JC's Planes and Projects

 

Great Planes UcanDo3D .46 ARF

Specifications: 

Wingspan: 58 inches

Length: 58.5 inches

Wing area:  900 square inches (per Great Planes)

Weight: 5 lbs and 15 ounces.

Transmitter: Futaba 8UAPS

Receiver: Futaba 8-channel PCM

Servos: 4 x 3001 Futaba on flying surfaces, 1 x Hobbico standard for throttle, and 1 x 3010 Futaba high torque on rudder.

Power: Saito .91 four-stroke

Prop: APC 15 x 4 W

Features: Sullivan “head-lock” remote glow lighter, Dave Brown light 3” wheels and 2” Vortech spinner, 6V 1100mah RX battery.

 

My selection of the UcanDo3D .46 as my latest project was motivated by watching a fellow club member fly his 60-sized version of this same kit.  He had a Saito 100 for power with an APC 16x4 W prop and it hovered on partial throttle and had outstanding maneuverability.  It also landed slower than a butterfly with sore feet.  In short, watching Art D. fly his ship looked like so much fun I had to have one.

I was going to get the 60-sized kit, but I only had a Saito .91 available.  The word on the net was that a .91 was marginal for 3D in the .60 kit.  The 60-sized UcanDo (UCD) is a deceptively large airplane that would not fit in the back of my Saturn.  I do have an airplane trailer but I wanted the flexibility of throwing the airplane in the back of the car and just going.  I opted for the .46-sized UCD and it has turned out to be an excellent choice so far.

I had not built-up an ARF since my H9 CAP two years ago.  I had purchased that airplane as a close-out so it really reflects a state-of-the-art ARF of maybe five years ago.  The H9 CAP is a quality ARF, but it is also very much over-built by today’s standards – it is too heavy for its size.  Based on this experience, I was very pleased with the quality of the UCD.  I can honestly say that the UCD is every bit as good in quality, construction, and weight as something that I would have built from a kit.  The airplane is definitely designed to fly and not to crash.  It is lightly built but rigid.  And hey, if you do crash it Great Planes has all the parts available for purchase separately. 

I was also impressed with the quality of the covering.  It is all Monokote and is done in a scheme that I would have never attempted.  The Monokote needed very little shrinking despite being in my very dry house.  It isn’t perfect, but it is every bit as good as I could have done.  I was also impressed with the fiberglass cowl and pants.  Very good quality and pre-painted to match the covering.  The kit is also very complete with all hardware, a fuel tank, and wheels. 

Since I can’t leave well-enough alone, I made the following slight modifications. 

1.      I used my Saito .91 for power.  I did not fly my GP Giles G-202 at all last year.  It flew fine, but it is a bowling ball with wings.  I liberated the engine and electronics from this lovely airplane and returned it to a prominent position on the wall for “static display.”  The Saito .91 is reportedly marginal for the .60 UCD, so I decided to over-power the .46 UCD.  I did not expect any problems since the Saito is lighter than the OS .70 Surpass that the UCD .46 is designed for.  Of course Great Planes warns you not to use a .91 on this airplane and the use of this size engine voids the warranty.

2.      I upsized the supplied wheels to 3” Dave Brown light treaded types.  I fly off of a grass runway that can sometimes get a little long.  It seems like ARFs always come with dinky wheels that are impractical for grass L.

3.      I used a Sullivan Head-Lock remote glow lighter and a Great Planes Easy Fueler.  The cowl on this bird is tight causing the glow plug and fuel lines to be inaccessible.

4.      I used 6-32 nylon screws to hold the cowl on.  I just drilled and tapped the supplied wood mounting blocks to accommodate them.  The kit includes small metal screws that will most likely start chewing and cracking the cowl under vibration.  The nylon screws won’t come loose and won’t harm your cowl.

5.      I purchased a Dave Brown Vortech 2” spinner and had them custom-cut it for the APC prop.  This is my third Vortech spinner and I like them.  They are excellent quality, custom-cut, quickly delivered, and inexpensive.  They are a great value.

6.      I used a 6V, 1100 mah battery for faster servo response and more torque.

7.      I did additional fuel-proofing.  Amazingly, the kit did come with the firewall and other exposed areas fuel-proofed.  I beef-ed it up with a heavier coat of Z-poxy.

8.      I used a Dubro cable assembly for throttle actuation.  The cable is more easily snaked around in that tight nose.

9.      I used Dubro heavy-duty long servo arms as recommended for 3D in the back of the manual.  The longer arms will get you the 3D throws you desire!

10.   I attached the canopy with six small screws left over from the hardware pack.  The canopy is large and I saw no point in gluing it down.  Being removable will allow me to clean the inside if it gets too dusty. 

Anyone with a little building or ARF assembly experience will have no trouble putting this bird together.  In fact, I spent most of my time cutting and fitting the cowl.  As I mentioned before, this is a tight cowling.  Yes, it is nice and streamlined, but not removable without some work.  For instance, the muffler header basically locks the cowl on.  To get the cowl off, you have to remove the muffler and header.  This means you have to align access holes for everything – muffler, high and low needles, easy fueler, remote glow, mounts, pressure line, and crankcase breather.  I got pretty good at it after a while J.

I have been a fan of Dubro and Sullivan fuel tanks since I built up my first Kadet trainer.  I have never had one fail.  It was my habit of replacing ARF fuel tanks on past projects like the H9 Cap and Model-Tech Sukhoi.  I intended to do the same on the UCD, but it is not really possible.  The nose section is essentially designed around the included fuel tank!  Yep, the formers fit right around it and the cap pokes right through the firewall.  I assembled and pressure tested the tank and found it to be sound so I used it.  I really did not have choice.

Once everything was assembled and installed it was time for the “balancing act.”  The first attempt was with the battery placed rearward as shown in the assembly pictures.  It came out tail-heavy.  I ended up having to place the battery as far forward in the fuse compartment as possible to get near the specified CG of 4.75”.  This is just the effect of the light weight of the Saito compared to the OS 70.  An addendum states that the airplane is controllable as far back as 6” from the LE.  However, the 3D tips section as written by “two-time IMAC Freestyle Champion” Mike Cross states that he likes the 4.75” position the best.  Hey, that’s good enough for me!  If you do use a lighter engine like an OS .46 FX, new OS .70 “Ultimate”, or Saito .72, you will most likely have to place the battery up in the fuel-tank compartment to avoid adding lead.

I was very pleased with the way the UCD looked but what about the weight?  I hung it from a Stren digital fish scale and read 5 pounds and 15 ounces.  Wahooo!  At less than 6 lbs with a Saito .91 this thing will be a hovering fiend – once I learn how to hover that is J.  The low-pitch “wide” APC prop will be used initially.  I know that Art liked the 16x4 W version for his Saito 100 .60- sized UCD.  The prop is like a paint stick the pitch is so minimal. 

Summary:  A great quality, great looking airplane, assembles fast and easy - go out and get one and I’ll see you in the Spring!    

Flying the UCD

1/16/04 – Well, we have seven inches of snow outside and more coming tomorrow.  I won’t have a flight report for a few more months! 

 

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