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I want to fly an A-4 at Flite Fest...

I'll definitely build another one sometime and see if I can make her look just as good, but see if I can shave a couple hundred grams off her.
 

Tonero311

Well-known member
OMG that's FRIGGIN' AMAZBALLZ!! That looks absolutely stunning! I would feel vain telling someone I designed that plane, you did a really great job on the build and finish. Can't wait to see the maiden!

There are rumblings of a larger incarnation, maybe not quite as large as my 72" version, but I can't say much more than that. ;)
What I would do to get my hands on the plans and parts(that monster radial) for Big Al's Cessna. That is a thing of beauty I immediately wanted to build. 30 minute touch and go's too on that set up. Great job on that one Ben. Quite a few of your designs have caught my eye and are on my future build list.
 
I built a what I'll call an A-4 v7 frame this weekend. I don't have the electronics yet and I wanted to build it anyway. Maybe someday I'll open it up and add the fan and other electronics. Until then, it'll look awesome hanging in the garage with the rest of the fleet.

I took photos of parts of the build that I was looking for when I started. Hopefully they help others when they are piecing it together as they start cutting too.

I started with the main fuselage and upper fan mount.
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Then the lower fan mount.
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The inlet floor. This is a pressure fit with a couple of glue tacks so I can pull it later to put the fan in.
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Now for the mid mount and the tail cover.
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I used the v8 thrust tube diameter and shaved the fuselage down to fit. I glued the end piece in as two halves because the foam was really thin.
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I had to cut the inlet bifurcation pieces to get the thrust tube in. I think if I had been putting the fan in, I wouldn't have had this problem because I would have done the thrust tube before I put the tail cover on.
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Here is the start of the nose piece. I glued in two moves so I didn't have to rock it down onto the table.
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I used kvcanar's method for forming the canopy and it worked great. I took the easy road and used one sheet of foam and then flat sanded it to sit nice.

Final shots before paint. Note the that wings, vertical stabilizer and horizontal stabilizer aren't glued yet. I'll glue them if I ever put the fan in.
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It weighs 358 grams as a bare frame and it will probably take another glue stick to attach the wings and stabilizers.

I have to say that the nose was really easy to build and should put anyone off. Just bevel all the joints slightly and squish the foam down with a bbq skewer until it meets nice.

I think the nacelles where the most challenging as one piece and now the 3 piece should be way easier.

Awesome build, thanks Ben!!
 

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Nice job, looks great! A word of caution about paint, the tail assembly is very sensitive to warping due to uneven paint application. I ended up with a bit of anhedral in my horizontal stabilizer due to the fact it is difficult to get even paint on the underside of the stabilizer while it is attached to the fuselage.
 
Mid7night,
10 flights on it now ........ and it flys GREAT! I’ve always tinkered with 50mm and a couple of under powered 64mm fans and this is my first 70mm project. Great plans. Great plane! Thanks for putting this out, Mate! I added a clear canopy for looks and a ventral fuel tank to make launching easier (I suck at the pancake toss method). Used the minwax brush on/wipe off method to prep for paint and avoid warps.
Cheers!
Mac.
 

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Daniel Liutan

Well-known member
Mid7night,
10 flights on it now ........ and it flys GREAT! I’ve always tinkered with 50mm and a couple of under powered 64mm fans and this is my first 70mm project. Great plans. Great plane! Thanks for putting this out, Mate! I added a clear canopy for looks and a ventral fuel tank to make launching easier (I suck at the pancake toss method). Used the minwax brush on/wipe off method to prep for paint and avoid warps.
Cheers!
Mac.
Looks great ! A flight video would be brilliant!
 
Looks great! Glad it's flying well for you. That scheme looks awesome! I think I might need to build another one for myself. :D
Thanks Mid7night! She flys really well - even on a cheap 70mm fan.

Daniel - The 70mm is totally worth the build. I’m currently flying Zephyr1’s MiG 21 off a 4S 50mm and it flys really well, but after flying the A4 a bit I’m rebuilding the MiG with a 64/70mm unit. Here’s the MiG Next to the A4 - it weighs in at 31oz painted. About 11oz less than the A4 but the both have around the same wing area.
 

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I finally put an FT Aura-5 Lite in the A-4! Warning: Do not try this unless you want to never fly again without it.... Yes, it's THAT fun. :D:p

HAHAHAHAH. I have a few Auras myself.

Cheers!
LitterBug

EDIT: The simple plug and play design makes these so much better than messing around with iNav or Ardupilot. Stabilization on a tiny FPV wing helps a lot to reduce the waggles which can be incredibly nauseating.
 
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dap35

Well-known member
I'm planning on upscaling this to 125% (~36" wingspan) and using a 90mm 6s EDF and retracts. There is a big jump in weight for a 90mm EDF, so it may be an expensive experiment. Since I already ordered some slick looking Callie Graphics, I am committed. I may add flaps as well.

Any recomendations for retracts?

Here's the target EDF:
Powerfun 90mm, 6s

https://www.rc-castle.com/index.php?route=product/product&manufacturer_id=113&product_id=8108&page=3

- Outside Diameter : 98.0mm
- Ducted Fan Length : 81.1mm ( With Wing Intake Ring )
- Rotor DIameter : 90mm , 12 Blades
- Overall Weight : 372g ( Whole Unit )
- Motors : Powerfun High Performance D3541 1450Kv Outrunner Brushless Motor
- Working Voltage: 6S 22.2v
- Static Thrust : Around 3000g At 22.2v (102A) , Around 3700g At 25.2v (124A)
 

rkozak

Junior Member
Hi, I'm getting ready to cut the V8 version with my MPCNC needle cutter. I'm concerned about the scale though. When I import into inscape i do it in the manner that I've always done it. But in estlcam the scale on the plans do not match the1" (25.4mmx25.4mm) grid. Should I be concerned?
 

Addicted

Elite member
Hi, I'm getting ready to cut the V8 version with my MPCNC needle cutter. I'm concerned about the scale though. When I import into inscape i do it in the manner that I've always done it. But in estlcam the scale on the plans do not match the1" (25.4mmx25.4mm) grid. Should I be concerned?
Just select all, and scale up or down 'til the 6" scale on each of the sheets matches to 6 inches. You can draw a 6" line to measure.
Be sure to deselect the 6" line when scaling, of course.
 

rkozak

Junior Member
Getting Close.......

Couple a minor mods:
  • Balsa strip on rudder leading/trailing edges as well as balsa strip on all other exposed trailer edges & tips. This helps with protecting edges when transporting.
  • printed servo covers.
  • I found the top of the nose to be an issue , so a separated the bottom piece from the 3 top angels and glued it to the nose first. Then I sanded edge angles to make a flush join before I glued the top in place.
  • After forming the canopy and gluing it to the base the creases looked not to great. I removed the paper from the canopy and sanded the foam to clean it up. Then I applied a few thin coats of poly fill spackle (sanding between coats).
  • Current weight with 4 cell Turnigy Nana-Tech 4500mah is 1299 grams (45.82oz).
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