Building Tips and technical articles. > ARF'S

My SV-11 ARF Build

(1/3) > >>

Jeremy Chinn:
I'm nearing the completion of an SV-11 assembly/build. I thought I'd throw some of the things I did here on the ARF section - maybe for my own memory, maybe for someone else's benefit.

I'm not a huge fan of ARF's- I've only assembled a handful, most of those were airplanes that I designed and I was building pre-production proofs. I expected some issues and worked through them, documenting stuff so the factory could fix them. I'm glad that we've got ARF's available from Brodak, but honestly I'm somewhat disappointed in the level of error I'm finding in them.

The SV-11 I'm putting together was actually in stock at my LHS. It was a glow version, but I'm building it electric. I was an early convert to electric power over 20+ years ago, so converting a glow design does not bother me. To get this done, I made a firewall mount for the motor and tied it into the glow engine beams. I then made 1/4" diagonal grain blocks to tie the firewall into the next former back. All of this was epoxied into place. I like to epoxy in place and hit with a heat gun to allow the epoxy to run into all the cracks/edges. I set my thrust line with my old Robart meter and based it off the thrust line of the stock beams.

I have yet to finish making my battery packs, so I will do that before making a battery tray and finalizing the location of the Castle Phoenix 50 ESC and the Climb&Dive  Timer.

I love wheel pants on airplanes, but I fly from grass, so I did not mount the ones I prepared. However, since I did not like the blow-molded plastic stock units, I had a nice set of fiberglass pants that matched pretty nicely in size and I painted them and the landing gear to match the plane. I also took a few mins to round over the leading edge of the landing gear.

Though I did not get a pic, I decided I did not like the crimped leadouts, so I ordered some new leadouts from Brodak and installed wrapped leadouts in their place.

When I installed the wing and horizontal, everything went pretty nice and square. However, when I went to install the canopy, it was readily apparent that it had a huge 3/16" gap between it and the wing. To fill the gap, I cut some wood with my stripper and soaked it. Curved it over my monokote iron and glued it in a layer at a time, doing some taper sanding in different places to make it fit. I eventually got a good fit and then monokoted over it with white. Its a good fit overall now, but the trim does not match (Its now a good 50footer airplane). The clear canopy was also a bit like a crime scene - fingerprints everywhere from glue used to install at the factory (maybe I could track down the worker who installed it  ;D ). To cover all of that up and give the airplane a little more character, I got out my airbrush and shot the canopy silver with some good black shadowing. A quick light coat of Rustoleum Clearcoat covered the whole thing up nicely.

For hardware, I used the stock horns, but used new Robart heavy duty 4-40 ball links in the stock ball links place and used a washer on the outside of each as a 'keeper', just in case something were to ever begin to fail. I made a new carbon fiber flap pushrod with new 4-40 thread and Robart Ball links.

Motor is a BadAss 3515-710 and will run reverse with a 12-6 APC pusher prop. An Innov8tive Solutions spinner made for the pusher prop caps all of that off.

I hope to get it flying in the next few weeks if the weather will give me a break and I can get a few packs built.

Full spec will be:
Brodak SV-11 Glow ARF Converted to Electric
Badass 3515-710 motor
Castle Phoenix 50 ESC
6s 18650 Molicell Li-Ion Battery
APC 12-6 Pusher Prop
Climb and Dive Timer
64' lines (per the suggestion of my buddy who has done well with his)

Jeremy Chinn:
A couple more pics.

Jeremy Chinn:
The SV-11 is ready to go. We’ve got a Frosty Fingers fly-in on New Years Day, so it might get a maiden that day.

Having days off work has been super helpful in providing some time to finish things out.

For the arming plug, I found a, STL file on Thingiverse.com for an XT60 connector. I printed it on my son’s new 3D printer (I had to try it out, right?). I modified it for the Deans connectors I’ve always used and installed it.

I mounted the Climb & Dive Timer on a plate mounted away from the battery and deep into the cowling.

The ESC is mounted in what was the pipe tunnel. I made cooling holes in the cowling and used the existing holes in the fuselage.

The timer starting button is mounted in the fuse opposite the arming switch- that way I should not hit the start button while putting in the arming plug.

I finished my first battery and it came out at 323 grams. Not bad, but I can get it down a little lower. My leads on the ESC are too long as well (I can drop 1/2-3/4oz there). The battery mount plate is screwed to the stock glow engine mounts. Velcro on the plate and a strap through the plate hold the battery solid.

The cowling is held in place with neodymium magnets. I like the rear mount I created, the front mount will need to pass the test in flight. I also added an edge along each side to keep the cowling edges aligned.

Jeremy Chinn:
Pics of the starting switch and cooling holes.

Jeremy Chinn:
Battery, timer mount and interior.

Navigation

[0] Message Index

[#] Next page