Dave Smith’s Blog

If you want to give your ParkZone T-28 Trojan unlimited vertical flight for under $30, today is your lucky day. Just head over to hobbycity.com, and pick up one of these Turnigy 35-36C motors.

Here’s what you’ll need to do the upgrade:

1. The new motor (duh)
2. A Phillips-head screwdriver
3. An everyday drill and an ordinary drill bit
   (not sure of the drill bit size — you’ll figure it out)
4. A new prop (I use an APC 10×3.8). The stock prop’s shaft is too wide for this motor’s prop adapter

You may be asking:

• Do I need a soldering iron? No.
• Do I need to cut some wood or aluminum for a firewall? No.

Here’s what you do:

1. Unscrew the three screws that secure the cowling to the nose of the plane
2. Unscrew the four screws that hold the plastic motor mount to the firewall
3. Disconnect the three motor wires (red, yellow, and black)
4. Unscrew the motor from the motor mount
5. Use the cross mount thing that came with the motor to pencil in the 4 new holes you’ll be drilling
6. Drill the holes (be sure to use a drill bit that is the same size as the old holes
7. Screw the motor on to the mount, connect the wires, and put the whole thing back on the plane
8. Hold the plane straight up, power it up to full throttle, and release
9. Watch it fly straight up to the clouds like a friggin’ rocket

Here are some photos of my (not so) handiwork:

This is what it looks like when it’s done. The motor isn’t quite as long as the stock motor, so I tossed a nut on the shaft before I put the propeller on. Without that nut, the prop would be rubbing on the cowling.

Here’s the motor bolted to the stock motor mount. I was in the process of screwing in the 4 mounting screws when I took this.

Here’s where I drilled the 4 new holes for the new motor (circled in blue). The new motor has two holes that are perfectly spaced to line up with the stock motor mount, but the other two holes are actually closer to each other, so you have to drill. I opted to drill 4 new holes, but you may get away with using just two of the stock holes, or even drilling only 2 new holes. I wasn’t quite willing to trust that, and after seeing just how much torque this motor provides, I’m glad I didn’t.

You may also notice in the photo above that this motor has a really weird prop adapter. Rather than tightening on to the shaft, it actually screws onto the bell of the motor. Notice that the motor has a shaft that extends out the aft side of the motor (if you wanted to mount it in reverse). I’ve never seen that in a motor before, but I like it. It seems much sturdier with 4 screws on the bell than a single set screw or “clamp” style prop adapter fastened to the shaft.

The Results

I took it out to the flying field today and did my usual hand launch. Except this time I only launched it using half throttle. It flew out perfectly. After a couple seconds, I punched it up to full throttle and aimed the nose at the clouds. It flew perfectly vertical for a good 5 seconds, showing no signs of slowing down. It was awesome. I was flying huge loops, square loops, vertical rolling ascents. It was great.

The Electronics

I used the stock speed controller (ESC), but I also have a ParkBEC because I don’t trust the stock ESC’s integrated BEC at all, having heard lots of horror stories about it. The stock ESC showed no sign of overheating, though it was about 45 degrees F outside. The motor stayed cool too.

I used a new Zippy 2200mah battery from hobbycity.com. It did great too. No signs of overheating. It came down just barely perceptibly warm to the touch. Within seconds, it had cooled to room temperature. This was the first flight of the new Zippy battery.

My Watt’s Up tells me that the 10×3.8 prop makes this motor pull exactly 30 amps. That’s a lot of amps for this ESC, so I also bought a SuperSimple 50A ESC from hobbycity.com, which I have not installed yet. I may wait to see how the stock ESC performs for a while, because I just don’t want to solder all that crap again (including the ParkBEC).

Bottom Line

This motor is awesome. I plan to use the T-28 as an Aerotow plane soon, so this motor will give me exactly the torque I need. The plane is still quite a slow flyer compared to my Stryker, but even though the T-28’s top speed is lower, it has better vertical.

This entry was posted on Saturday, November 22nd, 2008 at 7:44 pm and is filed under RC Planes. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.