Wright Stuff C

[klastyioer]

anyone use the 20:1 winder from the ama glider kit? i would only have it as a backup, since its super cheap and i wouldn't need anything else from the kit besides the winder. im thinking it might be kinda not good since its like 9 bucks, but i dunno. so has anyone used it before?

[CrayolaCrayon]

anyone use the 20:1 winder from the ama glider kit? i would only have it as a backup, since its super cheap and i wouldn't need anything else from the kit besides the winder. im thinking it might be kinda not good since its like 9 bucks, but i dunno. so has anyone used it before?

Sounds interesting...

[klastyioer]

one thing we noticed in the ff kit is that the motor stick isnt very stiff even with the cf reinforcement and is screwing up our planes because its warped. any suggestions?

[CrayolaCrayon]

one thing we noticed in the ff kit is that the motor stick isnt very stiff even with the cf reinforcement and is screwing up our planes because its warped. any suggestions?

Maybe a kevlar truss?

[klastyioer]

one thing we noticed in the ff kit is that the motor stick isnt very stiff even with the cf reinforcement and is screwing up our planes because its warped. any suggestions?

Maybe a kevlar truss?

hm okay

[bjt4888]

Katy,

Our FF kit motor sticks are very stiff after applying the carbon reinforcement on three sides per the instructions. Did you use duco cement thinned with acetone to apply the CF? I thin duco at not quite 50/50; more like 66/33 duco/acetone for this application. Also, we apply one thin coat to the stick and wipe it off and let dry for two minutes and then a medium bead of duco and apply the carbon quickly,smoothing the carbon with a finger to draw the glue through the CF (appplied quickly so that the glue is still wet when applying CF). The first layer (pre-glueing) helps adhesion as duco likes to stick to dried duco.

After about 2 minutes, we apply a third layer of duco by applying and smoothing with a finger (which removes a lot of this third layer). This third step we do portions of the CF at a time to be sure that the glue is nice and wet.

I have used this three step duco process with students for years and it works well. A sampling of motor sticks in our FF kits indicated that the wood supplied was in the 4 lb/cu ft range and a little more (the 12” sticks weighed between .75 g and .98 g) and this 3-step duco carbon attach process adds .0112 g/inch. Totals finished stick weights were 1.5 g to 1.6 g, for the majority of them. All are very strong and stiff.

The FF kit described method of attaching also works and is similar to what I do when building airplanes for myself, but it requires a little more skillful feel for the glue.

Brian T

[klastyioer]

Katy,

Our FF kit motor sticks are very stiff after applying the carbon reinforcement on three sides per the instructions. Did you use duco cement thinned with acetone to apply the CF? I thin duco at not quite 50/50; more like 66/33 duco/acetone for this application. Also, we apply one thin coat to the stick and wipe it off and let dry for two minutes and then a medium bead of duco and apply the carbon quickly,smoothing the carbon with a finger to draw the glue through the CF (appplied quickly so that the glue is still wet when applying CF). The first layer (pre-glueing) helps adhesion as duco likes to stick to dried duco.

After about 2 minutes, we apply a third layer of duco by applying and smoothing with a finger (which removes a lot of this third layer). This third step we do portions of the CF at a time to be sure that the glue is nice and wet.

I have used this three step duco process with students for years and it works well. A sampling of motor sticks in our FF kits indicated that the wood supplied was in the 4 lb/cu ft range and a little more (the 12” sticks weighed between .75 g and .98 g) and this 3-step duco carbon attach process adds .0112 g/inch. Totals finished stick weights were 1.5 g to 1.6 g, for the majority of them. All are very strong and stiff.

The FF kit described method of attaching also works and is similar to what I do when building airplanes for myself, but it requires a little more skillful feel for the glue.

Brian T

this helps a lot, thank you
as for the tailboom, any advice on how to make it stiffer?

[bjt4888]

Katy,

As the FF design (and all other near-tandem designs fitting the rules) come out a little nose heavy, you could add a little carbon to the tailboom, if you want, without being concerned about the small amount of extra weight.

The 3k carbon tow supplied with the kit is a little more than needed for a part like the tailboom. You could use 1k carbon tow, which only adds about .005 g/inch. Or, you could add a short bit of the 3k tow to the mid point of a part, maybe an inch of tow, or so.

I’m actually thinking that the tailboom as designed should be stiff enough though.

One more note on the carbon on the motorstick. If the tow isn’t attached as well as you like, you can examine by flexing the stick slightly in the direction of the carbon and hold it up to a light source so that there is a little glare on the CF. Doing this gently and repeatedly should let you view any sections that are not glued well; these sections will “buckle” and be visible. Mark on the stick a little dot next to each unglued spot and then put a drop on CA glue above and below this spot so that the glue wicks under the CF. When putting the drops of CA on the stick and CF, don’t flex again and set the stick aside to completely dry. Do one side of the stick at a time and let completely dry and cure (2 hours) before doing the other side.

I would use very good quality, fresh, medium CA for this.

Brian T

[klastyioer]

Katy,

As the FF design (and all other near-tandem designs fitting the rules) come out a little nose heavy, you could add a little carbon to the tailboom, if you want, without being concerned about the small amount of extra weight.

The 3k carbon tow supplied with the kit is a little more than needed for a part like the tailboom. You could use 1k carbon tow, which only adds about .005 g/inch. Or, you could add a short bit of the 3k tow to the mid point of a part, maybe an inch of tow, or so.

I’m actually thinking that the tailboom as designed should be stiff enough though.

One more note on the carbon on the motorstick. If the tow isn’t attached as well as you like, you can examine by flexing the stick slightly in the direction of the carbon and hold it up to a light source so that there is a little glare on the CF. Doing this gently and repeatedly should let you view any sections that are not glued well; these sections will “buckle” and be visible. Mark on the stick a little dot next to each unglued spot and then put a drop on CA glue above and below this spot so that the glue wicks under the CF. When putting the drops of CA on the stick and CF, don’t flex again and set the stick aside to completely dry. Do one side of the stick at a time and let completely dry and cure (2 hours) before doing the other side.

I would use very good quality, fresh, medium CA for this.

Brian T

yeah we have pretty stale glue at our school but i just ordered a 1oz bottle thats a month old at most so i could use that
thank you!

[Rossyspsce]

Anyone have good ideas for transporting WS on planes?