Request for beam calculation, please.

[FTG-05]

Gotta beam calculation I need some smart people to do for me, please.

Here are the basics:

- Assume qty two 1" x 1" x .120" tubing, positioned side by side, separated by 6"
- beams are 6' (72") long
- Two point loads, L1 and L2 are located 1' from each end (ie. 4' apart centered on the beam)
- The two point loads are the same ie. L1 = L2.
- The two tubes are connected using expanded metal on the bottom lengthwise; for the purposes of this calculation, the mechanics of materials of the EM is ignored other than the fact that it fixes the two tubes to each other and prevents the two tubes from twisting or separating from each other.
- This beam is used for overhead lifting i.e lifting a "vehicle" for work underneath it - hence use whatever safety factor is appropriate for this work and situation

What is the max load for for L1 and L2 for this beam assuming a) L/240, b) L/360 or c) L/480 max deflection. Recommend that max deflection you would use.

I'll hold off giving the purpose of this beam until later, if you don't mind, I want to focus on this calculation vs. the purpose.

Thanks,

 

[joeu235]

Good luck. Anytime I've asked a question like this, I always get 10 people saying "ask an engineer"

 

[frugalangler]

I do remember a member offering to do similar calculations for anyone wishing to construct a 'sky crane' or such, seemed he had the knowledge and tools to do the calcs.

Check here: http://www.tractorbynet.com/forums/projects/341935-garage-bridge-crane-post4992042.html#post4992042

 

[Rock Crawler]

Re-read your post... with less haste. I see what your doing here.

 

[Rock Crawler]

ignoring the connecting material as he requested, assuming that the beam is simply supported at either end, and provided that the point loads are applied evenly and in a way that does not alter the cross-section of the steel member (no holes or deformations).

The loads corresponding to his max deflections are as follows:
L1=L2 for a) 132lbs, b) 88lbs, and c) 66 lbs

Obviously there are two point loads, so X2 for total load on the beam...

 

[FTG-05]

ignoring the connecting material as he requested, assuming that the beam is simply supported at either end, and provided that the point loads are applied evenly and in a way that does not alter the cross-section of the steel member (no holes or deformations).

The loads corresponding to his max deflections are as follows:
L1=L2 for a) 132lbs, b) 88lbs, and c) 66 lbs

Obviously there are two point loads, so X2 for total load on the beam...

If that's anywhere close to being accurate - this isn't gonna work. I need about 1000 lbs. per beam.

This is for two platforms that would attach to my shop lift to lift smaller "vehicles" like my Kubota ZD326 ZTR (1700 lbs) or my RTV (1975 lbs). I planned to do 2 of these, one for the front wheels, one for the back wheels.

Back to the drawing board....

 

[frugalangler]

1" X 1" isn't very large, even though it's nearly 1/8" that's not much more than a 1-1/4" steel pipe.

I've actually been wondering something similar, I've a quantity of surplus 2" square 3/16" wall tube, wondering what a pair of those might support at the center-point spanning about 8' as in a poor man's gantry crane? or, would stacked and welded periodically along the length improve against parallel horizontally placed?

 

[Rock knocker]

What is the max load for for L1 and L2 for this beam assuming a) L/240, b) L/360 or c) L/480 max deflection. Recommend that max deflection you would use.

I'll hold off giving the purpose of this beam until later, if you don't mind, I want to focus on this calculation vs. the purpose.

How could anyone recommend a deflection if the use is secret?

 

[Rock Crawler]

Why would you even consider a 1000 lb load on such a tiny member? 2x2x0.25 would be something to consider and it's still dirt cheap. 4x4x0.25 would be much better if you want a human under that load.

 

[countrybumpkin]

Is something like this what your trying to accomplish ?

 

[FTG-05]

Is something like this what your trying to accomplish ? View attachment 539832

Yep exactly. Except homemade.

Not as HD and certainly not as expensive! $1200!!! Ouch!

Also does not have to have adjustable width.

And now I know what they are called: Lawn Mower Adapters.

Thanks!

ETA: And it's from the same people that made my lift: Atlas. here's my lift: Atlas(R) PV-12P Overhead 12, lbs. capacity Adjustable Height 2 Post Car Lift (EXTRA WIDE/EXTRA TALL) | GSES

 

[FTG-05]

Why would you even consider a 1000 lb load on such a tiny member? 2x2x0.25 would be something to consider and it's still dirt cheap. 4x4x0.25 would be much better if you want a human under that load.

Ability to drive over it. Obviously it's going to have to be something heavier duty.

 

[FTG-05]

Maybe I need to think orthogonally:

 

[countrybumpkin]

Yep, I’ve too thought about building one also, I had seen that style also hen I was looking for the pic I posted.

 

[FTG-05]

Yep, I’ve too thought about building one also, I had seen that style also hen I was looking for the pic I posted.

Plus the advantage of the type on my post #13 is that it would also be useful for small car that sometimes a pain to find a hard point. Use that platform cover a good part of it with that 3/4" hard rubber mat from Tractor Supply (horse stall mat) and lift away. Another advantage is that the structure is oriented front-back vs. side-to-side, so it won't interfere with anything in the center of the vehicle.

 

[Gary Fowler]

Without doing any calcs, I wouldn't even attempt to lift my lawnmower with a 1x1 square beam as configured.