I have a very nice Aeroworks extra 300 that has a Da 100 in it. The planes elevators were reversed on take off and the plane tipped over forward and slightly ( I sid Slightly chipped) both end of my carbon fiber Mejlik prop. Its barely noticelable but u can feel small chips on both ends. Now getting to the issue at hand, htere is a noticeable differance in the planes sound now and quite a bit of vibration in the wings and body of the plane when its crancked up. is htis cause something is wrong with my motor or is it cause my prop is now out of balance?? please help!!! Thanks guys

Please make sure to NOT use that prop! It is now a safety hazard! I'm sure it is also the reason for the vibration.

Post pictures of it please!

not visible, but u can feel it

Originally Posted by RCHUGHES

Post pictures of it please!

Anytime a prop has it the ground or any other object hard enough to do damage, that prop should be discarded. The risk of injury is far too great to chance

I have heard of ground strikes causing the crank counter balance move. Worst case. Balance the prop and if it still does it you might need to send in the motor.

sounds like a bent crank shaft. easy to fix now,not so later. most likely would replace the bearings as well

That big carbon fiber Mejlik prop is expensive; I would just "dress" or clean up the tips on a belt sander, balance it, and reuse it. No prop manufacturer would ever recomend reusing a prop, but actually you can if the damage isnt' too bad. Especially a carbon fiber prop, never a wood one though. Also, thin CA works great on CF. So after you dress the damaged tips, wick some CA into the area you sanded.

As with any prop, repaired or new, don't stand in the propellor arc, or in front. If it does fail, thats where the shrapnel goes.

Forgot to mention, I used to have that same Aeroworks Extra, even same engine. Nice plane, nice engine! I rebuilt my DA-100 after a high-speed crash, the bearings were fine. These bearings are huge. My crank was bent a little, and I was able to straighten it. I doubt you crank is bent, probably just shakes from the prop damage.

Originally Posted by jdracing3

Anytime a prop has it the ground or any other object hard enough to do damage, that prop should be discarded. The risk of injury is far too great to chance

Not always, a slight chip can be sanded and polished out and balanced. just depend on how bad its chipped and if the Resin is cracked how it is cracked. Full scale guys Don't throw away props when they chip and they have far more to loose! I mean if you have the extra $150 have at it but a simple sand and polish may save a dime or two... hence post pictures!

Originally Posted by jaccojenkins72

not visible, but u can feel it

From your discription here, this prop is hardly hurt at all, unless it has a crack that is hard to see. I've repaired and reused CF props in far worse condition. Put on some magnifiying glassess and look at the prop tips under a bright light, checking for cracks. Check the balance, and grind material off the tip of the heavy blade until it balances perfectly.

Originally Posted by jdracing3

Anytime a prop has it the ground or any other object hard enough to do damage, that prop should be discarded. The risk of injury is far too great to chance

Not always, a slight chip can be sanded and polished out and balanced. just depend on how bad its chipped and if the Resin is cracked how it is cracked. Full scale guys Don't throw away props when they chip and they have far more to loose! I mean if you have the extra $150 have at it but a simple sand and polish may save a dime or two... hence post pictures!

If you do it sand and polish I recommend doing it by hand to ensure you don't cause more damage, some guys are good with belt sanders and can do it no problem, but one slip and you have more damage

Right, I only use the belt sander if there is a lot of damage. In your case, some light hand sanding should do it. The thin CA also restores the smooth finish, so you don't need to polish it much. I usually do a little more sanding after the CA has hardened, with a very fine grit.

BTW, be sure not to breath the CF sanding dust . . .

You spent thousands on the plane .You spent many hours of building . You have many uninjued flying buddies. CHUCK THE PROP AND SEND THE MOTOR TO THE PROS AT DA. Cheapest and safest way to go.QUOTE FROM A FLYING LAWER BUDDY . IF IT HITS ME I WILL OWN YOU!!! just sayin be very carefull luck is always a very limited resource.It runs out at the worst possible time.I want to see all my FG buds FLYING not CRYING.. HAPPY EASTER

I doubt a small chip is the issue. I just replaced a crank in a da100 for the same thing. The counter weights spun, the cranks aren't welded or spun welded together. The counter weights,boss pins are just pressed together. It doesn't take much to spin them either. A carbon prop hitting the ground will no doudt spin it just slightly. Take it appart and look at it. A crank is cheap ( 200.00 ) and easy to install.