HINTS FOR HOMEBUILDERS

NUT AND PAL NUTSTARTER BY ALBERT A. BURGENER Some spots on an aircraft have limited space to get your hand or fingers

the stud for installing the nut and the next size larger to install the pal nut.

in to start a nut or a pal nut. One example of such a spot is the left hand rear stud when installing a Marvel engine. This tool solves the problem. Flatten the threads down on the pal

The washer used to hold the pal nut on should be as thin as possible and the rivet flush with the top of the washer, so that the end of the stud will not bottom out before the threads on the pal nut engage the threads on

nut on a flat plate with a rod or punch. Use a pal nut with the same thread as

the stud. It is easier and faster to use this tool to start all pal nuts, even if

Schebler carburetor on a Lycoming

they are in the open. Remember, after the pal nut has contacted the nut, turn 1/4 turn to lock. Note: Some pal nuts have the same wrench size as the nut and others have

the next size larger. I (This hint was submitted by Albert A Burgener, EAA 2787, 1907 E. 4675 S., Salt Lake city, UT 84117.)

NUT TO BE INSTALLED

PAL NUT VARIOUS SIZES

HANDLE - T4 ALUM

SPACER TO FILL GAP TO PAL NUT THREADS

COUNTERSINK WASHER TO MAINTAIN LOW RIVET PROFILE

UPSET RIVET ONLY ENOUGH TO HOLD ASSY TOGETHER. PAL NUT MUST ROTATE FREELY.

RECHARGEABLE BATTERIES BY WILLIAM BEZDEK Nickel cadmium rechargeable bat- lorans, and GPS receivers. NiCads, as teries have become ubiquitous in they have come to be known, are good battery powered devices. We use them for about 1000 charge/discharge cycles, in flashlights, children's toys, portable but they have an unusual property. radios, cordless and cellular telephones They must be completely discharged and, as aviators, in portable nav/comms, every time before recharging. If not,

they develop a "memory" of their lowest charge level and subsequently use that low level as their "empty" reference. They no longer have their original ampere-hour capacity. (Continued on the next page) SPORT AVIATION 113

HINTS CONTINUED

To prevent this some manufacturers arc now incorporating in their new chargers a discharge cycle to completely drain the batteries before charging. For most of us, however, we must manually deplete the batteries. To accomplish this I have constructed this "breadboard" of battery holders and lamps for the battery sizes my appliances require. I can discharge twelve AA cells, or four D cells, or two AAA cells at a time. The components came from my local electronics supply house. I was able to find metal AA battery boxes to which 1 was able to solder the center terminals of the lampholders, thereby reducing by half the wiring required. The AAA and D cell boxes arc wired in parallel with the AA cell boxes. This device also gives me the opportunity to examine each battery individually. Usually one cell in an appliance drains first, prompting

recharge of the whole group. Watching which batteries deplete first tells me their "memory" levels. I can discharge and recharge a cell repeatedly until it either returns to full capacity or evidences it needs replacement.

(This electrical hint was submitted hy William Bezdek, EAA 234278, 2861 Hagadorn Rd., Mason, Ml 488549457. Mr. Bezdek is a member of E AA Chapter 55.)

Snap-on FLUKE. Readers are invited to submit entries to EAA's Hints For Homebuilders, Att: Golda Cox, P.O. Box 3086, Oshkosh, WI 54903-3086. Entries will be reviewed by a panel of EAA judges. Readers whose hints are published in SPORT AVIATION will be awarded a 7piece Combination Wrench Set from Snap-on Tools, a $25 gift certificate plus a current catalog from Aircraft Spruce & Specialty, a Lenox 4012 Hacksaw Frame from American Saw & Mfg. Co. and a Pro 360 Digital Protractor from Macklanburg-Duncan. 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 Snap-on Tools, Aircraft Spruce & Specialty ($250 gift certificate), American Saw & Mfg. Co. (Lenox VBKMA-6 Vari-Bit Kit) and Macklanburg-Duncan ($250 cash). A Grand Prize will also be awarded by the John Fluke Mfg. Co. These awards will be presented during t h e E A A Convention. O u r thanks g o t o o u r sponsors f o r these awards. - • • . . : 114 JANUARY 1996