This ones been on my mind for some time now. Wanting some sort of overhead workshop crane that’s cheap to build, doesn’t take up any floor space and no need for expensive bulky structural steel. The idea of being able to dismount it and relocate it or even bolt it to a steel column anywhere has had me thinking for ages on its design.
After searching the web for ideas, I have come up with my own design, which I think will be suffice for what I want it to do. I am by no means a structural engineer or has this been certified by one but its not for commercial use and only for private use in my workshop. I’m building it to what I feel is a safe construction method with my 20+ years of knowledge in metal fabrication.
Like all my projects, they start off with a few design sketches, brainstorming a way to keep it cheap lightweight yet strong enough for a couple of hundred kilos.
For the pivoting action i have gone with a couple of Toyota Landcruiser trailer stub axles machined down to a round surface to work with. As you could imagine, this large tapered bearing design can take tonnes of weight and is a friction free, easy way to get this thing swinging with minimal effort.
Here’s the wall mounted section about to be welded. Using 75x50x8 angle I think will be a great way to fix it to any surface now or in the future. Using my jigging table See the build here! makes it a cinch to clamp it down flat for minimal distortion and to hold things square while i weld it.
Before I start welding, pre-heating the steel is an essential process for good penetration and a solid weld that wont break. I let that warm up till i could fry an egg off it.
Here’s the first part of the jib. Using only the steel I had at the workshop, not wanting to spend any money, I ended up making it from 40x40x4 SHS. The length and design was just the make it up as go approach not spending any time drawing on CAD or anything.
The jib length was made to 3.5m long by 850 high. With use of diagonal bracing, when fully welded will be impossible to bend.
For the dolly track I will be using some heavy duty Uni-Strut. Its been ordered and in transit, so in the interim, I’m going to make the dolly. Made from 10mm steel plate, I’m using some skateboard bearings I had lying around, again to save costs. They fit perfectly into the channel of the unistrut and using 4 each side, will distribute the weight nicely.
There she is. I used 8mm stainless round bar as the shafts and press fit them into the plate. To hold the bearings on I packed them to suit the width of the unistrut then tacked them on with the TIG welder.
Next was the third bearing assembly. This ones at the end of the jib and will pivot the second arm, making it an ‘articulated jib’ Note when jigging this up, its important to get all the parameters square and true to each other so when its in operation it doesn’t lean or swing by itself which could cause stress or twisting in the frame.
The top bearing hub will be welded to the jib, extra strength added with the use of 2 8mm gussets.
Now as the wall plate has the tapered bearing spindles facing the opposite way to each other, it would be stupid of me to weld this one on too. So my design includes a bolt-on bottom bearing.
Here i have tacked the bottom one on so I could drill the holes through the SHS without anything moving. The whole thing will be dismantled and bearings removed before I weld it up.
There it is all finished and ready to paint. Here you can see, well sort of, the unistrut welded to the bottom and an extra 10mm plate for more support for the end and also a stop for the dolly inside the track.
After a long day, and working into the night, the frame is finally painted. Time to go home. Cant wait to get it up tomorrow!
Loving being at work on a Sunday. Although its not really working when you’re enjoying yourself building things from scratch. Installing the whole thing alone took a while. Not an easy task but persistence prevailed and up she went without a hitch.
Using the forklift to hold the jib an the right height, I bolted the wall bracket on, packed the bearings and slid it on. Couldn’t of gone better to be honest. Once the jib was attached at the top it was a matter of inserting the bottom coupling and sliding the bolts through.
Before the bottom coupling went on, I had to quickly slide the dolly on and into the track as the other end is welded shut. If you look closely, there is a stopper incorporated into the bottom bracket locking it in but still having the option to take it out for servicing etc is a plus.
A work of art.
As designed, the jib folds nicely against the wall out of the way.
Next job will be to move that stationary hoist in background and attach it to the dolly.
So, the second stage of the build begins. The crane. Here lies a bog standard 240v crane I purchased off ebay. Rated to 500kg, it’ll do for me for now and to be honest, I cant really see the need to lift anything heavier than that. As you can see, H have attached my own hook onto the piss weak little hook. haha. This is to make it look more man like and be able to attach slings without any fuss.
Next was to use the standard mounts (the silver top hat shaped ones) and make up a dummy eyelet, the reason for this was to find the centre-point/balancing point before I make the real attachment.
Here’s the real attachment about to be welded. Note the plate goes right through the SHS for maximum strength, knowing the flatbar eyelet will never tear off the SHS when under load.
A quick paint and a stitch weld onto the standard brackets ad she’s all done.
Well that was a bloody waste of time. No matter where i sit the eyelet in relation to the crane, its never balancing correctly. Not happy.
Jake’s over it too. Time to go home…
After a few days off the project. Im back again, round two. A more sturdy attachment using the same principle as the dolly with the bearings in the track.
Looking more promising.
Time to hack the crane. Being so far in the air nobody wants a dangling controller that has a 1m long controller. How the hell am i supposed to reach that? Let alone use the crane, steady the work piece and juggle holding the controller at the same time!. So, I’ve purchased a 12v 2 channel wireless relay. Lets get busy!
Well its not looking promising. Unfortunately the switch gear is all 240v. Its also using this huge capacitor which i assume is to give full voltage to the contacts at any given point. Back to the drawing board.
Ok so 3 weeks have passed. I have been waiting for this little device to arrive in the mail. Its a 240v 2 channel wireless relay. Something you would find in a garage door opener for example. Here’s me doing a bench test but so far with not much luck. I have bypassed the switch to the relay but that f’ing capacitor has me stuffed. Without wiring it in the circuit nothing happens and with it, when i turn the power on its just reeling the spool in with no control of the switching. I’m going home…
Another few weeks have passed, and I’m at my wits end with that bloody crane piece of shit. Time to start fresh. Here i have purchased a 12v ATV winch. With wireless controller!. So much easier!. Its rated to 3000lb (around 1360Kg) which is way more than i need and to be honest, I doubt this could handle a tonne.
After about 20 mins shes already mounted to my dolly, control box attached and ready to hang. The anticipation is killing me. Having that crane jib above my head each day at work and not being able to use it is doing my head in.
Well its finally on! And it works a treat. Having it only connected to 4WD battery for the time being, if you see in the background, i have already made provisions for a 240v to 12v transformer sometime soon but for now its at least working!
Now to start on the articulated jib!
Stay tuned for more progress soon!