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By nirajshah31
#1337498
Hello
i'm designing a pikler triangle - you can google what is a pikler triangle
I wanted advise on how to design a pivot - see picture.

1) this pivot uses a bolt (red), which seems to allow a restricted movement between closed and open (to as is in the picture).
2) the black bolt is just used to once open it remains in place but isn't required for support/structure.

how is this made?
how can i add a feature that allows for opening to different angles whilst also maintaining structure & would the support then be on the bolts and how would i ensure it's secure & safe?

thanks
niraj
Attachments
open.jpeg
closed.jpeg
pivot.JPG
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Last edited by nirajshah31 on 20 Feb 2020, 12:04, edited 1 time in total.
User avatar
By Doug B
#1337510
The simplest way would be to have one bolt to act as a pivot & a second removable bolt that passed through corresponding holes around the circumference of the hinge that allowed the angles you required.

A thin metal plate fixed on both inside faces of the hinge that the bolts pass through would give added strength whilst not being visible.
By nirajshah31
#1337514
Doug B wrote:The simplest way would be to have one bolt to act as a pivot & a second removable bolt that passed through corresponding holes around the circumference of the hinge that allowed the angles you required.

A thin metal plate fixed on both inside faces of the hinge that the bolts pass through would give added strength whilst not being visible.


do you have a picture pls? i'm thinking there are holes between the pivot bolt and edge of the round wooden disc? so the metal plate requires the same holes as the wood as it's sandwiched in-between?
thank you
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By Bm101
#1337515
Blimey. A climbing frame changes the dynamics somewhat. I presumed it was for drying washing etc.
In your first picture the red bolt is the pivot. Both parts of wood can move freely. The black one is secured into the internal part. By cutting a curved channel in the outer part similar to the compass but at the top (Just under the red pivot) means you open the frame and gravity holds it open. No need to tighten any bolts etc.
With ghee scale of the wood being used you could engineer it to be mechanically sufficient or as Douglas suggested, use a metal plate on the internal faces.
User avatar
By Doug B
#1337516
nirajshah31 wrote:
Doug B wrote:The simplest way would be to have one bolt to act as a pivot & a second removable bolt that passed through corresponding holes around the circumference of the hinge that allowed the angles you required.

A thin metal plate fixed on both inside faces of the hinge that the bolts pass through would give added strength whilst not being visible.


do you have a picture pls? i'm thinking there are holes between the pivot bolt and edge of the round wooden disc? so the metal plate requires the same holes as the wood as it's sandwiched in-between?
thank you


I don’t have a picture it was how I imagined I’d do this the easiest way I could, but you seem to have grasped what I’m thinking.
Doing it this way would lock off the hinge preventing any unwanted movement in the hinge during playtime use.
To keep the nut & bolt heads child friendly you could recess the nuts & bolt heads into plastic spheres which would also make them easier to grip so tighten securely. I’d also add a park position for the bolt, holes that correspond when the frame is folded flat which would help prevent loss of the removable bolt
By nirajshah31
#1337533
Doug B wrote:
nirajshah31 wrote:
Doug B wrote:The simplest way would be to have one bolt to act as a pivot & a second removable bolt that passed through corresponding holes around the circumference of the hinge that allowed the angles you required.

A thin metal plate fixed on both inside faces of the hinge that the bolts pass through would give added strength whilst not being visible.


do you have a picture pls? i'm thinking there are holes between the pivot bolt and edge of the round wooden disc? so the metal plate requires the same holes as the wood as it's sandwiched in-between?
thank you


I don’t have a picture it was how I imagined I’d do this the easiest way I could, but you seem to have grasped what I’m thinking.
Doing it this way would lock off the hinge preventing any unwanted movement in the hinge during playtime use.
To keep the nut & bolt heads child friendly you could recess the nuts & bolt heads into plastic spheres which would also make them easier to grip so tighten securely. I’d also add a park position for the bolt, holes that correspond when the frame is folded flat which would help prevent loss of the removable bolt


OK got it!
Would i do this on both sides or just one side?
"I’d also add a park position for the bolt, holes that correspond when the frame is folded flat which would help prevent loss of the removable bolt"
I don't get it - Pls explain
thank you!
User avatar
By Doug B
#1337538
nirajshah31 wrote:

OK got it!
Would i do this on both sides or just one side?
"I’d also add a park position for the bolt, holes that correspond when the frame is folded flat which would help prevent loss of the removable bolt"
I don't get it - Pls explain
thank you!


I’d do it on both hinges.
When the frame is not in use & is folded up for storage have a hole that when the bolt is inserted it holds the frame in that position which will also prevent the bolt from getting lost.
By nirajshah31
#1337617
Hi guys
Say I don’t want multiple angles but use the bolt to ensure the frame stays in that position.
Is there a way that the bolt isn’t the only support keeping frame open? But just there to ensure it doesn’t close.
So without the bolt gravity would keep it open.
That means there needs to be some sort of restriction to the pivot mechanism... how would I achieve that? So it allows from closed to 60degree open
Thanks
User avatar
By MikeG.
#1337618
nirajshah31 wrote:....... there needs to be some sort of restriction to the pivot mechanism....


Mechanically that is the very worst place for any restraint mechanism. I say again, how about a rope connecting the two frames at ground level? To try to do it at the pivot is just asking for trouble.