Boomilever B/C

iwonder
Admin Emeritus
Admin Emeritus
Posts: 1112
Joined: May 10th, 2011, 8:25 pm
Division: Grad
State: TX

Re: Boomilever B/C

Postby iwonder » August 14th, 2013, 5:51 pm

Ahh, so if it creates more stability than compression members that are less than 5 cm apart on both ends I assume. Well sure, it would be more stable that way, but it's really a weight vs benefit problem. For me, because of my design I can't make the distal end narrower than 5cm or the loading block doesn't fit, but it you could, you'd need slightly heavier bracing on the wall end because there's a small spreading force on the end beams(though honestly the friction in the wall would probably hold most of that) and then you'd need a lot heavier distal end connection because the loading block would(in most cases) get in the way of the tension members. This would force you to move the tension members back, and you'd see an actual cantilever section on the distal end(think of a diving board) and that'd require a very stiff distal end to hold, even over the 2.5-3.5cm distance.

Overall, you'd probably have to test distal end configurations to hole it, and see if it saves enough weight to be worth it. But while you're doing that why not just make both ends narrower? As long as the width is grater than or equal to the height if the compression member then technically the extra bracing is just wasted wood.
'If you're the smartest person in the room, you're in the wrong room' - Unknown

fanjiatian
Member
Member
Posts: 243
Joined: March 16th, 2010, 6:46 pm
Division: Grad

Re: Boomilever B/C

Postby fanjiatian » August 14th, 2013, 6:47 pm

Ohh that makes a lot of sense!
I just realized that this configuration wouldn't work for mine either :P
In mine, the connection between the tension and compression member is aligned with the center of the loading block, so the minimum (and really maximum) distance apart my compression members can be is 5 cm.

Now that I think about it, this was a big problem last year. Often the loading block would slip through the compression members without actually breaking anything.

iwonder
Admin Emeritus
Admin Emeritus
Posts: 1112
Joined: May 10th, 2011, 8:25 pm
Division: Grad
State: TX

Re: Boomilever B/C

Postby iwonder » August 14th, 2013, 6:53 pm

Yeah, that happened to me a few times, I eventually looked down the end of the boom and relized that my compression members were spreading out. All I had to do was add a little member across the bottom that was in tension to hold them together, added like .12g and my boom held twice as much :D
'If you're the smartest person in the room, you're in the wrong room' - Unknown


Return to “Boomilever B/C”

Who is online

Users browsing this forum: No registered users and 1 guest