Another Wrong Slider
This square similar in size to the round ones previously reported fail the 3/8" metal moulding climb test. Also fails when paired on the sides or an additional applied behind deeper, and when doubled thickness.The only configuration found to climb 3/8" metal molding transition from hard floor to carpet was the long ways bars. However this cannot be consistently reproduced. There is an inherent tradeoff between fixing slick carpet and severe height transitions in these results
[found incorrect; see following posts]
They all increase carpet traction; floor transitions is the issue. Not all environments may have these narrow metal moldings.
The minimum spacer thickness for Magic Sliders is 3/32"; 1/16" did not correct slick carpet.
The "magic" brand sliders come with rubber backing and separate mounting tape disks, preferred for screw mounting. Put over two layers of 1" foam mounting tape (scotch tape over bottom for screw attachment).
Their bars just barely fit the screw holes for the battery covers. Others come with thick mounting tape backing, a bit thicker overall, still usable, and cheaper http://www.amazon.com/Waxman-4700595N-Furniture-sliders/dp/B000SL3SEQ/ref=pd_sbs_hg_1
Edit: saw in hardware, look narrower than the Magics, maybe inadequate.
The Magicslider Rectangles 3/4" x 4" http://www.amazon.com/Magic-Sliders-Slider-Rectangles/dp/B000KKXGAQ/ref=sr_1_10?ie=UTF8&qid=1362526755&sr=8-10&keywords=magic+sliders
Might not be found in stores, but haven't looked everywhere.
It is feasible to cut slices of these things.
The square did not improve over rectangles on the extra fluffy bath rug. Doubling thickness of the bars possibly made a slight improvement. Not clear whether anything can be done for that case.
Edit: Dimensions: front rollers 13/32" above the case bottom (another 64th if covered by heat shrink to soften). Magic sliders 9/32 thick. 1/16" foam mounting tape will compress under screw tightening.
3M viscoelastic auto trim double sided tape is thinner than 1/16" regular; two layers gives the 3/32" spacing.
Similar thin tape disks supplied with Magic brand sliders; two layers for the minimal spacing.
Some double sided transparent tape isn't very sticky -- 3M removable; use their permanent type. Tape does not stick well to raw wood; varnish or glossy paint required for adhesion. Glue does not stick well to duck tape, the kind of plastic used. Crazy glue or epoxy only, if even that. Yet there is double sided duck tape, better.