I installed a 35cc Xpwr motor in a new Redwing MXSR. Set up 12s w/ Castle Creations Edge 120A and 20 x 10 Falcon Electric Prop. Ground testing indicated a strong pull and about 70A at full throttle.
On the 1st flight - I advanced the throttle slowly and the aircraft became airborne before I was at half throttle. At 10-12 ft high and the throttle was just past 1/2-way point the motor "screamed" and stopped. So I did my best to land with 0 airspeed! My new airplane was beat up.

I took it back to the pits and tried the motor again. Same thing happened, it would run and at just beyond 1/2 throttle the motor screamed and stopped.

Back at the shop I pulled the cowl and checked all connections and the batteries. All appears fine. Ran the motor without the prop and it was OK. Put the prop back on and it does not like going past 1/2-throttle.

So I have another motor and swapped to check the ESC. The other motor ran fine and was able to run at full speed.

I think the ESC is good. It appears there is something wrong with the motor.

Anyone have any ideas?

Can I trust Xpwr motors ever again? I get that anybody's electronics can fail suddenly but this still sucks.

Your best bet is to call EF and simply ask your questions and talk about it. They are some of the best guys in the hobby and totally support their customers.

Had you reached out to them at all about this?

Was your motor new? Did you buy it direct from EF?

We'll be glad to help out, but you need to contact us before we can! When motors "scream" and stop, that indicated a loss of timing between the motor and ESC. Can be a variety of things related to ESC, motor, wiring, and settings and we'll be glad to go through the checklist with you. We'll ask you about your setup, go through all possibilities, and if necessary test your motor on our bench to determine any issues.

You can send me a pm here or contact us at the email or phone number on our website, www.extremeflightrc.com

Did you set the ESC to v. 4.22 firmware as recommended? This is a MUST!

Definately an esc flaw i have had to change every castle esc i have had on big motors to stop that half throttle cut out. Generally its a timing issue

Originally Posted by EXTREME FLIGHT

Did you set the ESC to v. 4.22 firmware as recommended? This is a MUST!

This. My 30cc motor had some strange noises in the mid range on an older FW. Updated to 4.22 it was much smoother and did not have the noises.

Originally Posted by nofreee

This. My 30cc motor had some strange noises in the mid range on an older FW. Updated to 4.22 it was much smoother and did not have the noises.

Exactly, this is why we highly recommend this firmware version in all of our Xpwr literature.

Boom!
Cant get a faster response/resolution than that!

It's so much easier/better when people contact us and let us help *before* it goes on the web, though. No high wire act that way.

Originally Posted by 3DHobbyShop

It's so much easier/better when people contact us and let us help *before* it goes on the web, though. No high wire act that way.

wholeheartedly agree.

Well, we'll get the customer whatever he needs. I *suspect*, as Chris does, that we'll find some setup issue as we go through the system, but if it turns out he needs warranty service on our product, we'll do that for him, no problem, in the states, with good turnaround.

Do you guys have any idea when you'll start offering spare parts for the xpwr line? I need a new motor mount and prop shaft mount. Buried one in and everything else is good except for those parts. Very happy with the build quality to survive my crash, the plane was completely trashed and the motor looks great minus the mounts.

We have parts...what is a "prop shaft mount"? I understand propshaft (or main shaft)...is that what you mean?

Sorry for any confusion. It's the prop shaft that is held down by the 3 bolts. The shaft bent in my crash. I couldn't find them on your website to order. This is for the 30cc motor.

Ah, the 30CC, which is different, gotcha. Sure, just call our warehouse at (770) 887-1794 and Zach will help you out. I told him you'll be calling, pls. give him an hour or two to get one pulled for you. Thx!