Go Bio. 500 mices in those little cages hooked up to a pulley system. Give the cat something to do while you're at happy hour.
Prehaps your lifts are defective. When correct you should end up needing to push the bed down.
__________________ Let those who can play, let those who cann't watch....
Keeping it simple is the right approach. A winch approach would use tremendous force if kept totally below the bed. I weighed the bed and it approaches 100lbs (on the edge) at the hallway entrance side with the other side hinged. Will be going with stronger pistons as this keeps the design simple and less space used under the bed. Thanks to all for the conversation.
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Mark
1984 31' Excella, mid bath, king size bed
1998 Chevrolet Suburban K2500, 7.4L/454 c.i., 4WD, Pullrite Hitch
AIR No. 2375
You may want to attach the base end a few inches lower to get it a better angle of attack. That way some of the force will be up rather than toward the foot of the bed.
If it requires 100 lbs at the end it will require 200lbs in the middle. I think those ratings on the pistons are in the vertical. You need to get out your trig book to figure the force at your starting angle to know if it offsets the weight at that point. Who said you wouldn't need this after high school.
__________________ Let those who can play, let those who cann't watch....
Paul, you are correct. I have come to a similar conclusion on the angle and location of the base of the piston. I had a horizontal start before...now I know why my back went out with the 100 pound starting weight before the piston lift vector begins to do any good. (Those free body diagrams from mechanical engineering class weren't a waste either.) It is looking like 2 gas pistons, in the 100 lb. to 150 lb. class depending on a mid-frame mounting location and angle. I am leaning towards a much more vertical implementation if the cyclinder and stroke measurements of the pistons allow this with respect to the depth below the bed for attachments (14 inches max.)
By the way, the Suspa.com website gives an application sheet that asks for the required input data so they can work out all the trig functions, lift versus weight, etc. and then allows them to select the correct size and strength of gas pistons they manufacture.
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Mark
1984 31' Excella, mid bath, king size bed
1998 Chevrolet Suburban K2500, 7.4L/454 c.i., 4WD, Pullrite Hitch
AIR No. 2375
It occurs to me that you could also use something like garage door springs instead of an electric winch. Your king size bed is close to 7' long. If you had brakets near the hinge like in the drawing I furnished they would probably be something like 1' long. Put one on each side of the bed and that would be something like 350 lbs of spring needed on each side. Would garage door springs be a lot cheaper than the struts? I don't know...
Found a website where you can order gas pistons online with a credit card: www.mcmaster.com. This website is very effecient!
Have calculated that two 150 lb. gas pistons about 33 inches long with a stroke of 16 inches and mounted on the floor for a better angle of attack (>45 degrees starting angle) should work when attached midway down the bed frame.
I will report back when they are installed.....
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Mark
1984 31' Excella, mid bath, king size bed
1998 Chevrolet Suburban K2500, 7.4L/454 c.i., 4WD, Pullrite Hitch
AIR No. 2375
Electric tounge Jack at a angle closer to the hinge point. Cheap and easy to find. Little bit of brackets to fabricate but no big deal. Remote the switch. leave and acess opening where you could reach in and pull a disconnect pin at the bottom pivot if it ever failed.
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1959 22' Caravanner
1988 R20 454 Suburban.
Atlanta, GA
Why not just use a pair of hood hinges off, say, a 1984 Chevy pickup?
Why does it have to have two motors, twelve pulleys, a mile of rope, and a threaded rod? The simpler the better...
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Terry You repair things with tools. You fix things with a hammer.
AIR#2611
The more exact category appears to be "gas lifts" or "gas springs" and there sure are a lot of possibles. I will have to take a closer look when I get a bit nearer to having a place for a bed.