How do i get my jigs to those 40 foot depths  would  a downrigger work for crappie fishing?

Hmm...couldn't you just let the jig sink to that depth? I'm a shallow water fisherman so I'm not sure. I would be interested in the answer to this one too.

On those occasions that I have fished water that deep for crappie, my tactic has always been to use a crappie rig with a 1/2 to 1 oz sinker on the bottom to get it down fairly quickly. When I say crappie rig, I am referring to the traditional 2 hooks on standouts type of rig.

Welcome to the Forums fclayton

Do a simple 'Net search (Google etc...) for this...

crappie + "deep water"

LOTS of good info

Use a heavier jig . use lighter line ,or add some split shot further up . you can always fish a jig under a slip bobber too.

You can put a heavy jig or weight on the bottom with lighter jigs further up the line every foot or so. Gets down quick and covers different depths simultaneously. Not good for brush piles though.

In a brushy area use a 1/8th oz lead head. In non-brushy areas [a drop off] use two 1/16th or 1/8th oz lead heads. Or one of each.
Split shot can be used to increase drop speed. Many fish will school up at one level or location/depth.
Many times I have gone to the bottom, then moved my jig up a few inches and as you come up, a bite occurs.
Have a black, blue, or red magic marker ready. After you set the hook. Quickly Place a mark on the line directly in front of your reel. Blow air on it fast to dry it.
Reel in fish.
After landing fish, go back to your mark. and try that depth again. Many times you catch fish. Sometimes you have to reel in line above that mark or lower your line below that mark to catch fish.

do crappie bite more at night , than in the daytime ? i have heard both. i would like more input. smetimes i think bait shop guys lie to me ! lol

Crappie seem to feed more in low light conditions early morning before sun gets up high or as sun starts going down. At night the use of lights works well, too. This year I plan on buying a couple of the green 18 inch fishing lights from Bass Pro about $24.00 each. Several things to remember the light is the structure you are fishing, but pick an area where crappie can be found. It will take 45 to 60 minutes to set up the food chain. The plankton will arrive first, then the bait fish, next the crappie, and the catfish. Do not fish to deep crappie come up to feed they are looking up not down. If you start catching more catfish than crappie shallow up.