I Built my first foamy! The story and a hardware question inside

[Mike oxbig]

I Built my first foamy! The story and now video uploaded check pg 2

Ok so first here's how my Saturday went:

I was at a craft store with my wife and the sale rack caught my eye. They were clearing out 5mm foamboard at a buck a piece so I bought 5 boards. I have been thinking about building a foamy for fun and 3d practice for a while so I figure why not now.

So after scrounging inside he spares drawer I came up with an eflite park 370 outrunner, eflite 20amp ESC, 3 hs 55 servos, and a ar6100. Off to the internets I go to find plans.

After a lengthy search I find this: http://www.rcgroups.com/forums/showthread.php?t=606425 the Infineon

. Not really made for 5mm foamboard and probably too advanced a build for a first timer but no one ever accused me of common sense and cautiousness. *the image shown and link are from rcgroups.com*

The build went well. I printed out the tiled plans and taped them together. I then laminated them with packing tape and then cut them out as templates. I plan on re using them to make spares so I used masking tape to attach them to the foamboard.

Then came the cutting. I was as conservative as possible with the foam and only used up a board and a quarter. The first board still had some foam left over for spares as well.

Assembly went well. I modified the firewall for a stick mount for the outrunner and ran the ESC into the battery bay. I know there will be no airflow on the ESC but from experience the park 370 these is overkill and should run cool.

Here's the Rx test mounted and the elevator and rudder servos in place.

After this point I really got into the build and totally spaced out on taking pics. It goes together pretty smooth and straightforward though.

So here it is assembled. Not much to look at but it should fly. In hindsight I should have cut the formers and filler pieces oversize and fit them in to avoid the unsightly gaps. Next time, next time. also note the writing on a few pieces. I should have flipped those.

It came out a little tail heavy with 800mah 2s I intended to run in it so I'm planning to order some 3s 800s. I glide tested it mocked up and it tracks nice but unfortunately I have run into a snag with the hardware I need some help with.

I built it up with dual ailerons but did not think ahead on how to attach the upper and lowers together. I'm hoping someone has an easy solution for that. I need to make a hobbyking order anyway so it would be great to get the hardware from there.

It also turned out that the local hobby shop sold me the wrong prop adaptor for the motor. I don't trust the guys there (they are all car guys) and write down part numbers from online before going in to buy. Despite this the guy at the counter told me my part number is wrong and sold me another. To his credit the package did say for the park 370 but is way too small. So until I get a new adaptor ( I really wanted a prop saver anyway) and figure out the aileron issue this model is grounded.

 

[colorex]

I built it up with dual ailerons but did not think ahead on how to attach the upper and lowers together. I'm hoping someone has an easy solution for that.

The Mikey's RC FPV v3 has dual ailerons - see how Josh Bixler did those.

 

[Mike oxbig]

Thanks colorex but I got it figured. I thought about it a bit and came up with this:

If you've ever bought hs 55 servos you've probably seen those really long servo arms. I cut the arms off the hub like this.

Then I slotted the end of the ailerons and glued them in.

You can probably guess where I'm going so here's the finished product.

I had watched that video previously but didn't think to look there. A google search brought up nothing either. I'm sure I'm not the first person to think of this but I'm feeling like a genius right now.

Now I just need a propsaver and the weather to cooperate and I'll be set. If I can convince the wife to work the camera a maiden video might follow.

 

[colorex]

I'm sure I'm not the first person to think of this but I'm feeling like a genius right now.

That happens to me too often.

 

[Mike oxbig]

Another question, I think I made a mistake! I didn't remove the paper backing from the foam. Do you guys think this will be an issue.

 

[colorex]

Another question, I think I made a mistake! I didn't remove the paper backing from the foam. Do you guys think this will be an issue.

I don't think it's a big deal. If you are going to practice 3D flying with it you'll want it as light as possible, but maybe you can still work the paper off. If you are just going fly loops, rolls, and other aerobatics then it's OK.

How much does your airframe weigh with the paper?

 

[teflyer]

I don't see it as a major probem. Just don't get the model wet or the paper will start to peel.

 

[Mike oxbig]

AUW without batt is 13 oz. The batt is 1.8 oz and I needed another 1oz to balance out.

I got lucky with the weather this afternoon. It went from sleet and wind to dead calm in a matter of an hour. I took the wife out to film the maiden. I got a total of maybe 15 secs before nose over and a broken prop. I borrowed a prop adaptor from my funjet for the maiden and I hit nose first. I ran home and changed out the prop. I figured the way the plane ballooned with power that I was still too tail heavy.

Next flight I removed the nose weight and added a second 800mah 2s. This time the cg was nose heavy but I felt better about my chances. That flight was even shorter. I felt the ailerons were anemic on the first flight and upped the travel but something went awry with the trim. I had to hold full right to try to keep level and it eventually rolled over and nosed in again. The result was another busted prop and a loose motor mount. That ends my day today.

I just ordered up some 1000mah 3s lipos and a propsaver and hope to get out again later in the week.

I need to edit the vid before I post it. It's the first time my wife has used the camera so there was some messing around before hand. Once done I'll post it here although it should probably go into "not quite flite".

The second flight was

 

[teflyer]

Do you thinkit might be the prop torque as well?

 

[Mike oxbig]

Could be the prop torque. I did add some right and down angle to the mount but the mount took a hit when it crashed. The first launch was straight and true but the second was uncontrollable.

I'm not really liking the single aileron servo setup. If you look at the angle the linkages sit at and the fact that the control horns are inboard as far as possible it allows for quite a bit of flex and the servo seems to be working hard. I added a longer servo arm to help get some more throw but I'm seriously considering going to a two servo setup. I'll give it one more go and then I might modify it.

I ordered my parts from a somewhat local distributor (greathobbies.com) and I should see the parts this week. The weather report looks bad for the next couple of days but hopefully will clear up for the weekend.

 

[Mike oxbig]

Ok so after a bunch of failed attempts to convert my video from quicktime to something useable for movie maker I just decided to upload it to youtube and just edit the edges. Bear with me as this is the first time using the camera for video and youtube to edit.

Heres the maiden, all ten seconds of it:

The aftermath:

The second flight:

As you can see it wasnt too spectacular. Both flight attempts are fails. The videos themselves are a bit of a fail too as I can see now that I fidget a lot and Im not looking into the camera. My wife also had a little trouble running the camera. Oh well, lessons learned for next time.

I have given up on apc props as I've blown through two on this plane and three on my funjet. I'm going to run a 8X4 prop from parkzone for my next run. Im waiting for gws props to come back into stock.

The plane is rebuilt and ready to go. I just haven't had the lack of wind to fly it yet. I'll post it when I do.

 

[treadd]

Being a super noob with scratch built planes, one thing that I've kinda gleaned from reading around and watching vids- biplanes seem like a difficult design to fly. Trying to work out stuff on super simple scratch build seems rough, I cant imagine the additional ones that come with a biplane. All I can say is, keep at it, and good luck!

PS- Your lucky you can even get your wife out there to film you- The best I can expect is some professional level eye rolling from mine.

 

[Brian fred carr]

I have so many builds that dont fly....most people call them a "pile of foam" but i call them "my babies" but the point is is never give up and one day they will fly and all the failures are forgotten

 

[Mike oxbig]

I actually did get this one to fly. I ended up going with a 1000mah 3s lipo and moved the outrunner out a little bit to get the cg right. It flys nice and the park 370 has unlimited vertical with a 8x4 prop.

I'm moving into a new house in a couple weeks and haven't had time to fly lately but once I'm settled I'll try to get a video of it airborne.