Sonic and Son of Sonic

 Just a location for submitting a pic to a chat group, really like the sonic 👀

Assembling the Eric Arnaud Sharkie racer foamy swept wing

Couple years back when Eric flogged me the EPP cores for a song, I promised him a blow by blow of the assembly - got engrossed in the build but just enough pics to talk to - the aim being a clean, stiff, zero awful fiber tape finish. 😎

Eric's EPP simply perfect to work with, the coarse block sticky back sand paper from Russ and the medium bar sander worked great right through, just taking off any outer loose bits here pre commencing.

Laying the first of three spars per wing, one top and two bottom. Marked out on the masking tape then blade cut to a depth to allow the 6mm by 1mm (available from the KZN online hobby shops and other) flat carbon spar to settle just below the surface. Then dribbled in medium super glue and finished with Builders accelerator, which provides filling itself just above spar on surface.

The lightweight hobby filler definitely the way to go after reading of some spackle issues, mine was old so wetted slightly and played nicely spreading with fingers, a peach to work with. Warning 1, leave over night to dry properly or it can clog like the block in pic - when properly dry then zero clog. Pleasing was no hint whatsoever of of a spar ridge or dip after sanding.

Was warned that the very slightly wetted hobby filler can shrink slightly and distort things so both cores went back in the blanks under weight to settle for a week, total overkill but this combo really rigid if you want to fix later. Note the three spars staggered (location quite arb but make both wings exact same and rather have level with root) 5mm out out at tip easily cut with big scissors, not healthy stuff to Dremel cut. The rear spar quite close to the elevon hinge line as I intended using the original EPP as elevons instead of balsa to retain the gradual reflex curve.

Everything barring servos was then inserted from the root and spaces opened using my trusty Antex 15 watt soldering iron to carefully heat open from the root. Three throws of ball type lead sinkers (ex Basil Manning) for the balance (see further on pics), I would guesstimate about 220g. The servos, receiver and 300mah battery all aligned dead on the CG line of 159mm but I would next time move the receiver and mini battery to give room for a ballast to tube bay - Eric does comment that the section easily carries ballast. Servos on CG, again masking tape first and marked for knife cut then opening routed out so servos approximate level with the surface. Servos glued in with Pratley white epoxy and the leads run internally through foam to receiver.

Then wing joined using Pratley white epoxy because any overflow sands beautifully and is close as dammit to the core colour. I went flat bottom, I guess one could lay flat top to give some slight illusion of dihedral.

Wing turned to bottom and two short offcut pieces of 1mm by 6mm spar let in to support the join and nestle against the existing spars. Again below surface and fill and sand as before.

Finished product showing the spars slightly proud at the tips, to locate the tiplets later on, hot glued on (no damn fibre tape please ;-). I used Richard Steinbach's magic pressed light cardboard tiplets, excellent solution. I gottit wrong on the location, the tiplet rear definitely to align with elevon rear next time, for aesthetics and stability.

I am glossing over ironing on the thin laminate (thanks to Russ for donating) after spray gluing (Alcolin brand I used), similar to any iron on and lots of you tube video guides. Start in middle and work out in zebra crossing fashion like they tell you. I also added a double layer laminate about 50 mm wide first at the top hinge line, thanks to a tip from Russ. My warning number 2, prick the bubbles with a needle as you go, you may think you have crushed heated out the bubble but it will return..... Warning number 3 don't spray glue both sides one time, the underside will grab fine residue etc. Again overnight dry is best, was really impressed how it helped lock down the laminate, how nice does the finish look? 👀😋

Underside after laminate is completed, can see the servos under laminate, just need slits for the servo arms to nip out once covering on. 

Top view, pre cutting elevon from below and using the laminate as a top hinge (proved superb). Classic Zagi mm width is 40 mm, I played with calculator to approximate 20% root chord and 30% tip chord, settling on 50mm wide, seems to work fine. Length was just past the servo bay, not all the way (see bottom pic). Inverted V cut from bottom not quite through to top hinge line - then cracked up and cleaned out for the hinge line, works a treat.

The mini rent a crowd on the day of the successful maiden flight

showing the incredibly thin and clean profile of Eric's wing section. The wing covered in plain ole contact vinyl, the only black and white version I could locate and seems fine for visibility. The seamless one sheet does all for each wing plan was thwarted by Warning 3, do not spray glue on top of the laminate to lock the contact or vinyl or iron on, it grabs just when you don't need and is totally unnecessary.

Top view at maiden arvie, eventually decided on a gap in the covering along the hinge line to prevent crinkling, all edges sealed with waterproof clear tape, pretty damn clean. The 159mm (20%) CG proved perfect and the normal additional reflex not needed at all, as the first launch revealed. 😆

We were ring fenced to two out of three classes for the Toss races and an easy decision to loan Sharkie to Steve Muesel who was flying it better anyway - herewith Russ about to launch for round 3. 😂

Steve with Sharkie on landing approach after placing second in all three rounds and second overall for the event. Commented on just how smooth the aerie flew. 

The wing with full aileron deflection showing clean hinge line, distance from root and the aileron horns used to drive elevons, the servo drive, pushrods and horns all bottom but would rather do top next time - tiplets also reset further back. My thanks to Eric for the excellent base to try out my ideas on, most happy with the result. 😃👌

Looking forward to Toss F3F 2022

In looking forward to Two Oceans F3F 2022 next week, I was disappointed that the last biggie F3F event 2013 results were not on the blog so rectifying that right now ;-)

Whilst the Highvelders Jason and Craig took that weekend, Dean Halley scooped third for the coastal local yokels, damn good job Dean! Also notice Reg Roets the racer lurking mid pack, also very well done for this part time social slope flyer. :-)

Much more practice has been on the go down Simonstown way, so very likely that the Toss lads will take some of the podiums spots for 2022, watch this space.

Black Arrow solid balsa slope glider (RCM&E August 1976)

 

Filing cabinet for tracking plan number and plan from fuzzy cell pics:

Dave Schaller Super Wasp maiden at Dumbe mountain 24 September 2020

 

Schwooooooop 👀😎

Really hot slope semi scale flying from Europe

These Facebook links to really hot semi scale sloping for lunch time breaks ;-)

Toxic

Baby Swift S1

Libelle

Toxic pass 2019

Swift Qwantas

Little Kobuz

This Youtube link for ABm has 21 videos:

ABM Airfoils

Soar-J '95 through 2004 cabinet

The F3J hand tow decade of Soar-J events featured the names of four guys and one gal and were renown for the 15 minute fly off finals. Robbie Cutler [Derek Perks aerie]took the first event very closely from fellow Natalian Dave [2m Easy Bird & Bird of Time], the only two pilots to max the fly offs that year. Rob was probably the most gifted of our Kzn F3J thermal pilots, a shame not to make it to a worlds.

The second year belonged to the amazing Michelle Goodrum, still the only lass to compete in both F3J and F3B world championships.

Dave had to wait to year three to step on to the top of the podium.

Then it was the turn of serial world champ attendees Craig Goodrum and Chris Adrian. I happened to call for Chris in one of his winning fly off and such was the intensity that he confessed he could feel his heart beating ;-)

F3J worlds trials meant much travel across Kzn and the Highveld, with one memorable event at Bloemfontein. A lot of results and stories have escaped to the ether.....

One hell of adventure and it would be nice to maybe see it reinvented in F5J form.

These are just bits copied off the defunct web site, no fancy cell cameras in those days:

Background:

My friend Robbie Cutler took the gold badge at the magical first Soar-J in 1995, made even more memorable by the Saturday late afternoon retiring of the mob to the club house for the rugby world cup and a celebratory thrash, culminating in a few "pit stops" for him on the trip home!  Karkloof is renown for its huge manicured fields, friendly club facilities and stunning weather. The locals have been well supported by the Highveld chaps, with John Lightfoot also bringing a Cape flavour to the Noodsberg event in 1996. 

Past Soar-J Winners:

1995 - Rob Cutler

1996 - Michelle Goodrum

1997 - Dave Greer

1998 - Craig Goodrum

1999 - Chris Adrian

2000 - Craig Goodrum

2001 - Dave Greer

2002 - Chris Adrian

2003 - Craig Goodrum

2004 - Craig Goodrum (F3J) & Simon Nelson (E Winch)

(Dion Liebenberg won all F5J events during this period)

Some web site pics of the mob

The Pure F3J aspect expanded to other contest forms to give more podiums. This from Soar-J  2003 being Johan de Lange, Chris Adrian, Michelle Goodrum, Craig Goodrum, Ian, Dion Liebenberg, Don Slatter, Pete Lonsdale, Fred Witstock and Adrian Baker.

The mob in front of the American muscle cars caravan - a solid supporter.

The year we hosted the late John Lightfoot from the Cape - at Noodsberg.

The late Gary Armstrong chopped his ear whilst towing Chris Adrian, who calmly stretched his tow line and launched bungee style.

Anton Coetzee rushing for a relaunch, so much part of the F3J contests.

Drew Kennedy? ;-)