Wicherek 15

czarobest Sat Apr 03, 2021 3:58 pm

Hello, I would like to show you my new model "Wicherek 15". It is a legendary Polish construction, designed by Wieslaw Shier who has written quite a few books, including one entirely devoted to this model, fuels, etc. A very respected modeller in Poland Smile

"Wicherek" in English would mean a "little whirlwind" or "slight wind" This model is very well known in Poland, every modeller has at least heard of it, and many started their modelling career from it.
In my case, it was the first wooden one and the first model with nitro engine (OS Max 10LA). It was 6 years ago and now I have over 30 engines Razz

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Unfortunately I crashed it last year so now I built a new one.

"Wicherek" is often modified and different versions are shown in the book. Glider version, free-flying version, control line or finally RC.
Additionally, in the "ABC Miniaturowego lotnictwa" (in English "The ABCs of Miniature Aviation") book about this model, there is a lot of information for beginner modelers about tools or engines.
And in the recommended engines for this model are also Cox engines from PeeWee to Medallion .15, although in those years in Poland they were probably not so easy to get.

The model is easily scalable hence many engines for different versions, mine is a "15" version with a span of 1400mm (~55 inches).

So much for the introduction Smile

. My version is heavily modified, Clark Y profile, added ailerons and caissons, and a few other things like using balsa. It was also lightly counted in XFLR5 program Smile

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The modifications themselves were also encouraged by the author showing different ways. The default version, however, was to be simple in construction and not to require materials difficult to buy in Poland at that time, such as balsa.

I installed the same motor as in the first Wicherek, the OS Max 10. Recently I made for it "by hand" a new connecting rod, you can see it here:

I built the model from scratch starting with this Very Happy

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And I continued like this:

And the final looks like this:

Here in the albums are all the photos from the construction and with finished model, there are more than here in the post Smile

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"Work in progess" photos: https://photos.app.goo.gl/5rmihFu6ZsyNwYvdA
Photos of finished model: https://photos.app.goo.gl/yiHoAndQUNuaM97HA

And the first flight was yesterday, unfortunately not entirely successful. The engine ran great as usual Smile

. The model has a low minimum speed, but unfortunately it tilted very much to the left. Despite setting the ailerons the other way, I could not turn right and straighten the model. Because of this I tried to land quickly and the model behaved poorly.

I assume wrong engine angle and something crooked in the geometry of the model, although I measured everything accurately and it was straight. It is also possible that the ailerons are misaligned.
Only thing that suffered during the crash was the chassis, which was too soft anyway, so I'll make a new one soon and keep trying Smile

. I hope to record a full flight soon with a good landing and a nice flight Smile

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I wrote this post to introduce you to this so popular in Poland model (and to show off Very Happy

) and I hope you will like it Smile

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I also hope you won't mind me showing the model on the forum without the Cox engine. But "Wicherek"s with Cox engines were also created Smile

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Kim Sat Apr 03, 2021 4:07 pm

Beautiful aircraft, and craftsmanship, and a handsome shop helper too!!! cheers

czarobest Sat Apr 03, 2021 4:16 pm

Kim wrote:Beautiful aircraft, and craftsmanship, and a handsome shop helper too!!!

Thank you very much Very Happy

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She likes airplanes almost as much as I like her Very Happy

:
She's here now:

And it helps with any model Cool

:

Oldenginerod Sat Apr 03, 2021 4:28 pm

That's fine until you come into your workshop one day only to find your cat firmly glued to your plane lol!

KariFS Sun Apr 04, 2021 2:06 am

Beautiful plane, a very versatile and Classic design. I like the colour scheme too Smile

Something strange about the in-flight instability, but I am sure you’ll figure it out. Maybe our expert fliers, Andras, Mauricio and others will chime in. All the advice I can give is to verify everything again, especially the engine angle (down and right a few degrees), but those you know already Old Bugger

It might be good to have a ”soft” landing gear, by bending it protected the rest of the model. Steel legs would probably have caused it to bounce or flip over in a hard landing, possibly even breaking something inside.

Good luck and keep the flight reports coming! RC Plane

getback Sun Apr 04, 2021 8:58 am

Nice !! Love the see through body style , does it have lights ? seen some wires going to the wing tips , Yes just recheck everything and get back in to the air ! Looked like min. damage . RC Plane

czarobest Sun Apr 04, 2021 9:15 am

Oldenginerod wrote:That's fine until you come into your workshop one day only to find your cat firmly glued to your plane

This kitty is quite cautious Wink

KariFS wrote:Beautiful plane, a very versatile and Classic design. I like the colour scheme too
Something strange about the in-flight instability, but I am sure you’ll figure it out. Maybe our expert fliers, Andras, Mauricio and others will chime in. All the advice I can give is to verify everything again, especially the engine angle (down and right a few degrees), but those you know already

It might be good to have a ”soft” landing gear, by bending it protected the rest of the model. Steel legs would probably have caused it to bounce or flip over in a hard landing, possibly even breaking something inside.

Good luck and keep the flight reports coming!

Thanks

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The chassis must be a bit stronger than it was because it was bending strongly under the weight of the model.

getback wrote:Nice !! Love the see through body style , does it have lights ? seen some wires going to the wing tips , Yes just recheck everything and get back in to the air ! Looked like min. damage .

Thanks too Smile

. Yes, I mounted lights and Arduino to control them. In the albums that I gave at the beginning you can also see more pictures of the assembly of these LEDs. I'll add a section with lighting to the next video. For now, I have only a short demonstration of the possibilities - these are addressable LEDs, but I haven't shown the most important flight mode. You can see the code here: https://github.com/CezaryHanczak/WicherekLights
And this short demo - Video with lights Link

I'm tweaking a few things for now and will keep trying with flying. Only the chassis has suffered, so I have to make new ones. But I don't know if it will be with leds again though.

balogh Sun Apr 04, 2021 9:20 am

KariFS wrote:........

Something strange about the in-flight instability, but I am sure you’ll figure it out. Maybe our expert fliers, Andras, Mauricio and others will chime in.....

Thanks Kari for calling me an expert.. Laughing

well, I would check the ailerons and give them a bit of a "right" trim...I see the plane tends to veer to the left..if no ailerons, then alternatively some shimming of the engine mount to the right by 2...3 degrees will also help keep the flight pattern straight..
And check if the wings are not warped..built up wings with oracover heat shrink skin can lose their straight shape easily if the foil is shrunk asymmetrically. I had that happen to me often..so I always look down the wing from its tip to the wing center to check warping..by ironing the slack side of the skin this can be well doctored.
Lay the right half wing flat on a table and chack if all 4 corners touch the table. I would assume either the outboard right leading edge corner is up, or, the outboard left leading edge corner will be down...either way will cause your plane to veer to the left.

the plane fell on its nose upon landing..by pulling the landing gear a bit forward the weels will be further away from the CG and the landing will not end in the prop hitting the ground so easy..if the gear cannot be bent forward then fix the RX batteries more to the aft.

I am looking forward to seeing the next vid.

czarobest Sun Apr 04, 2021 12:03 pm

balogh wrote:
Thanks Kari for calling me an expert.. well, I would check the ailerons and give them a bit of a "right" trim...I see the plane tends to weer to the left..if no ailerons, then alternatively some shimming of the engine mount to the right by 2...3 degrees will also help keep the flight pattern straight..
And check if the wings are not warped..built up wings with oracover heat shrink skin can lose their straight shape easily if the foil is shrunk assimetrically. I had that happen to me often..so I always look down the wing from its tip to the wing center to check warping..by ironing the slack side of the skin this can be well doctored.
Lay the right half wing flat on a table and chack if all 4 corners touch the table. I would assume either the outboard right leading edge corner is up, or, the outboard left leading edge corner will be down...either way will cause your plane to weer to the left.

the plane fell on its nose upon landing..by pulling the landing gear a bit forward the weels will be further away from the CG and the landing will not end in the prop hitting the ground so easy..if the gear cannot be bent forward then fix the RX batteries more to the aft.

I am looking forward to seeing the next vid.

In the video I had to keep the ailerons at maximum deflection in the other direction to keep the model from tilting Sad

. However, I found a significant error on my part. I set the aileron differential the other way around Paranoid

This is sure one of the reasons for the poor flight. Another thing is as you write the motor setting, it seems to me that I set too little angle to the right.
The wings are straight and even. I was able to make them well and they have high rigidity Smile

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I'm going to make the new chassis so that the wheels are more up front as you write.
Thank you for your advice Very Happy

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I continue to measure everything and check angles for find additional causes Smile

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balogh Sun Apr 04, 2021 12:09 pm

Thanks czarobest, I am happy to have helped a little, and wish you a succesful next flight.

MauricioB Sun Apr 04, 2021 12:16 pm

Thank you Kari for your assessment!
András has given good recommendations.
Let me give you my point of view, which coincides with Andras.
I summarize it as follows:
I have captured an image of your model, please I would need a photo of the front wing to be able to see better from here, but I can get an idea of what happens from my capture.
1) You have a twisted brim, this is normal when heat shrink material is applied and it is possible to correct it as András indicates.
2) It also gives me the senzación of an advanced CG, that tends to drop the tail, place ballast allowing the nose of your model to take it from 1/3 of the wing and from the first third, the nose falls about 15 degrees.
With these controls done, then perfectly center each moving surface, ailerons, stabilizer and rudder.
I will be attentive to your questions and I will answer you shortly.

Friend, here I indicate the following in this drawing:
With yellow arrows:
It appears that your wing is twisted in that direction which coincides with the flight path that you describe.
Solution, you must apply the method that András indicates by making the lines
A, A = AA, AA = AAA, AAA (be the same) indicated in green.
In black I indicate the following: First third of the wing, you must take from that point of the wing and see the nose of the model fall about 15 degrees, if necessary add weight safely as far as possible as it can be installed.

czarobest Sun Apr 04, 2021 12:39 pm

MauricioB wrote:Thank you Kari for your assessment!
András has given good recommendations.
Let me give you my point of view, which coincides with Andras.
I summarize it as follows:
I have captured an image of your model, please I would need a photo of the front wing to be able to see better from here, but I can get an idea of what happens from my capture.
1) You have a twisted brim, this is normal when heat shrink material is applied and it is possible to correct it as András indicates.
2) It also gives me the senzación of an advanced CG, that tends to drop the tail, place ballast allowing the nose of your model to take it from 1/3 of the wing and from the first third, the nose falls about 15 degrees.
With these controls done, then perfectly center each moving surface, ailerons, stabilizer and rudder.
I will be attentive to your questions and I will answer you shortly.

Friend, here I indicate the following in this drawing:
With yellow arrows:
It appears that your wing is twisted in that direction which coincides with the flight path that you describe.
Solution, you must apply the method that András indicates by making the lines
A, A = AA, AA = AAA, AAA (be the same) indicated in green.
In black I indicate the following: First third of the wing, you must take from that point of the wing and see the nose of the model fall about 15 degrees, if necessary add weight safely as far as possible as it can be installed.

Wow, thanks Smile

. I got to the point that the wings are straight - really Very Happy

. But I noticed what you showed by measuring the angles of attack of both wings and the right wing has a minimally larger angle . The problem is in the mount. So I need to correct that.

The balance was ok according to this calculator (link) and with the analysis in XFLR5 because I have counted decalage angle in this. In accordance with the analyses I have the horizontal stabilizer stuck at -1.5 degrees

Surfer_kris Sun Apr 04, 2021 3:13 pm

Nice covering job! Smile

Two things to check:

- lateral balance (make sure that the model is balanced correctly sideways along the centerline, not only back and forth)

- Aileron, differential throws. If you don't have differential throws, you might have adverse jaw and with all that dihedral on the wing the plane will turn in other direction, or not at all. In the slow-motion part you seem to have more down-throw than you have up on the other side? You want it to be the other-way around...

Good luck!

czarobest Mon Apr 05, 2021 4:23 am

Surfer_kris wrote:Nice covering job!

Two things to check:

- lateral balance (make sure that the model is balanced correctly sideways along the centerline, not only back and forth)

- Aileron, differential throws. If you don't have differential throws, you might have adverse jaw and with all that dihedral on the wing the plane will turn in other direction, or not at all. In the slow-motion part you seem to have more down-throw than you have up on the other side? You want it to be the other-way around...

Good luck!

Thank you

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I've checked the balance and it's ok, the wings differ about 1 gram from each other Smile

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As for the ailerons - I wrote about this a few posts ago - I made a big mistake with it and I set differential to the opposite way. As you pointed out Smile

. Of course I'm changing that.

NEW222 Mon Apr 05, 2021 11:53 am

Wow. Another beautiful model and build. As was said earlier above, the clear covering job looks great and able to show off your very nice workmanship.

czarobest Tue May 18, 2021 3:38 am

Finally, Wicherek was in the air Cool

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It flies well after revisions, although it still needs minor tweaks.
First flight a little ugly, but I'm posting in full because it's the first flight Smile

. The next one is better so I recommend watching them Razz

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The model max speed is about 70km/h (44 mph), the minimum speed is very low about 30-40km/h (18-25 mph) I think. When using the rudder while turning, it turns very nicely and does not lose altitude.

Overall I am very satisfied and the OS runs very well as usual Smile

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Last flight taken more in the evening, so you can see the model lighting.

balogh Wed May 19, 2021 1:03 am

Great flights and beautiful plane, czarobest. I like your altimeter and speedometer embedded in the video. I assume you have a GPS sensor and telemetry enabled receiver on board. But how do you insert the instrument readings into the vid?

czarobest Wed May 19, 2021 2:54 am

balogh wrote:Great flights and beautiful plane, czarobest. I like your altimeter and speedometer embedded in the video. I assume you have a GPS sensor and telemetry enabled receiver on board. But how do you insert the instrument readings into the vid?

Thanks

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Yes, I have FrSky GPS sensor and RC link with telemetry. I enable telemetry data logging on the SD Card in my Taranis X9D. After flight I have CSV file with logs which I then turn into altimeter, speedometer or or something else in DashWare - http://www.dashware.net/ . I then export the clocks as frames and edit the video along with them in a video editing program. If you need more information then I will try to help Smile

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balogh Wed May 19, 2021 4:44 am

Thanks, I have similar hardware like GPS sensor and telemetry receiver, SD card in my Futaba receiver but am not that computer minded to create such a great video and telemetry combination Very Happy

czarobest Wed May 19, 2021 4:55 am

No problem Wink

. It's not that hard, you can find tutorials on the internet and I think you can handle it Smile

. The hardest part may be preparing the data profile in DashWare, and the rest is pretty intuitive. If you try and have a problem then of course you can write to me Smile

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PS: My other video with gauges and a different model. - https://youtu.be/GUsdpeTAKdI

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