Building Materials in Asia?

[Casey]

Hi, I'm living in Taiwan and we do not have paper-backed foam board here. The foam board we have is much heavier with a more clay-infused board. I want to know how much a given piece of Adam's foam board weighs, so I can weigh an equal size piece of our stuff here and see how bad it's going to be.

There is lots and lots of coroplast here but how could you possibly make the Flite Test construction techniques out of that? And it's probably heavier than foam board too I'm guessing...

I feel very stuck because I really want to build some cool designs and get flying but I don't want to end up with some super heavy underpowered frustrating mess that hardly gets off the ground!

 

[rockyboy]

Welcome to the forums!

As for building from the heavier foam board, look into the posts by forum user Hai-Lee - he's down in Aus and has done a ton of builds using heavier foam board and has posted designs that work great with it.

I'm sure someone will chime in with the weight on the Adams board, but if you have access to lots of coroplast check out the SPAD (Simple Plastic Airplane Design) stuff too http://www.spadtothebone.net/

 

[Casey]

Thanks I will check that out once the forums have updated, as of right now it gives errors when I look for Hai-Lee's posts. Also, it seems that spadtothebone website is decommissioned? Anyway more information on quick cheap building materials would be great!

 

[rockyboy]

The free plans section is still live on the http://www.spadtothebone.net/freeplans.htm - they seem to have stalled on their decommission / transition of website to a new address.

 

[Casey]

Just to follow up and as much for my own later reference, I have so far gotten a hold of three different potential building materials here in Taiwan.

The first is a skinless type of foam just called "pearl plate" (translated from Chinese) and I don't know how to tell what kind of foam it is. It is not white opaque like polysterene, and it seems like it is flexible... how would I know for sure what kind of foam this is if I have never handled a sheet of depron or EPP etc before?
One sheet of this material, at 60cm x90cm, weighs in at 116.6 grams.

The second is what passes for foam board here. I think it's similar to what they have in AU, it is foam core with a thicker card stock on both sides and almost a clay-like texture to it. It comes in multiple colors but I weighed a sheet of the white, and for the same 60cm x 90cm, it weighs 295 grams. That is nearly three times what Adams Readi-board weighs, and certainly unsuitable for FT designs!

The third I found was 3mm coroplast. Coroplast is everywhere in Taiwan for some reason, and it comes in many thicknesses and even enormous sizes. The problem with coroplast of course is that its reinforcement is only in one direction, and it tends to bend in only one direction, and it's difficult to cut across the flutes cleanly and make complex shapes with it. I weighed a 60cm x 60cm piece of 3mm coroplast at 143.6 grams, or about 50% heavier than the "pearl plate".

Where you guys could help me now, would be with the following:

1) any experience with making FT planes from coroplast, and how you solved the problems of the directionality of the flutes and how to make complex shapes from it,

2) any tips on how to figure out what kind of foam this "pearl plate" is, such as, "if it is X, then it will bend this much, or it will react this way to substance Y" I'm a science teacher so I'm not afraid of doing some experimental research if someone can point me in the right direction with their experience.

TIA!

 

[Hai-Lee]

The heavier FB does make great FB models and with some work stronger and of equal weight to the adams versions.
Here I make and sell FB planes through a local retailer and so far have received praise for their performance, simplicity, and damage resistance.
Should you wish to dabble in the heavier FB I can assist with techniques which can make balancing easier or even which planes will give you problems or will be far too tail heavy to consider constructing.

There is even a post or two on how to lighten the heavier FBs and how to use other materials in combination with the FB to make an FB plane even lighter yet far stronger than the original design whilst using the heavier FB as the basis for construction.

Here to help if needed!

Have fun!

 

[Casey]

OK I'm definitely interested! Is there a thread about this topic already, or could we start one in the appropriate section for people who have this issue in the future?

 

[Hai-Lee]

If you want to start your own thread, feel free.

Before starting I will say that each different Fb type has its advantages and weaknesses which is the same for all materials.
When I started doing FT type plane construction I had many failures or even flying tanks/bricks but over time I learned to use the Fb succh that I used its advantages and could accept its limitations or at least minimise them.

From memory each paper layer on the heavier FB accounts for between 30 and 40% of the total weight so the removal of a single layer of the paper drops the overall weight by 30 to 40% and with the thicker paper of the FB the strength is only minimally effected.

My favorite reinforcing material for the FB, (where needed) is thin Balsa 1mm or 1/32 inch thickness).

As a beginning may I inquire as to what flying experience you have and what plne or planes were you considering constructing?

Have fun!

 

[Casey]

Before I moved to Taiwan I had a ParkZone Cub which I flew "somewhat". I built one glow plane back in the late 80s (Carl Goldberg Eagle 63) and promptly turned it into splinters on its maiden flight because the tail came off I am looking at making a Tiny Trainer, a Mini Sportster, and then a Sparrow.

 

[Hai-Lee]

Great! We will start with the FT Tiny Trainer but before we do I will ask if your radio system is capable of setting up Expo?


Anyway the Tiny Trainer (TT) will tend to be a little tail heavy and possibly quite fast if built from the heavier Fb so I will now describe the changes I made which made it much more fun to fly and learn on as well as pose a few things to consider to make your experience much more pleasant.

The motor I use is a 3S 1400Kv of 121Watts - HK 2205c. It has a built in Prop saver. I fit a 8x4.7 SF (Slow FLy) prop and power the whole build with a 850mA 3S battery through a HK 12A ESC. The motor gives the plane plenty of "PULL" especially with the SF prop and the motor/battery extra weight help with the balance. The servos I recommend are the 3.7G turnigy and I do not fit them internally as per the original design but rather fit them in the outside of the tail boom after the plane build is finished.

The wings you should build are both the 3 channel wing and the sport wing. The servos I recommend in the sport wing are the 3.7gram servos again.

You can use the hotmelt glue for your build but I find that it can be tricky to use for the beginner and so I use foam safe clear craft glues which work very well but can take a while to dry.

Before you start you need to decide what your plane's finish will be. The 2 common ones for beginners are to tape the outside surface or paint it. Let me know before you start because the tape goes on before you cut out the plane and the painting happens when the build is almost finished.

Things to consider: The long span wing for really slow flying and a detachable landing gear to learn taxiing and ground take offs.

Comments?

Have fun!

 

[Casey]

My school is on the side of a hill, I've been thinking about designing the plane so I can treat it as a poewred sailplane when I want. In this case, the heavier material might be a help for penetration as long as it's not tail heavy. I was thinking about adding lightening holes in the material in the tail as long as that doesn't affect rigidity. I do also have access to this backless foam which I think is the same stuff as the inside of the KT board, and I could tape it on one side and use that for construction, but I don't know if that would give me enough rigidity, just foam and tape throughout. I have also heard about this really cool technique of pasting kraft paper all over the outside with diluted PVA white glue to make a hard outer shell but... at a certain point, the "quick and easy" advantages to using foam board get lost in all these extra steps, and I might as well use more traditional methods...

 

[Hai-Lee]

To make the design float a little better it is wise to increase the wing span a little. As for lightening it is easier to remove the paper on the internal surfaces of the fuselage and even on the wing, which I do not usually do myself. The removal of the internal paper does not effect the A or B folds as used in the plans.

As for making tail parts stronger you can use the old BBQ skewers and/or coat the exposed parts in Minwax, (wipe on, Oil based varnish) and paint using an aerosol paint. A light weight alternative to the use of the skewers is to use thin balsa strips glued into slots cut in the tail in the appropriate places.

As for the KT board it can be easily strengthened by the application of 1mm Balsa sheet on one side of the cut out pieces prior to assembly. It will still be lighter than the heavier FB but seriously stronger!

Personally I would not use the PVA glue as it can become extremely brittle over time and can also soften dangerously if the plane gets wet for too long.

I would recommend that we start out just cutting out the standard pieces in the heavier FB and we can then determine what steps to take ot finish the assembly keeping an eye on the overall finished weight.