what are the rules when testing battery packs? heard mention of a Expanded Scale Voltmeter and unaware of how this differs from a normal AC/DC meter. I'm asking because I flew yesterday, 30min stick time, didn't charge last night, Tx now says 10.0V, and Rx says 5.03V, but RX is only a 4 cell 4.8V pack. hmmm. The 23mV over voltage is weird since I flew without recharging. Do I need to test voltage or current while under load or anything, or is open circuit V at the battery good enough?

next, exhaust goo is running down throttle pushrod guide tube and onto the throttle servo. Is there a trick to stopping this? thought I'd add a little something to the rod to allow the fuel to drip before entering the tube.

Thanks guys..

btw, here's the meter Im using
[link=http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CT LG%5F011%5F008%5F002%5F000&product%5Fid=22%2D810&h p=search]Multimeter[/link]

Battery.. can't help you there..

Exhaust - the exhaust shouldn't be getting all over the throttle pushrod, or near it.. There should be a good seal between the muffler and the engine (gasket) and the exhaust tube pointing out.. unless you have a smaller cox type engine with no MUFFLER (I first wrote throttle..)! In that case, check out the pushrod seals that people use to seal off radio equipment in watercraft:
http://www2.towerhobbies.com/cgi-bin...?&I=LXD589&P=7

Is the goo (good tech term) coming from the exhaust port? if yes.. then several people at the local field just put 2 or 3 inchs of tubing on the port to get the exhaust a little further away from the plane....


if it is coming from somewhere else....that is a whole 'nuther story,.....

I'm sure it's coming from the muffler, but will recheck the gasket. And this is with a Dubro exhaust deflector too. Have thought my engines putting out too much oil and stuff, plane's completely covered when done flying including engine area, but everyone says "Just that type of fuel" or "Better too rich at the high end then too lean" etc.

You need a diffeent meter for checking your battery pack. An ESV (Expanded Scale Voltmeter) puts a load on the pack, without it you really aren't learning anything with the meter. The minute you put a load on the pack the voltage will drop.

I'm guessing that 30 minutes of flight time has your receiver pack pretty close to the point where your receiver will quit, or start seeing glitches during the next 10 to 15 minutes of flight. ALWAYS do an overnight charge before you go to the field, and then test the pack with an ESV after no more than the 3rd flight (and every flight after).
Dennis-

Just what I needed to know. thanks Dennis

Or invest in a voltwatch.

Andy

Right. The "Voltwatch" is a nice little piece of equipment. It's essentially an ESV that you mount on the plane so you can see the "Voltage" before every flight. The only problem is you need one for each plane, at about $10 each.

The ESV can be bought for around $15, but you actually have to remember to connect it.

(Not taking a shot at you Andy.)
Dennis-