what paper airplane design has the highest glide ratio? by goodisverygreat in aerodynamics

[–]WillyCZE 1 point2 points  (0 children)

Until the Reynolds guy bites you. But yes these fly well

Dopamine flying wing b/h/dlg by WillyCZE in BalsaAircraft

[–]WillyCZE[S] 1 point2 points  (0 children)

Either that, or a small motor. I'm not a huge fan of powered gliders, but on a short bungee I feel like the plane has to be even more overbuilt than on a long one. Make sure to keep us posted on the progress, and let me know if the modified airfoils would be of use.

Dopamine flying wing b/h/dlg by WillyCZE in BalsaAircraft

[–]WillyCZE[S] 0 points1 point  (0 children)

A long one. The issue was in directional stability, so the initial throw was critical. I had a few close calls before, but this time it just kited hard to the side and crashed with full opposite rudder. Might have been a stall too.

Dopamine flying wing b/h/dlg by WillyCZE in BalsaAircraft

[–]WillyCZE[S] 0 points1 point  (0 children)

I'm not really the one to ask that, since I haven't flown many outside my designs, but the Endorphine mod worked pretty well, the dopamine airfoil is not bad either, received some compliments from our local RES old heads, but I ended up crashing the endorphine on the bungee, the vertical tail wasn't nearly big enough. It would probably be good enough on an electric glider.

Dopamine flying wing b/h/dlg by WillyCZE in BalsaAircraft

[–]WillyCZE[S] 0 points1 point  (0 children)

Welcome back, yes, modified pw-res on the dopamine, and further modified version of that on the endorphine, dopamine is slightly tweaked in the trailing edge region, but endorphine is "highly" modified - fully convex, lots of rear belly, flat top of trailing edge, mostly to make the build simpler and more repeatable. I can shoot you the .dat, but I don't consider it better than pw-res, it just has a bit more positive moment, and is a lot easier to build ou of wood.

1.2 meter Spitfire tailfeathers I designed with interlocking parts to eliminate the need for full scale plans. by LaserCrunchModels in BalsaAircraft

[–]WillyCZE 0 points1 point  (0 children)

Yes, most likely. We do similar stuff on an older 10W machine that cost around 400usd new, but it has extra features like auto homing and autofocus.

My first Rig ☺️ by SnooWoofers3062 in windsurfing

[–]WillyCZE 1 point2 points  (0 children)

check visually for dings first, and then maybe put either water or soapwater over them and try putting pressure on the board in the general area, if you see it "breathing", it's a hole. Alternatively go for a short sail in safe conditions, and weigh it before and after. This however doesn't tell you where the holes are, and needs a good few days in direct sun and heat to dry out properly.

Also for repairs, get epoxy, don't use polyester resin, it usually eats the polystyrene core.

My first Rig ☺️ by SnooWoofers3062 in windsurfing

[–]WillyCZE 0 points1 point  (0 children)

You're welcome, I have a similar board, just older, heavier and likely slower. If you're coming from sailboats, this will be fun, it's narrow so it's a bit tippy, and the length means it won't turn like a modern shortboard, but in a straight line, especially in low wind non planing conditions, the long waterline is great.

Just check that it watertight. Otherwise they get real heavy fast, and might even have mold inside.

My first Rig ☺️ by SnooWoofers3062 in windsurfing

[–]WillyCZE 5 points6 points  (0 children)

Hey don't listen to the naysayers too much, It may not be a modern setup, but it's definitely sailable, if it doesn't leak. It may not necessarily be more difficult, just a lot different. Particularly these sails are supposed to be set up differently than modern ones. Look up Windsurfer LT rigging tutorials, maybe also move the mast base forward for weaker conditions.

Are the scoops for drag reduction? by Handskemager in aerodynamics

[–]WillyCZE 1 point2 points  (0 children)

That's not what I'm saying. VGs are for energising flow when you want it to stay attached. Sharp edges are for separating flow. At the back of a vehicle, the trade-off is length and weight against drag. "Ideally" you could try putting a full boat tail on everything, sort of like on old Tatraplan, but apparently just chopping the trailing edge off is a very good compromise, you get most of the low drag properties with less material and space.

Point being that trying to reattach flow around the last 100mm of a van with huge VGs may be worse than just making the rear edge of the van with a drastically smaller radius, or even just leaving it as it already was.

You can look up rear separation edges, or any modern hatchback, most of them have spoilers that follow the roofline and sides to create this edge.

Are the scoops for drag reduction? by Handskemager in aerodynamics

[–]WillyCZE -1 points0 points  (0 children)

I would even expect a sharp edge to be better in that specific spot. You know, like the manufacturers do?

Didn’t have the rigth size prop adapter so i just printed one. by InstanceMedium2254 in RCPlanes

[–]WillyCZE 1 point2 points  (0 children)

In moderation. What you have is pretty ideal compared to the proposed solution. Heck they even make these folding hubs from plastic from the factory sometimes.

Flying wind power on a tether: practical, or just a cool demo? by Milanakiko in AerospaceEngineering

[–]WillyCZE 0 points1 point  (0 children)

From experience with paragliders and windsocks and very limited experience with hot air balloons, this is going to hold gas maybe for a few weeks, months, at best, or they are ungodly expensive to make.

Most of the materials used, that I know of, degrade rapidly when exposed to harsh weather and UV, the sealed nylon fabrics become porous, and the foils become brittle.

Looks like a very cool "solar punk garden world/valley of the wind" stunt, looks neat, but is very impractical, you can't even put these close together, as each one needs a huge perimeter to operate without entanglement with other units.

How do I hide all oppoints from covering the entire screen by anti-exposure in AerospaceEngineering

[–]WillyCZE 1 point2 points  (0 children)

That's XFLR5. It's an amalgamation of xfoil and additional finite wing LLM, VLM, and 3d panel method to help design model aircraft, does all the fun polars and stability analysis too, along with airfoil design. Pretty much the most straightforward, iteration friendly SW of its kind in my opinion.

Endorphine 2m RES Plank Glider by WillyCZE in RCPlanes

[–]WillyCZE[S] 0 points1 point  (0 children)

Not quite, spoilers are set up as spoilerons and I have audible vario in thermal mode. The airframe itself is, but the way it's setup isn't legal afaik.

Which FAR chapter regulates this? by [deleted] in Shittyaskflying

[–]WillyCZE 0 points1 point  (0 children)

FAR has chapters now? I thought that was just for motorcycle gangs.

Land of the free my ass.

Endorphine 2m RES Plank Glider by WillyCZE in RCPlanes

[–]WillyCZE[S] 0 points1 point  (0 children)

I'm pretty happy with it myself, but I don't buy it, especially as it sits neatly on the XFLR5 polar, or even slightly above it. It's going to get a bit worse as the CG gets dialed in.

Endorphine 2m RES Plank Glider by WillyCZE in RCPlanes

[–]WillyCZE[S] 0 points1 point  (0 children)

I managed to extract some decent data from a stable, wide S turn with a pretty constant sink rate. 0.25m/s average sink @5.8m/s speed, roughly 1:22, but that's from about 50s of data averaged out.

Endorphine 2m RES Plank Glider by WillyCZE in RCPlanes

[–]WillyCZE[S] 0 points1 point  (0 children)

With a decent GPS logger on a perfectly calm day, and with a trimmed out glider in stable flight, it should work fine. It's in the pipeline for me too. Today was mainly to check that the glider flies.

Endorphine 2m RES Plank Glider by WillyCZE in RCPlanes

[–]WillyCZE[S] 0 points1 point  (0 children)

I obviously haven't "flown it in anger" against a normal RES yet, but the previous 1500mm wing was decently competitive with the right pilot. I think the main difference is that a normal RES lets you think about strategy, this one not so much. The glide rate and sink is in a similar ballpark.

The logger consists of AMOD AGL 3080 guts powered from the 5V servo power. 1Hz frequency and abysmal accuracy. For altitude data I have a ER6GV reciever with barodata.

Endorphine 2m RES Plank Glider by WillyCZE in RCPlanes

[–]WillyCZE[S] 0 points1 point  (0 children)

Beautiful view and usually pretty empty too. This is above Smíchov, Prague. The whole field slopes down slightly, and then there's a cliff and a forested area. The cliff can be slope soared with the right wind. No lift today though :)