Darrinc

My Feedback: (5)

Here ya go.

http://www.plascore.com/

http://www.hexcelcomposites.com/Mark...mb/Default.htm

Hexcel has some really nice litature on how to use the honeycomb, but you have to call to get it.

rcairplanenut

Here is a trick that I do on the topside of fuselages.
Instead of carving out a ton of balsa wood and building a brittle turtle deck, I build a composite top. I hot wire and file/sand foam to the shape of the turtle deck, then use a slurry of micro balloons & epoxy on the foam first then glass the foam with at least 2 layers of 4 oz. e-glass.
I am using Aero Poxy from Aircraft Spruce as the epoxy.
In summary it’s standard Rutan stuff applied to standard RC planes.

Give it a try on your next pattern plane

SGG

Darrinc

My Feedback: (5)

I would take that "plug" and make a mold, then do a single layer carbon layup on a 45° and add 1/8 balsa stock to the edge for bonding. Super, super light, you can make them all day and your only adding ounces instead of a pound or 2 with the heavy blue foam.

That technique would be a Rutan pole model, not a flight unit.

rcairplanenut

I typically build only one of each type of model, building molds for a RCM Gitano (some one else design) would be a waist of time for me. I have found it is equal to the weight of a built up former/stringer/skin/balsa block turtle deck (the foam is also hot wired on the inside maintaining a ½� thickness). The weight of that red shell in the picture is 4 oz. NOT pounds. The whole purpose of this thing is for scratch builders that want to have an easier time building turtle decks on one time only builds for a particular design. E-glass over foam is the way Rutan built the Long Eze, that is what I am referring to.

I plan on building a mold for the whole fuse of the other aircraft, it is my own design, for the purpose of an exact reproducible out side geometry and a low effort to time ratio on the shells. This aircraft is also a prototype, not a production model!

I always run my RX antenna inside the fuse, a carbon shell around ½ of it would block the signal. The weight saving benefits of Carbon on a shell that is in close proximity to your RX antenna are not worth a 1000$ crash because of lack of signal ( I have seen this happen, many times)!

All my aircraft fly sir, I do not believe in hanger queens!

SGG

Darrinc

My Feedback: (5)

At the end of the day, no matter how hard I've tried, nothing is lighter than balsa. (thats after 13yrs of trying and capacity of very exotic material to experiment with)

I would at least hot wire the foam down to 1/8"inch. I have done single layer skin turtle and hatch decks up to a 35% Extra with no problems. As far as the signal problem, I have had no problem with any of my all carbon 35% planes. It is only a ground plane when you attach it to a ground.

Glass over foam is cheap for full scale (material cost), but your money is in your time finishing it out. For your top deck. I would just deck it with contest balsa and hotwire it thin.

BTW, Burt did not belive in vacuum bagging when he designed the Long EZE. (I just find that funny)

Mike Melville probably built his the quickest, and he made it the lightest, the fastest and best flying (acrobatic) Long EZE.

But is sure is ugly up close.

He just wanted preformance, and I have no problem with that!

rcairplanenut

PRECISION HELICOPTERS INTERNATIONAL LLC
What are the advantages of G10 fiberglass side frames?
G10 is a very durable and stiff composite material that holds up well under the stresses and vibrations inherent to RC helicopters. G10 does not develop cracks from vibration and has just the right amount of flexibility to provide a stiff main frame assembly while maintaining the ability to absorb extreme loads from heavy landings or crashes. Another benefit is that G10 does not have the RF interference problems associated with carbon fiber. Lastly, G10 is less expensive than carbon fiber and safer to work with during the manufacturing process.
Source

http://www.phiheli.com/faqs.htm



On line discussion of RF interference with Carbon

Source

http://www.rcgroups.com/forums/archive/index.php/t-5619

Direct from the horses mouth
A quote from one of the 3 “Gods� of RC radios Futaba

2. Receiver antenna routing recommendations:
a. Keep the antenna as far as possible from servo wires, metal pushrods, ignitor wires, anything carbon fiber, or anything else that may conduct electricity. Be aware that truly metallic (metal-colored MonoKote is not) and carbon fiber finishes can affect radio range as well.

Source

http://www.futabarc.com/faq/faq-q331.html

Need I go on???????


If you have decent skills in hand wet lay-up fiberglass a good finish is not that difficult.

In the photos are 2 RCM Cloud Dancers I used my methods and the finished weights for both aircraft came out the same as their published weights in the construction articles. Then only time spent on the prep work was an application of Balsa filler and its sand down. The V tail is greatly admired by the members of the RC club I belong to, especially the finish. In fact many people ask me how do I get such a great finish on these aircraft.

I have lost count of how many RC aircraft I have built and this method I have found, is faster and less tedious then anything you can do in balsa that will match this finish, this includes a finish with no buckles in its surface.

Instead of trying to shoot me down for what ever I say, you might just want to this as another possibility on how to construct an aircraft.


This cat and mouse game is getting old.

davidfee

SGG,
I really don't want to get involved in any disagreements but, this whole "carbon fiber crashed my plane" thing is way out of hand. I'm not saying it's just you... it's a widespread myth. The fact is, it is possible for carbon fiber to cause some problems in some cases... but so can the metal clevise on the end of your pushrod. I'm going to post a picture below. The models pictured are competition electric sailplanes at a RTF value of over $1700 each. They use a pressure-molded carbon fiber tailboom and the antenna goes right down the middle of it, right next to the carbon fiber tube pushrod. Under power, the models fly at over 150MPH and they spend a lot of their time very close to the ground. Then they spend 10 minutes specked-out during the duration task. Radio interference problems are incredibly rare. I have a hard time believing that the carbon tailbooms are significantly harming the radio reception.

YMMV,
-David

rcairplanenut

It all depends on what you want to do. It is a possible risk even disclosed by Futaba, a division of Great Planes, I think we have all herd of these guys. Some EAA guys paint there composite planes dark colors on purpose to prove a point. If your willing to do that, hey what do I care its there equipment, not mine. Personally I just lost an aircraft dew to a .25-cent Diode in Receiver, an aircraft not responding to your commands is a scary proposition. I make my own choices, you make yours. At the end of the day its an individual choice. Darrinc has it out for me, I am just defending my ideas with facts. I deeply regret putting anything on Darrinc thread seeing what it has turned into. This is a hobby people not the Mob. Every thing on RCU should be taken as a suggestion, something to think about.

The web site link you gave me David is very helpful, also the lay up secludes. More stuff like that is what we need, lets end this slamming of other peoples ideas.

“Be the grease in the gears of progress not the glue in the gears of progress�.

iskandar taib

My Feedback: (5)

Or check out molded balsa construction, which is the latest rage in CL Stunt. Molded wing leading edges, molded turtledecks, molded fuselage sides for semi-scale planes, etc. etc. Make a form (can be quite complex), mold the balsa onto it using hot towels (I kid you not).

http://www.clstunt.com/cgi-bin/dcfor...rum=DCForumID1
http://www.clstunt.com/htdocs/dcforu...mID1/7778.html
http://www.clstunt.com/cgi-bin/dcfor...rum=DCForumID1
http://www.clstunt.com/cgi-bin/dcfor...rum=DCForumID1

Magne

A bit off topic in this thread, but when "molding" balsa (around a polystyrene plug) I have found that the balsa softens a lot better if soaked in a mixture of 10% ammonia and water. There was an article in an english magazine some years back describing this, and I tried the method. You definitely need protective equipment, such as breathing mask, eye protection etc, as ammonia probably isn't too good for you.
Magne

Darrinc

My Feedback: (5)

iskandar taib,

All I can say is WOW!!!!! Very nice!!! Have you guys tried this on anything big???

Have you tried 2 layers of 1/16 with each at a different angle? Kind of like / \, that should increase the stiffness.

Or putting lightening holes in the inside sheet of balsa? (although, unless it's heavy balsa, I havent found much weight savings from lightening the balsa, but it does save a lot on glue)

BFoote

Carbon killing reception is rather a myth... What kills reception is VIBRATION and Carbon that has DRY spots that allows it to vibrate and come in contact with the antenna... Ran our antenna right by the servo wires in a Carbon Tube... no problems... thanks... Had planes die only when the crystals die. If you want perfect clear reception, say for TV signal out, then yes you need Fiberglass, but still not much, to allow better reception of GPS signals In and Transmitting of TV signals back to you. Aircraft noses are Fiberglass for Raydomes, Very specially oriented fibers of fiberglass. We aren't trying to transmit and recieve Hyper critcal signals here guys

Brian

rcairplanenut

BFoote

Did you even read what happend to the SAE plane that i was working on?????????

Dave_Gherardini

Did you even read what happend to the SAE plane that i was working on?????????



nope.he didnt,,,,.hehehehe..o well ,, that happens some times...myths to some folks, facts to others,,,diference in density can lead to difference in outcome..have to compare apples to apples.

davidfee

???

Darrinc

My Feedback: (5)

Just use Astroquartz and there won't be a reception problem. Maybe a finacal problem though.

The coolest thing I ever saw at a SAE was this semi flying wing design that was flying at it max weight, it turned for final and a gust of wind hit it and it exploded like someone shot it with a shotgun. Parts and pieces where falling from the sky for a few minutes. I've never seen anything like that!!!!

kblack

What tape do you use?

BFoote

of course I read your "idea of what crashed your plane" its a joke bud, something more basic is always the problem... usually human stupidity... not that I haven't ever been the problem before ... =)

BFoote

well unless your CF was super thick and it was acting like a faraday shield which would be the same case with whatever conducting material you use surrounding an antenna, my tubes were single layer 5 oz cloth thus there are numerous epoxy holes that do not contain CF. If its solid CF then yes you would have a problem, most uses of CF on model airplanes are not thick enough to inhibit reception.

Brian

BFoote

I should quantify this statement.
From Futaba's standpoint they are in CYA mode(Cover your A... ) Max range is their only goal. For SAE weight lifting airplanes and pylon racers we are never far away from the pilot, thus our mission is not max range! It is Aerodynamic efficiency.

Another point, were your wires twisted where your antenna was run? Mine were because I know from an electrical standpoint that this helps cancel EMI nosie on the wires and the EMI noise error transmitted to the antenna.

rcairplanenut

Wow 5 months for a reaction to that statement.
Sorry Bfoote, but I’m not going to play that game anymore.

Enough of that,

Hi darrinc, how goes space ship one, has Rutan had any more flights since the X prize win?
The land shark is awesome

SG

BFoote

IT wasn't for you I replied it was to clarify for others who might read this site.

cheer up bud
Brian

Darrinc

My Feedback: (5)

I've been reading that some people where looking for some tips and techniques so I thought I would bring this thread back up to the front.

I must apoligies for the carbon/radio discussion in this post. If I could remove them I would.

I have more time now, so I should be able to answer some of your questions if nessesary.

I'm also adding a link for my composite repair on my Comp-Arf.

http://www.rcuniverse.com/forum/m_3379769/tm.htm

AeroRCmodels

Thank you very much for putting the information here. I hope you will post more great ideas and techniques!

daven

My Feedback: (1)

When I get a chance later today, I'll clean up the thread.

Great info.

Thanks,