Dihedral setting

[calgoddard]

Any additional weight from tip plates is extremely minimal. The 2017 WS rules provide a very liberal weight budget in any event. Most students should be able to build airplanes very near the 7.5 gram minimum using hobby shop balsa wood.

[Kyle_Guo]

Ok, I will use tip plates then. They seem so much easier to do since you don't need it to be perfect, just 90 degrees. I guess this concludes my question of dihedral setting since I will not be using them.

[Kyle_Guo]

Yes, Duco is a household cement of the same type of formula as Sigment and Testors and is a favorite of the indoor modeling community. Thinned with acetone about 30% to 50% is ideal. Small fine tipped applicator squeeze bottles for this thinned glue can be Purchased from gun dealers. Gun owners use these bottles to hold light oil.

Brian T

Does it have to be acetone? I thought I had acetone but when I opened the lid on the can, it seems like it all evaporated. I have a bottle of Paint thinner, can that be used as a substitute? It says "mineral spirit based" on the bottle.

[bjt4888]

Acetone should be used to thin duco. You can also use untwined by putting a small amount on a piece of waxed paper and applying with a toothpick.

Brian T

[Kyle_Guo]

ok, I will get some acetone

[bernard]

ok, I will get some acetone

If you've never used acetone before, read on. Acetone will dissolve a lot of common plastics, so pouring into plastic cups is not recommended; use a glass beaker, candle holder, etc. Also not good on the skin, very drying. And very flammable, store away from heat sources. Use in a well-ventilated area if deemed. necessary. Read the warnings on the label. Sample acetone MSDS: http://www.sciencelab.com/msds.php?msdsId=9927062.

[bjt4888]

Kyle,

I will add to Bernard's information above. Acetone should be handled only by an adult coach and must be handled exactly per the MSDS that Bernard attached below.

Brian T.

[Kyle_Guo]

If it can melt through plastic, will it be a problem if a 30:70 glue/acetone mixture be used in a plastic applicator bottle? The bottle is something called a "Fineline applicator" and appears to have pretty hard plastic but flexible enough to squeeze to get the glue out.

[jander14indoor]

Acetone will dissolve many plastics but not all. I use small plastic bottles with needle tops to dispense my thinned glue. I've had them for years. If the item you have in mind is meant for glue, it will handle thinned glue fine.

One caution with tip plates. They do need to be very parallel and in line with the flight path, otherwise they act as brakes adding drag fast (think of snowplowing in skiing).

And dihedral doesn't need all that much accuracy. The exact amount isn't critical, though you should be fairly close from side to side.

Jeff Anderson
Livonia, MI

[Kyle_Guo]

I have seen some people's planes without dihedrals or tip plates. It appears that they have made the 2 wings tinted upwards very slightly to make the entire wing a dihedral. This seems easier since only one joint is needed, but is it as effective?