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View Full Version : motor dissassembly sequence,turnigy sk' 50


tobydogs
02-25-2010, 01:34 AM
hello my friends here at the motor threads,i have a new turnigy 50-55-580kv sk series motor ready to ship back to hongkong.shipping will cost have the value of the purchase price.

i once tried to seperate the bell housing on a motor like this one...
i remove the shaft collar,removed the spring clip,removed a set screw...and pulled...now the bell would slide alittle and stop.couldn't get it apart by hand.:mad:

is there another part to be released?is it the strength of the magnets?if thats the cause how should i pull this motor apart without ruining it?

the reason i need to repair it is loose magnets,and i would also p/u boca bearings if i knew what size to order.

if i do go foward,whats the best glue to use on the magnets? all in all i hope to get a replacement.they are out of stock and i still need to find out what hobbyking warrenty is as i bought this motor 12/12/09 as a christmas present to go in the gp rv-4 40,and only assembled the motor yesterday.heres a picture of the setup,and any help with the correct repair seaquence would be great.
thanks,stu:)

birdDog
02-25-2010, 02:31 AM
Sometimes there is a little brass spacer that resides below the C-clip and before the bearing. That can get hung up in the c-clip groove and not let the shaft pull through.
Could also be that the set screw on the locking collar has raised a burr on the shaft and is not letting the shaft pull through the bearing, there are very tight fits there.

If you can see a little circle cut into the shaft where the locking collar was, try poking just the shaft though a plastic bag and filling the area a little. The plastic is so that you dont get metal from the file into the magnets and rotor. Be carful with the magnets as they will try to jump together from quite a distance. If they slam together they can crack of chip corners off. Once you compromise the coating, the magnet will slowly fail. I would also suggest safety glasses since if the magnets do slam together, them little fragment really fly (don't ask how I found this out, but it hurt)

I have a Turnigy 50-55B and i think I used like a couple .035" drills for spacing the magnets. That is on the gold motor though. I used some "PC7" epoxy because it is pretty stiff but only handles sustained temps below 200*F.

tobydogs
02-25-2010, 02:40 AM
THANKS birddog,i was just ready to hit the buy now button for the turnigy 50-55a-400kv gold type motor...and then the email alert went off.

how do you think the gold to sk series differs,and how did your rebuild hold up?i see hk has 100+ of the 50-55a-400's in stock.now i may wait and decide wether to work on the broken new motor or not.

thanks again my friend,stu

birdDog
02-25-2010, 02:58 AM
Not sure how they differ but that is the problems I had with mine. Mine is the 600kv version and I run a 13x10 at about 45 amps on 4s. The motor is mounted in open air and runs good (for now). It's mounted on a beat up Extra 260 40E airframe.
Don't forget to take your cell count into account if dropping 1/3 kv rating.
Since you are working ona new build, I would go with a new motor.

tobydogs
02-25-2010, 03:40 AM
i don't know what happened,but i went to cancel the motor order....next thing i know my email is filled with confermation of purchase......i mustof hit the wrong button:eek:....yeah...right:rolleyes:.

i also agree with you that this build deserves a new motor ,not a newly repaired new motor..lol.

now with the cell count,i was going with6cell4000mah [2 3cells in series],i use this with the 50-55-580kv and a 13x6apc e prop

from what i read at the hk forums,[taken with a grain of salt]the average set up for the gold 50-55-400kv was 5 or 6 cell and 14x6 eprops using 80ampesc. model weight 3 kilogram=6+lbs and acheived vertical.
any feedback on this info would be very helpful as the rv-4 will be around 6lbs.

thanks birddog,and i would like to hear from others on there thoughts of repairing trunigy motors or any brushless repairs i should look to do if and when i open this motor up.

tobydogs
02-27-2010, 10:39 PM
hey gang...new question and i haven't tried and wouldn't unless someone else has succeeded.

question is,can i add ca adhesive with a needle syring applicator to the bell magnets without opening the motor?this would be done on 2 other 50-55-580 motors that run now and are installed in planes but may also have loose magnets down the road.i'v read many use ca to reglue magnets.

the motor vents are large and it looks like this could be done slowly by doing 3 magnets at a time and rotating the motor to do all the mags.1 drop per magnet.

if this is absurd to attemped,i won't. its sad to think i should pull motors apart to check for or add adhesive to magnets.

i'm glad to be here to run these thoughts by others who may have already tried and know the outcome already.

thanks,stu

i'm still waiting to hear from hking if they'll replace my new but damaged motor.....it may be a $50 trial to repair....i hope not.

tobydogs
03-16-2010, 02:37 AM
just recieved the 50-55a-400kv turnigy gold motor for the rv4.

1st thing i did was to remove the c clip,brass washers and pulled the motor apart ,the shaft didn't pull out completely but i was able to inspect the bell magnets and windings on the motor.

i must say that the gold motor magnets are epoxied the full length of the mags with no space to add epoxy......i'm also glad to have been able to inspect for any debri/metal filings.it was very clean inside.no oil residue on the inside bell...very clean!

now to go foward with my build as i'd lost the drive to complete it till the motor arrived.will be running this set up with a 13x8e apc and 6 cell4000mah zippy.i installed the motor/mount and esc for trial fit and all a go!

thanks again for the advise to open the motor up for inspection,now time will tell if the qc at hk has gotten better.
stu

kyleservicetech
03-24-2010, 10:57 PM
hello my friends here at the motor threads,i have a new turnigy 50-55-580kv sk series motor ready to ship back to hongkong.shipping will cost have the value of the purchase price.

i once tried to seperate the bell housing on a motor like this one...
i remove the shaft collar,removed the spring clip,removed a set screw...and pulled...now the bell would slide alittle and stop.couldn't get it apart by hand.:mad:

is there another part to be released?is it the strength of the magnets?if thats the cause how should i pull this motor apart without ruining it?

the reason i need to repair it is loose magnets,and i would also p/u boca bearings if i knew what size to order.

if i do go foward,whats the best glue to use on the magnets? all in all i hope to get a replacement.they are out of stock and i still need to find out what hobbyking warrenty is as i bought this motor 12/12/09 as a christmas present to go in the gp rv-4 40,and only assembled the motor yesterday.heres a picture of the setup,and any help with the correct repair seaquence would be great.
thanks,stu:)

Several years ago, I built up four of those "Go brushless" motor kits, and glued the magnets in place with thin superglue. Then, after that was done, I held the rotor horizontal, and filled in the space between two magnets on the bottom with baking soda, from your kitchen. Take a Q-tip or similar item and make absolutely certain that this baking soda does not stick above the level of the magnets on either side. (You'll find out why later)

Then, take very thin CA, and place a few drops on the baking soda, just enough to saturate the baking soda. To much CA will simply run out, and get all over everything. Then rotate the housing, put baking soda on the next pair of magnets, hit it with CA, and so on til done.

That CA/Baking soda trick is very old trick. That combination is so hard, you need a file to remove it. And, its heat resistant. Before you try it on a motor, try it on some scrap stuff first to see how you like it. And try to remove it from the scrap stuff with a heat gun! (Use plenty of ventilation, just in case)

tobydogs
03-25-2010, 12:25 AM
thanks dennis,i got a new motor from hobbyking and like others suggested,i opened it up.
the insides were very clean,no oil residue,no metal filings.i blew it out any way and wipped it all down.
i check the epoxy on all the magnets and the spaces inbetween each magnet was filled the full length with a solid epoxy....no place to add thin ca.i hope they glued the mags on with out oil residue.this was a gold turnigy and the issues i had were from the black sk series.
just to repeat,the sk smaller motors i'm using have been trouble free.the 50-55-580kv sk motors had a issue in the past and i now will have 3 models with these motors........i hope qc at hk has improved.

thats very interesting with using baking soda,i'll try mixing it up to check it out...thanks again dennis.i still have a replacement motor coming thats the sk series,looking foward to opening it up to check the epoxy on it.
stu

kyleservicetech
03-25-2010, 02:31 AM
thanks dennis,i got a new motor from hobbyking and like others suggested,i opened it up.
the insides were very clean,no oil residue,no metal filings.i blew it out any way and wipped it all down.
i check the epoxy on all the magnets and the spaces inbetween each magnet was filled the full length with a solid epoxy....no place to add thin ca.i hope they glued the mags on with out oil residue.this was a gold turnigy and the issues i had were from the black sk series.
just to repeat,the sk smaller motors i'm using have been trouble free.the 50-55-580kv sk motors had a issue in the past and i now will have 3 models with these motors........i hope qc at hk has improved.

thats very interesting with using baking soda,i'll try mixing it up to check it out...thanks again dennis.i still have a replacement motor coming thats the sk series,looking foward to opening it up to check the epoxy on it.
stu

Yep
CA + Baking Soda = Instant Concrete :tc:

tobydogs
07-27-2010, 03:54 AM
hey gang,when i started this thread a while back....i hadn't opened a bl motor to check or repair ,so here a quick report on the same motor i described in the beginning.

the picture is of the hog bipe planes power setup after an awful lawn dart landing[crash] that drove the motor and prop into the ground....the 100amp esc that was securely mounted inside the fuse was ripped from its screws and the cover came off.

i opened the 50-55-580kv sk turnigy and dumped out some dirt. while pulling the motor apart i found 3 magnets loose from their mounts in the bell housing. i cleaned all part and lubed the bearings with oil.

i glued the magnets back into place with thin ca and went around the bell housing to double check all magnets......then after it dried ,i did it again.

put everything back together. i cleaned up the esc and re soldered new plugs on it...it works!!!!even after the crash. i ran the motor while holding the x mount and all ran really smooth:ws:. well i still have to mount it to run a bench test of the esc and motor with a prop to check it with a watt meter. i had to cut one of the bolts that holds the prop adapter on do to the thread locktite bond was to strong and the hex head stripped. thank goodness for dremel cut off wheels,that bolt though small is hardened steel.

if all gos well with the bench testing i'll have a $99 esc and $40 motor to use again. just don't know if i should trust the servos even though they fell strong with no indication of striped gears. heres a few pictures of the motor and esc apart......[popcorn]

MustangMan
07-27-2010, 04:02 AM
Congrats on recovering the gear. Sounds like it's well on the road to recover!:D

kyleservicetech
07-27-2010, 06:30 AM
i glued the magnets back into place with thin ca and went around the bell housing to double check all magnets......then after it dried ,i did it again.


If anyone is concerned about the strength of the glue joint when re-attaching magnets to the "bell", try this old stunt.

Take ordinary plain baking soda, and use it to fill the gap between the magnets being re-attached. Make absolutely certain that the baking soda is lower than the magnets, so it will not hit the stator when the motor is re-assembled.

Then place a drop or three of thin CA on the baking soda. This turns the baking soda into instant concrete. Very strong, and if it sticks out above the magnets, the only way to trim it down is with a small file.

CA is also pretty resistant to temperature, so it works well. Keep it away from bearings and so on though!

harttvboy04
09-02-2010, 02:32 AM
Hi all.

I was working on the bell housing coming ( more like unscrewing) from the shaft adapter and I lost that brass washer. Where can I find one of these? If they are at the local hardware store, what size are they? I appreciate any help here! I have another that I just maidened today- wow! 6.5 pound twist on a 14x7 prop = almost 250 watts per pound on my twist 60! Please help- a mustang is down and there are many messas needing to be shot down! Thanks all!

Chris

P.s. I used jb weld to re- attach the housing :) that's definitely not coming off!