My new electric stunt plane Sbach 342

[Ruslan Kurenkov]

Hello friends!
On this weekend, August 25 and 26, we had a training session.
Sergii brought me a new Sbach 342 which he built for me this month, I was very pleased.
We set up a new technique on electric traction. Experienced two different in power electric motor and two different in diameter and step three-blade propellers. We tested new batteries and many different electronics settings. There was very good sunny weather, the wind was 3-4 meters per second, the air temperature was 28-33 degrees. For two days, each made 10 sorties. Electronics tuned very easily and worked perfectly. The power of the small motor Cobra 35/15/18 with the propeller 12.5 / 6 was enough. The rest of the battery charge after the full complex of figures + 4 circles was from 35 to 40 percent. The flight time in a circle is 5.2 - 5.4 seconds. Lines 0.0145x63'
We had two wonderful days at the Chaika , Kiev.
They got a lot of positive emotions from flying and communicating with a lot of sportsmen.
Many thanks to all!
Ruslan Kurenkov

more fotos          https://www.facebook.com/media/set/?set=a.1843047929106997&type=1&l=58f6c57bad
                       

[Bob Hunt]

Your new plane is beautiful, Ruslan! May you have thousands of great flights with it!

Bob Hunt

[Ruslan Kurenkov]

Hi Bob
Thank you very much for your good wishes!
I will learn new techniques and the basics of electricity.
Today I tested another propeller 13/6.
This is a propeller for another Cobra 35/20/18 which is larger and heavier.
I'm under this propeller set less speed and flew.
Flies much better than with 12/6 and with 12.5 / 6
The motor was heated after 5 minutes of flight as well as before at air temperature 90 F .
The rest of the battery charge is 30 percent.
All advise to put the battery easier on 5 cans and not at 6. I'll try.
Regards
Ruslan

[Randy Cuberly]

The Airplane looks great Ruslan!  You have my wishes for the very best of luck with it!

Randy Cuberly

[Frank Imbriaco]

Hi Ruslan :
I will echo the previous comments. Beautiful aircraft. It sounds as though you are experiencing stunt heaven !
Best,
Frank

[Vitalis Pilkionis]

Hi Ruslan, gorgeous plane. But I think for 5S and 13x6 you probably need Cobra C-3520/14 with 700kv.


Vitalis

[Vincent Judd]

I've always loved the looks of the Sbach Ruslan.  Yours is no exception.  Traditional looks, traditional paint scheme.  I hope it provides you with many wonderful flights.

Best of luck with it.

Vince

[Ruslan Kurenkov]

Hello, friends !

The Airplane looks great Ruslan!  You have my wishes for the very best of luck with it!

Randy Cuberly

Hi Randy
Thank you very much for your good feedback and nice wishes.

Hi Ruslan :
I will echo the previous comments. Beautiful aircraft. It sounds as though you are experiencing stunt heaven !
Best,
Frank

Hi Frank
Thanks for the nice words.
I am very pleased.
I test a lot of aircraft modeling equipment as a member of the team to achieve maximum results in a short time. My friend Sergii produces two models, the Maestro (the wing and the stabilizer is an ellipse) and the Sbach (with a flat wing and an even stabilizer). I'm now testing the second option - this is the Sbach airplane, which for the first time was personally built for me in an electrovariant order. Previously, the Sbach was only under Stalker 76. My test is a variant of the Cobra motor 35/15/18 and the selection of the best propeller for this motor. Sergii is now testing his new aircraft Maestro plane with an electric motor Cobra 35/20/18 and is testing the best propeller for this engine. We are constantly exchanging test results every day. Two years ago I personally tested only different synthetic oils for the Stalker 76 engine for my friend Oleg, the engine manufacturer Stalker, I did 100 flights for each variant of the oil. After the tests, we selected the optimal ratio of synthetics and castor oil and the percentage of oil in the fuel. In parallel, I tested various variants of control lines for the length and thickness of the lines (400 flights). My friend Andrii, the manufacturer of composite aircraft Extra and Raven , the manufacturer and developer of the most optimal fuel tank for Stalker engines and the best propeller for Stalker 66. All tests with different tanks and propellers (500 flights) I made on his plane Raven, after which he changed his geometry and produced an Extra plane which is already a level higher in its characteristics. In this mode, I have been pilot test for the last 5 years since I manage my own control line club Chaika (seagull) in Kiev and I can fly almost every day.

Hi Ruslan, gorgeous plane. But I think for 5S and 13x6 you probably need Cobra C-3520/14 with 700kv.


Vitalis

Hi Vitalis
Thank you for your good feedback.
Electromotor Cobra 35/20/18, as I wrote above tests Sergey. Soon there will be full results. Now we are waiting for the tests for new propellers from Igor Burger. Test results will be a little later. I will publish them.

I've always loved the looks of the Sbach Ruslan.  Yours is no exception.  Traditional looks, traditional paint scheme.  I hope it provides you with many wonderful flights.

Best of luck with it.

Vince

Hi Vincent
I'm very glad to hear from you.
Thanks for your message.
This is an amazing coloring.
I specifically ordered only the original one.
Sergii became the owner of the World Cup in 2012 on a semi-copy of Sbach with an unoriginal coloring.

Thank you all for the messages.
I wish you many good flights.
Ruslan

[Ruslan Kurenkov]

Hello
This morning, as usual I did 4 training flights. I tested the setting of different timing values ​​in the Cobra motor controller. The first flight is 15 degrees ahead, the second flight is 10 degrees, the third flight is 7 degrees and in the fourth is 5 degrees. What a difference I did not notice, there is only a slight increase in the speed of the flight in a circle with a decrease in the degrees of timing. Who uses what timing values ​​on Cobra engines?
At the evening training in the second flight appeared at the start of a small vibration that disappeared after 2 minutes of flight. I began to perform square shapes and suddenly the motor spiked and stopped in the vertical position when dialing up. I miraculously saved my new plane from hitting the asphalt. I had to run back very quickly. After a successful landing, it was found out that the original crosspiece of the engine Cobra, which was packed with the engine, completely collapsed after 50 flights of 5 minutes.
It's too bad but the fragile metal could not stand the loads. I will milled a new frog securing the engine from a less fragile material and a little thicker.
I wish all excellent flights.
Ruslan.

[Frank Imbriaco]

Hi Ruslan :
Sorry about your misfortune, but glad you were able to save your beautiful ship. From an enlargement, it appears as though you used the  "X" cross mount supplied with the Cobra motor.
Not wishing to start a debate on the sidelines, but you may want to investigate front mounting the motor. Dean Pappas and Bob Hunt collaborated 10 years or so ago and developed a wonderful, simple, economical and extremely strong G10 composite firewall.
In my neck of the woods and elsewhere,too, we forward mount the firewall in the nose and front mount the motor to it.
What you experienced would've likely never happened with that system.
I'm guilty of a shameless plug, but get one from Bob. Your motor will fit it perfectly. Just trim the outsides and adhere with a slurry of epoxy/micro-balloons. Align the backplate of the spinner to the nose( I've hung ships nose-down to the floor while drying).  Shim space the backplate from the nose ring.
I like Hysol, an aero-space industrial epoxy made by Loctite. It doesn't run and takes two hours to set up and 24 hrs to fully cure. You'd destroy the airplane trying to remove the G10 mount with this stuff. Also recommend that you scuff it up some where the glue will touch and Ialso cut micro-short edge cuts to my mounts using a Dremel cut-off wheel. That step provides even more grip.
Good Luck

[Ruslan Kurenkov]

Thank you, Frank.
I really liked your answer and all your advice on how to mount the Cobra electric motor. I want to say that I have absolutely no experience of flying with an electric motor. I do not know how to correctly set all the adjustments to the Cobra motor. I really liked this motor. He has a very strong and large front bearing. This is very important when using large propellers with a large pitch. All the load with sharp turns is accounted for by the front bearing due to the large gyroscopic moment. I'm very interested in what your photo engine system you described above looks like in the photo. I was very grateful to you for the photo of this design. From the description, I can not exactly determine exactly how this fastening is arranged. Maybe you or Bob Hunt or someone else will post here a photo of the Cobra motor mount.
Thanks in advance.
Regards
Ruslan

[Frank Imbriaco]

Hi Ruslan :
If my memory serves me, go to the "AMPS UP" section here and scroll through Bob Hunt's "Electric Twin Back On Track" and you will see photos with front mounted electric motors.
From what I can see, your aircraft is made of composite material(correct me if I'm wrong) - so it requires a slightly different approach than a traditional balsa/ply fuse front end.
But, it's very doable. Just obtain the G10 mount and size/space it aft and according to the inside of the nose. With your motor front mounted to the  spinner, collette attached and spinner backplate/prop and nut secured- space it out from the nose ring about 3/32".
Hang the fuse from the tail so that the nose is pointing straight down. If your fuse  nose ring has a degree or so of right offset, match the backplate spacing accordingly. If no offset, go with that.
Bob's mount will likely require some trimming and shimming to get it just right somewhere about an inch, give or take from the nose ring.
Any gaps wider than 1/4" around the mount can be filled with epoxy saturated carbon tow , the HYSOL (or heavy ,slow cure epoxy slurry) will fill in narrower gaps.
I've done it this way with 2 M R/C pattern ships that use much larger motors(of course for the mount itself, I  used thicker composite-balsa sandwich material.)
Bob's mount should be available from his Robin's View Productions  in the Stunt hanger vendor's section .
It's a day's job if you take your time(and if you're as slow as me).
Good Luck,
Frank

[Ruslan Kurenkov]

Hi Frank
Thank you so much for the help, for the advice and for your information regarding the front mounting of the electric motor.
I am very pleased that you responded to me to help.
I know very little and I understand very little about motor mounts!
As you wrote, I very quickly found on the seller's page Bob Hunt all the necessary information about the engine mount through the G10 device Bob Hunt.
Here is a link to his page          https://stunthanger.com/smf/robin's-view-productions/new-product-hardnose-electric-front-mount/
I wrote in the subject of Bob Hunt my question about attaching the engine to Cobra 3515/18 and I'm waiting for his answer.
I very much hope that by installing this mount I will no longer know the problems with the aluminum mount which I destroyed right away in flight.
I wish you good mood.
Regards
Ruslan Kurenkov

[John Rist]

I also have had good luck with the Bob Hunt mount.  Because mine was a profile mount  I laminated mine with plywood to give me more mounting thickens needed for a profile mount.  Looking at your setup it should work well If you epoxy it in place.

[Ruslan Kurenkov]

I also have had good luck with the Bob Hunt mount.  Because mine was a profile mount  I laminated mine with plywood to give me more mounting thickens needed for a profile mount.  Looking at your setup it should work well If you epoxy it in place.

Hi John
Thank you for the photo.
You've got a very good and strong attachment based on the G10 device from Bob Hunt.
My nose mount on the Sbach already has a glued plywood for attaching the engine mount.
I'm also very glad that Bob Hunt quickly responded to my letter on this forum.
He will send for me his device G10 in Ukraine.
As soon as I receive mail G10 and install it on my Sbach, I will take a photo and a small written report after the first flight.
Regards
Ruslan

[Ruslan Kurenkov]

Hello
Today at the post office I received the engine mounts from Bob Hunt for my Cobra 3515/18 electric motor to Sach 342.
Mounts look very good.
It is immediately visible (even with eyes closed, to the touch) that the mounts are very strong and of very high quality.
I am very grateful to Bob Hunt for the extremely fast dispatch and delivery of fasteners G 10 for my aircraft.
Next week I will install the mount on the plane.
I am sure that such fastenings will never collapse from heavy loads.
After installing and testing mounts, I will definitely make a small photo report.
Thank you very much Bob.
Regards
Ruslan

[Vitalis Pilkionis]

Hi Ruslan,

I think those aluminum X mounts provides quite a significant cooling properties for a electric motor, so don't forget to check motor's temperature after flight if running without it, especially on the smaller 3515 motor.


Vitalis

[Frank Imbriaco]

Ruslan :
The Hunt mount is designed to allow air to pass through the motor !
The only other advice ( again from Bob)   - bifurcate the air inlet with several pieces of 1/32" balsa or 1/64" ply. You need to have the material flex into a semi-circle  so that the incoming air hits the bottom of the motor can.
Also, direct some air over the ESC.
For what it's worth, I've never had an overheating situation with the Hunt G10 mount. I've used them on 5 aircraft , including my twin.
Temps as high as 96 degrees F.

Good Luck,
Frank

[Ruslan Kurenkov]

Hi Ruslan,

I think those aluminum X mounts provides quite a significant cooling properties for a electric motor, so don't forget to check motor's temperature after flight if running without it, especially on the smaller 3515 motor.


Vitalis

Hello Vitalis
Thanks for the advice. I will surely consider what you advised me.
After each flight, I check the temperature of the engine.
After installing the new engine mount from Bob Hunt, I will also compare the temperature of the engine after the flight with my hands. If the temperature is slightly higher then this is acceptable. Previously, the engine was heated very weakly. I calmly held it with my fingers through the cooling duct.
Regards
Ruslan

Ruslan :
The Hunt mount is designed to allow air to pass through the motor !
The only other advice ( again from Bob)   - bifurcate the air inlet with several pieces of 1/32" balsa or 1/64" ply. You need to have the material flex into a semi-circle  so that the incoming air hits the bottom of the motor can.
Also, direct some air over the ESC.
For what it's worth, I've never had an overheating situation with the Hunt G10 mount. I've used them on 5 aircraft , including my twin.
Temps as high as 96 degrees F.

Good Luck,
Frank

Hello Frank
Thank you for the information on the fastening of G 10 from Bob Hunt.
Thanks to your help, I wrote Bob and very quickly received fastenings from him for myself and for my friend Sergii Solomianikov who has the same plane and the same electric motor as mine.
 I will certainly take into account your recommendations and recommendations from Bob Hunt on the installation of fasteners and on the modernization of air ducts of the ventilation and cooling system of the engine, battery and ESC.
Regards
Ruslan

[Ruslan Kurenkov]

Hello
Today installed the mount G 10 from Bob Hunt.
Fastening weight of 8 grams.
Used mounting bolts for 2 mm internal hex.
Conducted tests of the electric motor with a propeller on the table for 1 minute. Everything works fine. The mount is very durable, but it seemed to me that it strongly closes the air blowing for good cooling of the electric motor.
I have a question? Can drill, increase the holes for the passage of air? Perhaps this will greatly reduce the strength of the mounting structure?
Regards
Ruslan

[Vitalis Pilkionis]

I have a question? Can drill, increase the holes for the passage of air? Perhaps this will greatly reduce the strength of the mounting structure?

Hi Ruslan,

In my opinion you can cut additional slots at the edges without any risk.


Vitalis

[Frank Imbriaco]

Hi Ruslan :
Believe me, enough air flows thru the Hunt amount. Proceed with caution when removing  extra material as that same material maybe crucial for a strong bond to your fuse nose area. Please go back and re-read the installation instructions that we advised.  That method has  proven itself bullet-proof on dozens of  electric aircraft with hundreds  and hundreds of flights.
You are mounting in a composite fuse, correct ? I really urge you NOT to remove the area the modeler highlighted in red. But, it's your choice.
You will need to mix an epoxy slurry as I described to  adhere to and reinforce the mount edges and all around the backside of the mount. Did you remember to make some very shallow edge cuts( no deeper than 1/16") and scuff the areas where the epoxy makes contact ? You may even wish to cut some  1/4" -3/8"  thick balsa "rings" as spacers that match the rear side of your mount for even more  gluing area surface.
Remember to make  "bifurcate"  chin vents to flow cooling air to the bottom of the motor can and one to send air to the ESC and if possible, your battery.
You can also get a cooling spinner from Tru-Turn( be certain to set your collette - spinner backplate & prop  distances first before gluing) or some other vendor. I've used some of the nice plastic w/metal backplates  cooling spinners sourced from China that I located on eBay. They are cut for TRACTOR props. Tru-Turn will cut for PUSHER props and cut the vane in the backplate according to your wishes for TRACTOR or PUSHER.
Good Luck,
Frank

[Frank Imbriaco]

Hi Ruslan :
Upon close inspection of your pictures, it appears as though you are installing the mount using just screws. Without seeing what you are mounting Bob's mount to, I really can't further advise.

Good Luck,
Frank

[Ruslan Kurenkov]

Hi Ruslan,

In my opinion you can cut additional slots at the edges without any risk.


Vitalis

Thank you Vitalis
Regards , Ruslan

Hi Ruslan :
Upon close inspection of your pictures, it appears as though you are installing the mount using just screws. Without seeing what you are mounting Bob's mount to, I really can't further advise.

Good Luck,
Frank

Thank you Frank for a very detailed answer.
I will definitely take your advice.
On the epoxy resin, even at the stage of gluing the fuselage of the two halves in the forms, there was a very strong frame in the front part of the nose of the fuselage. This is a sandwich of four layers of birch plywood with a thickness of 1 mm each layer and 1 mm of glass fiber textolite. The thickness of the frame is 5 mm. In this power frame on epoxy resin, glued metal inserts (fungi) with internal thread M3 for 4 bolts on which the engine crosspiece is mounted. Instead of a duralumin crosspiece for mounting an electric motor, I installed a G-10 circular plate from Bob Hunt, then I drilled 4 holes 3 mm in diameter under it for a mounting bolt M3. On 4 M3 bolts, the G-10 Bob Hunt attachment is screwed to the power frame of my aircraft. (see photo)
I am not gluing G-10 into the fuselage.
I fasten it as previously screwed a crosspiece of aluminum. The G-10 mount is held very firmly. I'm just worried about reducing the purge cross section for engine cooling.
Thanks to Vitalis for his drawing. For the red lines can not go. I totally agree with you.
Regards
Ruslan

[Ruslan Kurenkov]

Hello, friends !
I want to ask you for advice on using the Cobra engine.
I tested two engines Cobra. These are 3515/18 and 3520/18
On the Cobra 3515/18 engine, the best results were with a three-bladed propeller from Igor Burger 12/5 UCT.
On the Cobra 3520/18 engine, the best results were a 13/5 three-bladed propeller from Pavel Kravchenko (Ukraine).
The Cobra 3515/18 worked perfectly in tandem with the propeller and the Thunder Pover battery at 2800mA at 6S, 25C, but only up to a wind speed of 7-8 meters per second.
The Cobra 3520/18 worked perfectly in any wind up to 10 meters per second with lines 63 feet long. If lines of 65 feet or more are used, the engine speed is no longer enough due to the low speed ratio per volt (540). And I did not test a propeller of a larger diameter or pitch. Maybe the propeller 13/5 is small for him?
I heard and read earlier that many athletes use a Cobra 3520/14 which has a higher ratio of revolutions per volt.
I want to know which propellers are well suited for this engine, which battery is ideal for this engine and what maximum line lengths can be used with this engine?
Regards
Ruslan

[Randy Powell]

Very slick. Nice layout.