load carrying capabilities of lumber/steel

From: Clint Wolff <vaxman_at_qwest.net>
Date: Sat Apr 7 17:42:26 2001

You forget the machine is mounted on casters, so you end
up with eight point loads of ~200 lbs each... Thin plywood
will help spread the load, but it will deflect also, spreading it
to an area much smaller than a 21" diameter circle. Multiple thin
layers will slide against each other during deflection and not and
much strength.

A single thick layer (1 inch?) would be best, but make sure the
joists supporting the floor can safely handle a 1500 lbs load.
Think how many joists will be under the machine. If the machine
is parallel to the joists, and directly above a single one you
will have problems. The best orientation is perpendicular to
the joists, and as close to whatever is supporting the joists
from below (beam or foundation wall).

clint

On Sat, 7 Apr 2001, Jeffrey S. Sharp wrote:

> This doesn't seem so OT to me, so I have removed OT from the subject.
>
> Quoting "Clint Wolff (VAX collector)" <vaxman_at_qwest.net>:
> > I am looking for an online reference to help me calculate how
> > much live load (AKA VAXen) I can put on my living room floor.
>
> I have thought about this same subject to prepare for the arrival of my first
> PDP-11 (boy am I excited!). This is how I came to a ballpark figure. The
> floor of my future machine room consists of 2.25"-wide wooden slats, of varying
> lengths (approx. 4'-6'), suspended above a crawlspace. I plan on putting a few
> layers of plywood (anything better for this?) on top of the floor to help
> spread the load evenly across the slats. Let's say I want to support 3 rack
> cabinets. Well, that's a width of 21" * 3 = 63", which, in slats is 63" /
> 2.25" = 28 slats. If the system weighs 1500 lbs, then that's 1500 lbs / 28 <
> 54 lbs/slat. I think my slats can handle 54 lbs.
>
> --
> Jeffrey S. Sharp
> jss_at_ou.edu
>
>
Received on Sat Apr 07 2001 - 17:42:26 BST