I attempted to make the PZL-230 "Skorpion" propeller variant (there are 3, in the image posted on Wikipedia). However I opted to use my "Ultra-High Bypass Fan" on it (with J90 having zero thrust), instead of just the basic pusher props.
Sadly, despite hours of efforts, it simply does not make for a stable craft and I'm uploading it as an abandoned project.
EDIT: Apparently I had built it slightly too small, as my use of the image from the Wiki as a guide didn't produce correct plane dimensions. Wing Area was way too small, needs to be 39.8ft (like 32ft as uploaded), length of around 32ft (29ft as uploaded), with a height of 13ft (vs 10ft). That height is debatable as to whether that includes landing gear. Taller gear WOULD help, as I noticed once it bounced off the end of the runway the extra air gap gave it the needed lift.
It does 'ok' in flight, but it takes the ENTIRE Wright runway, at 300+MPH in order to achieve liftoff (with slats extended). I've tried all wing types, mixtures of them, different AoAs, weight distributions, tried inverting the wings in the XML (since it it nosed UP in flight while flying upside down.... o_0), hell I even added Slats to the wings! Alas, it's a dud.
As such I didn't finish it but maybe someone wants a challenge to try getting it to work well. Currently it's missing a Rudder, which was going to be Hinge Rotator actuated thin piece of Wing Section. Also planned to skin the tail with fuselage parts in order to clean that up.
Since it doesn't fly well and has me stumped, I'm moving on.
This DOES have my first custom Landing Gear, which is the main thing that I'm super elated with! (If only Beacons didn't suck for throwing light)
As for the "Slats"... Surprisingly they do have an effect, just not necessarily the designed effect of producing more lift for shorter take off (well, take off at slower speeds, same diff in a way).
[Note: The cockpit and the sloping fuselage part behind it are scaled up, which causes mayhem with anything else getting connected, so be warned if you modify that fuselage part!]
Specifications
General Characteristics
- Created On Windows
- Wingspan 32.2ft (9.8m)
- Length 29.5ft (9.0m)
- Height 11.5ft (3.5m)
- Empty Weight 15,188lbs (6,889kg)
- Loaded Weight 19,186lbs (8,702kg)
Performance
- Power/Weight Ratio 2.108
- Horse Power/Weight Ratio 0.208
- Wing Loading 61.2lbs/ft2 (298.9kg/m2)
- Wing Area 313.3ft2 (29.1m2)
- Drag Points 1930
Parts
- Number of Parts 64
- Control Surfaces 12
- Performance Cost 467
@Thunderhawk It may help it, yea. I may indeed revisit it at some point. I've considered a global scaling up of it to see if that'd also help.
I built something new last night --albeit completely unrelated to this-- that developed a strange anomaly, for lack of a better way to describe it, that I have to figure out first before I even want to THINK of going back to this nightmare! haha This Skorpion just hates me, so I'm willing to give it the space it needs :P
@Formula350 Oh, my bad. Somehow missed that lol. I actually made a canard plane after this (for a competition I entered): http://www.simpleplanes.com/a/13k956/XR-76 . You can look over it if you would like to. I think your plane actually seems pretty stable, but it might need the canards to move completely up and down with motors.
@Thunderhawk lol Yea, I did indeed try that. Even mentioned it in the post you replied to :}
And indeed, as mentioned in my main post, made sure to try every possible combination of Wing Type (Symmetric, Semi-Symmetric, Flat Bottom) on main wings and the canards. Not just that but even the various segments of each wing (the back is technically 4 wings, 2 main big wings and then two itty bitty ones to make the curved tip).. It took a long time, but ultimately I had to give up as I was making zero progress :\
@Formula350 I have a similar plane design the has delta style winds towards the back but no front canards. I was able to solve stability issues with weight distribution is why I suggested it. Have you tried messing with the canards (set to symmetrical airfoil and make them controlled by VTOL to test it). Maybe move them around a bit and mess with the control inputs.
@Thunderhawk Yea I did... a lot
I forgot to mention, but there's a thin, rectangular piece of Fuselage colored bright red that's positioned roughly between the root's leading edge (mid-plane) that I set its Mass scale to 5, or maybe even 10. I spent a long time moving it around, to put the CoM higher than CoL, on the same level as CoL, forward, behind.
Unstable, was the common result. :(
(There's also 2000lbs worth of deadweight in the top two fuselage parts of the landing gear, just to push the CoM forward and to try and solve that weird issue of it wanting to Yaw all over the runway while taking off; removing that weight makes it Yaw even worse)
.
Heck, I even played around with it MORE last night, after posting this and finding out the dimensions were wrong. Increased the wings to the proper width, set the height taller (only by making the Gear taller for better ground clearance), and moved the canards further forward, back, up, down.
Granted, it did take off slightly sooner, just before reaching the warning stripes instead of after bouncing off the grass... lol But its overall flight performance was worse. (Still liked producing more lift when flowing upside-down... I'm almost certain the key to the problem is somehow related to that...)
The only "fix" I have left in my bag of tricks would be to add hidden VTOL Thrusters. Only reason I am reluctant to do that is because it is a real plane that shouldn't need that level of cheap tricks to get it flying well! lol
Clearly I have done something wrong that is simply outside my level of expertise to find and resolve... which is fine, I can accept that fact. :P
Maybe try experiementing with weight distribution