Intro: Collapsible Pull-up Bar
Our climbing gym needed a pull-up bar, we needed something to do instead of studying for exams, it was a match made in heaven. What follows here will take you through what we did, but should be viewed as more of a rough guide since anyone wanting to replicate this will probably have to change the design to suit the particular situation.
We had several goals for this project. The finished product needed to be sturdy and inexpensive, and it couldn't take away any wall space from the actual climbing section.
The design shown here folds down against the wall when not in use, and so far has held up to all the abuse we've thrown at it.
Step 1: Materials and Tools
Planning is all well and good, but most of the time the final choices are dictated by what is in stock at the closest hardware store. However, the parts used here are all fairly common so they shouldn't be too hard to track down. You will need:
- 1 meter of 40mm steel square stock
- 1 meter of 25mm steel tube (30mm may have been better)
- Some scrap 40mm steel angle iron
- 1 carabiner and two ...
- Two sturdy hinges
- Some vectran or rope (ideally not stretchy)
- Assorted bolts or screws for attaching everything securely to the wall.
As far as tools go, a drill, an angle grinder and a stick welder could probably get the job done but we hurried things along with a nice chop-saw as well.
If you don't have a friend with a welder, you could find ways of putting this together with bolts, but trying out welding was half the motivation for this project...
Step 2: Cutting the Metal to Length
The full length of the round bar will be used, so the only cut really necessary is splitting the square tubing into two equal lengths. If your stock is irregular as ours was, you may also want to trim the ends of everything to make them nice and square. We also cut two 50mm lengths of angle iron to weld to the ends of the round bar and bolt to the square tubung (don't worry, this will make sense in a moment).
Once the stock is cut, it's worth cleaning up the edges with a flap-disc on the angle grinder to make welding easier.
Step 3: Welding and Bolting It Together
Each half of the square tubing gets a hinge welded onto the end. Pay attention to orientation, and perhaps find better hinges than we did - ours didn't hold up terribly well to the welding process.
A 90 degree piece of metal is welded to each end of the round bar, giving us a flat surface we can bolt to the square tube.
Once we checked the alignment, we drilled holes to bolt the whole thing together.
Check the pictures for more info.
Step 4: Finishing and Painting
We sanded everything down, ground the weld into something more respectable and coated the whole shebang with some nice paint. It's amazing how much more professional things look with a lick of black gloss...
Step 5: Installation
I'll add some better pictures as soon as I remember to take some while in the gym. We drilled holes through the planks behind the climbing wall and attached the hinges with some long 8mm bolts (with some extra wood to spread the load). A 10mm bolt with a ring on the end forms an anchor point for the vectran rope, which goes up behind the campus board through two caribiners near the top of the wall and back down the bar where it is attached with a couple of clove hitches. It's this rope that takes the majority of the load, while the hinges just keep the square tubing in place against the wall.
By unclipping the rope, the bar can be lowered to lie flat against the wall out of the way.
Of course, we had to test the thing! Amazingly, nothing broke or killed any of us and even two people bouncing up and down (dynamically loading the system as it were) did little beyond bending the bar slightly.
That about wraps it up for now, at least until I can be bothered to put together a proper video and get more pictures of the finished project. This was a fun diversion, and hopefully will provide a useful service letting my fellow climbers get even more ripped.
Post questions etc down in the comments below :)