[Masterjuggler98]

That J-jop looks very interesting. I've never heard of it before but it seems simple enough. It's based on the r-hop; you just use silicone caulk/sealant to fill the hopup window while you have a rod filling up the barrel to make sure the caulk takes the right shape. I'll have to try this at some point and see how it works. Silicone caulk rubber is certainly rubbery enough to grip the bb. I'll also have to see if different caulks wield different results.

About the T-hop: this is why I made that whole post on how to google things. I did a google search on the t-hop and came up with this.

 

[Masterjuggler98]

Could the bad results you've gotten have been because the surface the bb contacts isn't smooth enough? HS5 tells us to use at least 400 grit sandpaper on the r-hop so we would need a surface at least that smooth on the j-hops to make legitimate comparisons.

I once saw this instructable on how to make something called "oogoo". It is basically type 1 silicone caulk mixed with cornstarch to make it cure within minutes. The moisture in the cornstarch cures the caulk which absorbs moisture to dry (ironic, huh?). I wonder if the cornstarch would give the caulk that extra hardness to work well. I've made things with the oogoo in the past and it is about the hardness of a hard rubber bouncy ball, and bounces nearly as well.

 

[Masterjuggler98]

I think you should use either packing tape or teflon tape as the outer layer of your shish kebab so you get the j-hop as smooth as possible. Depending on what duct tape you have it can be pretty smooth but because of the mesh that gives duct tape it's strength, it won't be as smooth as other tapes.

 

[Masterjuggler98]

You should check out the instructables page on the oogoo. The guy explains what the different cornstarch to caulk ratios do, the setting times, what it sticks to, etc. By the way, the oogoo was named after sugru because of their similar characteristics. Just an interesting fact.