Alright I've been having a hell of a time trying to find a simple design for a post based wood crane. It's not going to be handling heavy loads, it's to help lift me groceries up my rather steep porch cause I'm lazy. I had some work done and had the gents attach a post. Now I've salvaged the painted post to the right of it for potential reuse. I plan on getting a cheap winch and then mounting it either on the unpainted post or the painted which I plan to make the boom. I had planned on using a swivel base, but I was rethinking and they don't do well with the sheer that the design would cause. So do any of you old bones know if what I can use to do this? I'm not deadset on using the painted post.Note that the base is only bolted to the rail so this crane cannot accommodate much of a load and it isn't going to be used for that. The winch will be hand powered
>>2953688Forget the crane and just lower a rope and pull it up with your hands.
>>2953688If you really just want a thing for the sake of having a thing. Just put one of these on the top.
>>2953688Gin pole/sheerleg. Have it set on a hinge so it can fold over the side when not in use. Have a little pulley on it to help you out, the anchor line to the floor or wall will give you some extra strength so you don't brain anyone with melon just in case.
>>2953726Mind giving me a sketch, I've been looking at a hinge design but can't quite visualize how Id do it
why bolt to the rail and not the big ass post?
>>2953755see>>2953726>Gin pole/sheerleg.you were capable of getting here, you are capable of doing a simple web search
>>2953761Man this might be what I'm looking for, thanks for actually being helpful bud.Looking at what's going on here I might just cheat and use a lazy susan base then rig up a simple PVC sheerleg setup on top of it. >>2953757The post you are seeing is bolted to the other post in the railing. It is over the railing as I want my lift to get the goods up and over.
>>2953688if i was going to do this (i'm not) what i would do is get a couple of 2x4 cls, cut three lengths, (a jib, a mast, and a diagonal support) make the jib maximum say 1.5 x as long as the mast. (plus a small amount of jib sticking out to mount a pully) screw them together. cut triangles in 3/4 inch ply to match. glue, screw, about twenty coats of polyurethane varnish if its going to live outside. a couple of heavy duty pin style gate hinges attach it to the pole allow it to rotate around the post or lift off and away when not in use.only problem will be you don't want it to swing on the hinge while you are using it, so grab a cabin hook while you are getting the field gate hinges to hook the crane to the post to counter the torque from pulling the rope.the overall size will depend on the weight you are lifting and the clear span between the crane and the post fixings also. please at least understand moments of force before doing something like this. you know what torque is right?
>>2953811I understand most basic physics. Calculating their true limits is not something I'm seeking to do so I'm starting with a required low amount of weight and then picking a mechanically safe design. This is why I didn't opt to pick a lazy susan plate as I researched and found that they have modest at best shear force handling. There will be no heavy loads on this, it's for groceries not cargo.
Ok so I had a splash of inspiration. I think I'll use a square pipe flange on the post, then get a bit of metal pipe cut to the width of a board and threaded, then add a three way pipe fitting onto to tightly hold the board in place (add washers on both flange and three way split to spread force over more). Should be the easiest simple way to get a rotating piece that works I think. Also means the 2x4 would be the limiting factor and can recycle the three way to feed the winch line. Bottom of sketch is what I'm thinking. Also it should be sufficient to secure the pipe flange with lag bolts right? Again 75lb max load hereThoughts?
>>2954307Oh let me correct myself. Was thinking of another idea. No need for lag bolts for this, but out of curiosity anyone know how I can figure out the "strength" of a wood screw. Just need a theoretical value of force they can take
>>2954307I guess I should also double up the board to mount in that pipe piece so that it's twice as strong as well
>>2953726
