AMCross
Dec 06, 2004, 02:00 AM
!Introduction
| spec2
| @913716
|> <b>Wingspan:</b> |< 68"
|> <b>Wing Area:</b> |< 816 sq. in.
|> <b>Weight:</b> |< 10 lbs.
|> <b>Length:</b> |< 60"
|> <b>Wing Loading:</b> |< 28 oz/sq. ft.
|> <b>Servos:</b> |< Futaba S3151 digital servos
|> <b>Transmitter:</b> |< Futaba 7C
|> <b>Receiver:</b> |< R148DP
|> <b>Rx Batt:</b> |< Futaba 4C 1000mAh
|> <b>Recommended Engine:</b> |< .90 2-stroke<br>120-140 4-stroke
|> <b>Tested Engine:</b> |< YS140
|> <b>Tested Prop:</b> |< 16x10
|> <b>Manufacturer:</b> |< <a href=http://www.cermark.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=C&Product_Code=CER-A105&Category_Code=AAA>Cermark</a>
|> <b>Available From:</b> |< Your Local Hobby Shop, or online at <a href=http://www.cermark.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=C&Product_Code=CER-A105&Category_Code=AAA>Cermark</a>
For those of you who know me, or who have competed at <a href="http://www.mini-iac.com">IMAC contests</a> with me, you might already know that I'm a scale aerobatic plane fanatic. I could write pages on the history and my passion about these airplanes, and especially the Sukhoi. For those who don't know me, I literally "cut my teeth" on a Goldberg Extra as my first airplane, and competed in an IMAC contest before I could consistently land on my own. Suffice it to say, I LOVE these scale aerobatic airplanes. So, when I saw Cermark had released a Sukhoi the perfect size for my YS 140, and in a more feminine "pearl red" color, I just had to have it....
<small><i>Introduced by the Soviet Team at Békéscsaba, Hungary during the 1984 World Championships, the SU-26 was one of the first of the composite material, monoplane design aerobatic aircraft of the modern era. After a slow start (26th in 1984) the Sukhoi as become the mainstay of team Russia. Imported in America by Pompano Air Center, the Sukhoi SU-26 and its two seat variation the SU-29 are familiar sights at aerobatic contests around the world. The latest refinement is the Sukhoi SU-31, which is a single seat version of the SU-29 which makes greater use of lighter composite materials. (Courtesy of <a href="http://www.larrylowe.com/wac/Monoplanes.html">Air And Space World Championship Coverage.)</i> For more of the Sukhoi aerobatic family history, visit this <a href= http://www.russianaeros.com/history22.htm>Russian Aerobatic site!</a></small>
!Kit Contents
@913717:Cermark chose a balance between quality color presentation and excessively expensive “showpiece” boxes.
@913718:The large pieces were all bagged and carefully packaged.
@913719:The smaller items were similarly bagged, and included niceties such as the spinner and graphics transfer paper.
!Assembly
The Sukhoi’s manual was well written (although a little light in instruction in a few places) and a modeler building an aircraft of this type should have several quality ARF builds under his or her belt, so I will try my best not to bore you with every step as written in the manual. What I will try to point out is anything that I thought might be a concern or was just really cool.
@913720:The first step was to tighten the covering. Why mention this? The covering did not need to be touched up anyplace. What a nice change!
@913721:The hinges were recessed, as shown here, because the controls were recessed into a ball-and-cup style socket for ideal performance and dramatically reduced changes of flutter. IMPRESSIVE!
@913722:Note how neatly the aileron fit into the socket. I was also impressed at the proper geometry and engineering on Cermark's part, such that the hinges were a perfect fit in such a tight-tolerance application.
One other neat touch was that the tank cap protruded through the front of the firewall, so by simply removing the cowling, the tank could be serviced. (<i>Sorry, the photo didn't turn out well.</i>)
@913723:Either the wing joiner was warped, or the joiner sockets were not designed to fully account for the sweep of the wing, because the wing panels did not align well at all when joined.
@913724:Despite how scary the 9/32" gap appeared, I found the wing pulled nicely into shape, and simply coated the parts with epoxy, taped it, and allowed it to dry overnight.
!!Decal Application
The most time-consuming portion of the process was decal application. However, although Cermark forgot to mention it in the manual, they DID provide a WONDERFUL tool to make decal application easier. A product known as 'frisket paper', or decal transfer paper, was included in the box, but without instructions for its use, so I'll provide that here.
@913725:I peeled the unwanted background away from the desired lettering. Note the transfer paper laying below the decal in this shot.
@913726:I gently rubbed the frisket paper down onto the lettering.
@913727:The frisket had more 'tack' (stickiness) than the gloss sheet the lettering came on, so the lettering stuck to the frisket, and lifted off the backing nicely.
@913728:The adhesive on the decals would stick to covering with far more adhesion than the light 'tack' of the frisket paper (and to many other things also, be careful!), so the letters easily stuck to the aircraft.
@913729:The stars, with no clear inner decal, would have been a NIGHTMARE to apply without the frisket to keep their shape and avoid creases, etc.
!Power, Radio Gear and More
The engine range on this aircraft was quite large, but the selection was easy. I just so happened to have a YS140 that was truly a trusted old friend. Like all YS's, it required a bit more finesse, a gentler hand than some of the less powerful engines in this range, but the performance it provided was sooo worth it! If I were to buy this aircraft again, and needed to select an engine for it, my YS was honestly more than the airplane needed. I would likely buy something a little less powerful and a little less pricey.
I chose to use my new Futaba 7C for this aircraft, which I recently <a href="http://www.rcgroups.com/4405">reviewed for RCPower</a>, including the provided digital servos. Boy those babies were nice! So crisp, so responsive. I do love the feel of a digital servo.
As far as throws and CG, I used the stock CG. I'd like to tell you I had the throws dialed in carefully to exactly match the manual -- and it would be the truth!! Except that while working on my <a href="http://www.crosswindseqresq.org/rc-support.html">aftermarket book for the 7C</a>, I apparently wiped the Sukhoi's settings by accident. OOPS! So the maiden and several additional flights were at 100% of the available travel, with a low rate of about 40%, no exponential. I have no doubt that for future flying time, I will take the time to play with the throws, trying the manufacturer's recommendations, and adding some exponential. Even on low rate, the aileron response around center was too snappy for my personal tastes. Don't misunderstand, it was VERY controllable, just not competition precision soft.
!Flying!
+913735:A quick tour around this aerobatic beauty before we headed for the field.
+913736:A variety of precision aerobatic maneuvers, including flat spins and a gigantic knife edge loop. (Hope you enjoy the dead stick landing!)
+913737:Same video, medium resolution for medium speed connections.
+913738:Same video for dial-up users.
@913716:Ready to go!
@913730:All we need now is a first place IMAC trophy for this shot....
@913731:Can't you just imagine that big radial humming along???
@913732
@913733
@913734
I worked in the RC industry for about 5 years, full time and then some. It takes A LOT for me to get excited about an airplane these days....but, I have to tell you, am I excited to fly this girl again! I could spend the next 2 hours writing to you about flying this airplane. The video is flown by my husband, Mike Cross, 2 time US National Freestyle IMAC champion, and an unlimited class IMAC competitor for many years. Hope you enjoy it!
!!Take-Offs and Landings
The videotaped takeoffs have a bit of tailwag in them, but that was due to breezy conditions and less than flat "runways" (aka country roads). On smoother surroundings and less gusty days, take offs are dead on straight, with just a touch of rudder needed. The landings were smooth as glass, as the end of the video shows so well.
!!Pilot Skill Level
The Sukhoi is no trainer, but it definitely follows my favorite philosophy regarding aerobatic aircraft -- to be a good aerobat, the model must first be easy to fly! I would gladly recommend this as a first scale aerobatic plane to a pilot with some aileron trainer experience, and someone to help him/her get used to these larger glow engines and the visual differences of flying a larger bird.
!!Precision Aerobatics
Precision aerobatics -- pattern and scale aerobatic pattern competition -- are where this airplane EXCELS. The Sukhoi stayed right where I pointed it at all times, trimmed with no bad habits, had just the slightest of balloons on power application (meaning a mild thrust angle adjustment might be needed), and, beautifully, took ZERO rudder-to-aileron mixing for both flat turns and knife edge! It had just the slightest of rudder-to-elevator coupling, which would vary with minor changes in CG. The tank position was a bit further forward than I would've liked, as the bird gets slightly more tailheavy as the fuel is burnt off, but this wasn't a significant change and was barely noticable in flight.
I can't wait to find the time to get the factory rates set and fly the Sukhoi again. The only thing we struggled with was snaps, and particularly avalanches, which required significantly less aileron input even than my 'guestimate' low rates.
This bird LOVES to spin! It entered instantly, exited with just the slightest time needed to recover airspeed, and entered again on command. Even the toughest of judges would have a hard time claiming this model didn't break into a proper spin, as it clearly fell around the wingtip, without the slightest indication of wingover.
Like all good precision aerobatic planes, the Sukhoi is as happy inverted as upright. Dead center on the stock CG, the Sukhoi took the slightest of push to maintain inverted flight.
That large rudder was perfect for knife edge and stall turns -- and even the huge knife edge loop shown on the video. While the surfaces were not enough for the level of 3D that is 'all the rage' with smaller, non-scale aircraft, they were more than sufficient for the maneuvers for which she was designed, and at which her full-size counterpart excel.
The YS provided more than enough power for any maneuver asked; at just 10 lbs, I suspect on a less pricey, less powerful engine the Sukhoi would still handle vertical 8s, figure Ms, and nearly anything else asked of her.
!!Sport Aerobatics
Don't let my passion for scale aerobatics scare you into thinking this is a 'pattern bird' that wouldn't make the average sport pilot happy! Like all great aerobats, this aircraft is first a joy to fly, whether just lazily cruising the field, or practicing for the Nationals. It looks great on the ground and in the air, and has a nice large presence without being so big it requires gasoline power and all that goes with that. It is smooth flying and forgiving, and quickly recovers from those minor blunders we all make now and then.
!Conclusions
Cermark has a real winner on their hands with this Sukhoi. It looks great, builds easily, balances without an ounce of lead, and has a real presence on the flightline. In the air it is a pure joy to fly, with absolutely NO roll coupling, minimal pitch coupling, and not a bad habit I could fine. It's been a long time since I've had an airplane I'm excited to call my own and anxious to get in the air, but I think the Sukhoi and I might just have to hit the tarmac again tomorrow.
*Hits:
*Hardware packed with the parts that use them. For example, the cowl had the cowl mounting screws in a bag taped inside the cowl.
*Included graphics transfer paper.
*Fuel tank access via the cowling.
*No weight needed to balance.
*SUPERB flight performance!
*ABSOLUTELY ZERO rudder-to-aileron coupling, and nearly no rudder-to-elevator coupling.
*Misses:
*The instructions stated to glue the aileron hinges in both the wing and the aileron at the same time. I did this on the first wing and found it difficult. On the other wing panel I glued the hinges in the aileron first and then into the wing. It was easier to get everything aligned and moving smoothly.
*The wing joiner caused the TE of the wing to have a gap of about ¼”. Although this looked hairy, there was not problem in pulling it together with tape after coating the joiner and wing center ribs.
*The instructions were vague about how the axles and wheels mounted to the landing gear.
*There was not enough throw available to allow more than very basic 3D aerobatics.
*The quality of the screws provided, particularly the cowl screws, was lacking. They stripped a little too easily.
| spec2
| @913716
|> <b>Wingspan:</b> |< 68"
|> <b>Wing Area:</b> |< 816 sq. in.
|> <b>Weight:</b> |< 10 lbs.
|> <b>Length:</b> |< 60"
|> <b>Wing Loading:</b> |< 28 oz/sq. ft.
|> <b>Servos:</b> |< Futaba S3151 digital servos
|> <b>Transmitter:</b> |< Futaba 7C
|> <b>Receiver:</b> |< R148DP
|> <b>Rx Batt:</b> |< Futaba 4C 1000mAh
|> <b>Recommended Engine:</b> |< .90 2-stroke<br>120-140 4-stroke
|> <b>Tested Engine:</b> |< YS140
|> <b>Tested Prop:</b> |< 16x10
|> <b>Manufacturer:</b> |< <a href=http://www.cermark.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=C&Product_Code=CER-A105&Category_Code=AAA>Cermark</a>
|> <b>Available From:</b> |< Your Local Hobby Shop, or online at <a href=http://www.cermark.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=C&Product_Code=CER-A105&Category_Code=AAA>Cermark</a>
For those of you who know me, or who have competed at <a href="http://www.mini-iac.com">IMAC contests</a> with me, you might already know that I'm a scale aerobatic plane fanatic. I could write pages on the history and my passion about these airplanes, and especially the Sukhoi. For those who don't know me, I literally "cut my teeth" on a Goldberg Extra as my first airplane, and competed in an IMAC contest before I could consistently land on my own. Suffice it to say, I LOVE these scale aerobatic airplanes. So, when I saw Cermark had released a Sukhoi the perfect size for my YS 140, and in a more feminine "pearl red" color, I just had to have it....
<small><i>Introduced by the Soviet Team at Békéscsaba, Hungary during the 1984 World Championships, the SU-26 was one of the first of the composite material, monoplane design aerobatic aircraft of the modern era. After a slow start (26th in 1984) the Sukhoi as become the mainstay of team Russia. Imported in America by Pompano Air Center, the Sukhoi SU-26 and its two seat variation the SU-29 are familiar sights at aerobatic contests around the world. The latest refinement is the Sukhoi SU-31, which is a single seat version of the SU-29 which makes greater use of lighter composite materials. (Courtesy of <a href="http://www.larrylowe.com/wac/Monoplanes.html">Air And Space World Championship Coverage.)</i> For more of the Sukhoi aerobatic family history, visit this <a href= http://www.russianaeros.com/history22.htm>Russian Aerobatic site!</a></small>
!Kit Contents
@913717:Cermark chose a balance between quality color presentation and excessively expensive “showpiece” boxes.
@913718:The large pieces were all bagged and carefully packaged.
@913719:The smaller items were similarly bagged, and included niceties such as the spinner and graphics transfer paper.
!Assembly
The Sukhoi’s manual was well written (although a little light in instruction in a few places) and a modeler building an aircraft of this type should have several quality ARF builds under his or her belt, so I will try my best not to bore you with every step as written in the manual. What I will try to point out is anything that I thought might be a concern or was just really cool.
@913720:The first step was to tighten the covering. Why mention this? The covering did not need to be touched up anyplace. What a nice change!
@913721:The hinges were recessed, as shown here, because the controls were recessed into a ball-and-cup style socket for ideal performance and dramatically reduced changes of flutter. IMPRESSIVE!
@913722:Note how neatly the aileron fit into the socket. I was also impressed at the proper geometry and engineering on Cermark's part, such that the hinges were a perfect fit in such a tight-tolerance application.
One other neat touch was that the tank cap protruded through the front of the firewall, so by simply removing the cowling, the tank could be serviced. (<i>Sorry, the photo didn't turn out well.</i>)
@913723:Either the wing joiner was warped, or the joiner sockets were not designed to fully account for the sweep of the wing, because the wing panels did not align well at all when joined.
@913724:Despite how scary the 9/32" gap appeared, I found the wing pulled nicely into shape, and simply coated the parts with epoxy, taped it, and allowed it to dry overnight.
!!Decal Application
The most time-consuming portion of the process was decal application. However, although Cermark forgot to mention it in the manual, they DID provide a WONDERFUL tool to make decal application easier. A product known as 'frisket paper', or decal transfer paper, was included in the box, but without instructions for its use, so I'll provide that here.
@913725:I peeled the unwanted background away from the desired lettering. Note the transfer paper laying below the decal in this shot.
@913726:I gently rubbed the frisket paper down onto the lettering.
@913727:The frisket had more 'tack' (stickiness) than the gloss sheet the lettering came on, so the lettering stuck to the frisket, and lifted off the backing nicely.
@913728:The adhesive on the decals would stick to covering with far more adhesion than the light 'tack' of the frisket paper (and to many other things also, be careful!), so the letters easily stuck to the aircraft.
@913729:The stars, with no clear inner decal, would have been a NIGHTMARE to apply without the frisket to keep their shape and avoid creases, etc.
!Power, Radio Gear and More
The engine range on this aircraft was quite large, but the selection was easy. I just so happened to have a YS140 that was truly a trusted old friend. Like all YS's, it required a bit more finesse, a gentler hand than some of the less powerful engines in this range, but the performance it provided was sooo worth it! If I were to buy this aircraft again, and needed to select an engine for it, my YS was honestly more than the airplane needed. I would likely buy something a little less powerful and a little less pricey.
I chose to use my new Futaba 7C for this aircraft, which I recently <a href="http://www.rcgroups.com/4405">reviewed for RCPower</a>, including the provided digital servos. Boy those babies were nice! So crisp, so responsive. I do love the feel of a digital servo.
As far as throws and CG, I used the stock CG. I'd like to tell you I had the throws dialed in carefully to exactly match the manual -- and it would be the truth!! Except that while working on my <a href="http://www.crosswindseqresq.org/rc-support.html">aftermarket book for the 7C</a>, I apparently wiped the Sukhoi's settings by accident. OOPS! So the maiden and several additional flights were at 100% of the available travel, with a low rate of about 40%, no exponential. I have no doubt that for future flying time, I will take the time to play with the throws, trying the manufacturer's recommendations, and adding some exponential. Even on low rate, the aileron response around center was too snappy for my personal tastes. Don't misunderstand, it was VERY controllable, just not competition precision soft.
!Flying!
+913735:A quick tour around this aerobatic beauty before we headed for the field.
+913736:A variety of precision aerobatic maneuvers, including flat spins and a gigantic knife edge loop. (Hope you enjoy the dead stick landing!)
+913737:Same video, medium resolution for medium speed connections.
+913738:Same video for dial-up users.
@913716:Ready to go!
@913730:All we need now is a first place IMAC trophy for this shot....
@913731:Can't you just imagine that big radial humming along???
@913732
@913733
@913734
I worked in the RC industry for about 5 years, full time and then some. It takes A LOT for me to get excited about an airplane these days....but, I have to tell you, am I excited to fly this girl again! I could spend the next 2 hours writing to you about flying this airplane. The video is flown by my husband, Mike Cross, 2 time US National Freestyle IMAC champion, and an unlimited class IMAC competitor for many years. Hope you enjoy it!
!!Take-Offs and Landings
The videotaped takeoffs have a bit of tailwag in them, but that was due to breezy conditions and less than flat "runways" (aka country roads). On smoother surroundings and less gusty days, take offs are dead on straight, with just a touch of rudder needed. The landings were smooth as glass, as the end of the video shows so well.
!!Pilot Skill Level
The Sukhoi is no trainer, but it definitely follows my favorite philosophy regarding aerobatic aircraft -- to be a good aerobat, the model must first be easy to fly! I would gladly recommend this as a first scale aerobatic plane to a pilot with some aileron trainer experience, and someone to help him/her get used to these larger glow engines and the visual differences of flying a larger bird.
!!Precision Aerobatics
Precision aerobatics -- pattern and scale aerobatic pattern competition -- are where this airplane EXCELS. The Sukhoi stayed right where I pointed it at all times, trimmed with no bad habits, had just the slightest of balloons on power application (meaning a mild thrust angle adjustment might be needed), and, beautifully, took ZERO rudder-to-aileron mixing for both flat turns and knife edge! It had just the slightest of rudder-to-elevator coupling, which would vary with minor changes in CG. The tank position was a bit further forward than I would've liked, as the bird gets slightly more tailheavy as the fuel is burnt off, but this wasn't a significant change and was barely noticable in flight.
I can't wait to find the time to get the factory rates set and fly the Sukhoi again. The only thing we struggled with was snaps, and particularly avalanches, which required significantly less aileron input even than my 'guestimate' low rates.
This bird LOVES to spin! It entered instantly, exited with just the slightest time needed to recover airspeed, and entered again on command. Even the toughest of judges would have a hard time claiming this model didn't break into a proper spin, as it clearly fell around the wingtip, without the slightest indication of wingover.
Like all good precision aerobatic planes, the Sukhoi is as happy inverted as upright. Dead center on the stock CG, the Sukhoi took the slightest of push to maintain inverted flight.
That large rudder was perfect for knife edge and stall turns -- and even the huge knife edge loop shown on the video. While the surfaces were not enough for the level of 3D that is 'all the rage' with smaller, non-scale aircraft, they were more than sufficient for the maneuvers for which she was designed, and at which her full-size counterpart excel.
The YS provided more than enough power for any maneuver asked; at just 10 lbs, I suspect on a less pricey, less powerful engine the Sukhoi would still handle vertical 8s, figure Ms, and nearly anything else asked of her.
!!Sport Aerobatics
Don't let my passion for scale aerobatics scare you into thinking this is a 'pattern bird' that wouldn't make the average sport pilot happy! Like all great aerobats, this aircraft is first a joy to fly, whether just lazily cruising the field, or practicing for the Nationals. It looks great on the ground and in the air, and has a nice large presence without being so big it requires gasoline power and all that goes with that. It is smooth flying and forgiving, and quickly recovers from those minor blunders we all make now and then.
!Conclusions
Cermark has a real winner on their hands with this Sukhoi. It looks great, builds easily, balances without an ounce of lead, and has a real presence on the flightline. In the air it is a pure joy to fly, with absolutely NO roll coupling, minimal pitch coupling, and not a bad habit I could fine. It's been a long time since I've had an airplane I'm excited to call my own and anxious to get in the air, but I think the Sukhoi and I might just have to hit the tarmac again tomorrow.
*Hits:
*Hardware packed with the parts that use them. For example, the cowl had the cowl mounting screws in a bag taped inside the cowl.
*Included graphics transfer paper.
*Fuel tank access via the cowling.
*No weight needed to balance.
*SUPERB flight performance!
*ABSOLUTELY ZERO rudder-to-aileron coupling, and nearly no rudder-to-elevator coupling.
*Misses:
*The instructions stated to glue the aileron hinges in both the wing and the aileron at the same time. I did this on the first wing and found it difficult. On the other wing panel I glued the hinges in the aileron first and then into the wing. It was easier to get everything aligned and moving smoothly.
*The wing joiner caused the TE of the wing to have a gap of about ¼”. Although this looked hairy, there was not problem in pulling it together with tape after coating the joiner and wing center ribs.
*The instructions were vague about how the axles and wheels mounted to the landing gear.
*There was not enough throw available to allow more than very basic 3D aerobatics.
*The quality of the screws provided, particularly the cowl screws, was lacking. They stripped a little too easily.