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Quote:
Originally Posted by rickst29
I think that the large number of deck screws is more than sufficient for the entire anticipated load, although I don't intend to actually test that.
All of my deck screws are going through TWO layers of 1-inch wood (not only one). The floor definitely contains more wood along the street side and curb side edges - that's 1 inch thick and possibly more than 1" one wide (horizontal).
Placement of the 4 OEM bolts, holding TM's shorter and thinner L" plates against the floor, seems to imply more than 1" of width in those floor edge boards. But those plates and torsion bar guide holes are probably not carrying significant weight, even in lifted/open configuration.
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All of my pilot holes were cutting into wood (not foam) all the way up. Just two screws easily hold the lower assembly in place, that's maybe 15 lbs all by itself.
I'm unsure of the actual force from these gas struts, the "ratings" may be referring to the weight being lifted. And the gas strut force will be offset from screws, creating torque with a moment arm of about 6" from the row of deck screws. But I think that they could handle all the force themselves; slightly bigger wood screws (#10 or #12) would have provided even more strength than the #9 deck screws.
I'm not going to test that. I will be using the additional 1/4" support bolt holes.
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I changed my mind. and I found the use of 4" deck screws in large numbers, up and into the lower box sidewalls, to be to adequate for my "90 lb struts".
The side walls of the lower box seem to contain wood edging, at least 1x1" and possibly wider than that (height of wood between the two plates in the vertical sidewall base, along the floor in the vertical wall's installed installed position).
When I pre-drilled pilot holes for my desk screws, my drill bit was cutting wood (and not styrofoam) for nearly 4" of vertical height into the wall. One of my 1/4" thick, 12" long steel angle plates is mounted with 10 of these deckmate screws, the other is mounted with 11.
In contrast: In my 2006 model, the TM OEM bolts which hold the OEM "torsion bar support plates" into the outer edges of the underside (a few inches before the 90 degree bend each lift bar) seem to be into the floor alone drilled at just a slight slight angle towards the outside from (in comparison to vertical).
That thinner and weaker OEM plate (containing the single hole for the torsion bar passs-thru) supports the torsion bar near its outside end after the shell has been raised, and downward force is pressing on the torsion bar end from the lift bar.
I do not know of any instances where the plate itself has failed, although I have read reports of failure in the bolted connection (5 bolts) between the OEM bar support plate and the floor.
The lower support structure for my add-on strut is stressed in nearly the same way, in lifted position, by any remaining force force of the strut attempting to expand between its mount points.
The OEM bolt connection differs from my strut support attachment in 3 ways. #1, the OEM attachement was done with 5 bolts. (I used 8 in one case, and 9 in the other). #2 The OEM bolts have much bigger diameter than my deck screws. and #3, the OEM bolts are much shorter than my 4" deck screws screws, their threads rise only into the structure of the floor.
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My desk screws rise into the side wall, by more than one additional inch, at the edge of the floor. The thicker OEM screws, if relocated to rise into the sidewall, would not gain significant holding power, because the thicker screws were leave much less width of wood in the sidewall structure (attempting to grip the screw threads). My screws are also much more numerous.