Haardgrim wrote:I'm making the first two spears for our realm, in preparation for going to Sotahuuto this summer. For lack of nerf footballs (pretty much unknown over here), I'm going with a layered design with camping pad foam and two densities of open core, as shown here is this pre-assembly arrangement:
The thing I'm mainly concerned about is that the blue foam around the first piece of open-cell will behave so differently from the open-cell when squeezed that it will come apart. I could have the blue foam stop partway down the open-cell, which might help. Opinions?
I guess I'm a bit confused about your question, but I'll offer some of my own insight, as I've been relatively obsessed with making a better, lighter spear these days.
Basically the first thing you need to know is that the harder the foam, the closer it needs to be to the actual core of the weapon it's self. From your picture it looks like you've got at least one layer of blue to go underneath your open-celled foam, that's good, and if you don't already (again, hard to see from the picture) make sure you include at least two more blue foam layers between the core of your spear and the striking foam. That white foam is probably unnecessary if your tip foam is decent, and it will most likely cause the tip to bend excessively, which depending on where you are could result in a failed weapon.
My recipe for a good spear design:
1) Cap the raw core with a circle of leather, or a quarter (or similarly sized coin)
2) Attach a circle of foam atop the now blunted core, then:
3) Build a box around the core and cap the box with another layer of blue foam.
4) Box it again, and cap it again.
5) Attach tip foam, reinforce with strapping tape, add cover, courtesy padding and done.
This build will achieve a spear with a finished diameter anywhere from 70 to 76 mm, depending on foam thickness. Despite being somewhat low profile these spear heads hit well, and seem to last for years (You can ask Acorn about that one:))
Hope this helps!