Q-talk 6 - ODDS and ENDS
- Category: Q-Talk Articles
- Published: Saturday, 31 October 1987 06:11
- Written by Jim Masal
- Hits: 2005
Ralph Bradshaw keeps adding neat things to his composites product line. Now he has simple vacuum bagging supplies, West System epoxy and an effective, light firewall barrier. Write for his latest catalog: Alpha Plastics, 8734 Daffodil, Houston, TX 77063.
Scuttlebutt has it that Hexcell is developing a new epoxy to replace Safe-T-Poxy. It is reportedly less viscous, has better physical properties and less toxicity. Expected out in mid-88, it may come with total removal of Safe-T-Poxy from the marketplace.
Ted Fox sent this from Sport Pilot magazine: "A Dragonfly Mark II aircraft has experienced a case of elevator flutter at 140 mph in turbulent air. The flutter ceased as the aircraft slowed down and was landed safely." Movement was found "in several places in the control system where a tube is fitted within a tube and secured there with an AN-3 bolt." Viking Aircraft is designing a new control system to eliminate tube-in-tube joint to preclude flutter from this source.
All Q aircraft have tube-in-tube joints also. Some inexperienced builders while learning to drill nice, straight holes for the AN-3 connecting bolt have boogered up some holes and do not have a tightly fitting AN-3. With time, this will result in control "slop" and presto - flutter. Inspect controls before flight. Remember, if you have so much as only 1/32" play in each of 4 joints to an elevator, for example, the result will be 1/8" in the stick. GET THE SLACK OUT. Re-drill, replace tubes or consider taper-pins to replace the bolts.
COMPOSITES FOR MR. MEGABUCKS. While the all-composite Learfan project fizzled, Beech Aircraft has 3 Starships flying to complete FAA certification by Christmas with first customer deliveries in late '88. They've already ordered sets of vendor components for the first 50 aircraft. Beech is using 3 custom built C-scan devices to inspect fuselage and wing sections for voids and other flaws. The devices use a fluid-generated pulsed ultrasonic wave to detect faults, which are displayed on a seven color CRT. The wing scanner checks every point along the wing's span at 2-mm intervals and 4-mm intervals across the chord. Inspection of each half of an upper or lower skin takes 5 hours.
From Ted Fox, Mansfield, OH
Avgas may deteriorate some materials used in auto fuel filters. Test it before you use it!
From Bernie Pohl, Pine Bush, NY
New digital scale suitable for precision epoxy weighing is available from US General Tool Supply, Plainview, NY. It weighs in oz. or grams, 1-1000 grams, accuracy to 1/10th gram and costs $39.95. It runs on 5 AA cells, displays with an LCD and has a zero tare setting to eliminate the weight of the cup. Mine works great!
You can order a PDF or printed copy of Q-talk #6 by using the Q-talk Back Issue Order Page.