20" Mower "field" repair of the MOTOR

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  • Problem
  • Updated 1 year ago
  • Not a Problem
  • (Edited)
This is the first generation 20" mower without the fan.  After hitting a buried baseball sized rock, the mower stopped abruptly, and after starting up again, it was making a grinding noise.  When spinning the blade by hand, the motor still made the same noise.

At first, I thought a toasted a bearing; but after disassembling, I found that one of the four magnets had been dislodged from the motor case by the impact.  I was able to fix it back in place with 2 ton epoxy, and allowed it to set over night.  I have since used the mower through a few heat cycles (at least 10x 2.0/2.5AH batteries), so the repair appears to be permanent.

While it was apart, I took some measurements of the commutator diameter, and the brush length; not sure of the original dimensions, but this one seems to be in pretty good shape.  The manufacture date is 08/2013, so about three years old.



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(a)Typical Engineer

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Posted 2 years ago

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Blue Angel, Champion

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Sweet! Great job with the repair and pics!

You're fortunate that the magnet stayed together... quite often a piece will break off and the motor will grind it up into dust.
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Exrace

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Willing to bet from some others having this issue continued to run the mower after hitting the object ignoring the noise until the loose magnet came apart.
(a) Typical's magnet was in one piece with the photo clearing showing the epoxy let loose.
(Edited)
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Blue Angel, Champion

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I was thinking the same as I was typing. :-)
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(a)Typical Engineer

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I did attempt to run it, and it clearly was not right.  And when you spun the blade my hand one way, there was less drag. Once the magnet was loose, it was just sticking to the armature.  And when you reversed the direction, there was about 10 degrees of rotation of no drag, and then the magnet ran into the other ones, and the drag resumed.
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Exrace

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Great fix. Wonder if incasing all the magnets in a thin coat of epoxy would make them less prone to coming loose. Did you notice if the current white epoxy was brittle from age?
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Blue Angel, Champion

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On the original mower this could have been a consideration.

On the newer mower designs Ego has removed the keys from the blade mounting flange so the motor can decelerate slower than the blade. As far as I can tell (based on a lack of reports here), it seems to work.
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(a)Typical Engineer

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Exrace, the epoxy was hard, but not very brittle; to clean up the traces of epoxy was not very easy, e.g. it did not just flake off or turn to dust.
(Edited)
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David Watson Jr.

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I've have experienced the same problem... broken magnet. How did you clean the epoxy off?
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(a)Typical Engineer

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I did not really have  to remove the epoxy, basically the bead of epoxy that was left behind was my guide to where to put the magnet back.  I did scuff up the magnet side epoxy so that there would be good contact between that and the metal motor housing.
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David Watson Jr.

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Excellent. Thank You. One more question... what brand of epoxy? The Gorilla brand advertises 3500psi. The 2 ton I found advertises 2500 psi.
(Edited)
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(a)Typical Engineer

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matt.mackinnon, I like your idea of a sacrificial shear drive pin; I might look into seeing what it would take to make that modification.  It would definitely entail modifying, removing or replacing the round and non-round drive pins that fit into the blade.
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A few additional pictures: the upper is the top of the motor housing which houses the sealed bearing. The next one is how I clamped the magnet while the epoxy set. And the last is the chassis after you remove a bazillion screws, and then pull the top shroud off (left all the grass clippings on there to show how much gets and stays inside).


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David Watson Jr.

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I still can't find all of the screws.......... Thanks for the pics though. They will likely help!
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(a)Typical Engineer

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The tricky ones are about 8-12" in, you definitely need a long #2 philips screwdriver.  I think the four screws that hold on the rubber skirt need to come off too.
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David Watson Jr.

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Thank You
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David Watson Jr.

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Does the housing just "pop" off after all the screws are removed? Or did it take some prying?
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(a)Typical Engineer

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You should not have to pry anything.  First you take out the battery box, disconnect the wires after you loosen the screws and lift the box up a couple inches.  Then you disconnect the headlight wire harness from the control board.  Then take off the bazillion screws, all on the bottom, including the rubber flap.  Then you lift the top half off from the bottom half; and I'm pretty sure there were no wires connected to the top half at that point.  If you're removing the motor, you would have already removed the blade, and then you can remove the three screws from the bottom around the motor, which allows the motor to lift straight up.
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Mill-Chips

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I know this is an older post but i am having an issue with my motor and was wondering if you can shed some light on it.  I bought my mower 21"sp a little over a year ago.  now it won't come on unless i take the blade off.  however when i do the the rpm stays very low.  if i put blade on the overload kicks in because im guessing the rpms cannot pick up.  So i am thinking its related to the motor.  the thing is before i put it away the last time i used it, I was able to cut my entire lawn with no issues at all.  I would like to take it in for repair except i relocated for a job temporarily and just for me to ship it to a center will cost me about $300 plus the time to get it back.  Do you have any ideas of what i can check to try and get it running again.  Any suggestions will be appreciated.
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(a)Typical Engineer

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1) have you hit anything while mowing (rock, root, etc.)?
2) with the blade on, when you turn it by hand, is is smooth or rough?
3a) if the handle clamp safety feature is not working, the mower will spin up then drop back down
3b) will the mower spin up to full speed and keep spinning without a load (on driveway)?
3c) will the mower cut when being pulled backwards over grass?
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Mill-Chips

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1)i do have some rocks in my area but i didn't remember hitting anything hard and it worked fine when i put it away.  i even do about a minute test run after i clean it off to make sure it is running fine.
2) when i turn it by hand there is some resistence but it does spin in either direction
3) i double check the clamps by removing them and just pressing the switch myself it appears to run properly.
4) mower doesn't spin up at all with blade on goes into load protection mode.  If I take the blade off it spins up slightly then dips in speed and then back up again to its low rpm.  i actually have a vid i took with my phone to show both instances in the same location. not sure how i can post share it with you.  Maybe I can do it via dropbox or something. i do tend to here like a chhh chhh sound when it does spin up with the blade off, as though it may be rubbing on something.
5) it does not power spin up with the blade on at all just goes into overload protection.  Then with blade off its super low varying rpm with no load on driveway.  
I have clean it out with air and a brush thinking something was in it but still nothing though i see a ton of grass was trapped in there like in your pictures.  I'm at a crossroad because at $300 to try and fix it, coupled with the local home depot here not able to do repairs or even  carry the SP version.  It's like what happens if i did buy another one and it craps out again.  I love this mower and have the trimmer, blower and hedger.  Even bought some of the tools for my parents.  Would just hate to see this investment go down the drain without a fight.
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Michael G

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Chike - from what I have read here most Home Depots do not repair these on site. They ship them to service centers. Your mower must be under warranty so why not just bring it to your local HD and get it repaired under warranty?

Mike
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Mill-Chips

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Thanks for the suggestion and i contacted support who told me to send it to FL close to where I do live state side.  However when I came here the local home depot didnt even carry the ego mower and only said we can have it shipped to fl for you and then you will have to ship it here.  So i really doubt they will help me in getting it repaired especially when checking the local shippers i found the price to be about $300.  However that is an option I can look into.  Though honestly I would not give it much chance of success.
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Mill-Chips

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Michael G -  Just wanted to let you know I took your advise and contacted Home depot who then gave me the information for a local repair shop that should be able to assist me.  I was excited at finding someone only to have my excitement diminished when I got in contact with the shop.  They said oh you have an ego, sorry we aren't an authorized dealer and that are very strict about who works on their products.  Said the best he can recommend is calling Ego once again explain my situation to them and see if they can assist me.  They even said not to give up and see it through but honestly now I am more disappointed than I was when I started.  Seeing as though I own several EGO products, all that keeps playing in my head is that I may not get warranty coverage due to where I am located and let's face it, ego doesn't run cheap.  Guess i will have to reach out to them again before some final decision is made.  All the while my grass is growing higher and higher.  Not to mention we have weather pending that will sure give the grass new life., sigh