How to lock folding leg up posn?

[redknife]

I need advice on folding leg lock mechanism.
I am building a low floor drawing table for my daughter at her request. It needs to fold up to store. She wants to sit Indian style with legs under the table when working. Fold up and store when done. I mocked up the dimensions with plywood to let her check the ergonomics and size. The drawing reflects the dimensions that we agreed upon.
I am stuck on the best way to lock the legs sturdily in the open position



I can't have anything blocking her legs in the front such as a brass lid support. Thought about slide bolt. Would like the locking mechanism to be easy yet stable. I have seen dedicated folding leg bracket hardware which appear to have mixed reviews.

What would you do for the upright locking mechanism??? Any ideas are welcome.
Thanks

 

[Raymond]

Chris, have you thought about a wooden latch (one for each leg) that would mount under the table and latch into or over the cross bar of the legs?
https://www.google.com/search?q=woo...nV3f7QAhWojFQKHchVBmwQsAQINA&biw=1745&bih=898

 

[redknife]

Raymond- that is the realm I'm trying to engineer. I don't want it to wobble at all. Maybe a cam that is mounted to the underside of the top and compresses the top rail?

 

[chris_goris]

I need advice on folding leg lock mechanism.
I am building a low floor drawing table for my daughter at her request. It needs to fold up to store. She wants to sit Indian style with legs under the table when working. Fold up and store when done. I mocked up the dimensions with plywood to let her check the ergonomics and size. The drawing reflects the dimensions that we agreed upon.
I am stuck on the best way to lock the legs sturdily in the open position
View attachment 21730
View attachment 21731

I can't have anything blocking her legs in the front such as a brass lid support. Thought about slide bolt. Would like the locking mechanism to be easy yet stable. I have seen dedicated folding leg bracket hardware which appear to have mixed reviews.

What would you do for the upright locking mechanism??? Any ideas are welcome.

Thanks[/QUO



mount the legs inboard from where they are now (past vertical) so they open and will naturally wedge at the bottom.. no wobble!

 

[redknife]

mount the legs inboard from where they are now (past vertical) so they open and will naturally wedge at the bottom.. no wobble!

Probably would be simplest. I guess in that case I'd use a bolt pivot point rather than a hinge.

 

[Dave Richards]

You could still use butt hinges. I did a quick doodle to show how. I moved the legs in one inch from the aprons and angled them 10° from vertical. The tops of the legs are beveled at the same angle. There are some little wedges the height of the aprons to act as stops. They need to be trimmed away a little at the top so the legs will clear them when folding.

 

[jerrye]

The first thought I had was 6-8 rare earth magnets imbedded in and aligned along the top stretcher and apron of each side.

 

[redknife]

Dave- thanks. I like the wedges. I am concerned about the leverage applied to the 3 or so butt hinge screw attached to the top.
Jerry- thats a neat idea I would not have envisioned.

 

[Dave Richards]

Chris,

You could through bolt them.

Seriously, I think you'd be OK with two or three decent sized butt hinges. If you keep the legs nearly vertical as I've drawn them, there won't be that much of a load on the screws. She's not going to stand on the thing is she?

 

[redknife]

Chris,

You could through bolt them.

Seriously, I think you'd be OK with two or three decent sized butt hinges. If you keep the legs nearly vertical as I've drawn them, there won't be that much of a load on the screws. She's not going to stand on the thing is she?

Got it. I will say she has somehow gotten in to watching WWE, particularly the wrestler Roman Reigns, so you never know what stresses a table will endure!

 

[Dave Richards]

:gar-Bi

Maybe through bolts with fender washers, then.

Another thought might be to make slots for the legs to fit into instead of hinging them. Just add blocks on the opposite side of the legs from the wedges. Maybe a couple of rare earth magnets to keep them from falling out when the table is picked up. With strategic placement, the legs could still fit to the underside of the table and be secured in place with more magnets or turn buttons.

 

[nn4jw]

How about something like this?

https://www.amazon.com/Posi-Lock-Fo...=2025&creative=165953&creativeASIN=B001DSXSBQ

 

[redknife]

How about something like this?

https://www.amazon.com/Posi-Lock-Fo...=2025&creative=165953&creativeASIN=B001DSXSBQ

Jim, I considered those but thought reaching under to those latches would be kind of a nuisance for this size table. I also wondered about long term durability. Anyway, I think the angled leg plan is a good one.

Next I need to finalize the joinery and aesthetics of the legs while I work on dimensioning and gluing the top. I am thinking finger joints for the table apron. I will probably Domino the leg stringers vs M&T. I'll secure the table top with figure 8's on the short sides and wooden buttons in the middle of the long side (in between where the legs fold up).

I'm not sure whether to employ simple leg design as roughly depicted or something more stylized. Relative speed is a good thing for this project but I don't want a custom cherry/maple table to be ugly. :icon_scra

 

[gritz]

I would make the legs arched with a flat area across the top for two hinges. I would then have two drop or swing-down locking pieces that would be stopped/locked by magnets in them and in the arched leg. To unlock, turn on one side, flip the two locking pieces away into the arch void and fold the legs into the apron area.
I don't do sketch-up, but could whip out a drawing later in the week if you can't visualize this.

 

[Dave Richards]

Robert, I am trying to visualize your description. Are you thinking angled braces similar to what you would find on a typical folding table?

 

[gritz]

No. This is really just like a wooden smokehouse door latch with a modern magnet update. They would pivot from the end, not the center. I see them swinging from a screw in a block on the apron that is just a hair thicker than the leg. When the legs swing down, the latches drop and the magnets would center them, locking the legs.

You could also use straight legs with a 45 degree cut-off in each corner where the latches would store and then drop down over face of the legs when opened.