Installing a i beam hoist

[Don1357]

At the very least my 10/12 roof was done to widstand the 40 pound per square foot snow loads plus a 110mph wind load, so when none of those two are happening it should still be fairly resilient... see the two attached photos.

One third of my second floor is open to the area bellow to accommodate a yet to purchase lift. I would like to install an i-beam hoist in order to bring things up and down. My idea is to span about four of those thrusses, with two 2x6's sandwiching each truss, then bolting the i-beam to the 2x6's, for a total of four pairs of 2x6's. The heaviest thing I would probably want to hang from the hoist is maybe 600#.

Is there a way I could calculate how much weight i could hang from there? It would obviously put stresses in a direction the ceiling was not built to but all those 2x6's tying everything together ought to be good for something.

 

[rsanter]

600 pounds, no problem.
I would span at least 8 sections to be safe and for that weight you only need a small I beam or just use the unistrut system

 

[Don1357]

The thing is that spanning 8 trusses would be 16 feet of I beam. As it is I only need 4 feet to clear stuff into the second floor, I figure 8 to have a better anchoring on the roof

 

[matt_i]

Figuring out how to attach wood to steel and how to load the top chord of the truss, on the top, are a couple of challenges. Hoists always add some extra dynamic loading, either in accelerating the load like an electric chain hoist, or even just the notchy gear drive of a chainfall.

You should static test at 125% of your intended rated load at the end.

 

[rsanter]

The thing is that spanning 8 trusses would be 16 feet of I beam. As it is I only need 4 feet to clear stuff into the second floor, I figure 8 to have a better anchoring on the roof

That is only 8ft over each area, this will mean that you are not concentrating load at the end of the beam/channel

 

[Don1357]

Figuring out how to attach wood to steel and how to load the top chord of the truss, on the top, are a couple of challenges. Hoists always add some extra dynamic loading, either in accelerating the load like an electric chain hoist, or even just the notchy gear drive of a chainfall.

You should static test at 125% of your intended rated load at the end.

That is only 8ft over each area, this will mean that you are not concentrating load at the end of the beam/channel

I imagine if I sandwich each truss with 2x6 and use square bent U bolts bolted to the I beam I should be able to over engineer the attachment. U bolts like on the attached picture

The intent is only to use the center of the i-beam, all I need is enough clearance to move the load into the second floor. As a matter of fact I figure I better put the i-beam stops so even if it is an 8 footer all somebody can use is the 4 feet in the middle. I'll see what the steel yard has and now much it is. Even if I get a 12 footer I would still lock it down to 4 feet of movement.

 

[Monza Harry]

I put up a piece of sliding door track from a barn door and I use this for light loads up to ~250#'s with it screwed to some 2X (4 IIRC & Ridge beam is 1x6 IIRC)lumber cut to allow a decent contact area with PL Premium [for the wood to wood contact] and lots of #8 x 3" wood screws and the stock door hanging hardware. I use a small rope hoist Princess Auto, HF used to carry similar as I recall Harry
https://www.farmtek.com/farm/suppli...rs_hinges_latches;ft_door_hangers_tracks.html

 

[My Old Tools]

Be very careful of side loading. Any off center load will tend to side load the beam. Swinging loads are dynamic in many directions and hard to account for. Rolling trolleys have their own dynamics as well. I wonder if there exists load rated U bolts? My I-beam was fully engineered into the building structure when built. I'm still careful with moving loads.

Third picture is a small modification to the trolley to keep the hoist from tilting.

 

[tarmy]

This one is spread out over many trusses, designed for the added weight. I lift 800 lbs. waverunners off the trailer to dollies, unload my pick up and have lifted the tractor to service a rear wheel.

Account for the power su-ply cord needing to travel as well. A pic here shows mine.

As mentioned, have somebody knowledgeable look at you design/load. If you plan to be under or near the suspended load...why risk your life...

 

[marinusdees]

This one is spread out over many trusses, designed for the added weight. I lift 800 lbs. waverunners off the trailer to dollies, unload my pick up and have lifted the tractor to service a rear wheel.

Account for the power su-ply cord needing to travel as well. A pic here shows mine.

As mentioned, have somebody knowledgeable look at you design/load. If you plan to be under or near the suspended load...why risk your life...

Nice. but why so many tracks for the festoon?

 

[matt_i]

Definitely need to recruit some helpers. The S4 x 7.7 is almost 100 lbs @ 12' and lifted over your head to also test, fit, and connect fasteners if installing by hand.

The idea that trusses "share" the load works well when the load point is in the midpoint between them, but if you get out to the end, or roll right underneath a support/truss, that one truss bears almost all of the load. Bottom line for conservative design you should design it so that each support can handle the full load and then its neighbors are just there to help.

 

[Don1357]

I decided to go with the HF 1 ton chain hoist They have a 16' lift model that will be perfect. I don't plan on going over 600 pounds, the heaviest thing I need to lunge up there is the 15" planer and that is 520#, plus I may weasel out and take the engine off. Besides that the unisaw is upstairs already and if it needs to come down I may take the top off as well.

U-bolts: the size I need are used on truck suspension; if they can take the beating of a 5000# truck loaded with another 1000#, eight of those suckers (two per attachment point) ought to hold the beam in place. I can't engineer but I can certainly over engineer

Once I figure out the attachment I'll post what I'm up to.

 

[matt_i]

I'm not a fan of the U-bolt idea, loading the "bridge truss" on the bottom chord seems like a choice fraught with peril.

Instead I would look at an arrowhead type weldment -> shape of flat steel that would go vertically all the way to the top, right under the roof decking, then thru-bolt to equivalent flat steel on the other side, similar to flitch-plating. The vertical part of the arrowhead would be long enough to go lower than the wood framing.

Cut angle iron clips and weld those to the top flange of the I-beam such that the angle and vertical flat bar tail from above arrowhead can be connected with 1/2" bolts. The welds between the angle iron and I-beam (as well as arrowhead fabrication) are high confidence overhead welds, I would recommend doing those with a 7018 stick weld, DCEP or finding a person that you trust. Clean off mill scale on both hot rolled parts for the best quality weld.

Painting the entire assembly before mounting it would be best. Up near what I think is an ridge vent, its going to get enough exposure to slowly rust. The trolley will wear off the paint where it contacts but that's easily fixed with some sprayed rust preventative like LPS-2 or -3, or even Fluid Film.