Thursday, December 18, 2008

Weekend at Volksies

Not having had enough the previous visit, Norbert and myself decided to join some of the BERG guys for some more action at Tamatieberg. I thought we were in for another pearl of a day when we arrived at the slope and the first plane I unpacked and tossed off the side was my Toko. Although the wind started out well and we still managed to get some quality airtime, it started petering off later in the afternoon.

That was when the first casualty of the day happened when the lift died and Peter Karner lost his foam PSS Mustang. An unsuccessful search followed and Peter decided to wait and see if Mike, who had gone down to the farm, could spot it from the bottom. Not long after this the wind stopped completely before doing a 180° turn on us and a hectic 15 minute flight window ensued on the southern side of the mountain. The next casualty of the day occurred when one of the chaps from Northrand lost a beautiful (but very heavy) PSS Mosquito that he had converted from electric. The general consent from the onlookers was that the unfortunate pilot made the all too common nervous mistake of hanging on the elevator and not letting the plane pick up enough speed to get on step. The resultant "Whack!!" halfway down the mountain could clearly be heard at the top of the slope.

The flying was abruptly cut short when out of the blue, with little warning a thunderbolt struck very close to the tower behind us and everybody decided that discretion was the better part of valor and promptly packed up and left, just as the rain that had been threatening the whole afternoon started. It cleared enough a little later to allow me to get my customary spell of pre-sunset electric flying at the farmhouse with my E-Hawk 1500.

Just to show us how unpredictable Volksies could be, Sunday dawned bright and sunny with very little cloud. Typically you would expect a day like this to generate a lot of thermal activity that inevitably causes erratic flying conditions. Not this day. Mother Nature blessed us with consistent enough wind that we could fly anything and a good couple of big scale gliders were put through their paces. A handful of PSS planes and an assortment of other aircraft were also flown.

My F18 Hornet also got some airtime. Just as I was getting comfortable with the model it rudely reminded me that it has quite an authentic flat spin that needs a good 30-40m of vertical airspace and a healthy nose down attitude to recover from this maneuvre. Fortunately the only damage was to the pilot's pride....

The highlight of the day for me was when I could eventually entice my son away from the stick hut building that he and Russel was so enthralled with, to get some stick time on my aging Gentle Lady. Patience is not generally one of my strong points but the reward of seeing him complete some controlled circles and even a loop or two thrown in to keep his wandering attention on the task at hand, is reward enough for me to keep at it. Thirty minutes was all he could muster before the more interesting survival training excersize beckoned him to complete his and Russel's masterpiece of construction; a very authentic bushman shelter.

Peter Moore pitched up for the Sunday as well and had an absolute ball with his Shongololo and his ASW28. So much so that I decided that this was going to be my next slope project and the fuselage and all the required material has now been acquired. Still need to pay Dion a visit for all the scale goodies to go in the cockpit. Watch this space!!!

We decided to make the most of the opportunity offered by the excellent conditions and stuck around until 4pm before heading back. Plans are already on the drawing table to come back just after the new year to put a good start on the 2009 flying season.

Blake is getting more and more airtime independant from Dad.

Partners in crime!

No Norbert! You gotta throw it, not push it....

Thats more like it!

Tigershark in action during a low level high speed pass.

Monday, December 15, 2008

Exploding LiPo's - Spitfire shot down in Flames

Last week my trusty old GWS Spitfire met it's end. Finally!!!

But not in the usual way as you'd expect, with a crash , - it's had plenty of those. Each time it was repaired and flew again. (These little foam models are amazing and are so easily fixed)

This time it really was "shot down in flames" so to speak.

Without going into too much detail, one of my colleagues had an accident while charging a LiPo battery and it exploded and the burning battery ended up next to my Spitfire. By the time we got the flames extinguished the whole rear end was burned away.

Luckily all the equipment was undamaged, except the ariel wire! Phew!!!!

Anybody need a well used -"Authentic War Bird Look"- Spitfire wing? Just slight singing on the Aileron TE.

So what have I learned from this?
Don't fool around with LiPo's. They are unpredictably things and should never be left to charged on their own.

Also charge them in one of those fireproof bags.

Monday, November 24, 2008

Jets over Volksies

It has been a loooong six weeks since the ETB PSS fest and the anti-climax of not being able to maiden the Blue Angels F18 Hornet. Eventually I could bear it no longer and decided to return to Tamatieberg for another attempt at getting the model airborne. Unfortunately the F3B team trials was scheduled for this weekend, so the only person I could coerce to join me, without feeling guilty about robbing the team trials of much needed man power, was Norbert.

Weather forecasts on the telly were not very inspirational (60% chance of rain, both days), but after two weeks of solid work I couldn't care less if they predicted a hurricane with it's epicentre smack bang on top of the mountain! In retrospect I would probably have welcomed it.... I have a plane that I feel could very likely handle it and even thrive on it. But now I'm getting ahead of myself.

We arrived at the slope around 10:30am. I was amazed at the transformation in the landscape since our last visit. Everything had that lush Natal Midlands green to it (see the panorama shot above). First model to take to the sky was my trusted Zagi 5C, just to test the air and make sure there weren't any holes in it. As is so often the case on overcast days thermal activity was either totally absent or unnoticable. This meant the northwesterly could do it's magic uninterrupted. After a while it was evident that the wind was not going to let you down a few moments after launching your prized PSS possession.

For the long awaited maidens Norbert was up first with his F5. Apart from the fuselage being so wide as to make holding it difficult for my average sized hands, the launch went perfect and the Tigershark climb out confidently with a little flap deployed. Being the only two occupants on the slope has it's benefits. I stood watching for a while and then dragged the camera closer to shoot some pics while Norbert could enjoy the slope front all to himself. The F5 has quite a turn of speed and even seems to handle slow flight with a bit of flap, if not very scale like, at least quite elegantly. According to Norbert the F5's behaviour was totally predictable.

After about 30 minutes of flying Norbert brought it in for a nice controlled and dignified landing.

I opted for some quick and light action with my Mini Corado for a spell while Norbert put the F5 up for another bout. Gradually conditions improved even more, up to the point where you could fly the proverbial brick. Time for something heavier.

I discovered the flight pack on the F18 needed a top up charge, so in the meantime I put my Toko together for a flight that turned out to be the adrenaline rush of the weekend. This has been the first opportunity since I bought the plane in April, where I could really test out its capabilities. This 1.7kg carbonized adrenaline rocket was built specifically for DS with a bullet proof full carbon wing and it goes like stink. This plane literally brings out the speed freak in you and you can't but fly it like you stole it. The energy retention through turns and out of dives is something to behold. Coming in with a bit of height to start with, I could do loops of 100m+ in diameter without it losing too much speed to carry it over the top. During one specific speed run from behind I came in a bit lower than I expected and where another plane would usually have been buffeted and slowed down a bit by the usual turbulent section at the crest of the slope the Toko punched through it like it wasn't even there.

The 4 servo wing has been set up with flaps coupled to ailerons and makes for some very lively rolls. The ability to mix crow in helps you slow it down enough from Mach 1 for at least a semblance of a controlled landing. I slowed it down a tad too much and a bit of a hard belly landing stripped one of the HS85MG aileron servos (....?!) The first ever metal gear I have been able to damage to this extent. With the servo being epoxied and no spare gear sets on hand I had to sadly accept that I would not be flying this amazing plane again this weekend.

It wasn't long before Norbert decided to get his speed fix for the day and he put the DG600 together to take advantage of the excellent conditions. I had already assembled the F18 Hornet and felt comfortable that I could manage the launch on my own. Just to be sure I walked all the way forward to the spot where we usually launch the big scale models. This gives you enough recovery airspace between your model and terra firma should anything go wrong. Tentatively "bouncing" the plane in my open hand it felt like she just wanted to go..... so I let her.... and off she went. Two clicks of down trim had her flying straight and level and it wasn't long before I built up the confidence to pick up the pace to see what she could do. I found the elevator a wee bit sensitive and switched to dual rates which sorted it out. Rolls were crisp and axial. In the low fly pasts the digital servos in the wings were humming a quite agreeable tune, almost like an small electric motor. Although a bit of an anticlimax in the speed department, after having flown the Toko, the F18 was everything I had hoped to achieve with this re-incarnation of the first one I flew. It turned out the CG was perfectly set up, with a slow recovery from a shallow dive, it has a very "delicate" stall, but only after really hanging back on the elevator, it does beautiful loops and I'm sure it can benefit in some lead treatment to speed it up some.

The rest of the day was filled with a lot more airtime on both the jets and only late afternoon did I switch to my Zagi again. Although it was completely overcast the whole day we only had some scattered drops of rain, nothing to force you to stop flying though. A pity that I didn't think of sticking my camera in Norbert's hands to shoot some pictures of my models in flight. Next time I'll remember.... The low cloud at sunset made for some stunning scenery. Day end proceedings included a nice bottle of Nederburg Baronne shared between two friends around a cosy braai fire while the rain that threatened the whole day eventually arrived.

The Sunday turned out clear and sunny and as so often happens then, a lot of thermal activity as a result. So most of the flying was done with our thermal and electric ships. There was also some quiet times that I used to wander around and do some flora photography. There is an amazing variety of wild flowers growing on top of the mountain. Although I did manage to squeeze in some airtime on the Zagi as well. I would wait for a lull in the wind and just as it picked up again, toss out the Zagi to hunt that inevitable thermal that was building up somewhere in front. I managed to hook three of these boomers and climbed the Zagi to speck height each time. Then burned off all the height for some high speed passes, only to start the whole process again. Norbert was flying his well worn flying wing and being his usual adventurous self ended up doing two outlandings. He eventually had to retire the wing due to some structural damage purely from old age and too many landings. We reluctantly retreated to civilization just after 2pm, overall very satisfied with the weekend. We keenly await the next trip in three weeks time.

Tuesday, October 28, 2008

Allegro Lite Build Part 8 (at long last...)

It's been a while since the last post, my only excuse is that I have at least started again with the Allegro build. Since the last post on the AL I have acquired another AL shortkit and a Bubbledancer shortkit with booms! Now it's time I seriously start building, I've lost count of all the entries on my "still-to-build-list". Let's see.... there's the two Allegros (one thermal, one electric), the Bubble Dancer, Sailaire, Dynaflite Talon, a ±4m DG800, two Hill Billys, a Slipso 400 and a carbon slope aerie from Craig Baker.... Eish! So many projects so little time.

Back to the Allegro build. I have progressed quite well on the tip panels. Before continuing I first had to read up again on the instructions to make sure I am not forgetting something. The next step was to make the hardwood inserts that go inline with the shearwebs at the dihedral breaks. This prevents the soft balsa from being crushed during launches. Then I sanded in the recesses for the carbon carry through strips so that the carbon spar caps would sit flush and not make unsightly bulges. The carry through strips were epoxied in place at this stage.

Time to get sticky again. After doing another dry mockup of all the components, I made up some "goop" with cabosil thickened epoxy. To keep everything true and straight I am working on a glass top. At first I though it may cause problems not being able to pin anything to a building board but if you take care in aligning the parts correctly and use some masking tape in strategic places it all works out quite well. The cabosil mix is quite sticky which aids in keeping everything aligned. Carefully weighing everything down with small sand bags ensures that nothing moves out of place while drying.

After curing overnight the next step was to carefully sand the edges of the spar slightly round to eliminate sharp edges. This is important as the you now have to wrap the spar with kevlar tow and you don't want the edges cutting the kevlar. The kevlar wraps prevent the sparcaps from delaminating from the shearwebs and buckling. I got the kevlar tow from unraveling kevlar tape that I bought from AMT. The actual wrapping is quite hard on the muscles in your hand. I found the trick was to wind the tow on a dowel which I pinched between my toes! This way I had both hands free to do the winding ;o) The ends are tacked with CA and the wraps then wetted out with epoxy. Any excess is dabbed off with a paper towel. I am really trying to keep weight down on this bird and any careless use of glues, epoxies etc quickly add up to unneccesary weight.

Not having to wait for the wraps to dry (they weren't going anywhere...) I proceeded to glue in the leading and trailing edges. The root rib is then glued in, gussets added and the tip sheets glued in. I decided to apply a technique I learned when building the Sagitta 900 that ensures perfectly straight, sharp and very robust trailing edges that can take quite a knock before showing hangar rash. The last 5-6 mm of trailing edge is sliced off with an exacto, a spruce strip glued in it's place and carefully sanded to the correct profile to blend in with balsa TE. You end up with superb trailing edges that you simply cannot obtain with balsa. And this is what the tip panels look like at this stage. Sheeting the panels to follow next.

Friday, October 10, 2008

F18 Build - Finale

Couldn't resist one more post before we hit the mountain tomorrow. As I still had some time left I decided to add the forebody strakes to add to the realism. I finished her last night and was very surprised when I found that I didn't have to add any additional weight to her slim and sexy 1.075kg....;o) Here are some specs:

Weight : 1.075 kg
Wingspan : 1.222 m
Root Chord : 245 mm
Tip Chord : 145 mm
Wing Area : 23.83 dm²
Wing Loading : 45g/dm² (14.25oz/ft²)
Airfoil (wing) : RG15
Airfoil (tail surfaces) : NACA0009

Here she is in all her glory barring some small decal work to be lovingly applied tonight.

Hawk & Hurricane

It's now t-24 and it looks like I might make it after all!

The weekend got the fuzzes glassed, but the HTL took the whole of Sunday. Monday & Tuesday were spent installing servos & linkages and glueing the tailfeathers. The superfast 30sec epoxy from AMT is a real godsend. :)
Wednesday was scheduled for painting but disaster struck. The red enamel went fine, but the brown Dulux 50ml tester I bought at a premium of R20 caused all the trouble. I expected that thinners thins most paint but not this PVA. Initially it was fine but then it turned into a sticky ball in the cup and ruberised everything inside the spray gun after about 10min, so I spent the rest of the night cleaning tools.

Bought some brown QD enamel on Thursday and repainted it Thursday evening. Finalised the noseweight & linkages, and added some colour along the line. The paint is now by far the most expensive item of the build.

Tonight (Friday) will install radio and noseweight for the Hawk and add some more cosmetics. Had to have a Red Bull on the way to work today, so the wind better blow!

Wednesday, October 8, 2008

F18 Build - Part 9

So I've finally finished covering the F18. Man that's a job I really hate, worse than working with fibreglass and epoxy, but the result in the end really is worth the trouble. And this is what it looks like. The Blue Angels will be proud...

Also started cutting the bottom wing decals and finished the one half. I am not 100% happy with the proportions but it will have to do as there is not enough time to nitpick now...

This will probably be the last post before the weekend as the rest is elementary stuff. fitting the control push rods, balancing etc.

See ya all at the ETB PSS Fest.

Tuesday, October 7, 2008

F18 Build - Part 8

Time is running out blazingly fast and having lost almost a week due to going away on leave has put me back somewhat. The precious little time remaining will be better spent working on the F18 than blogging away and not finishing in time.....

I have progressed in the meantime, having :

a.) glassed the wings (with "live" peel ply hinges), the fuselage and tailfeathers,
b.) "plumbed" the servos into the wing and fuselage
c.) covered the wing, the fins and half the fuselage.

Major steps still to follow are to finish covering all the bits and pieces, fit all the tailfeathers, make all the control pushrods, plumb in the battery pack way up in the nose of the fuselage, cut and apply all the decals, balance it and set up the programming on the radio.

Here are a couple of pics just to keep you coming back.....

Monday, September 29, 2008

Hawk & Hurricane

Just to show some progress. Got the basics done now. Next step to glass the fuselages.
I cut the fuzz into 3 and then removed the inside of the middle layer. Makes the control rod & servo easy to install, but the edges distorted a bit. I don't want to do the same with the Hawk, but I don't have a good idea yet.

The fins are made of 4mm isoboard veneered both sides. I'm not sure its lighter than Correx but its a lot stiffer.

Thursday, September 25, 2008

F18 Build - Part 7

I scratched my head trying to decide how to "elegantly" accommodate the servo wiring in the wings, keeping possible servo repairs in mind. Sniffing around in my scrap bin I found the remains of my CMPro ASW28 wing joiners and immediately knew this was what I wanted. The servo plug fits nicely inside the tube so servo replacement/repair will be easily accomplished without massive deconstructive surgery. First step was to mark out where the tubes would go.Now I have been slowly but surely getting tired of all this manual sanding so out came my trusty Einhell (Dremel look alike). Fitted to this was a DIY router base, the idea coming from, I think, Gert Nieuwoudt.
The working end of the setup.
With the right bit inserted and a sturdy guide it made for a perfectly routered slot for the fibreglass tubes. As the tubes aren't there for structural strength, a couple of dabs of foam safe CA keeps the tubes in place.
All that remained was to add a balsa cap to finish things off.

Servos for F18

In my quest for some decently priced servos for the F18 Project I came across these little beauties. They are HD DS929MG ball-bearing metal gear digital servos weighing in at 12.5 gram from Heli Direct, supplied by Sandy Sutherland from XHeli @ R188 a piece + postage. Not bad compared to the close on R300 most hobby shops want for the plastic geared HS85. Unfortunately he only had three in stock, so I opted for two for the ailerons.

I'll probably end up with standard servos for the elevator as space is no problem inside the fuselage. Here they are shown sandwiched between a HS85MG and a HS55. It is the same width and thickness of the HS55 and only about 2mm higher. The torque should be ample for the application. Time will tell if they withstand the Volksies Test....

Hunting Provost 1/5th Project

Block shaped, carbon tows added

Hunting Provost 1/5th Project

Block shaped

Hunting Provost 1/5th Project

Basic block with grid drawn