proof of torsion box shelf strength

dirtydeeds
Senior Member

Posts: 305

proof of torsion box shelf strength Nov 13, 2007 21:32:59 GMT

Post by dirtydeeds on Nov 13, 2007 21:32:59 GMT

ive taken the following two photos to show (proove) the strength of a partial torsion box shelf

first the underside, to show it is an incomplete torsion box

shelf size 1080x270 made of

20x20 timber merchant pine frame, 6mm oak faced mdf, and 20x30mm white oak lipping

second

the load applied 135Kg = 21st 4lbs = 298lbs

(maker and client) to save the ladies blushes im heavier than she is but theres only 16lbs between us

dirtydeeds Senior Member Posts: 305	proof of torsion box shelf strength Nov 13, 2007 21:34:37 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by dirtydeeds on Nov 13, 2007 21:34:37 GMT ps yes it bends but with a 135kg load on a partially complete shelf what else do you expect

wizer Senior Member Posts: 367	proof of torsion box shelf strength Nov 13, 2007 21:57:11 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by wizer on Nov 13, 2007 21:57:11 GMT Thanks for this DD. Very interesting stuff.
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andy Global Moderator Posts: 698	proof of torsion box shelf strength Nov 13, 2007 22:13:01 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by andy on Nov 13, 2007 22:13:01 GMT Interesting construction Thanks for taking the time to demonstrate one side issue question is that a Steve Johnston picture I spy 'Best friends' I think

dirtydeeds Senior Member Posts: 305	proof of torsion box shelf strength Nov 13, 2007 22:26:44 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by dirtydeeds on Nov 13, 2007 22:26:44 GMT ive no idea about the painting but the partially complete oak radiator cover is also by yours truly
	Last Edit: Nov 13, 2007 23:00:34 GMT by dirtydeeds

dom Global Moderator Moderator Posts: 1,873	proof of torsion box shelf strength Nov 14, 2007 6:09:14 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by dom on Nov 14, 2007 6:09:14 GMT So DD, how do you get away with only half finishing everything, shelves, rad covers, ;D
	Quis Custodiet Ipsos Custodes

dirtydeeds Senior Member Posts: 305	proof of torsion box shelf strength Nov 14, 2007 22:10:35 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by dirtydeeds on Nov 14, 2007 22:10:35 GMT easy its a redundant shelf, they asked for 4, but only wanted 3 put in ps as of this evening the rad cover is complete the hi fi cabinet is semi complete and the main cabinet has been commenced

engineerone Horse's member Posts: 2,834	proof of torsion box shelf strength Nov 14, 2007 22:35:10 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by engineerone on Nov 14, 2007 22:35:10 GMT looks good mate, but i reckon that if you had put more ribs in, specifically a central spine, plus ribs at closer spacings, say 200mm, then i personally do not think the shelf would have moved. paul

nick Junior Member Posts: 69	proof of torsion box shelf strength Nov 15, 2007 10:59:53 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by nick on Nov 15, 2007 10:59:53 GMT dirtydeeds said: (maker and client) to save the ladies blushes im heavier than she is but theres only 16lbs between us So she is 141 pounds? Doesn't look that heavy .......

evergreen Junior Member Posts: 97	proof of torsion box shelf strength Nov 15, 2007 13:54:52 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by evergreen on Nov 15, 2007 13:54:52 GMT DD How is the the frame fixed together, please? Just glued? Glued and nailed/screwed? Any type of dado? Regards.
	Last Edit: Nov 15, 2007 21:08:08 GMT by evergreen

dirtydeeds
Senior Member

Posts: 305

proof of torsion box shelf strength Nov 16, 2007 21:05:06 GMT

Post by dirtydeeds on Nov 16, 2007 21:05:06 GMT

the frame isnt a separate entity that you can pick up and carry arround

i simply glued and pinned (paslode 18 guage pins) the frame pieces to the board, yes i did apply glue to points where each frame member meets another

the pins arnt for strength, just to hold the pieces while the glue set

i used 18 guage pins to minimise filling holes because the finish is just coloured wax

evergreen Junior Member Posts: 97	proof of torsion box shelf strength Nov 17, 2007 20:42:41 GMT Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by evergreen on Nov 17, 2007 20:42:41 GMT Thanks, DD. I would never have thought to make a shelf like that but I happen to be fitting out the cupboard under my stairs at the moment and I'll have a go. Regards.