EPP/CF/Coroplast thermal flyer lives again!

[CactusJackSlade]

Some may remeber my EPP pod, carbon boom, coroplast tail feather full house ship I posted a while back.

Here is the link:
http://www.foaminfusion.com/EPP2MTD.html

Well, as a thermal flyer it was great, but as a speed demon it had a few flaws that caused its premature destruction.... I did fly it all summer with these known flaws... then I pushed the limits a bit too much! Here is the story... and lessons learned:

I was flying inverted, screwed around for a bit then I did a screaming power dive. At near trminal velocity I pulled up.... nothing... pulled up MORE... still NOTHING. I fumbled for the crow mix switch to slow things down, but too late.... plowed the ground at full speed from about 200 + feet.


I had used a really light weight (and flimsy) boom on this one and the push rods were light and flimsy as well... the nose pod area flexed a little too. All around too much flex and under great speed it would not pull out of the dive... in retrospect i should have just tucked it under and slowed it down and re-gained control...

Actually i only broke the boom and a wing spar - both EZ to fix, ( I did waste the battery and Rx too.) I could have easily rebuilt it but I opted for an all new pod and boom of better construction and design.

Now the new design is about as stiff as a glass ship! I also made the ruddervators PULL to bring the nose up instead of pushing so no more chance of of flexing push rods in a dive.

I also went with a much stiffer Allegro boom from http://www.tailbooms.com which only weighed about 10 more grams but is super stiff.

The final thing I did that made the pod area SUPER STIFF was to insert 5 lengths of flat 1/32 x 1/4" carbon fiber strips throughout the pod/fuse area.

SO... it should fly like a charm now. We shall see. This should be my final design on this pod/boom type.

Here is the finished product. I will try to fly it tomorrw, weather permitting.

I will post new construction photos soon! On my foamie page:

http://www.foaminfusion.com


Thanks,

CJS

[CactusJackSlade]

I had many spectacular flights on the old ship design... now that is is a lot stiffer I will be able to "hot rod" this baby without fear!

[mhmitchell333]

Hi,
I know it says EPP foam. It looks like what I call hard crushable foam (NO GIVE) like you might find at Michaels or Franklins. No beeds . Is this correct. I still have a problem on whether to use the stuff I find at micjaels (cuts great eben with a scrowll saw. Or foam insulation (white beaded) sands terrible or pinl or blue fanfold which I have the most trouble with.

The hard foam also seems to be shiny crstaline in structure, very stiff.

[CactusJackSlade]

EPP is Expanded Polypropelene, not at all like the blue foam.

EPP has very obvious beads in them - it's like styrofoam, only made from polypropelene (hope I'm spelling that correctly!) which is a flexible plastic.

It gives and retains shape even after the most crushing of situations... EPS Expanded PolyStyrene (styrofoam) will crush and get mis-shaped after a few crashes, but it is lighter and more rigid than EPP.

I have moved away from EPS for my foamies, I'd rather have the long term survivability!... unless I absolutely have to have the lightest wing possible, then I might go EPS, hopefully with an EPP leading edge.

For the blue or pink fan-fold I use that only for REAL light planes tha I do not intend on crashing hard!

Hope this helps!

CJS