A perfect marriage between a town and RC pilots
Greg Gimlick
maelectrics@gimlick.com
Approximately three years ago, a small group of park flyers in North Carolina approached its town council members about flying in one of the town parks. Doug LeRoy and Jason Guetgemann worked with the town and, with some masterful diplomacy, sold the town on the benefits of designating one of the park fields as an official model airplane field. The town has embraced the Holly Springs Skyhawks RC Group and supplied support for the club’s inaugural electric fly-in. The town invited the club to display a booth and staff the AMA Mobile RC Flight Experience flight simulator trailer for the town’s annual Holly Fest two years in a row! This is a prototype for any other club or town to follow.
Propeller Problem Solutions
Electric power is mostly trouble free, but it still has its own challenges when securing propellers to motors and shafts. Propeller adapters come in different forms and fasten to motors in a variety of ways, depending upon the design. Large motors often use a threaded adapter that bolts to the motor housing. The problem comes when the cowl is in place and you try to tighten the prop nut without being able to hold onto the motor to keep it from turning. The bases of the adapters usually have parallel flat surfaces, but there isn’t sufficient
clearance to get a wrench in to hold the motor. I did some searching and found a seven-piece Grip Super Thin Wrench Set on Amazon. The tools are 1/8 inch thick and range from 3/8 inch to 1 1/4 inch in size. On my big airplanes, I can remove the cowl screws, slide the
cowl back slightly, and slip the wrench into the gap to hold the motor while I tighten the prop nut. When it’s tight, I just slide the cowl back into position and replace the screws. If you can live with a 1/8-inch gap between the cowl and the spinner backplate, that’s not even necessary. The wrench set was approximately $25 and has come in handy more times than I can count. I love collet adapters, but I’ve recently run into a couple of situations where they have let me down. It seems some manufacturing tolerances have
slackened. For the first time ever, I’ve had a couple of them come off this year. I used to use them on the 5mm shafts on some of my hotliners and never worried about them, but something has changed.
I measured the shafts on the motors of my E-flite Convergence vertical takeoff and landing (VTOL) airplane and they were identical, but the collet adapters didn’t fare so well. Out of four adapters that I purchased from various sources for this size of motor shaft, two wouldn’t tighten enough to be fully trusted. After losing a propeller on the Convergence in flight, I didn’t want to repeat the incident.
My solution was to roughen the motor shaft slightly with a file and cut a couple of grooves into it. I then put some Loctite Formula 680 Retaining Compound on the shaft and slid the collet into place.
It was harder to slide it over the shaft, but that was the goal of roughening it up. Loctite Formula 680 is a high-strength compound, so it’s much different from the normal threadlocker compound you might be used to. It will take some heat to soften it when it’s fully cured, but the collet has remained solidly in place for dozens of flights since the repair.
The last tool to help with motor/propeller issues is a multiuse tool from BangGood. The jaws of the pliers open to accommodate a motor body up to 45mm in diameter. Around the inside of the jaws, you’ll see a series of hard, silicon pieces that grip the motor without damaging it.
Other features on the pliers include 5.5mm, 7mm, 8mm, and 10mm wrenches. The 8mm wrench in the center of the jaw assembly perfectly fits the hex nuts on FPV antennas. The tool is available in a smaller size, but I find this version fits everything in my hangar that I need it to. The tool was approximately $8.
Final Word
That’s it for the month. I hope a few of the tips I’ve shared here will come in handy. Thanks for the responses to the EC5 connector piece that I wrote about in the October 2017 issue. I had no idea that those connectors had tripped up so many of us.
