Props and the misery they bring

[B Scott]

As I posted on another thread I recently bought 2 sets of carbon fiber props by Maytech (MTCP9060H) for my Typhoon H.
My first impression was less than satisfying as the balance of the props left much to be desired and the scuffing on the underside of the prop could have been cleaned up with a little bit of buffing.

I managed to clean up all but one of the props with a little buffing and some 800 grit sandpaper applied evenly over the undersurface of the blade to avoid cutting into and damaging the fibers themselves. I may well try Patr's suggestion of adding some tape or something similar in the future instead of sanding.

One of the props, however, was a right mess. They had gouged a furrow up the middle of the blad with what looked like a Dremmel while trying to balance it. This had cut through the carbon fiber weave and once I applied a bit of pressure to the blade, I actually heard a click and saw a small crack running up the blade. Can you imagine if it had shattered while in flight? A lengthwise crack would be so much worse than even the blade breaking off. and I seriously wonder if the H would be able to compensate for the changed lift for such a break.

I wrote to Michobby.com where I bought them but sadly it seems now that they have my money they feel no need to answer my inquiries. I sent an email to Maytech with a CC to Michobby but to be truthful, I do not expect much. But I do feel that I owe Maytech a chance to respond even if one of their sellers did not.

I really hate having to write negative reports about a product or business. I find it so much more fun to be able to announce "Hey, guys... XXX is a great place to buy or YYY has a fantastic new product." The other way around it gets so depressing. But even negative input can serve to help make an average business/product, into a great one by allowing people to improve. If you do not know what is wrong, you cannot fix it. I wish everything I write could be good news, but I guess we need to take the good with the bad to even it all out.

I guess at the end of the day all I can do is consider in money spent for a lesson learned and avoid aftermarket
products for my H

 

[PatR]

That has to hurt a little but the good side is you found this before flying them.

Just for future reference, Another method of balancing is by using clear fingernail polish thinned out out with acetone, or better still, 30 minute epoxy thinned out with alcohol to make it flow easier. The problem with both of them is you have to wait for the applications to cure before establishing balance. The volatiles (acetone/alcohol) evaporate and reduce the applied mass. Thin CA glue also works but usually “lumps” where it’s applied.

Save that bad prop and use it to test balancing methods to see which you might like best.

 

[B Scott]

I just got a rely from Maytech. It seems a lot is getting lost in (google) translation.
I informed them of gouge and crack along with the expensive consequences of it failing in flight. It seems they think I hold them responsible for my drone crashing.
Thier reply:
Hope you are doing well. Thanks for your info.
I am sorry but it is not avoidable to have crashes when we balance the carbon props. It is the nature of carbon fiber materials. We need scrath it when make balance on them.
LOL, So there you have it from the horse's mouth, it is in the nature of carbon to break after balancing. Is this the answer from some kid in customer service with no understanding of carbon fiber or Is it closer to the truth than we dare to admit?

 

[CraigCam]

It must be who is “balancing” them. I have 3 sets I bought from Carolina Dronz and they were properly balanced as promised. I have had no trouble with the Maytechs and like them better then OEM props.

 

[PatR]

LOL, So there you have it from the horse's mouth, it is in the nature of carbon to break after balancing. Is this the answer from some kid in customer service with no understanding of carbon fiber or Is it closer to the truth than we dare to admit?

Standard non responsibility clause: "We just make and sell them. We are not responsible for anything that happens while the product is used." The verbiage changes but the translation remains the same.

It's actually not in the nature of CF to break after "balancing", although the method used for the particular type of prop can certainly influence the outcome. There are a great many CF and glass "slurry" fiber props out there with literally thousands of hours on them after balancing.