Help needed: Housing stuck on Turnigy SK 5055-580

[steinar]

Hello,

I just bought a Turnigy Aerodrive xp SK5055-580 brushless motor from HobbyKing which became only a few seconds into the first test run.

I've discovered that it is not because of a louse magnet, as I initially thought, but a result of the outer housing shifting back until it reached the non-rotating back part of the motor and it became stuck. After being able to move the housing back the same thing happened again. In the two test runs it got stuck at 65 amps and 40 amps, respectively.

Complete setup:

• Turnigy Aerodrive xp SK5055-580
• Turnigy Type C Light Wood propeller 13x8
• Turnigy Brushless ESC 85A w/ 5A SBEC
• ZIPPY Flightmax 5000mAh 6S1P 20C
• Turnigy amp meter between battery and ESC

I can ship the motor back to Hobbyking and probably they will provide me with another one. However I live in Iceland, pretty much as far away from Hong Kong as one can get, so the shipping is very expensive and takes weeks. Therefore I would prefer fixing this myself, if possible.

Photo of the motor and a video of the second test.


The motor where the incorrect position of the outer housing is clearly visible. Click here for a full resolution image.

YouTube Video

[cpmalish]

your scarring me I just got my Turnigy 5055-600 in the mail and installed on my H9 ultra stick hopefully going to test run it on sat. or sun. wish me luck thanks,Chris

[steinar]

Small update: I'm able to screw the housing back to its original position. However when running above half power it will always loosen again, even though I've tightened it as hard as I possibly can. Perhaps my propellers are unbalanced, I've tried two so far, but still I find this strange.

Any thoughts?

Good luck with your maiden Chris!

[MustangMan]

It appears that your motor is missing the spacer washers which position the rotor relative to the stator. You might try removing the retaining ring or collar from the rear of the motor and pull the rotor and shaft out of the motor. Usually there are one or two spacer washers on the shaft that keep the rotor moving too far back and contacting the mounting flange. While you have the motor apart you should also check to make sure the mounting flange is securely attached to the stator (inside part where the wire windings are).

[steinar]

Once I've tightened the outer housing (to the rotor's end cap) the distance between the rotor and stator is correct. The problem is the housing becoming loose. Due to the direction of rotation of the motor it will unscrew as far as it can go.

One solution would be to simply turn the motor around and attach the propeller using a shaft adapted, then the motor torque would actually tighten the housing. I wonder how the end cap of the rotor became loose in the first place and whether thread lock glue like loctite will solve this?

Thanks,
SH

[av8djc]

I had the same thing happen. With it out of position I applied some green locktite bearing retainer both outside and inside then pushed it back in place. I then wiped off any excesive "glue". At that point i drilled and tapped for a very small flat head retainer screw on two opposite sides through the steel can and the aluminum right at the edge of where it had the gap. Wish I could take a picture but I'm away from home right now. On most of the very large motors these retaining screws are used to keep the can in place. I think they must have had a bad batch of these but this procedure will fix it.

[steinar]

Thanks guys! I got a heat resistant threadlocker, similar to loctite, from a local dealer which I applied yesterday. Today I've done several tests using three different propellers without any problems, amazing how much power such a small motor can produce!

To conclude the thread: High strength & heat resistant threadlocker is a simple and sufficient solution. Additionally, adding two screws on the opposite sides at the edge is probably a good idea.

Regards,
Steinar Hugi

[cpmalish]

so what did you get for watts I ran mine today with a 5s 5000mah turnigy lipo and I got 950 watts at 53 amps with a 13x6 wood prop thanks,Chris

[steinar]

Battery: Zippy 6s 5000mah 20C

Turnigy Type C Light Wood propeller 13x8: 78.5 amp, 1664 watts
JM 12x6: 55 amp, 1196 watts
TGS Sport 12x8E: 72,76 amp, 1525 watts

Rated power is 1580 watts so TGS Sport 12x8E is the chosen one I suppose. The 13x8 is definitely too large for 6s. After I placed the order at HobbyKing I found pretty good test results for this motor at Bungymania. I notice they have two different results for the same 13x8@5s setup.

[av8djc]

Like I said I'm away from home until Tuesday but if memory serves me I'm running a 15x6 on 4s but I'll check and report back

[BEAR-AvHistory]

5S5000 Turnigy Cherry 15X8 1237watt @ 66amp - MAS 13X8X3 1100watt @ 59amp - MAS 14X8X3 1377watt @ 77amp

[steinar]

The thread-lock broke and the front cap/housing got unscrewed once again. The threads are showing wear as a result of my previous failed test runs. This time I used highest strength thread-lock I could get (permanent lock). Additionally I drilled, tapped and thread-locked 3mm machine screws, each on (exactly) the opposite side of the other as av8djc suggested.

Initial tests look ok, will report if anything happens but I have a pretty good feeling about this now.

Regards,
Steinar Hugi

[hangtime]

My motor did the same thing and I have the Loctite drying on it right now.. I'm glad I found this post, I'll get the drill and tap out to put some screws in it.

[steinar]

I've done a few bench tests on mine after adding the machine screws and its looking good so far. Note that I used thread-lock on the screws as well, we don't want them coming loose and shooting out of it at full power. Just make sure they are positioned exactly against each other to keep the motor in balance. You can verify the distance is the same both ways around using a piece of paper, for example. Also cleaning out all the metal and dust of the magnets before running it quite is important.

I've seen comments about the front cap coming loose on other Turnigy SK motors as well, seems to be a design issue.

Good luck!

[stuart]

hello gang, i have 2 turnigy 580's in use,one is the sk5055 580,they other is the gold 5055 400kv.

if possible ,could someone post a few pictures of these added screw locations i have not had the same issue you are but loose mags are the 5055 580 curse,and that i have delt with even before first test runs. open em up and clean em out,reglue with thin ca all around the bell housing.

thanks,stu

[hangtime]

Take a look at the screw location on the TGY 63-54-A Motor. On the 580kv motor the screws should only be needed on the prop hub end.Y

[stuart]

thanks for that picture! wow,what a pita,shaving will jump on those mags,clean outs a must like said before.
i used locktite on mounting screws and had to drill the machine screws out.this was on the new,unused 50-55-600kv gold turnigy...tried to cover the venting openings but now must clean out the shavings.

i wasn't fully understand the problem until now. i never unscrewed the 2 pc's you had issues with.

thanks again,stu

[bob ponte]

Steiner, this motor will spin end cap out and lock it up, i've two of them and they both freeze up after 40 sec. of running. Don't fight the issue put three (3) small screws through body of motor into end cap.equal distance apart for balance. Caution! protect magnets from chips...Works great good motors. Bob Ponte