H960 blank panel clips

Pete Turnbull pete at dunnington.plus.com
Wed Jul 29 04:57:46 CDT 2015

On 29/07/2015 07:24, Vincent Slyngstad wrote:

> I've placed a new design at:
> http://svn.so-much-stuff.com/svn/trunk/3D/rack-bracket/bracket-new.jpg

> I don't know if the design will work -- will the slit will provide
> enough flexibility, will the post crack, etc.

That looks pretty good to me, and the only refinements I'd suggest are 

Firstly, to add a small fillet to the junction of post and flat surface, 
so that there's a small radius, perhaps 0.5mm - 1.0mm, at the 
transition.  The sharp transition will concentrate any stress, and a 
radius will reduce that.  I'm not sure how much difference it makes for 
a 3D-printed object but it would be significant for injection moulding. 
  The lack of any radii is actually part of the problem with the 
original, and the breaks always occur right either at the sharp 
transition between post and flat surface, or more often between post and 

Secondly, and maybe less importantly, to make the lower part (maybe half 
the length) of the post a slightly smaller diameter - but not to the 
extent of reproducing the ball-on-a-thin-post of the original.  This 
eases alignment, because as Al pointed out, the panel always tilts or 
twists as it's removed and that puts a bending strain on the joint - in 
this case, now at the post base than than just below the ball.

Maybe that post should be a short spring ;-)


Pete Turnbull

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