Thread: Help with potential racking?

Common problem on a table project.

One needs to think about putting stretchers in between the legs? (i.e. pieces of material about half way along the height of each leg joining them together - usually done along the perimeter edges of a table)

Also with the legs you have selected, they seem to me to be suited for a much smaller table, and wouldn't have much in the way of rigidity. Because you can only screw them in to the table top, they're not going to be very rigid.

Take a look at this table (the result of a random Google search): Diversified WoodcraftsOak Table with Plain Apron and ChemGuard Leg
| Fisher Scientific

See how the legs are joined in along with aprons around the top, and then stretchers about 2/3rd way down joining the legs? All that adds rigidity, which prevents racking.

I suspect, for the size of table you have created, you are likely going to need to also create your own legs, with stretchers and an apron structure of one sort or another (there's a couple different ways they can be done). A good way to do this will be using mortise & tenon joinery, but we don't know what tools and equipment you have, so please feel free to share, and flick up a photo of the table - ideas and suggestions will come from that

This may sound like a complete cop out but first what do you plan to use this table for?
If a desk or computer spot have you the funds and need to just get 2 two drawer filing cabinets and put the top on them.
This will support them and leave about 1 metre in the centre for you to sit into.
You would also have the drawers to stash stuff in.
H.

Originally Posted by fatpenguin

1. Would it help to move the four corner legs further out? At the moment they are sitting 60mmx60mm away from each corner, but would it potentially provide more stability if I move them closer to the edges of the table?

no.

2. Would it help to change the table leg? Perhaps something like this (ADILS Leg, black - IKEA) with a slightly wider base?

no

3. Or should I skip all this and just add a wall mount?

You could

4. Any other suggestions?

Personally I would go with clear out's suggestion.

However, assuming the racking is mainly in the longitudinal direction, here is a suggestion that should easily allow you to retain what you have,
Get a widish (150 x 20mm) board long enough to run past the two back legs by about 50 mm.
Using 4 U-bolts large enough to go around the legs to fix the board to the legs - like this.
Screen Shot 2021-07-21 at 6.37.03 am.jpg
If you look around you should be able to find some attractive stainless steel U bolts that won't detract from the look.
Or buy galvanised ones and paint them black to match the legs.

+1 for clear outs suggestion.

But those legs are adjustable. Work out how to adjust them - probably involves screwing out the feet.

Then: Remember, if it racks, then one or more legs must be the wrong length, so
Get or make 2 small wedges and place one under the apparaently shortest leg and another under the diagonally opposite leg,
Put a spirit level on top of table and adjust the wedges until the spirit level says the table is perfectly level,
Remove one wedge and screw out the foot until it contacts the floor,
Repeat where other wedge is,
Test level. Repeat if necessary.

Originally Posted by GraemeCook

+1 for clear outs suggestion.

But those legs are adjustable. Work out how to adjust them - probably involves screwing out the feet.

I doubt that will help much.
Racking can still occur even if all the feet/legs or a table are all firmly placed on the ground.
Racking on a table happens usually because the structure is simply not rigid or braced enough to prevent sideways or back to front movement parallel to the ground.

Thank you all for your suggestions and comments. Super, super helpful.. otherwise I was going to have to try trial and error - but glad I can draw on your collective knowledge!

Originally Posted by Midnight Man

One needs to think about putting stretchers in between the legs? (i.e. pieces of material about half way along the height of each leg joining them together - usually done along the perimeter edges of a table)

Also with the legs you have selected, they seem to me to be suited for a much smaller table, and wouldn't have much in the way of rigidity. Because you can only screw them in to the table top, they're not going to be very rigid.

Take a look at this table (the result of a random Google search): Diversified WoodcraftsOak Table with Plain Apron and ChemGuard Leg
| Fisher Scientific

See how the legs are joined in along with aprons around the top, and then stretchers about 2/3rd way down joining the legs? All that adds rigidity, which prevents racking.

I suspect, for the size of table you have created, you are likely going to need to also create your own legs, with stretchers and an apron structure of one sort or another (there's a couple different ways they can be done). A good way to do this will be using mortise & tenon joinery, but we don't know what tools and equipment you have, so please feel free to share, and flick up a photo of the table - ideas and suggestions will come from that

Thanks for your suggestions MidnightMan and for clearly explaining the need for rigidity. The racking certainly surprised me when it first happened, but I can see why the table needs more rigidity.

I've attached some pictures of the table to my post. Unfortunately I have both a limited skill set and a limited tool set! I have a hammer, screwdriver, drill... I probably could scrounge up some kind of blade. And of course consumables.. I could purchase or borrow some tools of course, I just have no idea how to use them lol
PXL_20210721_080710702.MP.jpg
PXL_20210721_080323557.MP.jpg

Originally Posted by clear out

This may sound like a complete cop out but first what do you plan to use this table for?
If a desk or computer spot have you the funds and need to just get 2 two drawer filing cabinets and put the top on them.
This will support them and leave about 1 metre in the centre for you to sit into.
You would also have the drawers to stash stuff in.
H.

It doesn't sound like a cop out at all - it sounds like an easily implementable fix. Unfortunately, this was supposed to be like a dining bench near the kitchen window (attached photos). It's something to keep thinking about though because there certainly is the space for it. I was only planning to have seats on one side of the table, but I don't imagine it will be very effective if I only stabilise one side with a drawer solution.

Originally Posted by BobL

However, assuming the racking is mainly in the longitudinal direction, here is a suggestion that should easily allow you to retain what you have,
Get a widish (150 x 20mm) board long enough to run past the two back legs by about 50 mm.
Using 4 U-bolts large enough to go around the legs to fix the board to the legs - like this.

Thanks BobL for your clear answers to my many questions. I had suspected that moving and changing the legs wouldn't make any difference, but it's good to have confirmation. Appreciate your design mock up & suggestion too. Would your suggestion also work were the racking mainly occurring in the other direction, if two boards were placed on the two sides of the table (connecting both sets of front and back legs?)

Originally Posted by GraemeCook

But those legs are adjustable. Work out how to adjust them - probably involves screwing out the feet.

Thanks GraemeCook. I have tried to use the adjusters as much as possible. It does help with the racking, but it doesn't eliminate it completely. The spirit level tells me the table is level..... I haven't specifically tried the method you are suggesting though, so it's worth going back and trying again.

as someone who recently tried to use those legs as well... ditch them.

Ensure that the 2 centre legs are not taking more than their fair share. If they are even fractionally longer than the ends then the table will want to balance and rock from the centre.

This will cause a lot of instability. You could try raising the adjustable feet on the centre legs so they are not touching the floor and test the stability before and after making the change. If it's better then you had the centre feet set incorrectly.

Originally Posted by fatpenguin

Thanks BobL for your clear answers to my many questions. I had suspected that moving and changing the legs wouldn't make any difference, but it's good to have confirmation. Appreciate your design mock up & suggestion too. Would your suggestion also work were the racking mainly occurring in the other direction, if two boards were placed on the two sides of the table (connecting both sets of front and back legs?)

Yes it will help.

The easy way to stop the table moving would be to use two L shaped brackets and screw to the underside of the table and to the wall. If you can screw to the wall.

If you can’t screw to the wall here’s a suggestion.
Screw a suitable piece of wood eg about 250mm x 50mm x 50mm to the underside of each end about 50mm in from the edge.
Then make up two sets of sliding wedges and using something suitable to protect the wall jamb the table solidly ‘tween the walls.
H.

Originally Posted by havabeer69

as someone who recently tried to use those legs as well... ditch them.

Hahaha yes. I may have to.

Originally Posted by clear out

If you can’t screw to the wall here’s a suggestion.
Screw a suitable piece of wood eg about 250mm x 50mm x 50mm to the underside of each end about 50mm in from the edge.
Then make up two sets of sliding wedges and using something suitable to protect the wall jamb the table solidly ‘tween the walls.
H.

Great idea to jamb the table between the walls. Is this sort of what you mean clear out? Except below the table?

011093063-main.jpg

That’s basically how sliding wedges work.
Yes under the table and the block to slide the wedges against should be parallel to the wedges not at 90% as in your pic.
H.