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Re: Rotax 532 powered KR2

Posted: Sat Mar 29, 2014 7:13 am
by Henni
Hi Avgas,

My eetste KR2 was klaar, behalwe vir verf en afwerking, 1985. Ek het n baie sterk belly airbrake ingebou wat binne in die romp ingetrek het en die spasie voor canopy vir n bagasie ruim gebruik. VW1835. Standaard taildragger retractable. Carb bo-op engine monteer met airscoop bo-op cowling soos Toyota Fortuner.

Haar na Vanderbylpark vliegveld geneem vir toetse. Begin met taxi runs. Ongelukkig het daar so lae druk bokant cowling gevorm dat dit bo 60 mph die gas uit carb gesuig het en op canopy gespray het. Het haar die hele naweek so hoog soos 80 mph op die grond gehad met stert hoog sodat sy nie per ongeluk vleg nie.

Hoekom se ek dit? Ek is vertroud met die KR2 op die grond en nie bang vir die stertwiel nie. My konstruksie werk het my toe verskuif na n plek waar ek nie verder kon bou nie en ek het haar verruil vir n microloght. Sakkie Hallgreen het hierdie in n artikel in die Aeronews geplaas.

So ek besin nog oor n stertwiel. Gaan vandag my wiele en aliminium haal, dan sal ek finaal besluit.

Groete,

Henni

Re: Rotax 532 powered KR2

Posted: Sat Mar 29, 2014 7:23 am
by Boet
Laat ons dit nou mooi so saamvat. Watter AP, wat sy sout werd is, sal die KR uit teken met n 532. Ek sal nie. :wink:

Re: Rotax 532 powered KR2

Posted: Sat Mar 29, 2014 7:46 am
by avgas
Is daar 'n mod approval of kan mens net voortgaan?

Re: Rotax 532 powered KR2

Posted: Sat Mar 29, 2014 8:53 am
by JvTonder
Ek weet ook maar min veral van 'n KR af maar wat ek wel weet is dat ek eerder met 'n stertwiel 'n noodlanding sal wil maak as so iets ooit moet gebeur. Jou kanse vir oorlewing is net soveel groter.

Groete

Re: Rotax 532 powered KR2

Posted: Sat Mar 29, 2014 2:26 pm
by Henni
Great!

I now have proper wheels with proper brakes. And the aluminium for the engine mount. That's after a 350 km drive, that is. She'll stay a taildragger. Will not make any mods, as it will only add construction time. I will make a cable operated trim tab for the elevator as per the original KR2 plans though. If I'm done with the weels, the trim tab and the mount and not yet have a new engine, then the 532 it'll be. I yearn to fly again & can't wait any longer. I'm also not getting any younger! The deal I offered with the bike is a good one. If no one interested, then it was not meant to be.

Spoke to yet another person today with many problem free hours on a 532. They just flew a 582 aircraft fom Mosselbay to here. So I'm no longer too concerned about our planned South Coast trips. She'll be light, has flaps & with the VCs I'm going to install will definitely stall in the low 40 mph range, same, maybe even lower than my Mizer I flew before. If I had the money, I would have flown something else, that's for sure! I'll heed to all the professional advice given about the 532 in the link below. That's the best I can do for now.

Here are all the pros & cons of the 532 & how to fix them.

Here's a happy user.
quote wrote:I have been flying a Model 2 Kitfox with Rotax 532 ( pre 582 ) for 12 years and 450 hours.
The 2 stroke never let me down
I'll post first construction pics soon. It's time to talk less & build more & now I have no more excuses as I now have everything I need to get started on her.

Cheers all,

Henni

Re: Rotax 532 powered KR2

Posted: Sat Mar 29, 2014 3:53 pm
by Rudix
Hi Henni,

Glad you have the wheels sorted, now time to get her going!

I think the trim tab is really useful, makes flying the planes with a sensitive elevator easy. Both mine have electric trim tabs, you might consider one based on a model aircraft servo (heavy duty), I have seen plans in the internet for the controller. My unfinished KR has a cable trim tab but I am not really happy with it. I think installing an electric one is simpler and maybe even lighter.

I found the stall on both the KR's to be a non-event, and at a lower speed than I will ever fly but installing VG's can only make it even better.

Just make sure you get the CoG towards the front of the range, else she really becomes a handful on the elevator.

Happy building!
Regards,
Rudi

Re: Rotax 532 powered KR2

Posted: Sun Mar 30, 2014 10:29 am
by Jean Crous
Henni bel my op 072 6716 240 , dalk kan ek help met n engine.
Jean

Re: Rotax 532 powered KR2

Posted: Mon Mar 31, 2014 7:36 am
by Henni
Ha!

To think I rented & pulled a one tonne trailer 350kms for this... I actually went for something else, but the seller was kind enough to offer this as a alternate at a reduced price as I would not have used half of the other stuff I originally intended to purchase.

Stripped everything yesterday and started to fit the new wheels. I actually wanted bigger wheels, but ended up with original stock standard KR2 wheels & brakes in the end. At least they'll have much less drag & they are in a very good condition.

The only thing I would like still is proper rubber vibration dampers for the engine mount. If anyone has some lying around, I would like to purchase from you please. Also, if anyone has a square tube microlight main kingpost (similar to the one in the pic) lying around, I would like to purchase from you as I'll most probably need more of this. I have been told that the longer prop will put a lot of strain on the firewall & I want to make sure that the engine cannot twist the main mount under full load.

So, finally I've started working on her.

Cheers all,

Henni

Re: Rotax 532 powered KR2

Posted: Mon Mar 31, 2014 4:48 pm
by Rudix
Henni wrote:Ha!

To think I rented & pulled a one tonne trailer 350kms for this... I actually went for something else, but the seller was kind enough to offer this as a alternate at a reduced price as I would not have used half of the other stuff I originally intended to purchase.

Stripped everything yesterday and started to fit the new wheels. I actually wanted bigger wheels, but ended up with original stock standard KR2 wheels & brakes in the end. At least they'll have much less drag & they are in a very good condition.

The only thing I would like still is proper rubber vibration dampers for the engine mount. If anyone has some lying around, I would like to purchase from you please. Also, if anyone has a square tube microlight main kingpost (similar to the one in the pic) lying around, I would like to purchase from you as I'll most probably need more of this. I have been told that the longer prop will put a lot of strain on the firewall & I want to make sure that the engine cannot twist the main mount under full load.

So, finally I've started working on her.

Cheers all,

Henni
Hi Henni,

Glad you have started!

I am sure the standard wheels will be fine, she will never really be a rough field plane so you might as well go for the drag reduction. Are the brakes cable operated?

If you attach the engine mount at the same points as the original you will be fine, many guys are running vastly more power than the original using the standard firewall without any issues.

Have fun!
Rudi

Re: Rotax 532 powered KR2

Posted: Tue Apr 01, 2014 6:02 am
by Henni
Hi Rudix & all,

This is why I need more material - to get the loads transferred to those attach points. However, thought about it last night & think I can come up with a plan using what I have.

Yes, the brakes are cable operated. Don't think you'll find anything fancy on this KR2 when completed. It'll be as basic as Ken Rand initially intended for it to be.

I have a few thousand KR2 pics I've collected over the years. It is so nice to put these on a flash drive, insert into our TV and scroll through all of these before going to bed. Only this time I'll join the other enthusiasts rather soon. Life is good & it keeps on getting better...

Included: Some nice reads I've collected over the years. If the attachments difficult to read, you can read original over

1.Here

and really also

2. Here

All the best mates,

Henni

Re: Rotax 532 powered KR2

Posted: Tue Apr 01, 2014 8:22 am
by Henni
Hi all,

Another nice read from:

http://www.pilotweb.aero/features/fligh ... _1_1650078

This aircraft reminds me of nothing so much as Sir Alec Issigonis’s classic car, the BMC Mini. Not the watered down version made by BMW today; the Mini I’m referring to is the tinny, boxy, but iconic original from the Swinging Sixties.

Like the Mini, the Rand KR-2 is low on horsepower, cramped and a little challenging to fly/drive, but full of character and hugely economical. There are 25 of these homebuilts on the G-register and hundreds flying in America.

Buy a used one and you would be getting a high-performance two-seater that is remarkably cheap to run, thanks to its VW engine. Or you could buy a kit and build one (visit www.fly-kr.com).

The secret of the KR-2’s performance is its construction from wood, foam and fibreglass, which makes it light and beautifully streamlined. It is also normally built with a retractable undercarriage, further aiding streamlining.

Most (like the example featured here) should be considered a roomy single-seater that can also be flown over short distances with two occupants. Nevertheless, a few years ago, one British couple did fly their KR-2 two-up all the way out to Australia. The Mini inspired similar feats over long distances, in the same ‘quart from a pint pot’ spirit.

Few Volkswagen-powered aeroplanes are as fast as the KR-2. Ken Rand claimed a maximum cruise speed of 180mph. This might be exaggerated, but the type does have an impressive cruise performance with low fuel consumption.

The downsides are that the KR-2 is amateur-built; that it’s a taildragger, and rather a challenging one at that; and it’s rather cramped in the cockpit two-up. These drawbacks should, though, be reflected in the price. Affordability is the KR-2’s best feature.WHAT’S IT LIKE TO FLY?

Step up an easy six inches on to the small wing walkway, then down into the cockpit. Grip both fuselage sides to take your weight, and carefully slide your legs forward under the instrument panel.

Sit down, strap in, and pull on the cable behind your head to close the canopy. Head and knee-room were just adequate for this six-footer. Only 35 inches wide, this cockpit would be snug for two, but full control throw is easy and the stick forces are very light.

Combined with those relatively big control surfaces and the airframe’s ultra-light weight, this presages snappy handling. Press the toe brakes, switch on the master, twist open the fuel cock, pull out the choke knob, pump the throttle twice and crack it a quarter-inch, turn on the ignition, select ‘start’ and the diminutive propeller spins into life with a most un-Volkswagen-like purr.

Check the oil pressure, release the brakes and you’re slowly, gently away. The direct tailwheel steering is excellent, with a tight turn radius at full pedal travel, but super-fine precision over small deflections.

Allen has warned me the brakes won’t hold the aeroplane against more than 2,000rpm, but for low-speed manoeuvring, they’re fine. Because of a non-standard, though very sleek Lancair canopy and my rearward seating position, the forward visibility was not very good over to the right, and ahead was only just acceptable, although it was fine to the left; but I had to rely to some extent on peripheral vision while the tail was down on the runway.

I’d optimised my seating position with conformal foam cushions, so this was the best I could do, with my head hard up against that finely-tapered canopy. Engine run-up was straightforward, the electronic ignition indistinguishable from the magneto type.

With no flaps or electric pump to remember, pre-departure checks were similarly minimal although, given the aeroplane’s history, (the canopy once opening in flight) I was particularly careful checking the dual canopy bolts, double hinge latches and mechanical secondary lock.

Allen suggested I should first try some high-speed runs, to get the feel of this very short-coupled aeroplane – who was I to disagree?

Lining up carefully, I slowly opened the throttle, but I needn’t have worried.

RAPID ACCELERATION WITH LIGHT PEDAL PRESSURE

Acceleration was surprisingly rapid, while directional control was no problem, just the lightest of left pedal pressures being needed to straddle the centre-line. Within seconds I could cautiously raise the tail, revealing a brilliant view of the runway speeding inches below my bum, and still there was no inclination to wander. Then I gently closed the throttle, and immediately understood Allen’s caution.

The tail dropped almost immediately, and I over-corrected for the tiniest tendency to veer right, promptly finding myself treadling the pedals to stay within reach of the centreline. This aeroplane would be easier flown off grass, but its short undercarriage legs with minimal spring travel would need a lawnbowls runway. After a couple more high-speed runs on the narrow tarmac I quickly got the hang of it, and returned to discuss things with Allen.

That’s when I discovered that, despite its and mechanical secondary lock. Allen suggested I should first try some high-speed runs, to get the feel of this very short-coupled aeroplane – who was I to disagree? Lining up carefully, I slowly opened the throttle, but I needn’t have worried.

Acceleration was surprisingly rapid, while directional control was no problem, just the lightest of left pedal pressures being needed to straddle the centre-line. Within seconds I could cautiously raise the tail, revealing a brilliant view of the runway speeding inches below my bum, and still there was no inclination to wander. Then I gently closed the conservative RAF 48 aerofoil and stout eighteen per cent thickness-chord ratio, the KR-2’s very shortness gives it a limited, four-inch centre of gravity range.

I am taller and heavier than Allen, so he had to remove his normal seat to improve my legroom, putting my increased weight further aft, and the aeroplane on its rear limit. Fortunately, Allen has two removable two-pound ballast weights bolted to his sternpost. Undoing these and topping up the fuel moved the C of G forward, so now I could go flying.

This time I had no difficulty straddling the centreline, the tail rose gently as speed increased, and after 300 metres I was airborne at 45 knots and accelerating nicely. I could have retracted the wheels, but elected to raise the nose, peg the airspeed at seventy and climb to 500 feet before attempting any internal gymnastics or external aerobatics.

The undercarriage mechanism is in the cockpit’s centre, to the right of your inboard knee on the main spar’s forward face. First, you pull on the upper toggle to withdraw the locking pins via cables – although Allen suggested it would be easier to press down on the mechanism’s upper knuckle. This allows the main gear’s transverse beam to swing to the halfway position under air loads.

Then you push the lower toggle forward until the whole, very visible mechanism rotates through ninety degrees. There was a satisfying double click as the pins popped into the up-locks, easily checked, and I sensed the acceleration as, relieved of that drag, this nippy little aeroplane surged upwards. Both VSI and stopwatch measured 800 feet per minute – not half bad under Beetle power on a red-hot 35°C day!

The controls were light and effective, and I needed slight left rudder pressure to keep in balance. Reaching 3,500 feet, I let the aeroplane accelerate, then reduced rpm to 3,200, at which the Rand steadied at a commendable 120 knots indicated, or 125 knots/144mph TAS. 3,300rpm gave 125 knots IAS, while 2,800rpm still returned a steady 95 knots. These numbers are extremely good when you consider this 2,074cc VW burns only from eight to twelve litres per hour, giving a fuel consumption over fifty mpg – at 120mph as the crow flies!

Not surprisingly, this short-coupled aeroplane was only just stable in pitch – but as befits a professionally-designed aircraft, it was positively stable, even under full power in the climb, which is usually the limiting case. STABLE IN YAW, AND VERY RESPONSIVE

It was also surprisingly strongly stable in yaw, considering its short fuselage. Unfortunately, we must have removed rather too much tail ballast, because I had to slide the trim lever fully rearwards after take-off, and there was still a small residual pull force needed in all flight phases, so it was difficult to establish roll stability, but I think it was probably neutral. I have to say I was pleasantly surprised at the Rand’s handling, which was much better than I had expected.

It is a lively, responsive, aeroplane, with nice, crisp controls and a good, fighter-sharp roll rate, but not at all twitchy or squirrelly. Control forces were comfortably light in all three axes, and it needed the merest breath on the rudder to coordinate turns. I have to say, its general handling was exemplary. And so were its low-speed manners. Closing the throttle caused a very slight pitch-down, and the speed decayed slowly, but it gradually unwound through sixty, fifty and forty knots, when a slight trembling buffet started in the airframe.

Finally, at 38 knots the stall warner sounded, and at 37 the nose gently nodded away. Holding the stick back against the stop merely caused it to rock and wobble, still in light buffet, but there was never any untoward behaviour.

Allen had warned me of a left wing-drop, but provided the ball was centred, I experienced none. At just 45 knots indicated, although it felt mushy, there was still good control in all axes, while setting 1,800rpm depressed the stall to 35 knots. Looking out at those tiny wings, I was amazed at the Rand’s good manners, however a glance at the VSI revealed a trap. It was down past 1,000 feet per minute. So, now I knew why Allen used a higher-than-expected approach speed. With that sink in mind, I decided to fly a couple of practice approaches and go-arounds at altitude, observing the VSI. In fact, I found no problems, and everything went well at Allen’s recommended speeds, even prolonged sideslips and slipping turns at 55 knots, although full rudder caused some airframe buffet. I even tried cycling the undercarriage a couple of times. The only factor of note was a slightly increased requirement for stick back pressure with the wheels extended (as you would expect from their position). This made it a little more difficult to hold the airspeed accurately in check, but of course, that was preferable to the airspeed decaying if I was distracted.

Back in the circuit, I followed Allen’s advice, slowing early to enter downwind at eighty knots. Decelerating to 75 and reaching forward to my right, I pulled first on the upper undercarriage toggle and then the lower one to extend the wheels. At this airspeed, it was not difficult, and Allen has extended them at over 100 knots, although the pull force becomes higher with increased speed.

Flying a curved base leg at seventy knots with 1,600 to 1,800rpm gave me the best visibility of the runway. Reducing speed on final to sixty raised the nose, causing my view to deteriorate, but I could still see enough. A little right-rudder sideslip helped considerably, although it did further increase the required backpressure.

Slowing to 55 knots as I crossed the fence, I raised my head right up to the canopy for the best possible view. Unfortunately, that had me peering though the magnifying, reading part of my bi-focal sunglasses, so I opened the throttle and went around. There was no sink, although the Rand did take a couple of seconds to accelerate to seventy knots, after which the manoeuvre was routine.

Everything was easier without the sunglasses, and the merest of flares led to a positive three-point touchdown. As Allen advised, I simply let her roll, concentrating on steering while holding the stick fully aft, as Allen had warned me of the KR-2’s light tail. Slowing to a walking pace within perhaps 500 metres without any braking, I finally squeezed the brakes at around twenty knots and turned off the runway.

Henni

Re: Rotax 532 powered KR2

Posted: Tue Apr 01, 2014 10:38 am
by Henni
Hi all,

Found this installation pic of nearly the exact same engine as mine. Pity my prop is so long as I would have liked to install engine upright exactly like in this pic.

Keep well all,

Henni

Re: Rotax 532 powered KR2

Posted: Tue Apr 01, 2014 1:35 pm
by Jean Crous
Henerik my maat, kyk mooi...........daai ratkas en joune is altwee die "B-box" , die een in die foto is in die regop manier aan die enjin gesit. Haal jou ratkas af, en draai hom 180 grade..........EN............ :shock: :shock: :o :o ...........hey presto .... :!: .....jy kan dan jou enjin net soos die een in die foto monteer ## ## ## ##
Jean.

Re: Rotax 532 powered KR2

Posted: Tue Apr 01, 2014 1:54 pm
by Henni
Jean,

Wens dit was so. Sal more 'n foto of twee pos - myne het definitief nie dieselfde offset nie. Dit was die eerste ding waarna ek gekyk het.

Miskien is ek verkeerd en ek hoop van harte so...

Groete,

Henni

Re: Rotax 532 powered KR2

Posted: Tue Apr 01, 2014 3:10 pm
by Henni
Hi Jean,

I stand corrected mate. I looked wrong, my box is the same. It is my desire to mount the engine upright and now I can!!! Sounds silly, but Im elated. The part of the engine protruding above the gearbox will be covered by a bigger spinner. Ill make the cowling top like the Grunman Tiger, I think it is, and it will not look ugly as those other Rotax KR2 pics.

Tx my friend for the advice,

Henni