VQ Warbirds T-34C Turbo Mentor

Written by Terry Dunn Fly the popular Navy trainer Product review As seen in the November 2017 issue of Model Aviation.

Bonus Video

Specifications

Type: ARF warbird Wingspan: 61.4 inches Wing area: 623 square inches Length: 46 inches Radio: Futaba 14SG 2.4 GHz transmitter; Futaba R7008SB receiver; two Futaba S3152 standard digital servos; four Futaba S3150 digital mini servos Needed to complete: Power system; radio gear; basic assembly tools Minimal flying area: Club field Price: $239.95

Test-Model Details

Power system: Electrifly RimFire .46 brushless motor; APC 11 x 7E propeller; Castle Creations Phoenix ICE Lite 75 ESC; Pulse 5S 4,500 mAh 35C LiPo battery; Castle Creations BEC Pro Power output: 59.5 amps, 1,152 watts Power loading: 135 watts per pound Flying weight: 8.5 pounds Wing loading: 31.6 ounces per square foot Duration: 7-plus minutes

Pluses

• Great scale looks with panel lines and rivets. • Powerful warbird flight performance. • Parts are included for glow or electric power.

Minuses

• Some assembly steps are challenging. • Modifications are required to install the optional retractable landing gear.

Product Review

The T-34 Mentor is an unsung hero of our military arsenal. Since it was introduced in the mid-1950s, the Mentor has been used by the US and several allies as a trainer and general support aircraft. There is even a light-attack variant. That’s quite impressive for an airplane based on a civilian design: the venerable Beechcraft Bonanza. Early T-34 airplanes were powered by a 225 hp, six-cylinder piston engine. A more powerful turboprop version, the T-34C Turbo Mentor, was designed in 1973. Examples of this aircraft can still be found in U.S. Navy hangars. The VQ Warbirds replica of the T-34C is a balsa and plywood ARF with a wingspan of slightly more than 61 inches. It can be powered with either an electric motor or glow engine. It certainly captures the look of a T-34C. Right out of the box, it has many interesting features and unique scale details.

Assembling the T-34C

This model provided my first inside look at a VQ Warbirds product. The kit has a lot to like. Not only are the wooden components pre-covered with iron-on film, but the covering has printed insignia, panel lines, and rivets. Those features alone provide a tremendous boost to its scalelike appearance. The covering on my kit did not have any wrinkles or loose areas.

The VQ Warbirds T-34C is a balsa and plywood ARF with nicely built components and great scale details.

At the risk of spoiling the ending, I’ll tell you now that this kit produces a great-looking and terrific-flying model; however, my path to that outcome was not always smooth. Although the factory-built components are quite sturdy and well made, integrating those pieces occasionally required slight improvisation. I’ll point out the problem areas in my rundown of the assembly process. Most modelers who have previously assembled ARFs will be able to recognize and work through these hiccups. Assembly begins by installing the aileron and flap servos. The manual specifies full-size servos for the ailerons, but the mounts are sized for mini servos. I used four Futaba S3150 mini digital servos. They fit the factory cutouts perfectly. I found it easiest to mount the servos with the output shafts located away from the hinge line. The provided pushrods attach to the control horns with a threaded metal clevis. An EZ connector is used on the servo side. I’m not a fan of EZ connectors, so I put a Z-bend in each of the pushrods with my Hobbico Z-bend pliers. The resulting linkages are strong and slop free. The kit includes fixed landing gear with simulated gear doors that provide a nice, scalelike touch. VQ Warbirds offers a set of retracts specifically designed for the Turbo Mentor. I installed the retracts on my model. These are nice-looking units with functioning oleo struts. The gear requires some assembly. No instructions are included, but the steps are intuitive. I suggest filing flat spots on every shaft that interfaces with a setscrew. Be sure to use threadlocker on all of the machine screws as well. I had to perform a few tweaks to the airframe for it to accept the retracts. The openings for the wheel wells in each wing were slightly small. I used an X-Acto knife to cut through the wing sheeting and elongate the openings by roughly 1/4 inch. A plywood rib within the wheel well prevented the main wheels from fully retracting. A similar issue affected the nose gear. I simply sanded away the problem areas with a sanding drum in my Dremel tool. The tail feathers are glued into factory-cut slots in the fuselage. My example came out perfectly square, with no shimming required. The elevator and rudder horns are held in place with snap-in keepers. The manual instructs you to add CA glue to the keepers. I’ve seen similar control horns on park flyers, but never on a model as large as the T-34C. I was concerned about the durability of this setup, but it has worked perfectly so far.

Removing the large fuselage hatch provides open access to the roomy radio compartment. Note the plywood shelf that the author added to relocate the flight battery more rearward.

I used Futaba S3152 full-size digital servos for the rudder and elevator. I again used Z-bends in lieu of the EZ connectors. I did, however, use an EZ connector for the nose wheel steering linkage. All of the servos are wired to a Futaba R7008SB receiver with a Futaba 14SG transmitter. Each of the wing panels slides over a tubular aluminum spar and is secured to the fuselage with a single bolt. When I initially inserted both wing panels onto the spar, there was a significant gap between the wing roots and the sides of the fuselage. I shortened the spar by 1/4 inch with my band saw to remedy the issue. Mounts are included for using either a glow engine or an electric motor. A fuel tank is also provided. The glow engine mount uses a pair of nylon beams that bolt to the firewall with the engine horizontally oriented. A .46 two-stroke or .70 four-stroke engine can be used. I decided to go with an ElectriFly RimFire .46 brushless electric motor and an APC 11x7E propeller. The electric motor mounting system is simple, but also tough and infinitely adjustable. Four 100mm-long 6mm bolts protrude through the firewall. A plywood motor mount is fastened to these bolts. The exact placement of the plywood mount is determined by adjusting nuts on the 6mm bolts. It took me a few tries to tweak the motor’s position so that it properly interfaced with the fiberglass cowling, but the result looks great. The motor is controlled with a Castle Creations Phoenix ICE Lite 75 ESC. I was concerned that this ESC’s built-in BEC would be overtaxed by the demands of powering six digital servos and three electric retract units, so I used a Castle Creations CC BEC Pro connected to the flight battery to power all of the onboard radio gear.

The Turbo Mentor can use an electric or a glow powerplant. The author used a RimFire .46 brushless motor paired with a Castle Creations ESC.

The flight battery is a Pulse Battery five-cell 4,500 mAh LiPo. I appreciate that the battery comes with pre-tinned power leads. Adding a Deans Ultra Plug connector was a snap. Just as valuable to me, I found that all of the stickers are placed beneath the battery’s outer shell of heat-shrink tubing, rather than outside of it. This makes it easy to securely attach self-adhesive hook-and-loop tape. The cockpit area is outfitted with a single pilot bust and instrument panel details. It looks nice and there is room to add more details. This kit also includes scale features that help differentiate the Turbo Mentor from earlier variants. Large exhaust stacks for the turboprop engine are attached to the cowling. Other features specific to the T-34C include ventral fins on the bottom of the fuselage and strakes on the horizontal stabilizer. These accents add to the model’s overall appearance. I attached the parts using Pacer Formula 560 canopy glue. My initial balance check indicated that the T-34 was going to be significantly nose-heavy. I decided to fabricate an extension to the battery tray that allows me to locate the battery approximately 3 inches rearward. I cut a simple rectangle from 1/4-inch light plywood and attached it to the stock battery mount with a combination of 30-minute epoxy and wood screws. The battery is held to this mount with hook-and-loop tape as well as a strap. With the battery in this modified location, I still had to add 11/2 ounces of ballast to the tail to achieve the suggested center of gravity location. My completed, ready-to-fly Turbo Mentor weighs 81/2 pounds.

These plastic strakes are a nice scale accent for the T-34C. Masking tape holds the parts in place while the canopy glue used to attach them to the model dries.

Flying the Turbo Mentor

All of my flights with this model have been from a grass runway. As you would expect from a model with tricycle gear, it tracks well and is easy to handle on the ground. The power system has plenty of pull to get the T-34C quickly up to flying speed if you want, but gradual, scalelike takeoffs look better. After it is in the air with the landing gear tucked away, the Turbo Mentor cleans up nicely. It might look like a trainer, but it flies like a fighter! This is not an aircraft for inexperienced pilots. The model has a good combination of speed and vertical performance. My T-34C even cuts through the air with a great-sounding whistle! I found the suggested control throws to be too sedate for my taste, especially the ailerons. I reprogrammed them to have 3/4 of an inch of throw on high rates, and 3/8 inch on low rates. I applied less dramatic increases to the elevator (9/16 inch on high; 3/8 inch on low), rudder (13/4 inch on high; 1 for low), and flap throws (9/16 inch for half; 11/8 inch for full). The T-34C likes to be flown fast. It feels solid and tracks well. High-rate aileron rolls are quick and axial. Low-rate rolls require only a little elevator correction. The RimFire .46 motor pulls this model through large, round loops and tall Hammerheads. Vertical performance is good, but not unlimited. There’s plenty of pull on tap for any type of warbird maneuver you can dream up. Rudder authority is sufficient for Hammerheads and stall turns. I can’t quite get the T-34C to do knife-edge flight, but long, banked photo passes are a thing of beauty. I’ve been setting my timer for 7-minute flights and finding that I still have quite a bit of reserve power when I land. I will continue to expand my flight time comfort zone.

This might be a model of a trainer, but it has the performance and handling of a fighter!

I prefer to take off with half flaps. The Turbo Mentor simply flies itself off of the runway. When it comes to landing, I might choose either flap setting, or none at all. It all depends on how much wind is blowing down the runway. Calm days call for full flaps to help slow my approach and shorten the rollout. The internal rods of the main landing gear are slightly soft and can bend rearward during landing on rough runways. The good news is that they can be bent back into place without disassembly.

Final Approach

Despite a few minor challenges during assembly of the T-34C, I’m happy with the finished product. My only gripe with its appearance is its elevated stance on the landing gear, but that’s a trifling (and possibly correctible) issue. The VQ Warbirds Turbo Mentor T-34C is really at its best in the air. Not only is this model fun to fly, but it has a great look, a great sound, and a powerful presence when it takes to the sky. —Terry Dunn [email protected]

Manufacturer/Distributor:

VQ Warbirds [email protected] www.vqwarbirds.com

Sources:

Futaba (800) 637-6050 www.futabarc.com Castle Creations (913) 390-6939 www.castlecreations.com Pulse Battery (978) 206-6037 www.pulsebattery.com