.35 profile weight

[David M Johnson]

Again asking for opinions.  On a .35-.40 profile airplane, 42" wing span, what would be a good overall finished weight for the plane.
David Johnson

[Alan Buck]

Hi David I,m building a Prowler 48" w.s. 490 sq. in 25-35 eng. weight 37-42ozs

[Geoff Goodworth]

42" is fairly small for a .35–.40 powered model.

I fly my 42" Shoestrings with FP20s and the combo weighs about 28–30oz.

[Dennis Moritz]

I have a Flite Streak came in as 36 ounces with an FP40. Surprised me, thought it would weigh less. ARF wing, scratch built extended fues. Flies well.

[Chad Hill]

My 42" Brodak kit Flite Streak checks in at 24 oz with a Fox 35, 9" Schimitar prop, light weight wheel, 3 oz Brodak tank. Brodak Buster is 28 oz but I knowingly built it heavy.

[Russell Shaffer]

A Flite Streak with an FP40 should fly very well indeed.  Probably keeps the lines tight?

[Dennis Moritz]

Come to think of it, I put a Tower 40 in the Streak. Added an extra head gasket or two and .272 venturi. (I think) Smaller than the .283, which will howl with no extra head gaskets. Engine can be needled so it will run a constant rich two stroke. Useful stunt run. Sounds great. The Streak will fly slower than optimum at this setting. Speeded up a bit, flies well. The extra weight no doubt a function of the fairly heavy wood fues, (it was an ARF wing after all), the five ply doublers, the genuine hard maple unequal length motor mounts run near the leading edge and the extended nose and tail moments. An experiment for stunt. When the speed is right, flies pretty good. Not the best choice for competition tho. I plan to take out the extra head gaskets, pop in a big venturi, and let the engine scream. Towers can put out power and stay tight for years.

[Ward Van Duzer]

The Prowler is a little small, but is a fully sheeted foamie. My feelings...a little small for a foamy and likely to build a little porky for that size model. Yes, I had one.


W.

[MrSteve09]

Dave,....

On my Hole Shot that has a 42 1/2 inch wing span and is powered by an OS 35 FP it weighs in at 32.8 ounces!!  Keep in mind the fuselage is only 3/8 balsa instead of the usual 1/2 balsa normally used for profiles.

Hope that helps.

Steve T.

[Steve Helmick]

A couple of crude rules that I like are: Weight in Oz. = Disp. in tenths of a cubic inch. This tells us that a .35 powered model might be good at 35 oz, or a .19 powered model at 19 oz.

A better rule is that a stunt model should have adequate static thrust to more than equal the weight of the model. This is easily tested by running the engine on the ground and pointing the nose vertically. If it doesn't want to climb out of your hand, it needs more umph. A flat pitched prop will skew this test and show the superiority of the 2-2-2 type of run.  Steve

[David M Johnson]

Thank you for all the reply's
David

[Brett Buck]

Dave,....

On my Hole Shot that has a 42 1/2 inch wing span and is powered by an OS 35 FP it weighs in at 32.8 ounces!!  Keep in mind the fuselage is only 3/8 balsa instead of the usual 1/2 balsa normally used for profiles.

Hope that helps.

Steve T.

  If you can build it to 32 oz, that will work dandy with a 20FP or a 25LA.

    Brett

[Steve Fitton]

My stock (Brodak) kit Veco Tomahawk weighed about 28 ounces (monokote covering). An FP-25 flew the snot out of that little plane.  Putting a .35 on it would have been massive overkill.

[phil c]

as little as possible.  Likely weight will be around 28 oz.  Much over 32 oz. and you will have problems doing pretty stunts.