flyguy0101 - 30-8-2013 at 08:39 AM
Alright figure there are a lot of smarter people than me and am tired of googling. I need to figure out the correct size of angle iron i need for a
simple lever. here is what i know:
@------*--------W
@= pivot point
* = Actuator point (1600 lb linear actuator- more than enough only need 1100lb to lift)
W= weight of load 400lbs
length of lever is 44", and actuator is 13 inches from pivot
queston is will 1/8" 2x2 angle iron be sufficient or will it bend if not strong enough what is best size to use
thanks in advance
scott
Demoknight - 30-8-2013 at 08:45 AM
I am no engineer, but I am an iron worker. I would say for 400lbs, you should look at 1/4" 2x2 instead. I have a lot of experience with static loads
on angle, and I would say that 1/8" just probably won't cut it. You can almost bend 1/8" across your knee. You could maybe go with 3/8" if price or
device weight is the main issue, but I wouldn't go any smaller. Mind if I ask what you are building?
flyguy0101 - 30-8-2013 at 08:52 AM
@demo- it is a lift for the lid on a trailer i am building- will raise the lid off the trailer, while maintaining level and will raise it 44" above
the top of the box. There will be four levers but the other 3 will only assist with gas shocks. inspiration comes from this- www.herculoc.com then click on the youtube video. Critical issues must be able to keep my gear on the lid and access the box/bed. Load will
include 4 bikes and 2 ww kayaks, or a ww raft with full rowing rig. I posted a pic of the trailer progress somewhere on here.
Scott
Demoknight - 30-8-2013 at 09:51 AM
I just saw your other thread. That is a pretty snazzy trailer! Since that gives more context to what you are trying to do, what are you using for
the lid, wood? If you have several attachment points along the angle and the lid, that should add a lot of strength and stiffness. You would
probably be just fine with the 1/8" after all. The reason I said it would not be strong enough before is because it would bend and twist easily.
With the lid attaching to it to take torsion out of the equation, it should be pretty damn rigid.
Demoknight - 30-8-2013 at 09:55 AM
Also, the weight of the load is evenly distributed along the entire top of the lid. I was thinking that you were trying to hang 400lbs off the end of
the angle, which would probably twist and bend right around that point.
Windy Heap - 30-8-2013 at 11:14 AM
@------*--------W
@= pivot point
* = Actuator point (1600 lb linear actuator- more than enough only need 1100lb to lift)
W= weight of load 400lbs
length of lever is 44", and actuator is 13 inches from pivot
is your load, 400 pounds, or 1100 pounds?
explain, as you have a long moment arm there with the weight cantilevered out 31 inches from your lifting force vector.
flyguy0101 - 30-8-2013 at 02:58 PM
@ Windy- i am lifting total weight of 400 lbs. because of the lever arm i have to increase 3:1 but when i ran it on a calculator it came out at
1030lbs.
@demo- the lid will be a foam core with 1/4 plywood "I" beams 1/4 ply on bottom and three layers of hand laid fiberglass. I will use one layer of
polyester cloth and two layers of mat glass and polyester resins. I have layed up several whitewater squirt boats and helmets- although that was
using a mold this is more like laying up a surfboard. I will glass in a 2x4 perimeter for rack and lift points. Should be about 100 lbs and will be
able to walk on it.
Scott