New Product Xaircraft X500-D $300 ARF brushless quad from China

[G-unit]

I bet the noise is a vibration in you frame,,can u do a video of what is going on.

[jesolins]

Sid,
If you cannot turn the prop on the motor shaft by hand to make it slip, then that is not the cause. If it is slipping, you will have to shim it to make it tight. Yes, motor/prop unbalance can cause different sounds at various throttle settings that hit the harmonics of the unbalanced condition. That can also cause your accelerometer and gyros to go into a state where they are giving garbage for angular information.
Cheers,
Jim

Originally Posted by Sid3ways

I'll have to verify it. I just went through 2 more packs in the dark outside and the quad flies perfectly fine until I hit about 70% throttle. Then I hear that humming noise and it acts like I'm giving a good amount of right rudder. If I throttle down, it will stop spinning to the right and act like normal. I'm ditching these tri-blades for the 1045s tomorrow and will report back. I'll have to see what I can do about balancing as I have no balancer.
It sucks because I can't really fly fast or make it shoot up otherwise I lose rudder and its hard to recover. :/
What is making that whurring noise when it does it? Quad is almost silent until I go high throttle, does an unbalanced prop make that noise?

[Sid3ways]

Well disaster struck me too but not nearly as hard as I thought it was going to. Trying to get this totally crappy video from my Blackberry and hit my neighbors house at 10pm at night and he comes outside with a flashlight and boxers. Talk about embarrassed

Only broke 2 props really so I took them all off. I did run it up without the blades on there and the noise was not there at full throttle, so the noise only came on when the blades were on there. Hopefully the 1045s won't have this same noise, otherwise I'm going to have to see what is up with each motor.

Here is the video, the quality is horrible but at least you can see it turn right and you can clearly hear the noise it makes under high throttle. I did a few bounces so you could see me quickly stab the throttle and then showed how great it hovers in place at normal throttle.

X500D Quad Rudder Issue (1 min 26 sec)

[G-unit]

This is the one from when i crashed with the locked up motor,but i just stopped recording and then it crashed.

FILE0001 (6 min 44 sec)

[importon]

2 quads down in 1 week! that's just bad luck. I feel for you buddy.

Originally Posted by G-unit

This is the one from when i crashed with the locked up motor,but i just stopped recording and then it crashed.

[jesolins]

Sid,
Never run the motor without props at full throttle for any length of time unless you want to roll the dice on burning up your motor and or ESC's. Short blips without props are OK to test operation and rotation, but never go full throttle.
A 10PM crash of a quad on a neighbors roof...lucky it was a flashlight in his hand..., but seeing him in those boxers must have been pretty scary too......
Cheers,
Jim

Originally Posted by Sid3ways

... I did run it up without the blades on there and the noise was not there at full throttle, so the noise only came on when the blades were on there.

[G-unit]

Originally Posted by importon

2 quads down in 1 week! that's just bad luck. I feel for you buddy.

If it wasn't for bad luck i wouldn't have any luck at all.
no big deal new parts will be hear on Monday,so i hope the weather is good

[Doofer]

Originally Posted by Sid3ways

Well we drilled it out to 6mm but that stupid little step at the bottom of the adaptor is a tad bit to large. I was able to screw the top down and it forced the props over that little step but then the only way to get the prop off was to dang near mutilate the prop. Oh well. RCD sent my X500 with some larger tri-blades, GWS 9050s I believe. They perform pretty well and I haven't had any stability issues with them. I'll have to get the 845s back on there because I had a low battery and thought wth, it barely would climb at all so I took them off thinking something else was wrong.

I drilled my 1045s (3mm) out in 1mm steps to 6mm, then used a tapered reamer to get that ~0.2mm step at the bottom end, as 6mm was fine for the threaded part of the adapter.

[bob.titus]

Originally Posted by Doofer

I see that some boards like QP offer control of prop pitch - does this mean if you lose a motor, it will keep flying (opposite prop goes into -ve thrust, remaining two motors make up the lift)?

The possibility of using variable pitch props in the future has been discussed with George, but so far, as long as I know, there is no support for variable pitch on the QP board.

Nevertheless, this could be a nice feature indeed, I'm sure George will take good note of it

[bob.titus]

Originally Posted by jesolins

Sid,
Never run the motor without props at full throttle for any length of time unless you want to roll the dice on burnng up your motor and or ESC's. Short blips witout props are OK to test operation and rotation, but never go full throttle.

Hey Jim,

this really puzzles me... why would a motor or ESC burn if driven full throttle with no load? It does not make too much sense to me since it seems RPM is controlled by the ESC isn't it?


I'm not saying it was clever or anything, but I have frequently driven many motors full power for periods of time (I just did on 2 motors that needed new bearings one hour ago) without ever having any problem with them or the ESCs, no overheating, nothing abnormal really.

Could you please tell me the reasons for this?

Bob

[jesolins]

Hi Bob,
Just as running too large or too small a prop can damage a brushless motor/ESC, running them without props at full throttle for more than a split second can do wiring/heat/magnet damage and is not recommended by several manufacturers. This damage might not show up immediately in that full throttle several second or more run, but the damage done would show up later as stuttering starts hot motors weak motors, etc. In other words, the minor damage done to overheated windings, bearings and magnets would progress over time. Remember that even a low Kv unloaded motor can reach speeds ten's of thousands of times its watt load Kv rating. The heat goes somewhere when that happens and it is not usually a good outcome. Will it damage a motor every time if you run it unloaded at full throttle? No, but why take the chance!? You don't need to ever run motors at full throttle to see if it is a working setup anyway...just simply blip the throttle if there is no prop on to determine functionality or rotation direction... Further, if an ESC miss-cues while at full throttle providing high current, it will run that current through one winding pair and eventually take out the motor, and the ESC if it wasn't already damaged.

A brushless ESC has 3-12 or more FETs depending on the model and any one going bad either by itself or because of a processor timing error, can take out a motor, kind of a cascade effect of damage...
Here is a good motor testing link: http://www.wattflyer.com/forums/show...62&postcount=1
A good explanation of heat effects on brushless motors and resultant damage: http://www.rcgroups.com/forums/showt...ps#post7157040 (touts Scorpion motors, but applies to all and well explained.)

In my years of taking a survey asking folks who have had ESC's smoke and motors burn up on them, the common theme was that they had been doing extensive bench tests running the motors at full throttle without props and insufficient cooling. Not sure why someone would do that anyway? I do know that those that don't practice running their motors at full throttle with no props on for testing don't seem to find their motors and ESC's burning up at some later point...
Cheers,
Jim

Originally Posted by bob.titus

Hey Jim,
this really puzzles me... why would a motor or ESC burn if driven full throttle with no load? It does not make too much sense to me since it seems RPM is controlled by the ESC isn't it?

I'm not saying it was clever or anything, but I have frequently driven many motors full power for periods of time (I just did on 2 motors that needed new bearings one hour ago) without ever having any problem with them or the ESCs, no overheating, nothing abnormal really.
Could you please tell me the reasons for this?
Bob

[Sid3ways]

OK new issue now. Since that crash I put the new props on and went to fly it today and now the right motor only spins up from the initial turn on but when I throttle up, it stays at idle. Makes it a little difficult to fly with 3 motors, what do I need to check since it obviously is getting a signal because it starts and stops just fine but it simply won't do anything else even with gyro input from me tilting the quad or ail, elevator, rudder inputs.

[RCvertt]

Originally Posted by Sid3ways

OK new issue now. Since that crash I put the new props on and went to fly it today and now the right motor only spins up from the initial turn on but when I throttle up, it stays at idle. Makes it a little difficult to fly with 3 motors, what do I need to check since it obviously is getting a signal because it starts and stops just fine but it simply won't do anything else even with gyro input from me tilting the quad or ail, elevator, rudder inputs.

That's just the secret tricopter mode which some bad motors helped me discover once as well

Try swapping ESC's to see if that one went bad

[bob.titus]

Thanks Jim,

very interesting indeed, I will be more careful about this from now on!

Got some reading to do now, cheers

Originally Posted by jesolins

Hi Bob,
Just as running too large or too small a prop can damage a brushless motor/ESC, running them without props at full throttle for more than a split second can do wiring/heat/magnet damage and is not recommended by several manufacturers. This damage might not show up immediately in that full throttle several second or more run, but the damage done would show up later as stuttering starts hot motors weak motors, etc. In other words, the minor damage done to overheated windings, bearings and magnets would progress over time. Remember that even a low Kv unloaded motor can reach speeds ten's of thousands of times its watt load Kv rating. The heat goes somewhere when that happens and it is not usually a good outcome. Will it damage a motor every time if you run it unloaded at full throttle? No, but why take the chance!? You don't need to ever run motors at full throttle to see if it is a working setup anyway...just simply blip the throttle if there is no prop on to determine functionality or rotation direction... Further, if an ESC miss-cues while at full throttle providing high current, it will run that current through one winding pair and eventually take out the motor, and the ESC if it wasn't already damaged.

A brushless ESC has 3-12 or more FETs depending on the model and any one going bad either by itself or because of a processor timing error, can take out a motor, kind of a cascade effect of damage...
Here is a good motor testing link: http://www.wattflyer.com/forums/show...62&postcount=1
A good explanation of heat effects on brushless motors and resultant damage: http://www.rcgroups.com/forums/showt...ps#post7157040 (touts Scorpion motors, but applies to all and well explained.)

In my years of taking a survey asking folks who have had ESC's smoke and motors burn up on them, the common theme was that they had been doing extensive bench tests running the motors at full throttle without props and insufficient cooling. Not sure why someone would do that anyway? I do know that those that don't practice running their motors at full throttle with no props on for testing don't seem to find their motors and ESC's burning up at some later point...
Cheers,
Jim

[G-unit]

I tried some night flying,here is a small video
http://www.youtube.com/watch?v=p1LoGHLHfoU