Question relating to sizing of pins and what calculation to use
Question relating to sizing of pins and what calculation to use
(OP)
Hi there, firstly thanks for taking time out to look at and hopefully answering my question.
I am currently designing a stacking skid system the three will be connected together by means of four pins.
Please have a look at the attached PDF for a clearer idea of what I plan to do. I am just not sure of what calculation I should use to determine the pin size.
The outer cylinder diameter is 80mm and the inner cylinder that goes into it is 40mm in diameter. The resulting sling load on each pin is 23303Newtons.
Again many thanks.....Tony
I am currently designing a stacking skid system the three will be connected together by means of four pins.
Please have a look at the attached PDF for a clearer idea of what I plan to do. I am just not sure of what calculation I should use to determine the pin size.
The outer cylinder diameter is 80mm and the inner cylinder that goes into it is 40mm in diameter. The resulting sling load on each pin is 23303Newtons.
Again many thanks.....Tony





RE: Question relating to sizing of pins and what calculation to use
e.g.:
You talk about pins, but the only identifiable objects in the sketch appear to be socket head capscrews.
You talk about a sling, but don't show it.
Please add some detail.
Mike Halloran
Pembroke Pines, FL, USA
RE: Question relating to sizing of pins and what calculation to use
RE: Question relating to sizing of pins and what calculation to use
I have attached two files one called problem. In this I have tried to detail the drawing a bit better. However you will probably get a better idea in the attached pdf called problem3d. In this you will see two skids. The top one will sit on the bottom one. Then all four courners will be "pinned" the top skid will then be lifted (by a sling not shown) which in turn will lift the bottom one due to the four pins. As mentioned the load on each pin will be 23303N or 2375KG which ever you prefer. So to recap I cant figure out how to work out the pin sizing.
Tony
RE: Question relating to sizing of pins and what calculation to use
RE: Question relating to sizing of pins and what calculation to use
If the 40mm tenon is indeed cylindrical, a reasonably sized crosspin will leave essentially no net area with which to lift anything.
Machining a 40mm tenon from an 80mm round is fairly expensive, as is efficiently terminating the other end of the round to a skid.
It appears that you plan to have two interchangeable skids, and to use the upper ends of the posts of whichever one is uppermost as padeyes for lifting. Lifting applies bending loads, for which you have perhaps not accounted. That's why you need to show the sling to be used.
I mean no offense by this, but you appear to need local help with both drafting and engineering. By local, I mean an experienced person, right there, looking over your shoulder and pointing out mistakes as you make them.
We cannot do that from here.
Please rent an engineer.
Mike Halloran
Pembroke Pines, FL, USA
RE: Question relating to sizing of pins and what calculation to use
For a first pass, look at simple shear.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Question relating to sizing of pins and what calculation to use
Ted
RE: Question relating to sizing of pins and what calculation to use
Mike Halloran
Pembroke Pines, FL, USA
RE: Question relating to sizing of pins and what calculation to use
RE: Question relating to sizing of pins and what calculation to use
The pin will be in double shear as stated by others, have a look at the bolt in double shear at this site, the same formula apply to your situation:-
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RE: Question relating to sizing of pins and what calculation to use