Stainless Kammback for Previa Redux. Now With More Stainless!

[orange4boy]

I had a the inspiration to work on the kammback or partial boattail, if you will, a couple of days ago.

The top part is now finished except for closing off the end. I cut new trailing edge pieces and extended the lower section rearward to make the end angled instead of vertical as it was in the prototype.

I also slightly reduced the inward angle of the sides as they were somewhere around 20˚ which is fine if all is perfect. I think it looks miles better now and the wake should be a bit smaller. The top piece of lexan is unchanged.

I'm still thinking about how to finish the bottom section. I would like to be able to use it for storage but it should be easily removed and light weight. More thinking required.

It's only a little bit heavier now but I need new struts. I have to prop it up to keep the back open. New struts should hold it up fine.





The prototype for comparison:

[Christ]

Shelf on the bottom:

Attach cantilever (is that the correct term?) brackets back at 45*ish so they hold on the top of the hatch, where the top of the extension starts.

From about the middle of the "arms", extend back to the rear of the "tray", making sort of an upside down "y" shape. Add L brackets to the lower sections of the extension for added support of your new "tray" area.

[NeilBlanchard]

Cool -- what is the dark gray material on the rear wheel skirts?

[orange4boy]

Originally Posted by NeilBlanchard

Cool -- what is the dark gray material on the rear wheel skirts?

None other than black coroplast.

Attach cantilever (is that the correct term?) brackets back at 45*ish so they hold on the top of the hatch, where the top of the extension starts.

From about the middle of the "arms", extend back to the rear of the "tray", making sort of an upside down "y" shape. Add L brackets to the lower sections of the extension for added support of your new "tray" area.

I'm trying to keep it lightweight enough for the hatch to still open but your idea made me think of those hitch mount cargo platforms which could be extended upwards and clad in coroplast. That way it's a cinch to remove.

Hmmmmm...

[COcyclist]

Cleanly executed, all your mods look great! I'm glad to see this resurface. I love the side view on the ferry. You sure live in a beautiful place.

[jime57]

Nice execution. Have you done any tuft testing along the top?

[Christ]

Thought of something else, if you only plan on lightweight stuff...

Get yourself some metal conduit (or PVC tubing) and add a couple support struts from side to side across the bottom, then stretch cargo netting over them and secure it to the sides as well. You can close in the rear as much as you need with a piece of coroplast bent along the fluting.

[orange4boy]

Nice execution. Have you done any tuft testing along the top?

Thanks. I'm much happier with how it looks now with the angled end bits.

First I tested just the top piece to get the main angle, but once I built the sides, I tuft tested the top and sides on the highway with a friend watching. No videos though. Tufts were stable and smooth with no vortex generation on the top corners but there was a but of fluttering on the bottom end of the sides so when I rebuilt it, I reduced the side angles a bit.

I'm probably getting some wicked vortex action at the bottom edge which will be dealt with when I make the bottom part.

The top is now around 11˚ and the sides are more like 15˚