alex
Dork
10/21/09 8:14 p.m.
I'm new to the world of simple machines. Well, okay, I'm new to their use for non-destructive means. As somebody s-m-r-t once said, 'Give me a long enough lever and a place to stand, and I shall move the Earth. Or snap this bolt. Whatever, just hold my beer.'
Anywho, I'd like to rig up a pulley system to hang from the rafters in my garage, which I can employ to remove the utility cap from my new utility truck singlehandedly. (Alternatively, the system can require the use of both of my hands. Bonus points if you can design something that doesn't require me to put down my beer, though.)
All right, arm chair engineers: on your mark, get set, design!
NYG95GA
SuperDork
10/21/09 8:22 p.m.
Modify a garage door opener? 4 hooks, 1 push button.
alex
Dork
10/21/09 8:24 p.m.
Oh em gee. Push button. My mind is blown.
That said, I do like the idea of employing pulleys and rope and such. Very primitive.
What is the weight, dimensions, budget, etc.? Also, tell me about the rafters.......(picture yourself lying down on a chase and telling me about the rafters).
-Les
4 hooks, a pulley above the area where the bed of the truck would be, a pulley off to the side of the garage, and a harbor freight elec boat winch, 3000lb capacity elec winch with a pair of pulleys should move just about anything. WITHOUT putting down your beer. Or as my wife says you could "just get a chick to hold your beer"
the four corners, and the 5th pully below, are fixed to the rafters. They change the direction of the rope 90*, virticle to horizontal. The four corners should be swivel mounted, while the lower 5th should be fixed. The 3 in the center are floating. This will only work if the topper is somewhat balanced, but no guarantees regardless.
One handed, to hold your beer easily.
fastasleep wrote:
.......(picture yourself lying down on a chase and telling me about the rafters).
-Les
That's just disturbing.....it even scares my wife.
Two pulleys, one at center of cap, one at wall just above a cheap boat winch. Snap harness on cap, crank winch to remove. Install is reverse. Use cable, rope stretches too much.
My dad uses this system to install and remove a boat rack on his truck. The rack is stored hanging from said system.
Maybe modify this concept.
http://www.instructables.com/id/Bicycle-Hoist-or-%22How-to-get-the-wife_s-bike-out-o/
alex
Dork
10/21/09 8:33 p.m.
Well, it all began when the rafters forgot about my third grade musical...
I actually have no idea what the shell weighs, but I'm guessing heavy. It's one of those fiberglass utility shells that has no windows, and two doors along the sides where windows would be. Coupla hundred pounds, maybe?
For all intended porpoises, it's this:
Figure about 4x8 as dimensions. I'll have a ladder rack as anchor points, like the one in the picture.
Budget? As close to $10 as possible.
alex
Dork
10/21/09 8:34 p.m.
Spinout007 wrote:
fastasleep wrote:
.......(picture yourself lying down on a chase and telling me about the rafters).
-Les
That's just disturbing.....it even scares my wife.
Don't scare his wife. She seems cool.
alex
Dork
10/21/09 8:37 p.m.
Also, design a system where I can edit my post title for the proper spelling of pulley. Baxter.
I realized that I drew mine incorrectly, the 3 pulleys in the center are wrong, there should only be two.
alex
Dork
10/21/09 8:48 p.m.
xci_ed6 wrote:
I realized that I drew mine incorrectly, the 3 pulleys in the center are wrong, there should only be two.
You mean to take the center pulley out and draw the ropes from the lower two corners through the lowest pulley?
RossD
HalfDork
10/21/09 8:58 p.m.
modify the setup in the link but instead of pulling on the rope use one of these:
and sip your beer slowing because it can spill out of your grinning mouth.
include winch if you wish, this design involves a few pulleys, a few knots to essentionally make a Y junction.
as long as it isnt extremely off balance side to side it should be pretty stable
While I am an engineering student, this is 2 min of my time while tired.. might require more thought. call it a first draft napkin sketch.
additional though point.. forget the bottom Y's just go to the center of some lumber that attaches to the cap (at the ends of the board). takes out the travel reduction of the junction in those Y's.
alex
Dork
10/21/09 9:59 p.m.
I am a little concerned about having only one plane doing the lifting, only because I have doubts about my ability to consistently line up the truck perfectly with the pulleys. It seems to me - a pulley newb - that lifting from four corners simultaneously would be the ticket for uppy and downy stability.
But, Apexcarver, I see where you're going. Looks like you address my issue while keeping the number of actual pulleys to a minimum. On your lower drawing, the two circles at the far left and right aren't pulleys, but simple joints, right?
5 pulleys
at the front and rear of the cap it is transferring the vertical lift to a horizontal pull with one pulley each front and rear. pulley does a 90* change of motion.
at the center you do another 90* change of motion off to the side. the 2 ropes then converge at a Y junction to give you one rope doing the lifting. The pulley off to the side isnt critical, but it allows greater rope control without having to rub the rope agianst the cap while achiving maximum lift.
In order to keep the forces needed low I would encourage that the actual lifting be done in the same direction as the motion (straight up and down). (why those are pulleys and not simply junctions)
as for your concern about lining up.. side to side isnt all that difficult in a garage situation.. (been there done that, found myself consistent within 2-3" which i find allowable for the way this is)
as for fore and aft.. either make a wheel chock for the back that goes back to the wall or you could do what we did in our garage. hang a tennis ball from your rafter. find the right depth into the garage and hang it so that you know when the windshield or back window just touches the ball.. stop there.
I would think you may want some sort of double pulley system to reduce the effort to life the shell, so the rope doubles up. Maybe make an attachment point on the top of the shell so you don't have to deal with attaching four straps each time.
GlennS
HalfDork
10/21/09 11:05 p.m.
Gentlemen
After assembling a crack engineering team to tackle this problem, my team and i through complex computer modeling techniques have come up with the optimal solution. You can all send me a beer as i believe this will improve all of our lives.
edit: and you dont even have to be able to spell pulley right and your still a genius.
Luke
Dork
10/21/09 11:27 p.m.
And the Nobel Prize for achievements in the combined fields of garage innovation and domestic bliss, goes to...
It was so much easier in the old days.....
alex
Dork
10/22/09 12:13 a.m.
God I love you guys. And that's not just the Fighting Cock talking, if you know what I'm saying:
alex
Dork
10/22/09 12:14 a.m.
And how did you know my wife is blonde...?