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Wildflyer
10-27-2013, 02:45 AM
I have 2 E-Flite motors with magnet problems. I bought the motors on eBay as used motors, only 2 out of 4 motors have problems. The wiring seems to check out fine on all motors.

The Power 60 has 2 magnets that are broken in half at about the middle, I think it was dropped on the floor. I have the pieces with almost no chips missing.

If I glue these pieces back in place, removing any tiny particles, will this motor run properly?????
Or do I have to find magnets of the correct size and magnetic type?????

The power 90 is another matter, about 50% of the magnets are broken all to :censor: I have no idea what happened to this motor, unless it was dropped several times.????

Has anyone tried to buy an outer bell with magnet from Horizon Hobby?
Or is there any way to buy the correct magnets.?

Someone told me we can use JB weld to glue the magnets in outrunners. Is that true, or is there a better epoxy glue to use?

gramps2361
10-27-2013, 02:58 AM
Sorry to read you got some broken motors. I have heard people use ca, or epoxy to glue them back in. I don't have enough knowledge to give you a answer on how those broken magnets might work glued back in. If you can measure them this site has a lot of different sizes you might find the one you need. Good luck sure some motor guru will chime in with better help.
http://www.supermagnetman.net/index.php?cPath=37

tobydogs
10-27-2013, 03:09 AM
yikes! that really stinks:mad:. i have several eflite 60's in my planes and have considered them the best spent money on motors to date.[ i can't afford axi or scorpions]

several of the old turnigy SK series 50-55-580kv i had in all my larger planes had quality control build issues where magnets regularly came loose. i managed to pull the housing and drip ca into all area's of the magnets and did that on new motors i hadn't even used. now i have a drawer with 4 of these motors going unused.

I'm sure horizon service dept will have the answerers you need,but at what cost and effort to repair these 2 motors...it may be easier to return them if you can to the ebay seller and buy new ones.your a trusting person to buy used motors......i'v often seen irrissistable prices on them but hold off out of fear. i hope you can get it resolved cheap and quickly.stu

CHELLIE
10-27-2013, 03:17 AM
I have 2 E-Flite motors with magnet problems. I bought the motors on eBay as used motors, only 2 out of 4 motors have problems. The wiring seems to check out fine on all motors.

The Power 60 has 2 magnets that are broken in half at about the middle, I think it was dropped on the floor. I have the pieces with almost no chips missing.

If I glue these pieces back in place, removing any tiny particles, will this motor run properly?????
Or do I have to find magnets of the correct size and magnetic type?????

The power 90 is another matter, about 50% of the magnets are broken all to :censor: I have no idea what happened to this motor, unless it was dropped several times.????

Has anyone tried to buy an outer bell with magnet from Horizon Hobby?
Or is there any way to buy the correct magnets.?

Someone told me we can use JB weld to glue the magnets in outrunners. Is that true, or is there a better epoxy glue to use?

Jb Weld or a high temp epoxy will work fine to replace the magnets with, just make sure to get the polarity right, a few tiny chips missing wont hurt a thing. use some thin CA to glue the magnet back together with, then epoxy it back into the motor housing, hope that helps, Chellie

high temp epoxy is not cheap

http://www.zorotools.com/g/Epoxy%20Urethane%20and%20Acrylic%20Adhesives/00052225/?whence=

solentlife
10-27-2013, 08:45 AM
I tried epoxying a magnet back into one of high power Westor motors ... it runs but not well .

As I see it there are two important apsects to make sure of :

a) That magnet sits against bell and is not raised in any fraction compared to the others ...

b) that spacing of re-glued magnets is carefully set so gap to next magnet is same as others ...

I keep meaning to go back to my Westor .. and re-glue ... see if I can sort it.

As regards motors that give up the ghost and basically become shelf ornaments ... DON'T THROW AWAY ... the shafts can be used in other motors, the magnets make excellent canopy magnets, magnets if same as another motor can be used ... even the windings wire is good as locking wire .... and even as flying wires etc. The bearings may be good to use ... Sharpen up the bell edge and use as cutter for perfect circles in foam for motors to pass through etc.

Just because it doesn't swing a prop anymore does not mean it's trash-can.

;)

Nigel

subzJC
10-31-2013, 07:08 PM
I have found the "steel" part in jb weld is
attracted by the magnets and will go
to places not desired. I wouldn't do it again.

kyleservicetech
11-15-2013, 06:12 AM
I have 2 E-Flite motors with magnet problems. I bought the motors on eBay as used motors, only 2 out of 4 motors have problems. The wiring seems to check out fine on all motors.

The Power 60 has 2 magnets that are broken in half at about the middle, I think it was dropped on the floor. I have the pieces with almost no chips missing.

If I glue these pieces back in place, removing any tiny particles, will this motor run properly?????
Or do I have to find magnets of the correct size and magnetic type?????

The power 90 is another matter, about 50% of the magnets are broken all to :censor: I have no idea what happened to this motor, unless it was dropped several times.????

Has anyone tried to buy an outer bell with magnet from Horizon Hobby?
Or is there any way to buy the correct magnets.?

Someone told me we can use JB weld to glue the magnets in outrunners. Is that true, or is there a better epoxy glue to use?

This thread is a bit older, but I've used CA to secure magnets in some of those Go Brushless motor "wind you own kits".

The procedure is to very carefully clean the area under where the magnet is going to be placed, perhaps even cleaning it with one of those micro-files available from Harbor Freight, among other places.

Then, place the magnet in place, and secure it with a drop of thin CA. Make certain you have the proper North-South orientation for the magnet.

Next, get a box of baking soda from the kitchen, and lay some of that baking soda on each side of the re-glued magnet, level across, front to back of the magnet. Make certain the baking soda doesn't stick out above the magnet. FYI, that CA/Baking Soda trick isn't new, that's been around for years.

Then hit that baking soda with a few drops of thin CA, enough to saturate the baking soda. The result is instant concrete. Removing any of it will require a metal file. And, it seems to be pretty much immune to heat.

I secured the magnets of a half dozen 150 Watt Go-Brushless motors. None of the magnets ever came loose.

kyleservicetech
11-15-2013, 06:18 AM
the magnets make excellent canopy magnets, magnets if same as another motor can be used ...

Nigel

For those in the USA, one supplier of these high powered magnets of all sizes from pin head size to giant size is:
http://www.kjmagnetics.com/products.asp?cat=11 Would not be surprised if they have replacement sizes to match some of the brushless motors out there.

We used some of those magnets in a very high powered magnetic actuator that moved about 1/2 inch with about 400 pounds of force behind it. Travel time was on the order of 10 milliseconds.

The magnets inside these things could lift some 500 pounds on a heavy steel block. And, those :censor: things were nothing to play around with. I got my fingers between two of them. It didn't stop bleeding for 9 hours. Make absolutely certain no children can get access to them. If two are swallowed, it's a medical emergency.

Wildflyer
12-18-2013, 04:26 AM
Thanks to a modeler on RCgroups, I now have a perfect running E-flite Power 90.
The one he had was damaged in some way other than the magnets and bell housing. So I bought it from him for a reasonable price.

I put his bell housing on my stator and bearings and BINGO I have a good motor.
I haven't had a chance to work on the Power 60 yet, but I have hopes for it also.

Ohm
06-06-2014, 06:20 PM
I found replacement magnets for my Eflite park 480 from these folks
hkcm.de engineering.com I tried to post a link to the site but something aint working right.
Any way HKCM will make a batch of custom magnets if you want to pay at least $250.00 for minimum order, the smaller the mag the more you get for the 250 and vice versa. BUT they do have in stock or left overs from other orders and with some searches done over time I found magnets that would fit and were stronger. Cost about $13.00. The stronger magnets lowered the Kv but a rewind with larger wire and fewer turns (star) will upgrade the Parks 480 into a much better motor than what came out of the box. Which in my observation are inefficient as sold imho.

Wildflyer
06-07-2014, 04:34 AM
Thank you, I did a Google search and found them at---- https://www.hkcm.de/app.contact.php?language=en&osCsid=ceecdb9cd6eb85bfbad336c9ec6aef08

I will measure my magnets again, and contact them.

I think you have to have a few more posts, in order to post a link. Just a way to try and keep this board clean, the mods do a great job.

Welcome to Wattflyer, please tell me more about rewinding, I have a Power 52 that I believe has a short in the windings, it will get warm slowly running at 4 amps with no prop.
I have several Park 480's but haven't flown them, what performance do you get out of your rewound one? (This reminds me of what we did with slot cars in the 60's)

kyleservicetech
06-07-2014, 05:37 AM
Thank you, I did a Google search and found them at---- https://www.hkcm.de/app.contact.php?language=en&osCsid=ceecdb9cd6eb85bfbad336c9ec6aef08

I will measure my magnets again, and contact them.

I think you have to have a few more posts, in order to post a link. Just a way to try and keep this board clean, the mods do a great job.

Welcome to Wattflyer, please tell me more about rewinding, I have a Power 52 that I believe has a short in the windings, it will get warm slowly running at 4 amps with no prop.
I have several Park 480's but haven't flown them, what performance do you get out of your rewound one? (This reminds me of what we did with slot cars in the 60's)

Here is another source of magnets.
http://www.kjmagnetics.com/products.asp?cat=11

kyleservicetech
06-07-2014, 05:43 AM
Thank you, I did a Google search and found them at---- https://www.hkcm.de/app.contact.php?language=en&osCsid=ceecdb9cd6eb85bfbad336c9ec6aef08

I will measure my magnets again, and contact them.

I think you have to have a few more posts, in order to post a link. Just a way to try and keep this board clean, the mods do a great job.

Welcome to Wattflyer, please tell me more about rewinding, I have a Power 52 that I believe has a short in the windings, it will get warm slowly running at 4 amps with no prop.
I have several Park 480's but haven't flown them, what performance do you get out of your rewound one? (This reminds me of what we did with slot cars in the 60's)

Your motors will get slightly warm while running with no load. The critical item is the no load current pulled, as compared to the motor specifications of no load current.

Shorted turns in a motor will result in increasing that no load current. And, at the same time, those shorted turns are going to get HOT. It would be a good idea to do this test with a fuse in line with your battery to the ESC. Don't want to blow an ESC on a shorted motor. A good fuse size would be perhaps 30 - 50% of the ESC current rating.

If you have access to a battery powered drill that can turn over perhaps 1000 RPM, chuck up your motor to the drill and slowly increase the RPM. (With all three leads isolated from each other.) There should be little or no drag on the stationary part of the motor, even while turning over at 1000 RPM. And, again, if your motor has shorted turns, spinning that motor at 1000 RPM with the battery operated drill is going to make those shorted turns get HOT. If you remove the bell from the motor immediately after spinning up the motor, it will be easy to locate the shorted winding. Just touch it.

Here is more info on checking out your brushless motors:
http://www.wattflyer.com/forums/showthread.php?t=35216

Check out posting #31 in this thread.

Wildflyer
06-07-2014, 06:15 AM
Just touch it.

I don't think so Denny, that's why I have an infrared thermometer.
I am going to get a contact probe type soon.

I haven't played with these motors for a while. I hope to get some time to check them soon.

kyleservicetech
06-07-2014, 06:24 AM
Just touch it.

I don't think so Denny, that's why I have an infrared thermometer.
I am going to get a contact probe type soon.

I haven't played with these motors for a while. I hope to get some time to check them soon.

Lol I knew someone would get me on that! I've got two infra red thermometers plus a couple of thermocouple types too.

ron_van_sommeren
06-07-2014, 02:20 PM
www.supermagnetman.com (USA)

www.supermagnete.eu (Europe)

Ohm
06-07-2014, 03:48 PM
Thank you, I did a Google search and found them at---- https://www.hkcm.de/app.contact.php?language=en&osCsid=ceecdb9cd6eb85bfbad336c9ec6aef08

I will measure my magnets again, and contact them.

I think you have to have a few more posts, in order to post a link. Just a way to try and keep this board clean, the mods do a great job.

Welcome to Wattflyer, please tell me more about rewinding, I have a Power 52 that I believe has a short in the windings, it will get warm slowly running at 4 amps with no prop.
I have several Park 480's but haven't flown them, what performance do you get out of your rewound one? (This reminds me of what we did with slot cars in the 60's)

I have an E-Flite Twist 3D 480 that was powered by the Park 480 (2810) with a TP 3S 2100 spinning the APC 12X6, the AUW came in at about 30oz. With a custom wound Silver Plum(?) (2808) ($6.00 from Leaders Hobby) the rig weighs in at 24oz AUW. Using a Star connection instead of Delta it reduced the current draw by about 10A @ WOT. With the a lower current motor (doing the same work) I was able to use a smaller battery (TP 3S 1350) pack since my WOT Amps dropped from about 29A to 19A. I also did some mods to the rigging to remove tail weight, so as not to have to add dead weight in the nose. Net results is a lighter airplane that performs better than OEM. Flite time is 6 to 10 minutes depending on how hard I want to fly it.
Big price difference between a 1350 and a 2100 so not only do I get a better performing plane but a significant savings on battery cost.

ron_van_sommeren
06-07-2014, 09:00 PM
... Using a Star connection instead of Delta it reduced the current draw by about 10A @ WOT. With the a lower current motor (doing the same work) I was able to use a smaller battery (TP 3S 1350) pack since my WOT Amps dropped from about 29A to 19A. ...By going from delta to star you lowered Kv by a factor √3. Kv_delta= √3 Kv_star. Same for torque. And since motorcurrent wants to go up with voltage squared and Kv cubed ...

Wildflyer
06-08-2014, 06:38 AM
www.supermagnetman.com (USA)

www.supermagnete.eu (Europe)

Thanks Ron,
I had contacted them, and they tried very hard but could not come up with the right size of magnets. The head guy even contacted me in the middle of a business trip in China, I thought that was pretty cool.
I haven't given up on these motors, just other things got in the way.

The Power 90 is working perfect, after a fellow modeler sold me the outer housing with magnets. I just don't have a plane that needs that size of motor. Guess I will have to do something about that.

If I could get a damaged power 60 with enough good magnets, that would be perfect.

ron_van_sommeren
06-08-2014, 01:40 PM
... Here is more info on checking out your brushless motors:
www.wattflyer.com/forums/showthread.php?t=35216 ...On Christo's diy motor building site
www.bavaria-direct.co.za
-> motor constants

ron_van_sommeren
06-08-2014, 02:54 PM
BTW wildflyer, you should replace all magnets. Otherwise you end up with different magnet-strengths. And glue them in alternatingly.
Here's a nice method that will give you bomb-proof magnets
www.torcman.com
(http://www.torcman.de/index_e.htm)-> downloads
-> Assembly Procedure TM280, 350, 430
-> Chapter 3: The Rotor

Wildflyer
06-08-2014, 04:46 PM
Thanks again Ron
I know I have to rewind my power 52, I will unwind it carefully to determine the winding pattern the used, and compare that to others.

I would only replace some of the magnets if they came from the same motor, and only then if I could not get a full set.
I know I should replace all magnets and that's where the problem starts. On these motors, the front of the magnets (deepest end in the housing) fit into notches in the aluminum front housing. If I could cut the end of a magnet down by .5 mm maybe I could find them easier.
I will study the sites you showed me, thanks.

Ohm
06-08-2014, 09:38 PM
Thanks again Ron
I know I have to rewind my power 52, I will unwind it carefully to determine the winding pattern the used, and compare that to others.

I would only replace some of the magnets if they came from the same motor, and only then if I could not get a full set.
I know I should replace all magnets and that's where the problem starts. On these motors, the front of the magnets (deepest end in the housing) fit into notches in the aluminum front housing. If I could cut the end of a magnet down by .5 mm maybe I could find them easier.
I will study the sites you showed me, thanks.

I have not heard of a method to safely and reliably cut magnets at home, but if you figure it out let us know.

kyleservicetech
06-09-2014, 03:57 AM
I have not heard of a method to safely and reliably cut magnets at home, but if you figure it out let us know.

If my fading memory is correct, cutting and breathing in magnet dust is not good for your health
:eek:

Ohm
06-09-2014, 02:11 PM
If my fading memory is correct, cutting and breathing in magnet dust is not good for your health
:eek:

Breathing air has proven fatal to everything that breaths it, how bad can a little magnetic dust be?:rolleyes:

Brner
06-09-2014, 03:47 PM
Breathing air has proven fatal to everything that breaths it, how bad can a little magnetic dust be?:rolleyes:

I really like your tag line.....:)

"There is nothing so simple it can't be done wrong. "

Welcome to Wattflyer.....

Wildflyer
06-09-2014, 05:41 PM
I figure after 62 years of woodworking (started when I was 4 yo) and 40 years of being a carpenter, I have at least inhaled an 8'- 4"x 4".

Somehow it seems I got rid of it, a little at a time, just like it came in.

Carpenters are too stupid or proud, to wear a breathing respirator any time, we or someone close to us are cutting wood. Dry wood dust is the worst as it will stay in the air for over an hour. I have seen this in my own shop.

The cup type paper masks are basically useless, unless you duct tape them to your face. WAY too much leakage around the edges. There are some good ones but they are hard to find.

My idea to cut a magnet is to clamp it between 2 strips of wood and then use my wet diamond saw to trim the edge. I have not tried this yet but I think it would work.

kyleservicetech
06-09-2014, 06:16 PM
I figure after 62 years of woodworking (started when I was 4 yo) and 40 years of being a carpenter, I have at least inhaled an 8'- 4"x 4".

Somehow it seems I got rid of it, a little at a time, just like it came in.

Carpenters are too stupid or proud, to wear a breathing respirator any time, we or someone close to us are cutting wood. Dry wood dust is the worst as it will stay in the air for over an hour. I have seen this in my own shop.

The cup type paper masks are basically useless, unless you duct tape them to your face. WAY too much leakage around the edges. There are some good ones but they are hard to find.

My idea to cut a magnet is to clamp it between 2 strips of wood and then use my wet diamond saw to trim the edge. I have not tried this yet but I think it would work.

Yeah, I also don't have much use for those paper respirators. I've got two of those full face mask rubberized respirators that can use either the charcoal filters, or a very good dust filter. They go for about $25 or so around here. These have one way valves in them for breathing in, and breathing out. Best investment I made for protecting valuable stuff. Having been born and raised on a farm with its usual amount of dust, I use that mask whenever cutting anything around here.

Also found in google that it is not a good idea to cut magnets without the proper equipment. Overheat them, and they loose their magnetism. Magnet dust can ignite, and the fumes from that ignition are poisonous.

One of the magnet supply houses indicates the proper way to cut their magnets is with a diamond saw, along with coolant. Looks like you're all set to go.

Wildflyer
06-10-2014, 02:27 AM
Thanks Denny
Almost any dust can ignite, even steel powder, if it can oxidize it can burn, and of course fumes from any combustion, are poisonous.

My diamond wet saw just seemed like a good idea. I didn't know I was right on.
Now I will have to check out how easy it is to cut a magnet. Probably easier than some tile I have come across.

ron_van_sommeren
06-10-2014, 02:54 PM
NdFeB dust is a health hazard:
en.wikipedia.org/wiki/Neodymium#Precautions (https://en.wikipedia.org/wiki/Neodymium#Precautions)

NdFeB magnets get mushy when exposed to moist in the air. Seal them with lacquer/resin/glue:
en.wikipedia.org/wiki/NdFeB#Corrosion_problems (https://en.wikipedia.org/wiki/NdFeB#Corrosion_problems)

From
www.supermagnete.de/eng/safety_neodymium.php (http://www.supermagnete.de/eng/safety_neodymium.php)
Untreated neodymium magnets oxidise quickly and disintegrate.

Ohm
06-12-2014, 04:26 PM
[QUOTE=ron_van_sommeren;950234]NdFeB dust is a health hazard:
en.wikipedia.org/wiki/Neodymium#Precautions (https://en.wikipedia.org/wiki/Neodymium#Precautions)

NdFeB magnets get mushy when exposed to moist in the air. Seal them with lacquer/resin/glue:
en.wikipedia.org/wiki/NdFeB#Corrosion_problems (https://en.wikipedia.org/wiki/NdFeB#Corrosion_problems)

From
www.supermagnete.de/eng/safety_neodymium.php (http://www.supermagnete.de/eng/safety_neodymium.php)[/QUOTE

I have read that uncoated magnets deteriorate when uncoated, which makes me wonder because the magnets I replaced in the Park 480 did not have any detectable coating on them. I left the magnets outside in the weather for a month to see what happens to them. hkcm.de offers no coating along with all the other types of coating. The funny thing is uncoated magnets are more expensive than some of the other coatings available. I bought some gold plated magnets a year or so ago because they were the least expensive in the size I was looking for. Although the coating is thin and they say to avoid allot of handling of the magnets as the gold will rub off. They sure do look good when installed.

Ohm
06-12-2014, 04:35 PM
By going from delta to star you lowered Kv by a factor √3. Kv_delta= √3 Kv_star. Same for torque. And since motorcurrent wants to go up with voltage squared and Kv cubed ...

Thanks for the math, to bad I don't understand it. I got the amps times volt thingy down after that I get confused with all the different symbols different folks use to describe the functions. In the sixty's we had a few old fashion symbols which don't exist on computer key boards. Maybe one of these days I'll take the time to learn what all that means. I think it is really neat to be able to calculate the future. I'm just so ingrained in the monkey see monkey do procedure and having success at it that it makes learning why it works hard to find the time. (translation, means I'm lazy)

Ohm
06-12-2014, 04:38 PM
Thanks Denny
Almost any dust can ignite, even steel powder, if it can oxidize it can burn, and of course fumes from any combustion, are poisonous.

My diamond wet saw just seemed like a good idea. I didn't know I was right on.
Now I will have to check out how easy it is to cut a magnet. Probably easier than some tile I have come across.

Wet cutting the magnets what a great idea, I think...

Wildflyer
06-13-2014, 05:02 PM
I have to a new blade for my wet saw, as I have totally worn the current one out.

Maybe today I can get there, then we will know.

Thanks for the tips about sealing the magnets, I would not have thought of that.

kyleservicetech
06-13-2014, 05:14 PM
Thanks for the math, to bad I don't understand it. I got the amps times volt thingy down after that I get confused with all the different symbols different folks use to describe the functions. In the sixty's we had a few old fashion symbols which don't exist on computer key boards. Maybe one of these days I'll take the time to learn what all that means. I think it is really neat to be able to calculate the future. I'm just so ingrained in the monkey see monkey do procedure and having success at it that it makes learning why it works hard to find the time. (translation, means I'm lazy)

For those who have worked with three phase power, these terms are readily understood.

But, for our use, that Wye and Delta configuration has been decided by the motor mfg when the motor was built. It could be changed afterward, but doing so would be dealing with real short motor magnet wires, and the problems associated with reconnecting them in the different configuration.

I did some of that Wye Delta stuff with those www.gobrushless.com motors I wound up some 10 years ago. (Still have those motors)

ron_van_sommeren
06-13-2014, 05:21 PM
Thanks for the math, to bad I don't understand it....
Kv_delta = 1.75 Kv_star
Kv_star = Kv_delta / 1.75

Double voltage and motor/battery current wants to quadruple (22). An n% increase in voltage will give a 2n% increase in current.
Double Kv and motor/battery current wants to increase by factor 222 = 8! An n% increase in Kv will give a 3n% increase in current.

kyleservicetech
06-13-2014, 05:39 PM
Kv_delta = 1.75 Kv_star
Kv_star = Kv_star / 1.75

Double voltage and motor/battery current wants to quadruple (22). An n% increase in voltage will give a 2n% increase in current.
Double Kv and motor/battery current wants to increase by factor 222 = 8! An n% increase in Kv will give a 3n% increase in current.


There are a number of very good computer programs that do all the math for you. The one I like is www.motocalc.com.

Another is Drive Calculator.
http://www.drivecalc.de/

Hey, that's an idea for a new thread!