FLUKI

By L. S. STUBLER EAA 40542 RD 4, Box 438

Montoursville, PA 17754 A neat inclinometer (slip/skid indicator) can be made by purchasing and modifying Edmund Scientific's

Lev-O-Gage® 11, Catalog No. Y36, 612, $11.95 plus $4.50 S&H (see photo). The instrument is prominently marked in 1 degree increments to a maximum of 10 degrees each side of center. It remains functional from O degree F. (freezer tested) to 120 de-

grees F. (oven tested). Modification is not absolutely necessary but a more attractive and compact (3-1/2" W x 1" H x 3/8" D) instrument can be had simply by cutting off the top, leaving just the calibration marks and the level vial. Dress off the top with a thin piece of plastic or plywood, sand smooth and

paint to match. Use the pressure sensitive tape that comes with the instrument to

LEV-O-GAGE II

fasten it in place or supply your own two-sided tape or VELCRO™ to do the job - just be sure it's level when positioning. Slip/skid indicators made specifically for aircraft vary in cost from $20.95 plus $2.55 for S&H to $45.50 plus $6.75 S&H ... so this is a bargain. When ordering, it might be best

not to mention that it is for aircraft use. (Edmund Scientific Co., 101 E. Glouchester Pike, Barrington, NJ 08007-1380, 609/547-8880)

By TERRY WILWERDING EAA 394194 621 N. 36th St. Omaha, NE 68131 Although timing checkers are not uncommon, the most inexpensive one that I could find is over $40. This one can be put together for less than $5, and is useful for other electrical work also. The heart of this checker is a 2.8 kHz piezo buzzer from Radio Shack. The part number is 273-065 and the last time I checked it was $2.49. This is an interesting device because it works from 3 to 20 volts DC. It is connected in series with a common 9 volt battery to the P lead and ground of a magneto. When the points are closed, the current flows directly through the magneto. When the points are open, the current must go through the primary winding. The inductance of the 74 MARCH 1993

Plead

273-065 buzzer

Magneto

Ground

9 Volt Battery

TIMING CHECKER

winding causes the tone of the buzzer to change noticeably as the points open and close. Also note that the ignition switch must be on when DELUXE VERSION the timing is checked, so there is a possibility that the engine could kick or even start when turning it over, with very DPDT serious consequences. Switch Due to the impulse couplings in the magnetos, this can occur even when the engine is slowly turned over by hand. I would recommend removing all of the spark plugs from the engine before the timing is checked. This ensures that the engine cannot in any way kick back or run. In any case it is always good policy to stay out of the arc of the propeller. A deluxe version of this checker is even more useful and requires only a couple of additional parts. Be276-1152 Rectifier sides checking for continuity (and timing), this version can check for electrical current in a circuit. The full wave rectifier (Radio Shack 276-1152, $1.19) makes it possible checking a remote or inaccessible which can be used for the unit. The legality of SETTING the timto use the checker as an audio test spot, since the sound can be heard light, without regard for polarity. for some distance. A piece of ing depends on the class and The double pole double throw masking tape can be put over the certification of the aircraft and en(DPDT) switch chooses between buzzer if the sound is too loud or ir- gine. To my knowledge, there is no testing for continuity and voltage. ritating. Radio Shack offers a restriction on CHECKING the timing The tester is very useful when number of switches and cases of any aircraft engine, however.

Readers are invited to submit entries to EAA's Hints For Homebuilders, Att: Golda Cox, P. O. Box 3086, Oshkosh, Wl 549033086. Entries will be reviewed by a panel of EAA judges. Readers

whose hints are published in any EAA magazine will be awarded a 3/8" Drive Socket Wrench Set. Aircraft Spruce & Specialty will also award a $25 gift certificate plus a current catalog. Members

are also invited to submit hints of an electrical nature. Any hint used will receive a Fluke Model 23-2 Multimeter with Holster from the John Fluke Mfg. Co., Inc. The contest will run from August through July of each year with a Grand Prize being presented by both Snap-on Tools (KR657 Roll CAB and KR637 Top Chest) and Aircraft Spruce & Specialty

($250 gift certificate). A Grand Prize will also be awarded by the John Fluke Mfg. Co. These awards will be presented during the EAA Convention. Our thanks go to our sponsors for these awards. SPORT AVIATION 75