Shop Garage Hoist - How it's going to kill me?

[Doggggboy]

You know the old fantasy: Shot by a jealous husband at 90.

Does it still count count if he's only jealous of your new hip?

 

[fixerup]

when i was lifting heavy object with the 2 ton gantry we had at work, I always wondered what weight I was lifting. It was not obvious sometimes, the paper work didn't always follow with the item and even if it did I had no way to check.
So for my homeshop unistrut gantry I bought a digital scale and won't lift anything if it weight more than 200lbs.
Mine is a similar unit and no remote

 

[SomeGuy]

when i was lifting heavy object with the 2 ton gantry we had at work, I always wondered what weight I was lifting. It was not obvious sometimes, the paper work didn't always follow with the item and even if it did I had no way to check.
So for my homeshop unistrut gantry I bought a digital scale and won't lift anything if it weight more than 200lbs.
Mine is a similar unit and no remote

View attachment 68320

I have a 660lb version of something like that, didn't even cross my mind to use it while lifting the welding cart....will have to try that at some point

 

[Engmaxx]

I'm sure it'll be fine if you use it within reason. Do not side load that at all, as you'll risk spreading the strut. I would love to have something similar in my shop for those awkward things that are just hard to lift and manipulate single handedly. A few of the next couple projects for me are going to be lifting device related, as I'm not getting younger, and the projects seem to keep getting bigger. Of course I said that last year, but other stuff just keeps wiggling it's way into the queue ahead of them. Damn line jumpers.....

Looking at that, the only thing I'd possibly add, which is just me overbuilding/overkilling it, would be some triangular gussets to the mounting plates to keep the strut from potentially spreading if side loaded. Needed? probably not. Worth taking the whole thing down to do it? Probably not either.

No need. These are plenty strong and stiff (1/4 inch thick). Silly me thinking I could hang the brackets first and then try to twist the rail in...not a chance. They all had to be slid on first and then I bolted them to a plate that I had first mounted to the joists. I didn't have the room to slide the rail in after everything was mounted so this was my only way.

 

[Dan Dubeau]

Ya, strut is pretty stiff stuff. The gusset suggestion was me just being nitpicky lol. I DO wonder how much side load it would take to actually spread one and spit the carriers though.......Most likely north of the hoists capacity I'd bet.

 

[SomeGuy]

No need. These are plenty strong and stiff (1/4 inch thick). Silly me thinking I could hang the brackets first and then try to twist the rail in...not a chance. They all had to be slid on first and then I bolted them to a plate that I had first mounted to the joists. I didn't have the room to slide the rail in after everything was mounted so this was my only way.

View attachment 68323

Yup, was aware of these brackets....would have had to figure out how to get threaded rod hanging down from the ceiling first before putting this up, it's the only way that style bracket will work. That's why I just welded on my own so I could bolt from either side, and it had the advantage of keeping the track from being able to rotate.

 

[mbond]

without running the numbers, or seeing your exact setup, it is almost certain that if it fails, the 2x6 joist will split along the grain near the end of your lag screws. when that happens, the load will move to other joists and a loud crack or popping noise will alert you.

the real danger in a system like this is that if that happens, but you aren't around to know or don't fix it, and then lift something else heavy later, it sill start to fail in increasingly dramatic ways. Probably it will take several of these events for it to completely fail, but it would be wrong to say that those loud noises don't matter because they have happened before

The problem is that while 2x6 SPF is quite strong when it supports a load distributed over it's whole length, point loads are particularly bad for wood. And a lag screw that goes only part way through relies on the cross-grain strength of the wood - which is much less than along the grain because of the way trees grow.

then you have lag screws that are close together. Each one produces a 'cone of influence' within the wood that starts at the tip of the screw and gets wider towards the bottom of the joist. if those two cones overlap, then the wood in that overlapping area has to support weight from both screws. the anisotropy of wood (the difference between along the grain and cross grain strength) makes these cones particularly wide and checks and knots makes them unpredictably wide.

to bear the load at all, the joist has to bend. That's how it can develop a reactionary force. The bending creates tension in the bottom part of the joist and compression in the top part. but it also creates perpendicular forces - forces that run across the grain.

in case you hadn't guessed, I am an engineer amongst other things

but taken all together, it would be a big surprise if this failed in any other way. and as long as you keep an ear out for cracking / popping sounds, and an eye out for loose or sagging lag screws, popped drywall etc. it should be safe enough.

but take all of that advice for what it is worth - a guy you have never met who claims to be an engineer on and internet forum and has never seen it