Vortex F3A build thread
#126
Join Date: Mar 2009
Location: Milton Keynes, UK
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Thanks Alex, your design is perfect. I was just wondering if this was done via software but its a case of using a slightly longer airfoil and then just trimming it, them im good:-)
#128
Thread Starter
I converted the cowl and canopy to .step format, you can find them here:
https://drive.google.com/open?id=1nI...62z4iLboSL5-e2
The cowl is approx. 5mm longer than needed in the nose area so it can be either cut straight for the contra unit or with 2-3 degrees right thrust. You can also use different spinner sizes (83-89mm). The cowl and fuselage balsa structure are overlapping on a distance of 15mm.
The canopy is approx. 5mm larger where it meets the fuselage to compensate for any errors during the assembly of the fuselage balsa structure. It needs some trimming to fit the fuselage perfectly before the canopy frame is attached.
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pdewaegep (01-27-2020)
#129
Thread Starter
In order to have complete building instructions, i will add some CAD images to illustrate what is left to do to finish the airframe.
Today's update shows the motor mount and cowl attachment to the fuselage. Since i didn't get that far with my Vortex build, i highly recommend reading Isaac Najary's Fantasista build thread. There are some similarities for the cowl and motor mount assembly:
http://www.rcuniverse.com/forum/12034186-post33.html
http://www.rcuniverse.com/forum/12034187-post34.html
Today's update shows the motor mount and cowl attachment to the fuselage. Since i didn't get that far with my Vortex build, i highly recommend reading Isaac Najary's Fantasista build thread. There are some similarities for the cowl and motor mount assembly:
http://www.rcuniverse.com/forum/12034186-post33.html
http://www.rcuniverse.com/forum/12034187-post34.html
#132
Thread Starter
I bought several pairs a few years ago from F3A Unlimited, but i think you can find them in other hobby shops too:
https://www.f3aunlimited.com/f3a-unl...h-pair-style-b
They have a few different versions, so make sure you get the type B in the link above. Anyway, i found them to be a little heavy so i cut them and made them smaller (and 7g lighter).
https://www.f3aunlimited.com/f3a-unl...h-pair-style-b
They have a few different versions, so make sure you get the type B in the link above. Anyway, i found them to be a little heavy so i cut them and made them smaller (and 7g lighter).
#133
My own Vortex is almost wood finished so I have started the work of the cowl and canopy. The plugs are 3D printed and then I have aplied filler and sanding before paint so they are pretty much finished now so next up is to make the molds.
#134
One wood finished simplified fin version of the Vortex
It is a bit rought as i wating with the final sanding just before covering.
It is a bit rought as i wating with the final sanding just before covering.
Last edited by Krille; 11-23-2019 at 05:12 AM.
#136
Thread Starter
#138
Yes it does. The printing it self took about 100 hours for the canopy and 50 for the cowl but in hands on time its more like 15 minutes. It takes some time to do the filler/sanding/painting of the parts but its alot less work this way instead of doing a plug from balsa or other material.
The mold for the cowl is now ready. Planing of making the first cowl soon. The mold stil needs some cleaning up from the blue mold clay.
The mold for the cowl is now ready. Planing of making the first cowl soon. The mold stil needs some cleaning up from the blue mold clay.
#141
I use the Falcon set with wheel pants.
The first cowl is out of the mold.
I use resin infusiuon with vacuum to get the optimal resin/fiber ratio.
I made 2 version.
One with 2 layers of 160g m2 carboon. Final weight for one cowl half is 55g (left one in picture)
And one with one layer of 110g fiberglass and one layer of 160g carboon. The weight is 44g for that half (right one in picture)
The lighter version is probobly strong enough but i will go for the stronger one. About 110g for a complete cowl is not bad at all.
The first cowl is out of the mold.
I use resin infusiuon with vacuum to get the optimal resin/fiber ratio.
I made 2 version.
One with 2 layers of 160g m2 carboon. Final weight for one cowl half is 55g (left one in picture)
And one with one layer of 110g fiberglass and one layer of 160g carboon. The weight is 44g for that half (right one in picture)
The lighter version is probobly strong enough but i will go for the stronger one. About 110g for a complete cowl is not bad at all.
#142
Thread Starter
Great work Krille, the cowl looks beautiful and 110g is a lot lighter than i ever hoped for such a large part. The resin infusion process is definitely worth the extra effort.
I realized i forgot to add a few things in my previous posts, so i attached a few more images with the remaining details.
I also think i made a mistake: the ESC support should probably be added after the cowl is attached to the fuselage. Unfortunately i can't edit the previous posts to change this.
I realized i forgot to add a few things in my previous posts, so i attached a few more images with the remaining details.
I also think i made a mistake: the ESC support should probably be added after the cowl is attached to the fuselage. Unfortunately i can't edit the previous posts to change this.
#144
My model is now finished for covering.
Here you can se how i did with the frame for the canopy.
Weight for the complete aircraft with motor, esc and prop/spinner is 3168g
Here you can se how i did with the frame for the canopy.
Weight for the complete aircraft with motor, esc and prop/spinner is 3168g
#145
Thread Starter
#146
Thread Starter
I thought I should add a few words about the control horns, linkages and a suitable spinner.
There are many options on the market for the control horns, but the ones included in the drawings were designed specifically for the Vortex so i would recommend using them.
For the rudder pull-pull system i had to consider that the wires are crossed inside the fuselage and go out through the small bowden tubes (representing 2 fixed points). I determined that a 3mm offset on the rudder servo arm is needed to make sure both wires are slack-free at all rudder deflections. Without this offset, one of the wires would be tensioned while the other would go slack when the rudder is working.
The aileron linkage geometry was designed to keep 90 degrees angles between the pushrod and lever arms, which should result in a perfectly symmetrical movement of the ailerons. If different control horns are used, the geometry of the linkage can be compromised and the model may need some differential mix. Even if the maximum throw of both ailerons is equalized using the endpoint adjustment in the radio, it is possible to have small differences between the 2 ailerons at intermediate stick positions.
My plan was to manufacture my own spinner so the nominal diameter is not standard size (89mm). But since the cowl nose is 5mm longer, an 85mm diameter spinner can also be used. I think the best match for the Vortex cowl shape is this 85mm Mejzlik spinner:
https://shop.mejzlik.eu/detail/spinner-34-3744
There are many options on the market for the control horns, but the ones included in the drawings were designed specifically for the Vortex so i would recommend using them.
For the rudder pull-pull system i had to consider that the wires are crossed inside the fuselage and go out through the small bowden tubes (representing 2 fixed points). I determined that a 3mm offset on the rudder servo arm is needed to make sure both wires are slack-free at all rudder deflections. Without this offset, one of the wires would be tensioned while the other would go slack when the rudder is working.
The aileron linkage geometry was designed to keep 90 degrees angles between the pushrod and lever arms, which should result in a perfectly symmetrical movement of the ailerons. If different control horns are used, the geometry of the linkage can be compromised and the model may need some differential mix. Even if the maximum throw of both ailerons is equalized using the endpoint adjustment in the radio, it is possible to have small differences between the 2 ailerons at intermediate stick positions.
My plan was to manufacture my own spinner so the nominal diameter is not standard size (89mm). But since the cowl nose is 5mm longer, an 85mm diameter spinner can also be used. I think the best match for the Vortex cowl shape is this 85mm Mejzlik spinner:
https://shop.mejzlik.eu/detail/spinner-34-3744
Last edited by Alex Voicu; 01-08-2020 at 07:58 AM.
#147
#150
Thread Starter
I’ve been thinking about a paintscheme for Vortex, and since i didn’t have too much time it was easier to start with the existent Audax scheme and modify it. I also tried to generate the templates for film covering; these can be used as a starting point but it’s impossible to perfectly unwrap all the compound curvatures to a flat surface. When covering the Audax, most of these templates were ok, but for some of the colors that were applied on top of others i had to use transparent film to get the perfect shape. The differences were small though and the templates were still useful to trace the curves through the markings on the plastic film:
Audax F3A - new project for 2013
The templates can be found at the link below and they can also be useful if you choose to paint the model. Obviously they need to be printed at 1:1 scale, and if you print the them on multiple A3 sheets, the red lines included in the templates can be used to align them correctly. The blue lines represent the theoretical centerline or edge of the fuselage, but since we can’t expect the templates to be accurate down to the millimeter, we need to cut the templates and film pieces larger in those areas. For the fuselage, the white color comes first and the wing/stab holes can be used as a reference for positioning. All the other colors will follow the edges of the white color.
The white stripe at the base of the canopy is not part of the fuselage templates because it's actually painted on the canopy.
https://drive.google.com/open?id=190...1zU18MUyCQbX50
Audax F3A - new project for 2013
The templates can be found at the link below and they can also be useful if you choose to paint the model. Obviously they need to be printed at 1:1 scale, and if you print the them on multiple A3 sheets, the red lines included in the templates can be used to align them correctly. The blue lines represent the theoretical centerline or edge of the fuselage, but since we can’t expect the templates to be accurate down to the millimeter, we need to cut the templates and film pieces larger in those areas. For the fuselage, the white color comes first and the wing/stab holes can be used as a reference for positioning. All the other colors will follow the edges of the white color.
The white stripe at the base of the canopy is not part of the fuselage templates because it's actually painted on the canopy.
https://drive.google.com/open?id=190...1zU18MUyCQbX50
Last edited by Alex Voicu; 01-24-2020 at 08:10 AM.
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