Making interlocking table base

[Stephen Bell]

Hi folks, I'm new to the page.
I am going to try to make an interlocking table base like in the photo attached from 18mm birch plywood but before I start I'd l'd like to ask some questions. I seen these in a photo that is below and think it looks classy.
I was just wondering how much of a gap should I use for the interlocking slots?
I'm not sure if the wood will expand much with moisture, but at the same time, I would like it to be a snug fit so the base is sturdy.

Also would 18mm birch be thick enough for this kind of structure - or how much excess I should give on the 18mm. This is going to be for a mobile casino business, so for each event, I will be setting it up and breaking it down.

Also, any suggestions on the type of paint I should use on birchply?

I'd be grateful for any advice or suggestions.

 

[Cabinetman]

I think that if I was doing it I would make one X and two halves hinged to the X then have some sort of "socket" to register into on the underside of the tabletop.
Ian

 

[TheTiddles]

The gap you need depends on the ply thickness plus paint, it’s unlikely to shrink/grow a lot, just measure and leave a mm or so. It doesn’t need to be close as that joint has a huge moment arm, the bit that resists is the top/bottom corner of the slot on the opposing face rotating about a pivot 300mm or so below it? It’s a hugely strong joint that you can have apart in seconds. Usefully both parts are the same so make one and template the others

 

[Stephen Bell]

I think that if I was doing it I would make one X and two halves hinged to the X then have some sort of "socket" to register into on the underside of the tabletop.
Ian

Thanks for your suggestion. Because its for mobile use I prefer to have as few a pieces as possible and easily assembly/break down.

 

[Jameshow]

How about using some piano hinges to joint the pieces to each other?
Fold the hinged wings out and pop the top on.

 

[Stephen Bell]

The gap you need depends on the ply thickness plus paint, it’s unlikely to shrink/grow a lot, just measure and leave a mm or so. It doesn’t need to be close as that joint has a huge moment arm, the bit that resists is the top/bottom corner of the slot on the opposing face rotating about a pivot 300mm or so below it? It’s a hugely strong joint that you can have apart in seconds. Usefully both parts are the same so make one and template the others

Thanks TheTiddles,
I got a bit lost in the technical terms - sorry.
Are you saying that its a strong structure for these interlocking pieces, and is it better to do it with 18mm or 25mm birch?
Any particular paint work best on birch ply?
I'm due to get materials this weekend

 

[Stephen Bell]

How about using some piano hinges to joint the pieces to each other?
Fold the hinged wings out and pop the top on.

That's actually a great idea.. i will have a look at that.

 

[Doug71]

I bought a slot together Birch ply workbench to keep in my van, it does get annoyingly hard to assemble if left in my van any length of time but if I then leave it in a customers house for a couple of days it slides together nicely again.

It probably only needs 0.5mm trimming off the slots but I never seem to get around to it......

 

[Stephen Bell]

Thanks Doug,
Yeah, the last thing i want is something that is annoying hard to assemble, hence the reason for asking for advise. I was actually thinking if I use 18mm ply to make the slot 22mm just to give a bit of breathing space, however I don't want to lose stability either

 

[Doug71]

Thanks Doug,
Yeah, the last thing i want is something that is annoying hard to assemble, hence the reason for asking for advise. I was actually thinking if I use 18mm ply to make the slot 22mm just to give a bit of breathing space, however I don't want to lose stability either

You will probably be fine with just a mill or so clearance, mine was CNC cut and didn't have any noticeable clearance at all when I got it, some silly person then thought it was a good idea to give it a couple of coats of thick varnish to protect it which probably didn't help.........

 

[Stephen Bell]

Ia it better to get it done on a cnc machine?

 

[Stephen Bell]

You will probably be fine with just a mill or so clearance, mine was CNC cut and didn't have any noticeable clearance at all when I got it, some silly person then thought it was a good idea to give it a couple of coats of thick varnish to protect it which probably didn't help.........

Is it better to get it done on a cnc machine?

 

[Doug71]

Ia it better to get it done on a cnc machine?

My bench was only CNC as I bought it as a ready made kit, it didn't cost much more buying the kit than it would have cost for just the sheet of Birch ply.

You could knock yours out in no time with just a handsaw (if you can saw straight).

Regarding paint if you just want simple black paint a lot of people seem to rate this stuff.

https://www.toolstation.com/bedec-m...3TlBh8aI20rV88x2EARoCQtwQAvD_BwE&gclsrc=aw.ds

 

[Stephen Bell]

My bench was only CNC as I bought it as a ready made kit, it didn't cost much more buying the kit than it would have cost for just the sheet of Birch ply.

You could knock yours out in no time with just a handsaw (if you can saw straight).

Regarding paint if you just want simple black paint a lot of people seem to rate this stuff.

https://www.toolstation.com/bedec-m...3TlBh8aI20rV88x2EARoCQtwQAvD_BwE&gclsrc=aw.ds

Thanks a lot.
Its to make up legs to support fun casino tables I hire out. The end product should end up like this

 

[TheTiddles]

Thanks Doug,
Yeah, the last thing i want is something that is annoying hard to assemble, hence the reason for asking for advise. I was actually thinking if I use 18mm ply to make the slot 22mm just to give a bit of breathing space, however I don't want to lose stability either

Remember it’s not using the whole length of the slot to take the load, you can put a heavy radius on the slot and leave clearance it’s still strong

 

[Stephen Bell]

I ended up doing these in mdf on a cnc machine. Photos attached. They still need to be primed and painted.

Considering Zinsser bin primer for the outside edges of the mdf. Has anyone suggestions on sealing the mdf edges that may work better than zinsser bin primer?

Also, the base is a little wonky, any ideas on how I could steady it?
There's a little bit of movement and a small gap between the slots of the interlocking sections

 

[Doug71]

Is there anything under the top to hold the legs in place?

If not fasten some laths under the top to create a kind of groove for the legs to sit in. Should cut down the wobble and stop the top getting knocked off!