Introduction: Boom Crane Pulley
Moving into a new house with nice new hardwood floors is hard enough. But if you need to climb not, one but two skinny staircases to get to the living room, moving in is simply a nightmare. Grills, couches, TVs, fridges, etc. are a pain to lift as it is, let alone attempting to traverse stairs. So instead of performing move-in gymnastics while breaking our backs, i decided to simplify things by building our own boom-crane pully system.
This project took about 2 - 3 hours from start to finish (not including buying the stuff).
I hope you enjoy my very first Instructable!
So the basic idea is that this is a 3-story house with roof deck. The living room is on the third floor, and has a balcony. The crane is mounted to the floor of the roof deck (the 'fourth' floor). This will allow us to pull things from the street level up to the third floor balcony. So the boom crane is saving us from having to bring things up two flights of stairs.
Step 1: Materials
I guess we'll start off with a list of items needed for the crane itself, along with some tools.
Materials for the crane:
2 1/2" x 10' diameter rigid conduit
2" x 10' diameter rigid conduit
two 1/2" x 5" bolts
a bunch of 1/2" washers & nuts
1/2" x 3" eye bolt
2 1/2" pipe brackets
flat head deck screws
60 grit sand paper
I got all my stuff from Home Depot. The two pipes are surprisingly expensive, and will run you about $100. Since this will stay outdoors, make sure that everything you buy is galvanized. This will prevent any of the metal parts from rusting.
Materials for the pulley:
Double wheel pulley
Single wheel pulley with second mounting point.
100' of strong climbing rope
40' of regular rope
I got the pulleys off of eBay for about $20 a pop. Just do a search for 'wood pulley.'
The rope was purchased from REI. This is definitely the most expensive part of the setup. Once again i wasn't sure what i would need, so i went with the sure thing. I got 11cm rope that could lift 29 kilo-Newtons. I'm not sure exactly how much that is, but the guy at the store told me it would lift a car, so it's good enough for me!
1/2" drill bit (for metal)
compound power saw
7" cutoff blade (for metal)
Step 2: The Boom Pole
All righty lets get right into it. I'd highly recommend having someone to help you out with this. It is definitely a 2-person job.
The first step is to drill some holes. The holes will all be 1/2" diameter.
While one person holds the pipe steady, the other person drills.
Put the pipe up on a piece of wood so that you don't drill through the roof!
The 2 1/2" rigid conduit will be the main boom. drill the first hole about 1/2" from the end of the pipe.
This hole is for the eyebolt.
The pipe came with a threaded connector, so i just tightened it and kept it on for stability.
It's tough to see, but try to drill as straight as possible.
Make sure to wear safety goggles, because the last thing you want is a piece of metal going in your eye.
The second hole is going to be about 2" behind the other one.
However, it needs to be at a right angle (90 degrees) from the other one.
This hole is for the support pole. It will attached to the side of the main boom.
Now we need to install the eyebolt. Insert it into the hole. On the threaded side, add one or two washers, and then a nut. Tighten this nut as hard as you can!! Then put on a second nut to keep the first one from unscrewing.
That's it for this pole!
Step 3: The Support Pole
Now you need to decide how long you want your crane to extend out. I'm not a mechanical engineer, but i can figure out the further the boom is from the building, the forces compound dramatically. But you don't want it too close, or anything you lift will be dragging along the wall on the way up!
I chose to go about 4 feet out beyond the wall.
The support pole is a little bit trickier. Since these conduits come with threaded ends, i didn't like that so the first thing i did was cut off one of the ends.
I used a compound miter saw fitted with a 7" metal cutting blade. Once again, have one person holding the pole. Cutting this thing produced a TON of sparks! In the future, i would wear gloves while doing this, as the sparks kind burned when they touched you.
It should go without saying that this step DEFINATLEY requires safety goggles!
Once the end is cut, i used some sandpaper to smooth out the outside & inside of the pipe. Now we need to drill our first hole. I drilled it about 2" back from the end of the pipe (the nice clean end). Once that was done, i needed to determine the length. I put a bolt through the hole and the second hole on the boom. This is just for testing! I slid it out over the edge and once i was happy with the distance, i made three measurements: the length of where to cut the pipe, the optimal place for the second hole (about 1" from the end), and also where to attach the pole to the railing.
Once we were all measured up, i pulled it back in, and disassembled it. I lined up the support pole in the saw, cut of the other, and sanded it.
We now need to drill the second hole in the support pipe.
Remember, it has to be at a 90 degree angle from the one on the other end!
If you marked it well in the last step, you should have no problem.
Step 4: The Railing
The last hole that needs to be drilled is in the railing itself. I'm not sure what the angle is (about 45 degrees i'm guessing), but once again, if you marked it well, then you'll be fine.
The railing is hollow, and it looks like it's made of 2" pipe as well.
You can either drill from the top or the bottom. I chose to drill from the top, because that's where I made the mark, but I needed to lean out over the railing.
Step 5: Assembly
Now we put it all together. Put a bolt through the second hole on the boom pole and one of the ends of the support pole. Put one washer on each side of the bolt, and one in between the pipes. Tighten it, and then add a second nut.
Slide it out over the edge like before, and the lift up the support pipe and line it up with the hole in the railing. Once it's good, put the bolt through the top, sandwiching washers in between. Tighten it, using two nuts.
Step 6: Mounting the Boom to the Deck
We now need to mount it to the deck. I used only three clamps: one close to the edge, and two at the very back of the boom pole.
Mark off holes, and drill them out using a wood bit smaller than the screws.
For the bracket near the edge, I ran into a problem. It appears that the plate that holds up the railing post was directly under the boom! So the hole on the right couldn't be drilled.
I switched to a metal bit and drilled it out. No problem!
And were done! Our crane is built.
Time to move in!
Step 7: The Rigging
To set up the rigging, you run the rope through the following path:
- Big pulley, wheel one
- Small pulley wheel
- Big pulley, wheel two
- Attach to small pulley mounting point
I opted to tie a loop and go through a carbineer for mounting to the first pulley. This way you can unhook it easily if need be.
The loop should be none other than ..... a bowline!
It's the strongest knot PERIOD and does not slip. Very safe, and sailors have been using it for centuries.
Attach the smaller rope to the hole in the smaller pulley. The purpose of this line is to guide the objects away from the side of the house. Since the boom crane only extends four feet, most objects need to be pulled away. It also prevents things from swinging wildly.
So the basic idea is that there will be one (or two) people on the ground that will pull the object up, while one person guides the object. A third person is on the balcony ready to pull anything over the edge of the railing, and safely onto the balcony.
The way the pulley system is rigged up, it results in a divide by four lift advantage to the person on the ground. It does use more rope than a single pulley system, but this way one person can do the lifting if need by. So if the object weighs 100 lbs, you only need to be able to pull 25 lbs.
Step 8: Boom Crane in Action!
We lifted all sorts of things up, the heaver ones being a TV, barbecue grill, and a fridge.
For the objects to be lifted, we simply used bright-orange truck tie-down straps. They're rated for like 3000 pounds, so it was more than enough. You just wrap them around an object like a present (crossed unterneath). This gives you a good point to lift from, and prevents the object from slipping out.
Well, the biggest question I'm sure you have is "How much can it lift?" Well, I didn't want to do any destructive testing to see its breaking point, because then I wouldn't have myself a cool crane any more!
But we lifted two big guys on it at one time, each weighing over 200 lbs, and there were no signs of weakening anywhere.
So I can confidently say that you can for certain lift 400 lbs on this thing. And that's a lot of weight.
Summer is coming up and we've got some great ideas for this thing, one being a tire swing! It will also make it much easier getting beer kegs up to the balcony.