ReChain tensioner - Revision history

Apm: /* Related */

2024-08-15T07:00:10Z

← Older revision		Revision as of 09:00, 15 August 2024
Line 121:		Line 121:
	== Related ==		== Related ==

			* Up: '''[[ReChain]] [[ReChain frame systems]]'''
			----
	* [[ReChain tensioner design attempts]]		* [[ReChain tensioner design attempts]]
	* [[ReChain positive locking mechanism]]		* [[ReChain positive locking mechanism]]

Apm: moved === Factoring tensioners and length adjusters apart === and added a concrete example

2024-08-14T22:41:28Z

moved === Factoring tensioners and length adjusters apart === and added a concrete example

@@ Line 18: / Line 18: @@
 This may be unachievable for some macroscale designs. <br>
 At the nanoscale inherent slipperiness of atomically precise surfaces and thermal motion help.
 == Factoring tensioners out of the frame system (take 1) ==
@@ Line 86: / Line 118: @@
 – arbitrary long range to tension and <br>
 – no or little frictive self holding forces <br>
 == Related ==

Apm: /* Factoring tensioners out of the frame system (take one) */

2024-08-14T22:26:27Z

Factoring tensioners out of the frame system (take one)

← Older revision		Revision as of 00:26, 15 August 2024
Line 19:		Line 19:
	At the nanoscale inherent slipperiness of atomically precise surfaces and thermal motion help.		At the nanoscale inherent slipperiness of atomically precise surfaces and thermal motion help.

	== Factoring tensioners out of the frame system (take ~~one~~) ==		== Factoring tensioners out of the frame system (take 1) ==

	Keeping tensioners in the final frame structure is … <br>		Keeping tensioners in the final frame structure is … <br>

Apm: /* Nonlinear tensioning mechanism in assembly-tool / end-effector */

2024-08-14T22:25:33Z

Nonlinear tensioning mechanism in assembly-tool / end-effector

← Older revision		Revision as of 00:25, 15 August 2024
Line 77:		Line 77:
	tend to have high frictive self folding forces (undesired). <br>		tend to have high frictive self folding forces (undesired). <br>

	The trick: With … <br>		'''The trick:''' With … <br>
	– having tensioner and length adjuster functionalities factored apart and …<br>		– having tensioner and length adjuster functionalities factored apart and …<br>
	– having tensioners factored out of the frame system …<br>		– having tensioners factored out of the frame system …<br>

Apm: /* Development progress */

2024-08-14T22:24:42Z

Development progress

← Older revision		Revision as of 00:24, 15 August 2024
Line 11:		Line 11:
	== Development progress ==		== Development progress ==

	For concrete design attempts see page: [[ReChain tensioner design attempts]. <br>		For concrete design attempts see page: [[ReChain tensioner design attempts]]. <br>
	Getting to a compact design that does not friction-self-lock is still an open challenge. <br>		Getting to a compact design that does not friction-self-lock is still an open challenge. <br>

Apm: /* Resulting factors after the factorization */

2024-08-14T22:24:04Z

Resulting factors after the factorization

← Older revision		Revision as of 00:24, 15 August 2024
Line 63:		Line 63:
	These may be [[ReChain extensible turnaround point]]s or [[ReChain plugged T junction]]s. <br>		These may be [[ReChain extensible turnaround point]]s or [[ReChain plugged T junction]]s. <br>

	② '''A [[ReChain tensioner tool]]'''. That is … <br>		② '''[[ReChain tensioner tool]]'''. That is … <br>
	A special tensioner device that can be used: <br>		A special tensioner device that can be used: <br>
	★ either as a ''special hand tool'' <br>		★ either as a ''special hand tool'' <br>
	★ or as a ''special end-effector for robotic tensioning'' <br>		★ or as a ''special end-effector for robotic tensioning'' <br>



	== Nonlinear tensioning mechanism in assembly-tool / end-effector ==		== Nonlinear tensioning mechanism in assembly-tool / end-effector ==

Apm: basic page (may need some reordering)

2024-08-14T22:23:31Z

basic page (may need some reordering)

New page

{{wikitodo|Add illustrativve image: https://en.wikipedia.org/wiki/File:Highfield_lever.png}}

== Purpose ==

In [[ReChain Frame System]]s tensioners are needed to stiffen the loosely pre-assembled structures 
by introducing tension into the [[force circuit|ReChain force circuit]]. 

It seems important to keep tensioners conceptually separate from [[ReChain length adjusters]]. 
In practice the lines can blur a bit. 

== Development progress ==

For concrete design attempts see page: [[ReChain tensioner design attempts]. 
Getting to a compact design that does not friction-self-lock is still an open challenge. 

Ideally we want tensioning functionality strictly separate from locking functionality. 
Especially locking from friction is undesired. 
This may be unachievable for some macroscale designs. 
At the nanoscale inherent slipperiness of atomically precise surfaces and thermal motion help.

== Factoring tensioners out of the frame system (take one) ==

Keeping tensioners in the final frame structure is … 
★ wasting space 
★ adding weight 
=> Factor tensioners out into the tools for assembly (possibly a robotic end-effector) 
See page: [[RepRec tensioning end-effector]] 

[[ReChain frame system]]s shall be designed such that tensioning and detensioning operations 
can be done at dedicated [[ReChain force hydrant]] locations. 
These can be spaced out from sterically congested areas ☺. 
That is: E.g. away from [[ReChain node]]s where many [[ReChain strut]]s converge and thus 
not much space is present (especially for a robotic end-effector) 

== Factoring tensioners out of the [[ReChain core system]] (take 2) ==

There is no need to keep tensioners within the frame system once 
they have fulfilled their purpose and tensioned the system. 
With a design that allows such a [:TensionerRemoval](./TensionerRemoval.md) after tensioning 
is should be possible to save a significant amount of 
size and mass in the final structure. 
Total design complexity is preserved if not increased. 
The now separate tensioning mechanism still needs to be designed. 

Many Tensioner designs ( See: [[ReChain tensioner design attempts ]] though 
are not removable after tensioning the system since they themselves form part of the tensioned system. 
That is: They can not be decoupled without de-tensioning the system. 
This is especially the case for [[ReChain center tensioner]]s (tensioners in the middle of a strut) 
instead of a [[trunaroundpoint|ReChain turn around point]]. 
To have [[ReChain center tensioner]] removable despite their position in the middle of a [[ReChain force circuit]] 
there is the need for the introduction of a [[ReChain plugged T junction]].

{{wikitodo|add new thought here - converting "chain bound tensioners" into seperable tensioner tools}}

=== Resulting factors after the factorization ===

When making the tensioners removable after tensioning (factoring that functionality out) 
then one ends up with two things: 

① '''[[ReChain force hydrant]]s'''. That is … 
Spots where the [[ReChain core chain]] is accessible from the outside 
and temporarily (or permanently) extendable: [[ReChain force hydrants]]. 
These may be [[ReChain extensible turnaround point]]s or [[ReChain plugged T junction]]s. 

② '''A [[ReChain tensioner tool]]'''. That is … 
A special tensioner device that can be used: 
★ either as a ''special hand tool'' 
★ or as a ''special end-effector for robotic tensioning'' 

== Nonlinear tensioning mechanism in assembly-tool / end-effector ==

Nonlinear tensioners have the advantage of high leverage ratios. 
That in combination with low frictive self holding forces. 
But ultimately once the load is high the travel is low. 
So the amount of tension they can put into the system when used naively is low. 
Linear tensioning mechanisms like screws on the other hand 
tend to have high frictive self folding forces (undesired). 

The trick: With … 
– having tensioner and length adjuster functionalities factored apart and … 
– having tensioners factored out of the frame system … 
one can alternate between … 
– tensioning with high nonlinear leverage and … 
– length adjusting under no load. 
One gets both … 
– arbitrary long range to tension and 
– no or little frictive self holding forces 

== Tensioner - categorization / classification ==

=== centerspanners & endspanners ===

Tensioners can be placed either at a center position or an end position of a [[ReChain strut]]. 

=== hullpushers & chainpullers ===

Tensioners can either push the [[ReChain hull segment]]s apart or pull the [[ReChain core chain]] together.
Tensioners may effect length change due to tensioning and resulting mechanical properties in different ways.
(locally concentrated length change in hull may be undesirable - due to misaligned alignment structures)

{{wikitodo|Add illustrative image: chain-core-reinforcement-details.svg}}

=== Intermixing of tensioning and length adjusting issue ===

Conceptually (for the sake of separation of concerns) it makes sense to 
separate tensioners from [[ReChain coarse length adjuster]]s. 
Practically their effect of operation can overlap. 
and separation of concerns in this regard may not be practical. 
(especially for compact designs) 

== Related ==

* [[ReChain tensioner design attempts]]
* [[ReChain positive locking mechanism]]
----
* [[ReChain length adjuster]]
----
* [[Tensioning mechanism design]]
* [[Static rebar profile force circuit]]
----
* [[RepRec tensioner]]

== External links ==

'''Existing tensioners to learn from:'''
* en https://en.wikipedia.org/wiki/Turnbuckle ( de https://de.wikipedia.org/wiki/Spannschloss )
* en https://en.wikipedia.org/wiki/Differential_screw ( de https://de.wikipedia.org/wiki/Differenzgewinde )
* toggle (joint) clamp https://commons.wikimedia.org/wiki/File:SceneryWagonBrake.jpg
* ( https://en.wikipedia.org/wiki/Highfield_lever — good illustrative conceptual picture)

== Page history before migration to this wiki ==

Created Monday 20 February 2017

[[Category:PagesWithGraphics]]