What did you crash today

[The Hangar]

I'd discharge and dispose. Last battery I had with a significant dent I figured "what the heck - let's charge it up". It seemed to be taking a charge just fine for about a half hour, and I didn't think anything weird was going on so I stepped out of my shop for a minute. Came back and it had blown up like a balloon and was super hot to the touch and making a "squeeeeeee" noise! Scared the crap out of me - it was a 4s4000mah so plenty of stored energy for a fire. I hauled it outside and threw it in a clay pot and covered it with wet sand quickly. About 30 minutes later it shrunk back down to normal size again. So it got the discharge and dispose treatment - but never came back in the workshop.

Did you check the voltage of each individual cell first?

 

[nhk750]

I use dented batteries too, but every time I dent a battery one of the cells fails a few months later. I guess just my bad luck, plus I am afraid of fires as the house is made of wood...

 

[The Hangar]

I use dented batteries too, but every time I dent a battery one of the cells fails a few months later. I guess just my bad luck, plus I am afraid of fires as the house is made of wood...

I've never had a cell fail before. I did blow up a battery accidentally but that was due to my own stupidity. I have the 4s that is dented and one of the cells is always a little below the others (0.03 volts) but I keep a close eye on it when charging and monitor it closely.

 

[The Hangar]

Yeah, I've done that and more. Solvent and compressed air, it needs to come apart. Thanks. Just need an allen key. I'm not going to go hog wild, it's only a $30 motor.

Are you going to toss the motor?

 

[Marty72]

I like to save money, but I really don't like fire. I had an incident with a small 1 cell battery and was amazed at the energy released by that little battery. So for now, I not saving damaged batteries. I do appreciate all the inputs.

I believe the motor can be saved. I found a small allen wrench (used for sprinkler adjustment) that fit. I pulled the motor apart, everything is clean now, applied a little light oil to the bearings and worked it in. Seems like it's fine now. I'll compare my other C pack motor to it tomorrow. A lot of sand was jammed in there.

 

[The Hangar]

I like to save money, but I really don't like fire. I had an incident with a small 1 cell battery and was amazed at the energy released by that little battery. So for now, I not saving damaged batteries. I do appreciate all the inputs.

I believe the motor can be saved. I found a small allen wrench (used for sprinkler adjustment) that fit. I pulled the motor apart, everything is clean now, applied a little light oil to the bearings and worked it in. Seems like it's fine now. I'll compare my other C pack motor to it tomorrow. A lot of sand was jammed in there.

Glad the motor worked!

 

[Wildthing]

New or old these guys can start a fire, so even if there are no dents in it and it is brand new means nothing. Proper storage when not in use, proper containment and not left alone while charging, proper containment while transporting.

 

[Marty72]

Glad the motor worked!

Yeah, maybe not. It at minimum the bearing are shot. It seemed smooth enough, so I hooked it up and ran the motor, sounds ok until about half throttle, then a high pitch sound gets worse with throttle, not good. So we will see.

 

[BATTLEAXE]

Yeah, maybe not. It at minimum the bearing are shot. It seemed smooth enough, so I hooked it up and ran the motor, sounds ok until about half throttle, then a high pitch sound gets worse with throttle, not good. So we will see.

Was it a squeal, I had that come from the ESC if I was using a less then half decent battery with a failed cell. Just a thought

 

[Marty72]

Nope, definitely not the esc. That esc is in the scout which I ran today with the b motor. I hooked it up to the c motor before installing it to check and sure enough.......no go. This has a metal sound!

 

[BATTLEAXE]

Nope, definitely not the esc. That esc is in the scout which I ran today with the b motor. I hooked it up to the c motor before installing it to check and sure enough.......no go. This has a metal sound!

I thought the squeal I had on mine I thought was the bearings but I found the ESC was telling me things were wrong with the battery, took a while to figure out though, after going taking the motor apart and doing a bunch of trouble shooting here on the forums.

 

[Grifflyer]

Yeah, maybe not. It at minimum the bearing are shot. It seemed smooth enough, so I hooked it up and ran the motor, sounds ok until about half throttle, then a high pitch sound gets worse with throttle, not good. So we will see.

Are you testing it with the prop on?

 

[Marty72]

No, but it's not the normal whirl sound, this is a screech. Metal to metal something is wrong sound.

 

[Grifflyer]

No, but it's not the normal whirl sound, this is a screech. Metal to metal something is wrong sound.

Hmm well I've had a motor screech at high rpm's whenever I took the prop off because it needed the resitance of the prop on to spin properly.

 

[Marty72]

Interesting, that does make sense. The bearing are probably designed to run with an axial load applied during operation. I'll run the other c pack tomorrow without the prop and see what it does. I did run the B pack motor after I heard the noise from the C pack motor. No comparison. I know they are different motors but....... But that's easy enough to check and I'll do it tomorrow, hopefully I wrong.

 

[Wildthing]

They are electric motors, they do not require weight or resistance of a prop to spin properly . Noise of course will be different with a prop on which is putting a load on the motor plus you have the prop making noise too.
There is very little to these motors but in order to service them you need to take it apart. If it spins true I would say it didn't bend the shaft or can, also you may have cleaned all the sand out (maybe) but what if there was a metallic spec of something in that sand and it is now stuck to the magnets inside and rubbing on the stator. You may have also washed all the oil out of the bearings.

 

[Marty72]

They are electric motors, they do not require weight or resistance of a prop to spin properly . Noise of course will be different with a prop on which is putting a load on the motor plus you have the prop making noise too.
There is very little to these motors but in order to service them you need to take it apart. If it spins true I would say it didn't bend the shaft or can, also you may have cleaned all the sand out (maybe) but what if there was a metallic spec of something in that sand and it is now stuck to the magnets inside and rubbing on the stator. You may have also washed all the oil out of the bearings.

Ok, so they aren't angular contact bearing, just plain old radials. I cleaned everything out, I found a allen wrench and took the motor apart. You are right, nothing to them.

So are these the bearings (size-wise) ? https://www.amazon.com/dp/B00XQ9198E/?tag=lstir-20

How have you been removing the old ones? prying them out with a screw driver or do you use some sort of bearing puller? Are you able to just simply push the new ones back in with your fingers?

 

[Wildthing]

Ok, so they aren't angular contact bearing, just plain old radials. I cleaned everything out, I found a allen wrench and took the motor apart. You are right, nothing to them.

So are these the bearings (size-wise) ? https://www.amazon.com/dp/B00XQ9198E/?tag=lstir-20

How have you been removing the old ones? prying them out with a screw driver or do you use some sort of bearing puller? Are you able to just simply push the new ones back in with your fingers?

Old ones are usually garbage so I will either with a small screwdriver or even an old shaft that fits through the center loosely and from the opposite end just tap it out, then go from the other end and tap that guy out. Putting in the new ones try to find something that is the same outside diameter and tap or press the new ones in. I soak all my new bearings in gun oil before I install them just for an extra bit of lubrication.
Usually the first bearing to go is the front one because of the weight of the prop .

Those 3 numbers are the size, I don't know what size you have , those you have listed should be 5mm shaft size, 11mm outside diameter and 4mm width. The motor manufacturer might list the bearing size or number , I just measure mine and then search for it. Most websites will have the size and the part number in the heading so searching is easy.

 

[Marty72]

Old ones are usually garbage so I will either with a small screwdriver or even an old shaft that fits through the center loosely and from the opposite end just tap it out, then go from the other end and tap that guy out. Putting in the new ones try to find something that is the same outside diameter and tap or press the new ones in. I soak all my new bearings in gun oil before I install them just for an extra bit of lubrication.
Usually the first bearing to go is the front one because of the weight of the prop .

Those 3 numbers are the size, I don't know what size you have , those you have listed should be 5mm shaft size, 11mm outside diameter and 4mm width. The motor manufacturer might list the bearing size or number , I just measure mine and then search for it. Most websites will have the size and the part number in the heading so searching is easy.

Ok, makes sense. I can always measure once I get them out. There is another technique for installing interference fit bearing but these are so small, it may not work. Heat up the bearing (oven), freeze the shaft. But if the bearings have rubber or plastic in them, the oven is a bad idea. Dry ice also works great. But you have to work fast. ha I don't have a press but I can make a bearing "press" with all thread, washers and 2 nuts. At this point, the motor is junk so no risk.



Thanks,

 

[Wildthing]

Ok, makes sense. I can always measure once I get them out. There is another technique for installing interference fit bearing but these are so small, it may not work. Heat up the bearing (oven), freeze the shaft. But if the bearings have rubber or plastic in them, the oven is a bad idea. Dry ice also works great. But you have to work fast. ha I don't have a press but I can make a bearing "press" with all thread, washers and 2 nuts. At this point, the motor is junk so no risk.



Thanks,

No you don't want to heat these guys period besides you would be heating the wrong part, you would want to heat what the bearings are going into and freeze the bearings. They are not in there that tight anyways , couple light little taps and they are in. .