F22 First EPP Foamie

[19000rpm]

Mar 25, 2010 16:52:03 GMT -6 akent said:

I can't glide this thing!
It just always noses in or turns to the side or something.

I changed the CG from 15" back all the way to 17.5 and I can't get the thing to glide. If I give it power, then it's good! But it's way too windy to fly it today. 35mph gusts that just take you by surprise.

I was trying to glide in my garage.
Sorry.
Kent

I'm not really concerned it doesn't glide. Swept wing planes don't normally glide well unless the CG is TOO far back and then they get really unstable except for high alpha. Thanks for trying though.

I was just concerned it was TOO nose heavy and I think moving the CG back to 16 1/4 - 16 1/2 will do it. It just looks and feels better now. The major weight sources (motor, ESC and battery) are closer together now and the CG farther behind the wing root and that all just makes sense.

We're in for strong winds tomorrow too, so the suspense will build until I get a chance to throw some power on.

I'll be shooting photos tomorrow and maybe uploading some. Thanks for your help.

[19000rpm]

Photos are taken. I'll try to get to posting them this weekend.

The Maiden: Winds blowing as forecasted at 25mph today. Weather forecast iffy for tomorrow. Wind and Rain. Rain='s wet field. EPP is like a sponge. Exposed Electronics='s I think I'm put off on the maiden until atleast Sunday.

Note: This EEP foam sucks up CA like a sponge. I went through a whole bottle on the build. That's getting expensive.

Does anybody have a cheap source for Foam Safe CA and Activator?

[akent]

That's why I use hot melt! It sticks at least as well as CA, but it is heavier.

This foam safe stuff is expensive!! Actually, I wonder if you even need foam safe on EPP? I haven't tried regular on it. As resistant as this stuff is to all the paint solvents, it might be ok! If you don't try it, I will later on some scraps.
FYI: Welders EATS depron for lunch.

Oh, one thing that I did on my original F22 that I should have done on the hotrod is after I taped the hinges on the top and before using strips on the bottom, I went along the mating surface on the bottom with some CA. It actually makes the top tape stick to the foam much better, and then creates a hinge from the CA! It is way stronger and doesn't give like it used to. After the CA, I added new tape strips on the bottom.

I'm getting tired of all this wind!
Kent

[19000rpm]

I'll try the CA on the hinge next time. They make CA hinges too, I just haven't tried them yet.

Yep, it's still real windy here too.

I think there is still too much flex in the front part of the fuse/ wing up to the prop slot. I'll take advantage of the windy day tomorrow to figure that out.

[BTCat]

FYI, Regular CA works great on the EPP. I had no problems with it.

[Solitaire]

I get my CA (foam-safe and regular) from HobbyCity. Can't find anything any cheaper. If the regular stuff works on EPP, then the HobbyCity no name brand should do the trick

I was reading a post in the foamy section at HC where one guy got his EPP Yak or Extra300 wet in the rain. He said the weight of that thing doubled and took quite a while to dry out. Fair weather flyers for sure.

[19000rpm]

Mar 26, 2010 18:46:50 GMT -6 BTCat said:

FYI, Regular CA works great on the EPP. I had no problems with it.

I'll try some regluar CA. I had it stuck in my head to never use regular CA on any foam.

Thanks, sol. I figured HC would have the best price. It's just such a long wait for the shipping. I'll need to plan ahead better.

Well, the weather man was right. It's raining and windy today. Tomorrow looks good though. 5-10

Edit: I decided to go with the lighter 1000mAh 25C battery for the maiden.

So, I'm even happier with the overall pkg now. It's both lighter and stiffer. I'm still a little concerned with the airflow over the back of the plane...I think I've had too much time to think about it. The proof will be in the flying ;D

[Gabe]

19k, regular CA doesn't eat up the foam?

[BTCat]

Mar 27, 2010 10:25:52 GMT -6 Gabe said:

19k, regular CA doesn't eat up the foam?

Not EPP. It eats all the others, though.

[akent]

This is all great info!
That's awesome that regular CA works. I have two large bottles from HC, too!

I think I posted somewhere that while Welders glue works great on EPP, it eats depron for lunch. Even magic markers eat depron.

That is very interesting about the 'sponge' effect of EPP! I would never have guessed that!
I was thinking of building a seaplane of some kind out of EPP. I guess I won't now. That's maybe the only good thing about depron. It floats great and does not slurp up water.
Kent

[BTCat]

Depron and Dollar General foam seem to disappear with any kind of glue except foam safe CA and Gorrilla Glue (white). I made a real mess of one piece when I put Welders on it.

[19000rpm]

[19000rpm]

So I get up this morning and the wind is blowing harder than previously forecast. Too much for a maiden and it's going to get even higher tomorrow. Typical spring weather around here.

[BTCat]

Yeah, the news had video of commercial airliners visibly blown sideways when trying to land at DFW airport yesterday. It will be better today. Only around 35mph tops

The F22 looks sharp. Looks pretty sturdy, too. I'm looking forward to your evaluation of it after the maiden.

[19000rpm]

Mar 28, 2010 6:47:28 GMT -6 BTCat said:

Yeah, the news had video of commercial airliners visibly blown sideways when trying to land at DFW airport yesterday. It will be better today. Only around 35mph tops

The F22 looks sharp. Looks pretty sturdy, too. I'm looking forward to your evaluation of it after the maiden.

Thanks, BT.

I still think there's a bit too much flex right through the prop cut out in the wing. I may add a CF tube on the top of the wing on each side by that area running from the leading edge all the way back.

Edit: After a closer look I think I'll run the tube on the bottom of the wing next to the skid back to the tube that goes across the wing. I think the strips I used on the skids weren't stiff enough.

I'll also add a tube just ahead of the elevons. That area flexes too much also.

If it stays windy I think I'm in serious danger of putting too much CF bracing in it. ;D