guess if you ever move you won't be taking the new table with you.        

[oliver2-44 10,778]

1 hour ago, 953 nut said:

Nice job.         I guess if you ever move you won't be taking the new table with you.        

Yep, at a little over 1500lbs total, that table sells with the house

[Beap52 1,476]

21 hours ago, oliver2-44 said:

 

 

Then again i think she had me mind made up to replace the wooden table......I like wood....but!

The good thing about stone surface table (which yours's s beautiful by the way) is it's less likely to absorb oil or carb cleaner when making WH repairs!  

[pfrederi 18,711]

1500lbs table plus 10 or so diners maybe another 1200 lbs plus chairs....Meal may be finished in the basement

[oliver2-44 10,778]

On 8/16/2025 at 8:23 AM, pfrederi said:

Meal may be finished in the basement

Not many basements in Texas. I,m sitting on 4 ft of natural decomposed granite gravel on top of a 50 mile granite dome.