Wood beam

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Steve welder

Steve welder

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Opinions please, a wood beam full 3 1/2 x 6 inches (not hard wood) with a 8 foot span supported adequately, has a 3/4 hole bored through 6'' part for a 3/4 eye bolt, would it be strong enough to hold 3/4 ton? Had 600 on it no problem but need to support around 1,200 now
 
Which is it? 3/4 ton or 1200lbs?

With the beam laid horizontal, and then oriented with the thick edge vertical, is the hole vertical or horizontal?
 
No. For example, a header for a door or window opening of 8’ (less of a point load) would be 2-2x10’s. Your single beam is actually weaker than 2 pieces fastened together and will deflect or fail.
 
jos51700 said:
Which is it? 3/4 ton or 1200lbs?

With the beam laid horizontal, and then oriented with the thick edge vertical, is the hole vertical or horizontal?
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any beam be it wood or steel would be placed the "hard" way......I knew someone would ask that and thats why I stated the 3/4 hole is bored through the 6 inch diameter
1500 is the safe factor as it gives me a little leeway, 1200 is around the weight dry/ no battery/ radiator empty
Moms68 said:
No. For example, a header for a door or window opening of 8’ (less of a point load) would be 2-2x10’s. Your single beam is actually weaker than 2 pieces fastened together and will deflect or fail.
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Thanks, I had my doubts and its why I asked
I had 600 on it many times and there was never the slightest deflection but doubling that weight I was skeptical
 
My father used something similar in the shop to pull motors for years. But it was laid across the rafters so the actual load was spread across 4 rafters and the main support was only 24" of spread. He never had a problem. I tore it out and never used it. You could see the rafters sag as you applied the load to pull the motor. My eyecrometer was really uncomfortable with that sagging. You already have an issue in your head because youre asking the question. I think you have two roads here. One road includes the line "hold my beer".
 
I would think that a point load, like a bolt in a hole, is different than the weight supporting capacity of the beam. I would be worried about the beam breaking at the hole as well as deflection.
 
It’s not strong enough and my cars in there besides
Going to look into a gantry type frame
Either make it or buy it
 
Jeff Seighman said:
How is the beam supported, is it like a swing set?
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It’s supported strong enough that’s not worrying me
It’s the span and like another guy said it has a 3/4 inch hole bored through it
Was ok for 500 lbs but this machine is more than double
I wasn’t thinking enough
I’m so tight for space and that’s the real problem
 
I would use it, use a 2" thick wall square or rectangular tubing in conjunction with the wood beam, would be better if used carriage bolts to sandwich the two together. I would go with at least 4' of metal the longer the better, metal on top of the wood.
 
Im imagining the hole is dead center for the eye bolt. Load applied in center of beam or closer to ends?
 
Steve if it were me, I would definitely use a 2 by 6 on each side with nails, find the bows & face them up and the ends flush with the bottom of your 4by6
 
Steve welder said:
It’s not strong enough and my cars in there besides
Going to look into a gantry type frame
Either make it or buy it
Click to expand...
Please let me know what you do there. I've been wanting to build "something" for a while now.
 
If space is an issue. You have lots of temporary and permanent options. Folding cherry pickers (rent, borrow or buy), I-beam trolleys, gantry's, lifts (unbolt k member and take out the bottom by lifting body), probably not best space option. You could move in to a bigger place.
 
Treblig said:
Yes and no................it might hold when you lift it an inch but then it might fail when you lift it a foot!!! Stress is accumulative.
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As an Electro-Mechanical engineer I can guarantee you that the 1200 lbs doesn't care if it's an inch off the floor or hung above the grand canon. Stress is the same in that beam.
 
I would not trust it. Make it stronger by adding 2x4s top and bottom then add 1/2” plywood the same width (8-1/2”) the full length on both sides. Box beam design, ply is stronger than just the wood.
 
dadsbee said:
As an Electro-Mechanical engineer I can guarantee you that the 1200 lbs doesn't care if it's an inch off the floor or hung above the grand canon. Stress is the same in that beam.
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My point was that the beam might hold as you initially lift something heavy but it could fail as the weight hangs there longer and longer. Just as bridges hold various weight but over time they fail even though they were designed to hold "x" amount of weight. I've lifted heavy items with a heavy duty rope only to have it fail at the worst possible time. Wood doesn't always fail immediately, especially if has a large hole drilled through it!! If you're a mechannical engineer you know there such a thing known as "stress over time".
Then there's the "elastic region VS permenant deformation VS fracture"....all these are time sensitive events while under the same load!!
Figure_06_03_01a.jpg
 
Working on powerlines I've seen plenty of wood arms holding up transmission lines. Many are 80+/- years old.

If it we're me and I was concerned I'd maybe go this route

20220102_151113_copy_768x1024.jpg


Careful with the block in the corner. That 700lbs is if the lines coming in and out are at 90 degrees. You can double the load if the lines in and out are parallel.
 
I made a mistake when I redid the garage while the walls were still open and the door wasnt yet installed
I could have have put a 4x4x 1/4 tubing on top of the beam and additional supports, I never anticipated lifting anything heavier than a engine and I did have a engine crane.
I will have to leave the machine were it is and work on it there rather than at home as thats the only option
Thanks for all the suggestions
 
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