Engineers how do you calculate max load

Hagar · 25 May 2018 at 12:05

As an engineer I would say that for a four leg table, design the leg loading as for a three leg table. The chances are that one leg takes next to no load (unless a perfect support, floor level and exact leg lengths).

Therefore if table design load is 50kg, required leg load = 16.7kg on a four leg support system. This also allows for eccentricity of load.

Minusorange · 25 May 2018 at 12:29

adolf hamster said:
you can reinforce the top easily enough, i'm typing this on a pair of ikea desks that have been joined together by the very technical means of a couple of angle iron sections bolted between them.

as for those big chipboard tops they work great, i have a couple of bases (i'd link but i can't find them on the site, but it's a self-contained unit with 4 telescopic legs at an angle) with a chipboard breakfast bar on it. that took 3 monitors, a printer, and tower and even sitting on it.

I've been lucky in managing to find off Gumtree 2 solid oak kitchen top cutoffs which are perfect size for boshing together a computer desk and solder desk which should do the job perfectly

jpaul said:
interesting

see here http://srjcstaff.santarosa.edu/~yataiiya/E45/PROJECTS/Bend Test of wood.pdf

So it seems Oak is the best of all woods, I wonder how Bamboo would fair, I'd imagine it would be close to Oak

Minusorange · 25 May 2018 at 20:55

Got 5 adils legs
An Alex drawer
A Lack shelf and bunch of Capita brackets to support the shelf to go on a fresh piece of solid oak which just need a whack of varnish
And some Trestle legs for my solder bench which is another slab of solid oak

The 2 oak boards were £50 and £100 spent on the rest, I just hope I have good craftsman skills to make it look as nice as it looks in my mind

adolf hamster · 25 May 2018 at 21:44

Minusorange said:
Got 5 adils legs
An Alex drawer
A Lack shelf and bunch of Capita brackets to support the shelf to go on a fresh piece of solid oak which just need a whack of varnish
And some Trestle legs for my solder bench which is another slab of solid oak

The 2 oak boards were £50 and £100 spent on the rest, I just hope I have good craftsman skills to make it look as nice as it looks in my mind

the adils legs are plenty strong, although because of the mounting they can have a tendancy to wobble side to side a bit under load, i'd reccommend screwing them down tight as you can, preferably into metal.

Minusorange · 25 May 2018 at 21:54

adolf hamster said:
the adils legs are plenty strong, although because of the mounting they can have a tendancy to wobble side to side a bit under load, i'd reccommend screwing them down tight as you can, preferably into metal.

Yeah I was surprised considering they're only £2.50 a leg

But..... **** Ikea it's like a black hole were time no longer exists, I entered at 3pm and didn't get out until 6

adolf hamster · 25 May 2018 at 22:36

Minusorange said:
Yeah I was surprised considering they're only £2.50 a leg

But..... **** Ikea it's like a black hole were time no longer exists, I entered at 3pm and didn't get out until 6

y'see this is why you need to go in prepared, and just skip the whole showroom and go straight to the bottom.

fortunately it's a copy/paste architecture, you've been to one ikea you've been to them all.

Minusorange · 25 May 2018 at 22:44

adolf hamster said:
y'see this is why you need to go in prepared, and just skip the whole showroom and go straight to the bottom.

fortunately it's a copy/paste architecture, you've been to one ikea you've been to them all.

Haha ironically, skipping through the showroom actually resulted in me having to run back around the whole ******* building to get the little legs I missed which despite being for holding up shelves was tucked away in the corner of the kitchen area

I also didn't pay attention to the map on the first run through or the run back and it was only after I'd gone back to the start did I see the map showed shortcuts

Next time I'm just ordering online instead of walking through Swedens idea of an airport terminal for furniture

Minusorange · 26 May 2018 at 18:38

All day working on this desk it's starting to look like a desk

The majority of the day was spent sanding the main desk and varnishing it

builder22 · 26 May 2018 at 18:48

looks good...much better than I imagined when you were talking of having 9 legs

Minusorange · 26 May 2018 at 19:14

builder22 said:
looks good...much better than I imagined when you were talking of having 9 legs

That was when I was going to use the particle board for the desk, this solid oak should fair much better when I'm finished with only 4 or 5 legs

jpaul · 26 May 2018 at 23:03

nice piece of oak
... but what's the shelf for then .. and why does it need 6 legs ... is it stable enough to put a monitor on ?

I cant post photos · 26 May 2018 at 23:06

jpaul said:
nice piece of oak

I get this a lot :cool:

Minusorange · 26 May 2018 at 23:19

jpaul said:
nice piece of oak
... but what's the shelf for then .. and why does it need 6 legs ... is it stable enough to put a monitor on ?

Shelf is for Monitor and if I got my measurements right my Midi keyboard should be able to sleep underneath so it's utilizing space

It was either 5 or 6 legs, decided to go with 6 just for extra stability and I had to buy in pack of 4 so I'd rather be left with 2 unused than 3, I'm hoping to drill some recessed holes for the legs to sit in comfortably so there's no chance of it sliding it around if I happen to knock the desk

Minusorange · 27 May 2018 at 22:51

It's complete and actually looks half decent

I cant post photos · 27 May 2018 at 22:58

Well done, that looks pretty good

teaboy5 · 27 May 2018 at 23:54

Minusorange said:
It's complete and actually looks half decent

Take the PC off the desk and it would look better.

Minusorange · 28 May 2018 at 00:00

teaboy5 said:
Take the PC off the desk and it would look better.

It gets real dusty down on the floor though

builder22 · 28 May 2018 at 13:23

Looks great minusorange...neat and tidy job. Its good to have a space for things like the midi keyboard...pita taking them.out a drawer or whatever when you want to use them

jpaul said:
interesting - if you do the calculation using https://www.physicsforums.com/threads/determining-youngs-modulus-by-bending-a-piece-of-wood.783911/
if there is no bracing/longitudinal support benath a piece of chip-board of worktop length I got 28.2 mm droop with legs in 4 corners and 50kg in middle
[based on chip board E=2000Nmm2]

see here http://srjcstaff.santarosa.edu/~yataiiya/E45/PROJECTS/Bend Test of wood.pdf

That's great...I've never even tried to do any of the maths...just have basic knowledge of strength for choosing materials but it sounds right!
I wanted to calculate deflection for some aluminium lshs/rhs a few weeks ago but never really got any where!

Minusorange · 28 May 2018 at 14:13

builder22 said:
Looks great minusorange...neat and tidy job. Its good to have a space for things like the midi keyboard...pita taking them.out a drawer or whatever when you want to use them

Cheers, yeah it's much better for easy access although that bench is going to be a solder/tinker bench as well, for a weekend project though it has been more fun than I was expecting

JBuk · 28 May 2018 at 15:39

Place more weight on support than it'll ever need

Did it break?

No : great, crack on

Yes : weld something to it and try again