Now comes the fun part. I get to take the laser cut steel panels I showed you in the previous post and begin to form them into their intended shape. When we built the first Shapely I chose to construct an internal armature to support the 16 gauge shell (shown in the next two pictures) .
Since Shapely and Shapely Two are intended for outdoor venues I want to ensure they can comfortably handle several people climbing on it as well as in-climate weather conditions. That armature worked well on Shapely but this time I decided to approach the structural requirements differently. I am making the lower section out of 11 gauge (0.120″) instead of 16 gauge (0.060″) material for several reasons.
- Shapely Two has a much more, shall I say, svelte look, making it challenging to fit an armature inside.
- I was so happy with the rigidity of the box construction provided on the first Shapely that I am confident the added thickness will provide plenty of structure
- best of all, it simplifies construction.
There are no flat surfaces on Shapely Two. A characteristic of virtually all of Jennifer’s work. Each side has varying degrees of curvature. Some are small enough that I can easily position them using blocks, clamps or just by pushing.
Others will require more aggressive forming to obtain the proper shape. Since I have yet to acquire a slip roller, I use this low tech bender for shaping the sheets. It is effective but I have to be careful not to put kinks in the panels.
Before I start bending each panel I need to establish the line it will curve along. Once that line has been drawn I add perpendicular lines every few inches. I align these perpendicular lines to the axis of the tube I am bending the sheet around. Skipping this step would risk putting unwanted twist in the panel.
Here you can see how two of the panels are fitting up. The closer I can get them to match without clamps the easier they are to tack together. Minor gaps can be adjusted out during tacking and final welding.
Another view of the fit up between the sides. The section closest to the camera will be pushed into position during tacking.
Once I am reasonably happy with the fit it is time to tack the panels together. To ensure that the base will be ”square” I fixture the panels on the top of the work bench and true everything up. You can’t have too many clamps.
Tacks are small welds that temporarily lock the panels together but can be easily broken or cut if necessary. I place tacks every 6″ to 12″ depending upon the curve. The tighter the radius the closer the tacks are together.
I am also paring the tacks so that any shrinkage at one tack is counterbalanced by a tack on the other side of the panel. This helps keep things from moving around. In the next picture all 4 sides are tacked together. Now I will set this piece aside while I tack the mating section together. Then I’ll come back and fit up the top plate (which must match the mating section) and install the bottom mounting plate.
I’ll cover that in the next post.