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Multiplex Cularis Electric ARF Sailplane Review

This new 2.6 meter Elapor foam glider from Multiplex is a full house glider with flaps, ailerons, rudder and elevator and can be flown as a pure glider or electric. Michael Heer reviews the electric powered version.



Just looking at the lines on the Cularis I could see the obvious ties to the EasyGlider and EasyGlider Electric. The Cularis comes in one kit that can be assembled as an electric powered glider or as a pure glider for slope flying or aerotow, or you can add a tow hook (not included) for thermal flying from a winch or High Start launch. It has two wing spars for strength, a flying horizontal stabilizer (instead of elevator) with an automatic retainer system that can be unlocked for quick removal and ease of transport, and the wings feature an automatic mechanical retainer system that electrically connects the 4 wing servos to the fuselage based radio receiver.

And in case you wondered, Cularis means “cloud.”

Wingspan:2610 mm, 102.75"
Wing Area:55 dm(squared)
Weight:1680 grams
Length:1260 mm
Wing Loading:30,5g / dm(squared)
Flap Servos:2 Hitec HS-65s with metal gears
Aileron Servos:2 Hitec HS-65s with resin gears
Ele/Rud Servos:2 Hitec HS-81s with resin gears
Transmitter:JR 9303
Receiver:Hitec Electron 6 channel
Receiver:9 channel
Receiver Battery:4 cell 1800 mAh
Motor Battery:3-cell 2500 Polyquest pack
Motor:Himax 3522-700
ESC:Motrolfly FM40A Opto Brushless Controller
Programming Card:Motrolfly E-PRG-1 Programming Card
Available From:Multiplex

Kit Contents

The Cularis came in its own special molded foam holder "box" which fit snugly inside the display box and held the parts safely in place. The kit arrived with no damage, protected inside a large brown shipping box. The parts included can best be described in two sections. Elapor foam parts included: the wings, bottom wing section covers, the fuselage in two halves, vertical tail and rudder, horizontal full flying stabilizers, Canopy and foam nose cone. All the plastic hardware and tubes to complete the plane including: wing spars, wing joiner system, controls horns and connecting hardware and tubes to connect the rudder, stab, ailerons and flaps to their servos (servos not included) including protective servo covers. Even decals were supplied. A very complete kit! If I were to add something it would be a tow hook and a tow hook mount but they discuss that in the included instruction manual.

Unlike the EasyGlider that has separate kits for the pure glider and the motorized glider, the Cularis is one kit that can be assembled either way.

Kit Requires:

  • 2 Hitec 81 servos for inside the fuselage
  • 2 Hitec HS65 servos with metal gears for flaps
  • 2 Hitec HS65 servos with resin gears for flaps.
  • Aileron extension wires: Multiplex Cularis pack (two 24"", four 12")
  • Two 6 inch aileron extensions for the flap servos
  • Two 3 inch aileron extension wires for the ailerons
  • CA glue medium to thick, NOT foam safe CA (1/2 oz or more)
  • Metric ruler or conversion formula mm to inches
  • CA kicker
  • CA debonder
  • Motor unit
  • ESC: Motrolfly FM40A
  • Programming Card: E-PRG-1 Motrolfly
  • Spinner:
  • Prop blades:
  • Exacto knife for foam trimming
  • Sanding block with fine sandpaper


Before you even start assembly get out your sanding block with fine sandpaper and sand off all the drag creating foam ridges you find on the edges of pieces. My plane had them in a number of places.

Cut the side slits for the flaps and ailerons but leave the foam hinge intact. Fold the parts, including the rudder hinge, back and forth to loosen up them; the hinge is initially very resistant and will strain your servos if this step is skipped. An alternative is to make periodic one inch cuts in the foam hinge so that there is less material and less resistance.

Center the control arms with your receiver before installing, especially the ones for ailerons and flaps as they will be hard to reach once installed. Trial fit them in place, and see if the servo covers will fit. With my Hitec HS-65s I have to cut off the outer two holes on the arms for the servo arm to fit under the servo cover.

The Multiplex Cularis set contains 6 wires. I used two 24" wires with the aileron servos. They might have been enough to fit the root mount, but didn't match up with the illustrations so I added two 3" servo extensions - one to each aileron wire in between the servo wire and the 24" extensions. The four foot long wires from the Cularis set I used inside the fuselage to reach the receiver. I used two 6 inch JR extensions on the flap servos. In the actual assembly they worked out well for me. Multiplex has extensions that are a little longer than the usual 24" and 12" for the aileron and flap servos. These longer extensions are now included in the Cularis Flight Pack (#M99218) and can be purchased separately in the Cularis Cable Set (#M85055).

Manufacturer's Note: "It is not possible to glue the material using white glue or epoxy. Please be sure to use cyano-acrylate (CA) glue exclusively, preferably in conjunction with CA activator ("kicker"). We recommend high-viscosity (thick) CA. This is the procedure: spray CA activator on one face of the Elapor (foam), allow it to air-dry for at least two minutes, then apply CA adhesive to the other face. Join the parts and immediately position them accurately."

I followed this recommendation for most steps. Regular thick and medium cyano-acrylate glue was used exclusively. Do NOT use Odorless (AKA “Foam Safe”) CA !


The wing came pre-built for the most part since it is molded Elapor foam. The aileron and flap servos had to be installed along with their extension wires, and the double wing tube spars had to be glued in place as shown in the pictures below. Multiplex has a new wire connection system for the fuselage and wing root that took a little study of the directions and trial fitting, but it proved to be easy enough once I fully understood the directions.

The next part of the assembly involves the wing connectors and wiring in the fuselage and then fitting the wing to the center connector and adding the parts to do so at the wing root. When the assembly of the wing root box was finished and secured, the wing tip was glued in place and the wing decals were added.

Wing Instruction Clarifications

After finishing my Cularis build, I found and read a long thread on the Cularis in the Foam Kit Forum that was started by Quacker. It has a lot of good information, but brought up a couple of questions so let me cover two points here: 1) The wooden dowels go all the way into the four # 60 wing rods on the wing root end. Those rods extend 23mm past the end of the foam. The dowels are not joiners, but are to strengthen the rods where they fit into the wing joining system at the point of highest stress.They go completely inside the rods and are flush with the ends of the rods. 2) The smaller #61 rods slide into the 60 rods and are positioned to fill the rod channels in the wing completely. The rods do not need to be cut; they need to be fitted into the #60 rods to the proper length and tack glued together. This is not covered well in the text instructions. I found grinding the end of the #61 rods on the inside end helped them slide more easily into the # 60 rods. This joining of the rods was shown in the pictures, but this could have been done more clearly.

Motor and ESC

The Himax outrunner brushless motor model # HC3522-0700 comes with connectors already soldered in place and matching connectors for the ESC. I soldered those matching connectors onto the Motrolfly FM40 amp Opto ESC. I also soldered a male Dean connector onto the battery wires of the ESC. The motor came with two motor mounts and a number of screws. The motor and ESC were set aside for later installation into the fuselage.


Two metal balls are supplied to use as counterbalance for the motor and battery in the rear of the fuselage. The question was whether to use one or two? I decided to use two and to mark the spots. I could cut out the spots for later removal if that proved necessary. I used both weights as I like to have my CG pretty far back. I have found in the past that Multiplex gives a fairly conservative forward CG location, and based on that history, I thought I would probably want the weight of both balls as I was using the recommended motor and battery pack.

Since some tubes had to be cut to length, and they only supplied the length in metric, the conversion formula is: 1.00000mm = 0.03937 inches.


I permanently glued my red vertical stabilizer into place and attached the rudder to its servo per the instructions without difficulty. The flying stabilizer also assembled and attached per the instructions. I initially left the removable stabs white, but I am thinking of painting them red or blue in the future for more color and better visibility of the Cularis from the ground. The removable stabs are a nice feature for storage and transportation.

BECs and the Cularis

I want to explain for Newbies why my Cularis has a motor battery and a receiver battery. Many electric powered planes use BEC (Battery Elimination Circuitry) to power the receiver and the servos connected to it from the same battery that powers the plane's motor. That system is fine for parkflyers, but BEC is not the best method for powering the receiver and servos in the Cularis. The Cularis has six servos and requires more power to operate than many BECs supply, and if you want to fly your glider and still have a safety reserve of power, it isn’t possible with a receiver powered via BEC. If my receiver and servos were powered off of the motor battery through BEC I would not know how much flight time I had since I would be using up power with every climb. If the motor stopped working in a climb, I would have a good idea I was getting low on power and should look to land soon. However, if my Cularis was on BEC and I turned off the motor moments before it would have shut down the motor on its own because of low voltage cut off circuitry, I wouldn't be aware of my low power status as there would have been no cut off. With the receiver using its own battery I know how long I can fly whether I use the motor or not; assuming I charged it completely before going flying. Thus it is for safety that I have two separate battery packs in the Cularis and my other large electric powered gliders.


I was surprised there was no tow hook supplied and even more surprised when the instructions told me that only .5% of Multiplex customers would be interested in a tow hook. The instructions cover how to add a tow hook, and I might do that in the future. Their recommended methods of launch are: motor, toss at slope and aerotow.

I had painted some parts for color on my Cularis before assembly so my completion involved adding some of the supplied decals that came with the glider. I will probably add more paint to the bottom of the wing in the future for a red, white and blue chevron.

Mac Powell finished his Cularis a full month before I had mine in the air. He used a larger Himax motor and I used the one Multiplex recommended. Mac prepared a chart comparing the two motors to share with everyone. My thanks to Mac!

Control Surface Movements

  • Ailerons: Up +20mm Down -10mm
  • Flaps Up: +2-3mm speed, -4mm thermal, -30mm Butterfly landing mode
  • Ful fly stabs: Up +14mm, Down -14mm
  • Rudder: Side to side 30mm

Cularis Himax Motor Tests: 3522-700 left side & 3528-800 right side numbers below

Weight/grams 160 196
Volts 12.54 12.54
Amps 0.07 0.06
Volts 11.30 11.00
Amps 21.72 29.00
Watts 243 320
RPM 6900 7300
All Up Weight
pounds 3.82 3.91


Launches and Landing

For launches I turn on the motor slightly and give a good, hard forward throw that is just slightly above level. I get my right hand onto the transmitter and move the throttle up to full. Once it gets up to speed it can do a very vigorous climb to altitude, and I can easily get six plus good climbs with my 3-cell 2500 battery pack. Once at altitude it handles very well as described below in basic flight.

Thankfully it has flaps or on several occasions I would have had to make turns low to the ground to keep from flying off the local park field! It has very strong ground effect and wants to keep on flying. The flaps even at just 50 degrees deflection give good stopping power and let me land where I want. Mac is still learning how his Cularis handles, and on the couple of flights I saw him make he came in a little hotter then he needed to on landing. If you are new to gliders and to flaps read the instructions carefully so you can use or program in the proper amount of down elevator to prevent ballooning when you deploy the flaps or diving when you retract them. Give your self plenty of room for your first landings and you should have a very small learning curve.


I had my elevator trim set for "level" flight with the motor off (actually a slow descent without lift). With the motor on full, the Cularis climbed unless I held in some down elevator. This was normal, and I wanted the trim set for the Motor Off position since that was when I was working to find lift. The Cularis would turn with just ailerons, but there was less yaw or no yaw when I mixed in about 30% rudder with the aileron. I could adjust my flaps with my transmitter and a couple of degrees of up trim, and she sped up nicely to get out of sink. About 4 degrees of down trim with the flaps really slowed her down but more importantly, she gave a greater tell when lift was encountered. In straight flight the tail would kick up hitting a thermal head on and catching it with the side of a wing. These tells let me locate the thermals above my local park and get an hour flight off of the first motor run one Saturday. I was having so much fun flying I didn't notice that I lost my initial landing strip to an adult soccer game. Fortunately, a short walk and I had another smaller softball field to land in without difficulty thanks to the flaps. The Cularis flies and thermals very nicely. Kick up the flaps to a reflex position and she can move right out of sink without using the motor.

I flew the Cularis on a very breezy day, and she slowed down going into a 20 mile per hour breeze but she was still able to penetrate without adding any additional weight. I have not yet taken her to the slope but I suspect that she can handle that well. There the motor will be used only to save me from any walks of shame because if the breeze dies, I won't have to land down at the bottom of the hill. I can just power up and fly back.

Forward stalls were mushy and she would drop a little, pick up speed and resume normal flight without my doing much of anything. Tip stalls almost had to be done intentionally. However, when at a steep turning angle with lost of foward speed I induced a couple of interesting slides downward before leveling the wings and regaining control with flight speed. The Cularis then recovered on her own. While she doesn't fly herself, I found her very controllable.

Flying with an Adjustable Trailing Edge

With the Hitec 6 channel Electron receiver, I initially used a Y connector in the fuselage for the flaps to share a channel. After my initial flights, I switched to a Berg 7 receiver and put the flaps on separate channels. I programmed the flight switches on my transmitter to have a Launch position with reflex for the ailerons and flaps of +2mm, a Normal Cruise position of flaps at -4mm and ailerons at -2mm positions. I had a Neutral position setting for flaps and ailerons for windy conditions and aerobatics and a Butterfly position for landing with down flaps, partially up ailerons and elevator slightly down to prevent ballooning. This made the Cularis an even more responsive glider! It climbed faster with the motor on and the reflex in the trailing edge. It was better at getting out of sink with the reflex. Its accuracy in landing was improved as well using the Butterfly. My Cularis will be remaining in this set-up as it is simply superior in handling vs. my original set up. If you can adjust the trailing edge like this with your radio be it with 6 channels or as I did with more channels, it is a better way to fly this glider! It flies well using 6 channels and a couple of Y connectors (flaps and to power the receiver), but it performs even better if you can control the wing’s trailing edge.

Aerobatics/Special Flight Performance

The Cularis did a very nice large loop, and as expected, a rather sloppy axial roll. It did a better than expected 1/2 pipe, but I gave myself lots of sky. Aerobatics were not its speciality but some can be done and enjoyed when you want a break from regular flying.

Himax and Motrolfly ESC

Both worked very well and I intentionally did a high speed run on the ground as if climbing and in the full speed short run neither the motor nor the ESC got too hot. The automatic shut off for low voltage was activated once during a high speed run after multiple climbs so it protected my expensive LiPoly battery pack. The hard brake on the Motrolfly ESC was programmed "ON" and stopped the propeller dead when I shut the motor down, and the propeller blades quickly folded against the sides of the fuselage. Start up worked equally well. I was very happy with how this blended combo worked together.

Is This For a Beginner?

Multiplex has other planes and gliders better suited for a beginner. This glider would be better for the intermediate and/or expert pilot. I would not recommend that a beginner assemble or fly this glider.

Flight Video & Photo Gallery of Mac Powell's Cularis

Now that you have seen me assemble mine, here are some inflight shots of Mac Powell's Cularis taken before mine was flight ready. Mac is a relatively new pilot and member of our club, and he does a good job of flying but he has to learn how to use the flaps and slow down his plane for landing as you will see in the video below. The Cularis was undamaged in the landing.


From Sunday Flyer to Competive Glider

If I were assembling the Cularis to be a pure glider there are a few things I would do to improve performance:

1) Reduce the width of the rudder at the trailing edge. Per the photograph below, the trailing edge of the rudder is about three times wider than it needs to or should be. Careful sanding of the rudder on both sides would allow the trailing edge to be about 1/3 of the current width and would cause less drag. This sanding with a block is much easier before any assembly takes place.

2) The trailing edge of the flaps and ailerons could also be altered to reduce drag. This is a more complicated procedure, but I have done it on balsa and foam gliders in the past. Here you add a triangular piece of spruce to the trailing edge of the wing - flat on the bottom with a sharp trailing edge at the back, and the front should be the same width of the wing’s trailing edge. Carefully CA the flap piece to the length of the flap, the aileron piece to the length of the aileron and stop there. It adds a little weight and wing surface but the real advantage is the reduced drag from the trailing edge of the wing. If the short length of the spruce is higher than the trailing edge of the flap or aileron some of the foam can be trimmed so that the foam trailing edge is the same length as the short side of the spruce triangular stock. For the pilot who has never tried this, it might be something to experiment with when making a repair. The proper white spray paint will blend it right with the foam.

3) Set-up the flaps for more downward travel. To do this you must sand off some of the bottom portion leading edge of the flap just behind the hinge. By removing some of the flap just behind the hinge line, the flap can be pulled down further. The edge of the red tape all across the flap area is where the sanding takes place. The servo is set up with the arm’s starting position facing 45 degrees back so that there is more forward servo (flap down) movement especially when adjusted for greater movement on a computerized transmitter. This is important as landing points often decide thermal contests here in the USA, and more flaps will give you more stopping power. (The normal flaps work well but if you want even more stopping power...)

I could use the Cularis in a pure glider contest by securing the folding props to the front sides of the glider with a rubberband and adding a tow hook for winch launches. Just another option some might want to consider.


The Cularis gives very good flight performance as a motorized glider with the motor on or thermal hunting and soaring with the motor off. No bad handling charactistics. The Cularis has impressed me as a very well engineered glider. It was a quick glider to assemble and a fun glider to fly.


  • The foam packing tray does a good job in protecting the parts during shipping and as a jig for wing assembly.
  • The Cularis is very well engineered and assembles easily and quickly for the experienced builder
  • The Cularis flies and thermals very well
  • Climbs very well with the recommended motor and prop combination.
  • Good performance with the Motrolfly ESC and Himax motor used in this review


  • After the wing tips were added to the wing panels, the box the glider came in couldn't be closed for storage with the wings inside.
  • Instructions/drawings could be clearer on a couple of issues. Hopefully my pictures will help.
  • No tow hook or mounting plate for tow hook was supplied

My thanks to Mac Powell for sharing his plane with us.

Last edited by Angela H; Sep 05, 2007 at 08:22 PM..
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Sep 06, 2007, 06:26 AM
Dr. Dave
Nicely done Mike. Your articles are always so complete. A model review to use the word loosely.
Sep 06, 2007, 09:43 AM
Registered User
Michael Heer's Avatar
Thanks for the very kind words Dave.
Mike H
Sep 06, 2007, 12:28 PM
"Have Glue - Will Travel"
dawnron1's Avatar
Great review, Mike!!!

Sep 06, 2007, 04:46 PM
Tu ne cede malis
MtnGoat's Avatar
Nice review. I'm super pleased with my C and it has gotten more air time at the slope than any of my other foamies since I picked it up. There's a build thread on the foamy kit forum for folks looking for tips.

I built mine as glider only using larger than stock S3102 servos because I have a lot of them, and I did not glue them in, I added basswood inserts as mounting blocks in all locations.

For the wing servos, the servo is located via the blocks and held in via small screws through the servo covers. I also left the fiberglass stiffening rods for the fuse the length they came and merely extended the channels they install in, may as well get as stiff a fuse as possible.

I also added a clevis at the rudder end of it's control rod so I can just unsnap the rod. I attach the rudder and winglets with tape, this way they remove easily and the box then holds the completed bird perfectly. Have had no issues with any of the taped surfaces, plain old 2" packing tape part of any foamy toolkit works fine.
Sep 06, 2007, 04:48 PM
The Reaper's Avatar

Motrolfy USA

hey micheal

nice review and im glad our esc and program card worked out for you . we are new and want everyone to be satisfied with our products and our service.

Sep 07, 2007, 01:04 PM
Registered User
OZZIE's Avatar
Picture DSC07387 shows no ventilation holes for the BL motor.
I am guessing there will be overheat failures for you in the near future!
Sep 07, 2007, 03:30 PM
"Have Glue - Will Travel"
dawnron1's Avatar
Originally Posted by OZZIE
Picture DSC07387 shows no ventilation holes for the BL motor.
I am guessing there will be overheat failures for you in the near future!
Look at pic # DSC07384. I see them as clear as day. If it's a Multiplex product, you can bet they've already incorporated adequate cooling into the design.
Sep 07, 2007, 03:56 PM
Registered User
OZZIE's Avatar
Hope so - time will tell, but axial flow-through cooling is much better than backside cooling shown here. I had overheat problems on my EasyStar - finally had to add cooling holes and scoops to force air over the esc..

I guess Multiplex didnt realize people would put more powerful BL motors on the Easystar - the esc got sealed into a foam chamber with no ability to remove heat!
Sep 07, 2007, 04:27 PM
"Have Glue - Will Travel"
dawnron1's Avatar

That is a very good point about the Easystar. I had one myself and you are right, there were no cooling holes for the ESC or battery for that matter. I ended up making a scoop for mine courtesy of a Dairy Queen Blizzard I think Multiplex has learned from it and improved cooling on the newer models. The Acro Master, Fun Jet, Easy Glider and Gemini all have an excellent cooling system.

Last edited by dawnron1; Sep 08, 2007 at 06:47 AM.
Sep 07, 2007, 08:30 PM
Registered User
Michael Heer's Avatar
Ozzie: You may have a point with some motor heads out there. I pretty much climb to altitude and go to soaring mode with the Cularis. If I feel a need for speed I will fly a different model. I have a couple that go 100+ mph in level flight. For my climbing and soaring the cooling has been completely adequate for the motor, ESC and battery pack per bench testing on timed runs. Mike
Last edited by Michael Heer; Sep 07, 2007 at 11:28 PM.
Sep 07, 2007, 10:37 PM
Slope and thermal
With a limited motor run glider you don't need cooling.
A 10 to 20 second motor run is followed by 5 to 10 minutes of motor off cooling time.

Also, the motor is typically run above its maximum continuous current rating. For 10 to 20 second motor runs, use the 30+ second burst rating on the motor. A 25 to 30 amp motor might have a 40 to 45 amp burst rating for 30 up to may be 60 seconds. See the manufacturers specifications sheet.
Sep 08, 2007, 12:06 AM
Electric Airplane Junkie
bhchan's Avatar

Glad to see you use a rx battery instead of BEC's and the explanation to the newbies are good.

What paint did you use? I was told Rustolium is better than others.

Brian, an EAJ
Sep 08, 2007, 06:41 AM
dalbert02's Avatar
Although this is not a plane I would purchase (I am not much into gliders) I was compelled to read the entire review. This has to be one of the best I have ever read. Plenty of pictures are always appreciated. I wish all reviews were of this high quality. A few magazines could learn something here. It seems like many magazines use a format that they just cut and paste the models name in. You know THE format, "The parts were individually wrapped and numbered", "The construction was better then I could have done myself", "The plane flew perfectly with just one click of (whatever) trim".
Thank you for such a great review,
Old Sep 08, 2007, 11:39 PM
$$$ in the bank
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