Frequently Asked Questions - 2010/02
Bob Aberle | [email protected]
Hinge tape
Q432: "I've noted quite often in your various construction articles that you recommend a hinge tape. This just doesn't seem practical for every model aircraft application. What are the limits when it comes to using a tape material as a hinge?"
A432: I have used tape as a control-surface hinge for a long time, but there are limitations and different tapes suit different applications.
- Fuel resistance: Very few tapes are fuelproof. That means hinge tape is generally restricted to non-fueled models—electric models and sailplanes.
- Size and weight: Tapes vary in flexibility and strength. Use a softer, more flexible tape on lightweight models so the servo doesn't work against a stiff hinge.
Two tapes I recommend:
- SR Gapless Hinge Tape (a 3M product supplied by SR Batteries Inc.): a clear, reasonably soft and flexible tape I use for models in the 8- to 48-ounce weight class. It provides a true gapless hinge when applied as one piece across the hinge area.
- Blenderm (a 3M medical adhesive tape): available in 1-inch rolls at drugstores and sold by Du-Bro as catalog item 916: Electric Flyer Hinge Tape. Blenderm is soft and flexible, works well on micro/indoor aircraft under 8 ounces, and has excellent adhesive qualities.
Application tips:
- Preparation: Hinge tape works best on hinge areas prepared with appropriate bevels for top hinging.
- Spacing: Proper spacing between the control surface and the main surface is critical. Too little space causes binding and restricts throw; too much causes flapping or vibration. I use scrap 1/16" balsa pieces as spacers and painter's blue masking tape to hold both surfaces on the building board. Remove the balsa scraps, apply the tape, and press it down thoroughly to get even spacing along the entire hinge.
Battery analyzer "wiggle" (Q433)
Q433: "I use a West Mountain Radio CBA-III Battery Analyzer and recently saw a funny 'wiggle' on the plotted graph. Do you know what caused this?"
A433: A similar graph artifact can be caused by a poor-fitting connector in the adapter cable being bumped during the test. I sent the scan to Del Schier at West Mountain Radio; he confirmed the likely cause. Make sure all connections are solid before testing.
AMA forums (Q434)
Q434: "I noted several months back in Dave Mathewson’s column that a new AMA Forum was being established. Can you tell me more about this outreach to the membership?"
A434: The AMA forums were being rolled out in late 2009. There are a couple of ways to access them from the AMA homepage:
- Top navigation: Under "Bringing Modelers Together," click the "Community" tab, then select "AMA Forums."
- Bottom of the homepage: Click the "FORUMS" link to open "Forum Navigation" (this is probably the better place to start).
When you first visit:
- Read and accept the forum agreement if you agree to the terms.
- Create a Username and Password. If you have trouble registering, contact AMA Information Systems for help.
If you need assistance:
- Click "Ask AMA" (top right of the homepage), then "staff directory."
- Scroll to the Information Systems department for names, phone extensions, and email addresses. The staff have been helpful in getting members onto the forums. Membership and participation will help the forums grow.
Q418 Follow-Up: Deans connector separation and Vaseline trick
Follow-up to Q418: I previously suggested using a clothespin to separate stubborn Deans Ultra connectors when both hands can't fit into an RC compartment. A reader offered an even easier method: apply a thin film of common petroleum jelly (Vaseline) to the connector blades, then insert and remove the connector halves a few times. The Vaseline works in and lubricates the contact surfaces, making separation much easier.
This method was reportedly originated by modeler Dick Allen (used during his time as a quality-control engineer at IBM) and is endorsed by Red Scholefield (AMA's battery columnist). A light application to the connector pins helps ease mating and separation.
Sources:
- Du-Bro
(800) 848-9411 www.dubro.com
- Sig Manufacturing Co.
(641) 623-5154 www.sigmfg.com
- SR Batteries Inc.
(631) 286-0079 www.srbatteries.com
- West Mountain Radio
(203) 853-8080 www.westmountainradio.com
- AMA
(765) 287-1256 www.modelaircraft.org
Transcribed from original scans by AI. Minor OCR errors may remain.
