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Title: Question about Boom Specs Post by: DN5135 on April 09, 2009, 04:41:08 PM I was reading the specifications and I am not clear on the ruling over blocks attached to the boom.
What I would like to do is slot the boom and carry the blocks through their bails on a rod inside the boom. The sheaves would still be outside of the boom and this would in effect be the same as mounting a slotted carrier on the boom with a rod to carry the blocks. I like the approach because it is cleaner, less expensive, and the block positions could be adjusted through multiple slots. I suspect this is not allowed, but that makes no sense to me if adjustable block positions are allowed. I was thinking of doing this with a standard 1.75"x2.75" aluminum boom extrusion. Title: Re: Question about Boom Specs Post by: Geoff Sobering on April 09, 2009, 05:26:34 PM What I would like to do is slot the boom and carry the blocks through their bails on a rod inside the boom. I'm not 100% clear what you're planning to do. Is it similar to the setup in the attached photo? Cheers, Geoff S. Us-5156 Title: Re: Question about Boom Specs Post by: Bob Gray on April 09, 2009, 06:06:57 PM The sheave of the block must be outside/clear of the boom. The rest of the pulley assembly may extend into the boom. Bob Title: Re: Question about Boom Specs Post by: DN5135 on April 09, 2009, 09:14:00 PM The picture is exactly What I wanted to do! Thanks for the help.
Title: Re: Question about Boom Specs Post by: Geoff Sobering on April 09, 2009, 09:19:48 PM The picture is exactly What I wanted to do! Thanks for the help. Anytime! Glad to be able to help out. As far as I know, it's a pretty standard technique for mounting blocks to a boom. I'd recommend narrower and more closely spaced slots than are shown in the photo to get a finer adjustment capability. I have a Bryant extrusion (I think) with about 1/4" slots milled on about 1/2" centers that seems better than the setup I had when that photo was taken. Cheers, Geoff S. |