Specifications Wingspan: 36" Wing Area: 346 square inches Length: 27" Weight: 13.5 ounces with an 8 cell 270 mah NiCad battery Wing Loading: 5.6 ounces per square foot. Motor: Great Plains T-280 with 4 to 1 gear box or any 280 size electric motor with 4 to 1 gear box. Prop: 10x4.7 APC slow flyer prop Speed control: Great Planes ElectriFly C-10 10 amp electronic speed control: http://www.electrifly.com/gpmm2000.html Battery: 8 cell 270 mah NiCad battery. Manufacturer: Great Planes. Price: $39.95 Website: http://greatplanes.com/airplanes/gpma0005.html

The Li'l Poke by Great Planes is a Speed 280 class parkflyer that was scaled down from the larger Great Planes glow powered Slow Poke designs. Styled with a fun retro vintage look and the low aspect ratio wing concept popularized by Andy Clancy and his classic Lazy Bee designs, the Li'l Poke gives a you a charismatic compact model with lots of wing area and exceptional maneuverability in slow flight. This model features a neatly done rubber band sprung landing gear that resists crash damage. It can be built with or without ailerons for 3 or 4-channel operation. There had been some discussion around Ezone that the model did not turn well on the smallish inboard ailerons, so I opted to build the stock aileron wing to research this for the review.

The Li'l Poke uses classic built-up balsa construction with a good number of high quality laser-cut parts to help with accurate and speedy construction. Lightweight wheels, pre-formed landing gear, lightweight pushrods and control horns are all included in the nicely packaged kit. I resisted the strong and highly common urge that all modelers have to modify and change things and built the model very close to stock for the purposes of this review. Great Planes supplied the Li'l Poke kit, a CS-5 Nano servo, an Electrifly C-10 electronic speed control, a T-280 Speed 280 class motor, a 4 to 1gear box with prop adaptor, a 7 cell 550 mah NiMH battery pack and a 10x4.7 APC slow flyer prop.

Li'L Poke kit contents. Items supplied by Great Planes for the review.

Construction

Construction is easy and swift, using CA glue throughout. It does take a few nights longer to build, cover and equip than a typical ARF or foam model. It is worth noting here that the plans and the highly detailed 24-page construction manual are extremely good, very comprehensive and of a quality seldom seen in the world of park and slow flyer models. (You can view the construction manual by downloading a .pdf version here: http://www.greatplanes.com/manuals/gpma0005-manual.pdf) The wood supplied in the kit was unusually high in quality for a mass produced kit. Some of the 1/8" square stock that is used for the tail surfaces and stringers on the fuselage were a bit too soft and that would be the only complaint from this reviewer about the wood. The laser cut parts were of very high quality and include wing ribs, wing tips, fuselage sides, the upper part of the fuselage formers, the firewall, the wing dihedral braces, the control horns and a few other small odds and ends. Lets move on to the building board.

Tail surfaces

Tail surfaces, framed up and ready to install.

The tail surfaces are built first from 1/8" square balsa stock. The only slightly unusual part is that Great Planes has you put together a large number of short 1/8" balsa strips to create the well-rounded outline of the tail shapes. You might find yourself wishing as I did that they had figured out a way to laser cut the curved shapes of the tails, as there is a lot of cutting and fitting here. In any case, the tail surfaces are soon complete and sanded to true the surfaces and round the edges.

Wing assembly

Wing, ready to cover.

The wing comes next and you get to use some of those excellent laser cut parts when you install the ribs. I opted to build the aileron-equipped wing, which is only slightly more complex than the non-aileron wing. The flat center section of the wing is built first and the two wing tips come next. The wing has a strong warp resistant four-spar design, with 1/32" balsa sheer webbing installed between the two front spars. Laser cut dihedral braces makes attaching the outer wing panels very easy. The 1/8" dowel wing leading edge adds a nice measure of ding resistance to the wing. One unusual part of the wing construction was that the LE of the ailerons, and the wing trailing edge where they are hinged to, have no wood between the upper and lower surfaces of the parts to close them out. I built mine stock, but if I were to build another one, I would add a small amount of 1/32" balsa in this area. The plans and instructions have you create your strip aileron linkage and pushrods from scratch, using supplied 1/32 inch wire and 1/16 inch aluminum tube. This works out all right, but does require a good bit of very careful wire bending and cutting. The resulting ailerons and linkage are not as stiff as I would like, but seem adequate for typical park flyer speeds. Great Planes also supplies a laser cut plywood aileron servo arm that you glue to your existing servo arm. It is crucial to use this part so that you get enough aileron differential for the ailerons to be effective. This modified servo arm gives near 100% differential. After the wing was complete, I gently block sanded the entire wing, with special focus on all external glue joints and the dark laser cut edges, to prepare the wing for covering.

Fuselage and final assembly.

Framed up fuselage with tail surfaces ready to install. Fuselage with tail surfaces attached. Construction complete and ready to cover.

Now it is time to tackle the fuselage. First, you create the lower part of the fuse formers from more of that 1/8" balsa strip. While the fuselage sides are laser cut, you must hand cut a gently curved top deck for the fuselage from 1/32" balsa sheet. It would have been nice to have this part laser cut, but it still goes pretty quickly. The fuse is assembled upside down over the plan and it is easy to get a nice square fuselage using a builder's triangle and pinning the parts into place on the board. The bottom of the fuselage gets sheeted while attached to the board, which also helps to keep everything square. Once this is done, you remove the fuse from the plan and add the upper laser cut fuselage formers. It is then time to add the horizontal and vertical tail surfaces to the fuse, followed by all the 1/8" square stringers on the fuselage formers that fair in all the way back to the hinge line of the vertical tail. I did it per the instructions and had no real trouble covering it later. After a little sheeting on the top of the nose and around the cockpit, the fuse is ready to sand and prep for covering. Before covering, I test fitted the entire model and ran into one small problem. The small rubber bands supplied for the landing gear were crushing the light 1/32" balsa fuse side between the dowel and the small plywood plate on the bottom of the fuse. I took the landing gear back off, and rebuilt that area, adding a small 1/16" balsa doubler on the inside of the fuselage between the forward wing dowel doubler and the bottom of the fuse. This cured the problem nicely.

Covering

Even though the kit suggested covering the model with Coverite CoverLite (Same as LiteSpan), I opted to use Nelson LiteFILM (same as Solarfilm SoLITE) covering. This is just like very thin, low temperature MonoKote, with no extra adhesive required. At .6 oz per square yard, it is very light, and is a little lighter than the CoverLite before adding adhesive to the model. Since the Li'L Poke had a certain vintage trainer look about it, I chose dark blue and yellow LiteFILM to create a sort of USAAF 1940's primary trainer look. The local hobby shop had some prewar USAAF roundels, so I was all set to give my Li'l Poke a PT-19 style finish.

Here is the Li'L Poke covered and ready to go in PT-19 style. Another view of the covered Li'L Poke.

This was my first experience with LiteFILM and I had no real trouble adjusting to it after 30 years of using MonoKote. It does shrink a lot when heated and does a great job of taking out wrinkles and going around wingtips and compound curves. I did over-shrink the tail covering and created an unwanted scalloping of the edges of the tail surfaces. I removed the problem areas of the covering and replaced it, shrinking with more care this time. I did discover that you did not want to let the covering touch adhesive side to adhesive side through the 1/8 inch tail surfaces. It would seal itself together and create a real problem. Later I re-read the LiteFILM instructions and found that they suggest coating the adhesive side of the material with a light dusting of baby power to help keep it from sticking to itself. This I will try on my next covering job with LiteFILM.

I gave the exposed wood in the cockpit and engine area a coat of black water-based acrylic paint. One detail still left after covering was to install the tailskid. I was not inspired by the clunky scrap balsa tailskid mounted on the bottom of the fuse as shown on the plans and opted for a 1/32" music wire steerable tailskid attached to the rudder, instead. This is working fine for now, but I will probably add a wheel to the assembly in the near future for better ground control. It is now time to hinge the control surfaces, which is quickly accomplished using Scotch brand Crystal Clear tape. The lower part of the rudder also uses a small CA hinge, as the tape would not work well in that location. The aileron torque rods are then glued into the inside of the ailerons.

Radio and power plant installation

Inside the roomy Li'L Poke fuselage: Note the Hitec Electron 6, the Hobbico CS-5 servos and the Great Planes ElectriFly 10 amp ESC.

After covering, it is time for the radio and power plant installation. I installed the suggested Hobbico CS-5 servos in the fuselage for rudder and elevator control. Although the plans suggested using double-sided foam tape for the servo installation, I opted for some hard balsa servo rails and screwed in the servos. It was simple and quick to create the 1/16 inch aluminum tube and 1/32" wire pushrods from the material supplied with the kit. I had a spare Hitec HS-55 servo that was put to use for the ailerons. I installed it as directed in the wing and added the laser cut 1/32 inch plywood control horn by sanding the upper surface of the stock control horn and using a generous amount of medium CA glue to attach it. After installation of the servo and new horn, the ailerons had lots of throw and nearly 100% differential. A command for aileron would give nearly 3/4 inch up aileron travel and 1/16 inch or less down aileron travel. With that kind of differential, there should be no adverse yaw on this model.

While at the local hobby shop getting the last few items needed to complete the Li'L Poke, I noticed that they had the new Hitec Electron 6 receiver in a Futaba version that matched my Futaba 8 channel radio. This is a new 6-channel dual conversion unit that is a little smaller and lighter than their venerable 555 micro receiver. It has a clear blue case that matches the Hitec HS 50 and HS 55 servos. It was advertised as weighing about 17 grams without the crystal and 14 grams without the case. On my scale, it showed 18.1 grams with case and crystal and 13.9 grams with no case. I thought the Li'l Poke deserved a nice new receiver and bought it on the spot. It was easy to Velcro the new receiver to the inner top surface of the fuselage, as shown in the installation picture. Great Planes supplied an Electrifly C-10 Micro Ultra High Frequency ESC for this review. It was velcroed to the side of the fuselage, next to the battery area of the model. I added a 6" Futaba aileron extension to the receiver to make it easier to install and remove the wing, which has to be done every time you change the battery pack.

I assembled the Great Planes supplied T-280 motor and 4-1 gearbox. The gearbox is one of the higher quality types for Speed 280 use and includes metal bushings instead of cheap plastic bushings. The gearbox includes a spur gear and a tiny container of locking adhesive for you to use when you put the spur gear on the shaft of the motor. I did this per instructions with no problems. The 10 x 4.7 APC slow flyer prop was picked for initial flights and mounted on the nice MP Jet collet-style prop adapter that Great Planes markets under their own name. After building up the motor, gearbox and prop, it only takes a moment to install it in the nose of the Li'l Poke using the three screws provided in the kit. One nice feature of the Great Plane electric flight components for their park flyers is that they come pre-wired with BEC type connectors and they are "plug and play". I happened to have an 8 cell 270 mah NiCad battery pack handy and I opted to use it for the first flights.

I plugged everything in, turned on the transmitter and did the normal routine of checking servo travel direction, servo throws and the function of the speed control. The Hobbico CS-5 servos worked as advertised, the little Electron 6 receiver was working great and it was time to test the speed control. I thought I had a problem at first and I could not get it to turn on, even though it was working my servos and receiver nicely. After reading the instructions, I discovered that it needed a careful movement of the throttle stick from idle to full throttle to idle again, before it would work. I wish that the C-10 could store that routine, because you must cycle the throttle like this every single time you plug in a new battery pack. Great Plains touts this as a safety feature, but I think it would be better and more user friendly if it remembered it for you or if you did not have to do it at all, like most of my other electronic speed controls. As all was working well now, I was ready for the first flight. The windscreen and pilot figure was not yet in place, but that could wait for a bit.

First flights

The Li'l Poke is easy to fly in close. Cruising by the author, low and slow. Showing off the Li'l Poke's classic lines.

I completed the model just before DEAF 2002, with the exception of installing a pilot figure and a windscreen. The Li'L Poke made its first public flight Saturday afternoon at DEAF, to a number of nice comments. My good friend Paul Willenborg was present and did a fine job of capturing the Li'l Poke cavorting in the air that fine October afternoon.

I found the Li'l Poke to be a pure pleasure to fly. With its light weight, low aspect ratio wing and low wing loading, it will turn on the proverbial dime. Loops and wingovers and barrel rolls were no problem, but true axial rolls do not seem to be its favorite type of aerobatics. The 8 cell 270 mah NiCad battery gives a flight of 6-8 minutes at various power settings. Takeoffs and landings can be a bit tricky and prone to ground looping, due to the forward position of the main landing gear. It might be worth bending it back to a better location. Sometimes, in a really tight turn, the Li'l Poke is very near a stall and the ailerons will not lift the low wing without reducing the elevator input. The rudder will almost always lift the low wing in a very tight turn, so keep that in mind.

I wasted no time in exploring how it turns on ailerons alone. I found that it does just fine on the ailerons, but remember: I put in every bit of differential that I could. I could easily see that if someone did it their own way and used a normal servo arm on the ailerons that did not give differential, it would not turn well at all. Nevertheless, it must be said that with that wing design, it actually does turn just a little bit tighter and better using rudder. I plan on doing some experimenting with coupled aileron-rudder mixing and feel that that will eventually give the best results of all. If you do build a Li'l Poke, go for the ailerons and use the near 100% differential. I personally think it is worth it.

Circling the field on an afternoon patrol. The Li'L Poke making a late afternoon fly by at DEAF 2002. The Li'L Poke in the sunset at DEAF 2002.

What I enjoy the most about flying the Li'l Poke is the slow cruising flight at about half throttle, just making laps around the field and making a low fly by, or a touch and go. This model is just plan fun to build and fun to fly.

After DEAF2002, I added a little bit of decorative trim, the missing windshield and a very lightweight pilot (a Hangar 9 1/10 scale Sportsman pilot works very well if cut off at the upper shoulders).

Here is the Li'l Poke with the final details added.

Conclusion

Things I really liked about the Li'l Poke:

• The delightful flight performance, especially on the recommended motor, gearbox and prop.
• The plans, instructions and overall design.
• The laser cut parts, the quality of the wood and the quality of the Great Planes electric flight components.

Things I did not like as much: (This is minor nitpicking here)

• There are a few weak spots on this model. If I built another one, I would add a few grams of extra wood in the following places:

  1. 1/16" doublers inside the fuse between the landing gear mount and the front wing dowel.
  2. A 1/32" doubler along the wing saddle.
  3. A 1/32" doubler along the top edge of the fuselage sides ahead of and behind the top deck of the fuse that creates the top of the radio compartment.
  4. The horizontal tail needs a bit more strength where it meets the fuse.
  5. The hinge line at the ailerons would benefit from being filled in with 1/32 balsa.
  

• The balsa tailskid is an obvious afterthought that is not up to the quality of the rest of the model. It needs to be replaced.
• Battery access is by removing the wing, which can get a little bit tiresome.

Overall, these are pretty small problems and do not really detract from the models great points.