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Beam Calculation - Check This Out

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ddurrett896

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Mar 29, 2015
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VA
Hey I have (2) 24" LVLs that span 22' that support part of my garage.

I admittedly don't know how to read specs and only needed to understand pass or fail for my permit.

Below is a picture from the engineer. I have a 1,200LB lathe on my trailer that needs to come off and was thinking I could use that beam like a Gantry Crane to hoist off the trailer an inch or 2 so I can pull out then lower down.

Will it support that 1,200LB load hanging? Thanks!

View media item 105247
 
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mcbane

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California
41plym is right. Just one detail: if possible get a properly rated strap over the top of the LVL to do the lifting. Dont count on a lag screw or a big wood thread eye-bolt into the bottom or side of the lvl.


Sent from my iPhone using The Garage Journal mobile app
 
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matt_i

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SE Michigan
+3 on the temporary posts.

Could be a post that you buy like a basement steel tube column with an acme screw or one that you make up like a laminated 4x6 and use something like a series of wooden wedges or even a 1 ton bottle jack. Just need to create a very slight compression, just enough friction to ensure the post doesn't fall over.

Suggest a roundsling or a web-strap flat sling over top of the LVL in a basket to the top hook of a lever chain hoist or a chainfall to lift the load. Lathes are top heavy, so be extremely careful. Many times the first cross-rib on the bedway casting is the best place to pick it up and run the carriage and tailstock down until balance is achieved with the headstock.

McMaster Carr and Grrrraainger are reasonable sources to look at rigging.
 
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Bretny

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I wouldnt use the beam. Your strap even if 3in wide is going to really dig into it...if it dosnt fail. I have moved many machines by rolling them on pipes and 1200lbs is well within a 2ton engine hoists limits.
 
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matt_i

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Bretny said:
I wouldnt use the beam. Your strap even if 3in wide is going to really dig into it...if it dosnt fail. I have moved many machines by rolling them on pipes and 1200lbs is well within a 2ton engine hoists limits.
Click to expand...

I disagree and here is why: a 1200 lb load on ( 3" wide strap x 3.5" thick for 2 ply LVL thicknesses) = 114psi.

Compressive strength of pine SPF is allegedly 4800 psi. (not sure if that's cross grain or end grain) but an LVL is considerably harder than a SPF 2x_ timber....
 
OP
D

ddurrett896

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VA
Bretny said:
I wouldnt use the beam. Your strap even if 3in wide is going to really dig into it...if it dosnt fail. I have moved many machines by rolling them on pipes and 1200lbs is well within a 2ton engine hoists limits.
Click to expand...

It’s getting it off the trailer. After it’s on the ground I’m good
 
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Samh

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Canton GA
ddurrett896 said:
It’s getting it off the trailer. After it’s on the ground I’m good
Click to expand...

I think what he is saying is using the engine hoist to lift up, then drive the trailer out from under it, then lower down. This is all assuming you have an engine hoist though.

but I agree with Matt_I on it.

Regardless of method, the more important question might be the lifting points you use on the lathe.
 
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Innovate1

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Jul 28, 2014
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Illinois near St. Louis, Missouri
Bretny said:
I wouldnt use the beam. Your strap even if 3in wide is going to really dig into it...if it dosnt fail. I have moved many machines by rolling them on pipes and 1200lbs is well within a 2ton engine hoists limits.
Click to expand...

This is not going to dig in any significant amount - probably not even noticeable amount. LVLs are pretty dense, especially with all the glue between layers and coating everything. I have used 3 or 4" straps around trees for many times that force for anchors when pulling over trees and never noticed any dents in the trees. :bounce:

1200 lbs really isn't THAT much. And a 24" LVL is HUGE. Probably not an issue even without the posts and with the posts definitely no issue.

Each end of the beam is designed to support up to 7611 lbs dead + live load for a total of 15,222 lbs. And you are adding 1200.

Put some posts and lift away. Just try to be directly under the beam so you don't put a lot of side force on things.

And watch the machine balance. As others have said many machines are top heavy so have to be careful on lift points so it doesn't want to flip over.
 
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vavet

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Ashland, VA
I like the idea of using a post on either side of the trailer. I had my two car lift scissor platforms on a pallet. I needed to get them on dollies to roll them to my other garage.
I built two small A-frames out of 2x4s. I used a 2x8 and lifted each platform by myself. One end of the the 2x8 was resting on the A frame on one side. I lifted the other end of the 2x8 with ratchet straps running under the platform and over the top of the 2x8. I had the mechanical advantage because the 2x8 basically served as a lever. I was moving it 3 feet for every 1 foot the platform raised.

Now...you're talking about 1200 lbs. That's a bit more, but the principal is the same. Get a longer lever....or get more people to help you lift.
I would probably hire a rollback tow truck to get it off and positioned where you want it, but if you insist on doing it yourself, made advise would be to lift with whatever means, then move the trailer, and then put the load down onto it's permanent home or a different mobile base.
 
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56Mark

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Fall Branch, TN
1,200 is nothing on an LVL that size. It looks like your live load calc also has a snow load of 280 pounds/ft factored in. It is plenty strong. I wouldn't even spend the money on the adjustable posts to put on either side of the trailer. I would build two "Tees" out of two 2x4s each and make them fit drive in tight under the beam (2x6's maybe depending on height). Get them in plumb and you can pick up a tank. A 3" strap is no concern either on the beam; the bearing area on most beams at the end isn't usually much more than that.
 
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nelstomlinson

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Interior Alaska
The snow load is assumed to be evenly distributed. The lathe's weight will not be. With temporary supports, I'm sure you'll be fine. I might not try it without the temp supports.
 
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WNYflyer

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Lockport, NY
Assuming you do a lift when there is no snow, then using your data sheet:

- The original design moment in the beam for the Snow Load ("S") portion only is approximately 12,705 ft-lb of the total design moment of 40210 ft-lb per my figuring. If you put a 1200 lb point load with say 25% vertical impact on the beam at the worst case for bending, mid-span, then the resulting moment is 8250 ft-lb which is less than 12,705 ft-lb. So if no snow you should be good bending stress wise but didn't figure deflection out.

- End shear due to snow is approximately 2310 lb while at the worst for the lifted point load it would be 1500 lb (1200x1.25) which would be the case if you hoisted near the end rather than mid-span.

- The actual bearing stress at the ends looks to be (7611 lb) / (3.5 inch x 3. 5 inch ) = 621 psi which is 83% of the allowable bearing stress. Therefore the allowable bearing stress is 621/0.83 = basically 750 psi. So to bear 1500 lb on the top of the beam you probably need 1500 lb / 750 psi = 2 sq inches of bearing as far as he beam is concerned.

- Per the design notes all the calculations are based on the top flange of the beam being laterally braced at no more than 4'- 4" o.c. Do you have that ? Don't know, but given the calculation I am assuming you do.

- As they say, the above is worth what you paid for it.
 
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