Reducing weight 4*60 tail
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Reducing weight 4*60 tail
Since the 4*60 stabilizers are solid balsa, has anyone tried cutting holes in the stabilizers to reduce weight in the tail. Can you selectively remove some of the wood, without weakening the stabilizers too much (possibility of adding support wires to the vertical stabilizer?). What are some other ways appropriate to reduce weight in the tail that have been tried successfully without discarding the existing design completely and starting over?Although, I would like to hear about any new design. I just crashed my plane and upon a rebuild, I would like to consider rebuilding the stabilizers....Please advise.....Wayne
#2
RE: Reducing weight 4*60 tail
Just my opinion:
If I were to alter anything, it would be to replace the solid stabs with built up ones. I would leave the original ones intact, as this plane is capable of really horsing or stressing those components. Without changing the type of wood to something really hard to maintain rigidity, I think control would start to get a little squirrelly. I know that once I get my first couple of flights in spring to loosen me back up, this airframe takes a beating. I think the thing to worry about most would be getting the stabilizers to twist once you start some of the higher energy maneuvers. Possibly adding support wires to the front and rear edges of both stabilizers could help, but how much drag will all the extra hardware add?
If I were to alter anything, it would be to replace the solid stabs with built up ones. I would leave the original ones intact, as this plane is capable of really horsing or stressing those components. Without changing the type of wood to something really hard to maintain rigidity, I think control would start to get a little squirrelly. I know that once I get my first couple of flights in spring to loosen me back up, this airframe takes a beating. I think the thing to worry about most would be getting the stabilizers to twist once you start some of the higher energy maneuvers. Possibly adding support wires to the front and rear edges of both stabilizers could help, but how much drag will all the extra hardware add?
#3
RE: Reducing weight 4*60 tail
Common grade balsa is what most model kits are made of, being the density 8~12 lb/cubic ft or 0.074~0.111 oz/cubic inch
Calculate how many cubic inches could you remove, multiply for the values of density in oz/cubic inch, and you will have an estimate of the weight loss of the stabilizers.
Multiply that value for 2.2~3 to calculate how much nose weight will you be saving by removing wood from the tail.
Worth it?
Switching to pull-pull controls will help.
Not sure if you can find any reference in these threads:
http://www.rcuniverse.com/forum/m_35..._1/key_/tm.htm
http://www.rcuniverse.com/forum/m_3144374/tm.htm
Calculate how many cubic inches could you remove, multiply for the values of density in oz/cubic inch, and you will have an estimate of the weight loss of the stabilizers.
Multiply that value for 2.2~3 to calculate how much nose weight will you be saving by removing wood from the tail.
Worth it?
Switching to pull-pull controls will help.
Not sure if you can find any reference in these threads:
http://www.rcuniverse.com/forum/m_35..._1/key_/tm.htm
http://www.rcuniverse.com/forum/m_3144374/tm.htm
#4
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RE: Reducing weight 4*60 tail
Yes I have done so on many airplanes but mostly old timer types. As the others seem to have hinted at, its often for very little gain especially on that type airplane.
If you are doing this to help with a CG problem (CG to far aft) Then here is a very effective method that simply moves the battery forward along side or under the engine and invloves no adding of lead.
John
If you are doing this to help with a CG problem (CG to far aft) Then here is a very effective method that simply moves the battery forward along side or under the engine and invloves no adding of lead.
John
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RE: Reducing weight 4*60 tail
Do you mean elevators and rudder? Maybe you are talking about the ARF? I built a kit and the horizontal and vertical stab are built up. I tapered all of my control surfaces from front to back down to about 1/16". That got rid of some weight and made them look much less clunky. I used an OS fs-91, cut off the cheeks and used a fiberglass cowl on mine, it was a bit nose heavy until I moved the battery back into the fuse behind the wing.
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RE: Reducing weight 4*60 tail
Thanks for the responses. Based on the calculation, I don't think that it would be worth it although, previously I added triangle stock on top and bottom of joints to horizontal stabilizer to strengthen and no doubt that is part of the reason my tail is so heavy. Also, upon my first rebuild of this plane, I used too much 2 part epoxy and added too much weight. I am starting a build of a 4*120 and will not make the same mistakes. I will cut off the cheeks and use cowl and build mostly with CA and in general be more careful about adding unnecessary weight. The orange plane is beautiful and I would be happy to make my 4*120 like that one. Thqnks, I will leave the 4*60 stabilizers alone. Wayne
#7
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RE: Reducing weight 4*60 tail
Are you dealing with a kit or ARF? The kit 4Star60 horizontal stab and vertical stab (fin) are both built up pieces - 3/16" core sticks covered with 1/16" sheeting.
#9
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RE: Reducing weight 4*60 tail
Looks like a Fiberglass Specialities one. They have them and wheel pants. For the wheel pants, I used the ones from the 60 size U Can Do, along with the Dubro heavy duty composit landing gear.
Don
Don
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RE: Reducing weight 4*60 tail
The cowl shall be Fiberglass Specialties. I bought the plane used but I believe that it was a kit. I suspect you are right about the build-up as I just supposed that it was solid which If sheeted I may have gotten fooled. Anyway, I have given up on the idea based on the responses. i like the idea of putting the battery under the engine. I probably won't be able to do that however since I am putting a DLE30 on the 4*120 which I am starting; but the 4*60 it would work good. I am going to be fighting too much nose weight on the 4*120. Wayne
#11
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RE: Reducing weight 4*60 tail
I stick built the tail pieces once on 4-star .40. The result was a nose-heavy airplane that needed the battery placed way back in the fuselage to get a good CG. I would leave it alone.