restricted pivot - pikler triangle

[nirajshah31]

How about a rope between the middle of the two lowest "rungs", the ones lying on the floor?

Oh so this relies on gravity to stay open and restricted max opening by the rope.
Ah- thanks.
But I want to secure it staying open ...
Ps rope isn’t Often child friendly

 

[Trainee neophyte]

How about a rope between the middle of the two lowest "rungs", the ones lying on the floor?

Oh so this relies on gravity to stay open and restricted max opening by the rope.
Ah- thanks.
But I want to secure it staying open ...
Ps rope isn’t Often child friendly

First of all, what does everyone else do? https://duckduckgo.com/?q=pickler+trian ... iax=images

There seem to be two camps here - best is a fixed, three sided triangle (doesn't fold, but is rock solid safe. This would be how I would go about it,given that my small, precious child is going to be testing this to the limits and beyond, especially when I turn my back for a moment.

The second option is a heavy bracket to protect the apex:

.

My plan would be to make a three-sided triangle, and have it pivot at all corners so you could fix it as structurally secure in use, but fold it up to put away. In other words, make one more side than you were planning, with or without bars, which would hold it together.

Anything that could fold up with a toddler attached seems like asking for trouble, especially if you are answerable to the overprotective tiger-mum. I see why you want to make one yourself - these things are expensive.

 

[nirajshah31]

Thanks for the reply.
Agree with your comments... but I want it to have 2 bars at the top so it can be perched upon
Must be foldable, safe and secure.
I saw this folding mechanism - but I am not sure how secure it is?!

Following this mechanism route, I was then thinking I’d add 1/5 circumference star (instead of the full star) and let it sit within a channel. This create my restricted pivot. Use a bolt to ensure it stays open.

I guess my two options to make it sturdy (assuming I still need to?!) would be
A) add another piece of wood at the apex (bolting to both sides)
B) add an arm to make a full triangle at the bottom.

Pls let me know your thoughts
Thanks

 

[Doug B]

If you don’t want adjustable angles then a triangular frame is the way to go either fixed or hinged so it can be folded up.
I definitely wouldn’t opt for rope or cord to triangulate it not for use with babies or very young children.

 

[nirajshah31]

Ok. Just wondering how this one could have been made? Seems the arms slot into each other. Two pictures added

 

[MikeG.]

How about a rope between the middle of the two lowest "rungs", the ones lying on the floor?

Oh so this relies on gravity to stay open and restricted max opening by the rope.
Ah- thanks.
But I want to secure it staying open ...
Ps rope isn’t Often child friendly

OK then, replace the rope with two bits of wood pivoted in the middle. If one of them overhangs the pivot you could put a pin through and lock them into place.

 

[MikeG.]

Like this:

 

[nirajshah31]

Thanks- I see what you mean.
I prefer not to use the bottom bar if possible.
See post #1337644

 

[MikeG.]

......See post #1337644

And you see post 1337618.

 

[nirajshah31]

Oooh- sorry missed that.
Thanks!
That design has been tested and passes CE/EU standards. So I assume it must work

 

[MikeG.]

Oooh- sorry missed that.
Thanks!
That design has been tested and passes CE/EU standards. So I assume it must work

It's manufactured in a factory. They have materials and tolerances you can only dream of. In a home workshop you will not achieve anything safe using the path you seem determined to follow. You aren't the first poster who has started a "how do I do this?" thread and only taken any notice of responses that support their predetermined plan. Well, sorry, but the course you are embarked on is the wrong one, and if you won't hear it, that's not our fault.

Good luck with this. I'm outta here.

 

[nirajshah31]

Okay okay.
Can I not at least understand the mechanism used.
And then as you say do something simpler in a home environment which is safe.

 

[nirajshah31]

Figured out the mechanism. See pic

For the bolt holding it together- should it just be a shoulder bolt or should I have some sort of ball bearing to aid rotation inside the joint?

Thanks

 

[Roland]

I’ve just posted this in another thread, but here goes again.

After his trial assembly I cut a smiley curve across the triangle plate. Loosen the bottom bolt half a turn and you can fold the frame for storage. The wooden knob only has to be finger tight to hold the frame open. The bolts are M5 furniture bolts with a T-nut on the other side of the knob, and a “threaded connector” on the other side of the spar. The top bolt is filed exactly to length so that it anchors but doesn’t bind.

 

[TheTiddles]

As Mike had pointed out, you seem to be looking for confirmation more than critical review.

Putting the stop a few mm away from the pivot creates the most force on the smallest area, so is asking for a failure. Just because someone has done it, doesn’t mean it’s right, and a CE Mark doesn’t mean it’s tested for all eventualities.

A cord at the bottom of the triangle is the easiest option but I would never recommend it, as with a bit of slack you’ve created a ligature, not a good thing to have around little ones.

Mike’s bi-folding link could be quite elegant if you planned it well, or use the quadrant approach as also described.

Never pivot on a screw, but using a ground steel shoulder screw against wood is going to result in one of those materials coming off worse. Increase diameter to increase area and reduce pressure.

Aidan

 

[nirajshah31]

Hi Aiden
Thank you for helping - i do appreciate it.
So i want two dowels at the top rather than a centre one, therefore using the rounded top is aethetically pleasing. but then as you say i run into trouble.

So, i'll add a removeable bar to make it a full triangle, using hand knob screw or furniture screw - so 4 (one on each end). Will be a pain to remove but makes it safe.

Centre pivot - please explain what i should do. increase diameter of the hole vs screw... so M10 screw but hole of say 20mm? reduce pressure by using a plastic washer? pls explain in as much detail/ picture of the item as possible

thanks again - i am taking your advice on board

 

[TheTiddles]

Regarding the pivot point, it’s probably not worth fretting over (engineering joke, get it??!). A barrel bolt would give you a smooth head either side (or you could counterbore it) and a smooth surface to rotate against, they’re very cheap but you might have to buy 20.

If you use a third bar to complete the triangle, you could use a spacer between the two sides so the bottom bar sits between the angled sides (that is probably confusing, but draw out the layup and you’ll see, hopefully)

Aidan

 

[nirajshah31]

Here’s my image with the bottom bar...

 

[nirajshah31]

Finished it - thanks for your help all!