Javelin build

[davidchoate]

I'm taking a break from my Edge to build a FF plane. I'm doing a Javelin in hopes it flies well and gets me interested in FF.

[davidchoate]

this plane has 2 locations for the rubber motor dowel. I bought 1/8" alum. tubing (an idea i got from Mitch) to use instead of wooden dowels, i'm not sure as to the advantage, but i'm sure its stronger. my question is what dowel location is better, and also they recommend a max of 400 winds on motor. i know i've heard people doing alot more. can u FF guys give me some advice for my first flights. i think i can handle the trimming myself, as i have been reading up on it. i should be ready to fly it by friday.oh, and im so used to usung silkspan i'm having wrinkle problems with the tissue, does ammonia mix make the tissue shrink less or more, cause thats what i used.

[davidchoate]

oh, i set my thrust angles for prop by sanding BO to 5deg. down and 5deg. right

[WIDDOG]

Wow super cool Javelin build.

I don't know anything about skilspan. However, with tissue there is a thing called "Stress Wrinkles". If your Appling the tissue wet this could be the problem. A way to eliminate stress wrinkles is to apply the tissue dry. Then to spray the tissue with spray water bottle lightly to shrink the tissue. Takes a little bit of feel to get it right but is worth the effort.

[ADW 123]

stress wrinkles will also develop If the tissue shrinks too much for the frame to handle. for light frames like these, too much shrinking will cause awkward bends in the parts which will either warp your frames (making trimming for flight very difficult) or will cause the light wood parts stuck on the tissue to shift in as the tissue shrinks (or both). covering dry will help. silkspan also has a lot of shrink... I hear of many people pre shrinking their tissue on a "window frame" to get most of the shrinking power out.

[davidchoate]

thanks for all the advice

[davidchoate]

almost ready

[davidchoate]

weighs 41g all done. cant wait to fly it.

[WIDDOG]

Super sharp looking Javelin. Please keep us posted on the flight performance.

[davidchoate]

did a few flights today. flies great. a slight turn to the right. i was too excited to time them,but i only did 300 winds. it even lands perfect! i used all kit stuff. my LHS only has Guillows motors & props. Where can I get the better stuff I heard about?

[davidchoate]

if you notice the weight on the nose i put there to balance it as per plan, but it flew way better a bit tail heavy. do i got too much down thrust?

[Wildpig]

The best way to tell if you have to much weight is to make several gliding only flights.

Reposition the wing as needed and change the amount of weight. Hopefully reducing the amount of ballast weight you need.

Once you have the best glide, leave it alone. No more adjustments. Then wind up the rubber motor and start making downthrust adjustments. A small amount to start with.

By the way, your model looks nice.

[Sai1704]

That's really nice! Looks like you could enter it for next year's "G" Challenge. It's great that you got your first FF model to fly.

[Mitch]

That model looks GREAT! the 2014 challenge has started and your Javelin is among the entries this year... I am wondering why Howard has not posted an announcement over here. He has posted the rules over on Yahoo.

The purpose for the tube as a rear peg instead of the wood dowel is to enable you to put your model in a stooge to hold it securely and safely as you stretch wind the motor. I usually use about 1.5 times the hook to peg length of rubber. That's when the rubber is relaxed. After braiding the motor it will be a bit shorter but still longer than hook to peg. The stooge will hold the model and you can stretch out the rubber 4 times or more that relaxed length, then start winding.

See how this model is secured. The pin goes though the tube and holds the model to the stooge as the owner prepares to start winding. He is also using a blast tube to protect his model in case the motor breaks.

I am still using my "tailgate" stooge:

Very simple. A piece of plywood with a couple of "L" brackets screwed in. I secure the plywood to my tailgate.

Even if you do not have a stooge. Someone can hold your model for you, they should put a pin thuogh the tube to hold the model securly:

When I say "pin" I am referring to a piece of heavy music wire that they can securely hold.

Hope this helps, Mitch

[davidchoate]

yes, it helped. i plan on trying the prop that came with my Edge. it's a slightly larger diameter than the one in the kit. Is this a good idea? i still cant believe it flew a 100 yards without a good motor and prop. i did have to add a piece of plywood where the thrust brg. rests against the front cause the balsa was chipping. again , does anyone know where to buy the good quality motors and props. Also ,Mitch , I noticed you used hooks to put through the loop on your braided motors. I have no problem finding the dental rubber bands,but could you give me more info on those hooks? I plan to try a braided motor soon, and one more thing, why is there 2 dowel locations. I've been using the one to the far rear of the fuselage. is this better than the one towards the middle of the fuselage? Oh I'm definitely hoked on FF now !