How to close the cover easily and open it difficultly (2/2) : Clearance

Mechanical Fixation For Ublo Components II

Hinge with two snap-fit joints A hinge with two snap-fit joints divided in 120 degree is the final selecton.

The clearance should be checked by the following method.

Relation between Cover-operable gap and snap-fit depth based on parametric. Snap-fit depth should be decided concerning security and appropriate
tolerance gap.
Original length of the cover will extend sligtly according to the depth of snap-fit joints and the hook.  New cover length is approximately assumed and composed of ARCS with 3 points:
hook ends, bisectors(intersection of operable ublo) and snap-fit joint ends (while it meets the operable ublo)

Tolerance Parametric based on the snap-fit joint length

Snap-fit stability is affected by snap-fit
coverage. (The wider in the proportion, the more secure and less shaking).
Snap-fit depth and the cover gap will decide sensitivity and strength of locking whether it is hard or soft.
Seeming likely the coverage of snap-fit(30mm or 20mm each in 120 degree.) doesn’t influence much to the certain value of snap-fit depth.
Even if we decide to one tolerance gap and one depth from the results, when it comes to the metal mold production, conservatively the smaller depth (or larger gap) should be the starting point. Loose fit goes tighter, but there is the limitation of way to revise.

Hook depth: 2mm
Snap-fit coverage: 32mm x 2

Hook depth: 2mm
Snap-fit coverage: 21mm x 2

Snap-fit for insulation chamber