can a ball bearing make a squeeking noise like a mouse? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 12:43:41 am
content: I need to repair my dewalt die grinder (newest least used tool broke), its making a noise like a field mouse at high RPMs. Right when I was ready to finish my project with the alumicut burrs. The aluminum flap wheels (zirca) and aluminum grinding disc does excellent with the regular grinder however.I assume its a ball bearing, and there are two to order, but normally ball bearings make this kind of grinding/ringing noise when they are fucked up.. this thing squeaks. It reminds me of rubber slipping or a chipmunk making noises (but very loud).Can a bearing make this noise? It's the one right near the colet. I assosiate bad bearings with rumbling, but I never dealt with a bad high speed bearing before (only stuff maybe up to 3kRPM)*this tool has taken a fall a while back, but it was fine. I think it fell when it had the paint stripping 'black sponge' on it. Its very wide, so it must have bent something inside of the head assembly when it fell. Thats how I suspect the damage happened. I will be making a tool holder for this tool now I think.BTW the tool does not make any noise when its run without the head, so I don't think its the bottom portion.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: August 15, 2020, 01:48:34 am
content: I had to fix my grinder a while ago due to bearing mishaps.Plastic casing overheated an had cracked letting in moisture.What happens if you were to squeeze a little grease in? Does noise stop/change?

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 01:50:21 am
content: I tried to get wd40 in there to see if it would help at least temporarily before taking it apart to get an idea of whats going on, but it did not help at all. I assume its not penetrating.I need to find a weird slip ring adapter to get in there (it needs to be long)The noise only happens in high RPMs, since its variable speed I can run it for without noise at low speed but I don't want to break it further

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: August 15, 2020, 01:54:48 am
content: Quote from: coppercone2 on August 15, 2020, 01:50:21 amSometimes high pitch squeaks and squeals are oscillations. Check for non-round parts that should be round. Check for any slop in moving parts.Maybe the grinder just likes to squeak.

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 02:16:49 am
content: so its likely not a ball bearing then?

author: bill_c
author_rank: Regular Contributor
timestamp: August 15, 2020, 03:46:50 am
content: Corded, battery, or air powered? How old is it?A bearing with ALL lubricant removed can squeak but it will usually fail horribly in a short time.WD40 is not really a lubricant, its good to use to as a test for stuff like this, but it does evaporate. Its also good at removing grease from stuff.Any chance of a recording of this noise?When you get into higher speeds, be careful not to put too much grease in a bearing or it will overheat. Typical fill for a bearing at 24k rpm is 3-5% of NLGI ViscosityGrade 1 or 0.

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 04:39:25 am
content: I am going to replace them but I am thinking its going to be difficult to find out what is squeaking at those speeds without all kinds of adapters to make bearings go at high speeds, so my plan was just to spend 10$ on new bearings. im waiting on the shipping for a spring clip tool and the bearings at the same time..if the first reply was 'no its a shaft that bent I have seen this before' I would have waited on the orderI just wanted to know if it was something obvious that is not a bearing, but it sounds like a fairly good betIts battery powered, a few months old and has like less then an 2 hours of use on it total. It must be fall damage. Most of the use was low RPM paint stripping for salvage. It's annoying because its a critical tool for me right now. Should probably get another one so two are available.

author: KL27x
author_rank: Super Contributor
timestamp: August 15, 2020, 07:16:51 am
content: For a holder, I just clamp a piece of angle iron to w/e bench or work surface I'm using. The back of the guard hooks right over it. W/e you use for a "stand," it's probably more convenient to make it clip to the edge of a bench top then to stand on its own!

author: DimitriP
author_rank: Super Contributor
timestamp: August 15, 2020, 11:14:39 am
content: QuoteMy pool pump did the same thing after not running it for a while. Stopping it and starting it would "take care of it". Replacing the bearings made it a lot quieter overall and hasn't squeeled since.

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 08:29:17 pm
content: studying the diagram a little, i realized there is a plastic bit in there, on top of a bearing. I suspected it might have heat damage, so I did this testTake a rag, put it over your finger (or glove), and press on the top of the grinder while you spin it up (normally it heats finger too much and is painful). I noticed if I put light pressure on it, the noise went away, from the top.I tried another experiment, I put it in a carpenters vise for like 10 minutes, with decent tension. When I reassembled it, the noise went away. I think the noise was comming from some heat deformed plastic thing, because it sounded like suqeeky plastic. The bearings are sealed and new.. I guess I need to replace them anyway.. but maybe it was just alignment problem fixed by vise? I think its a bunch of press fit shit in there, so when I pushed it all together as it was pushed together when it was assembled, maybe it realigned something correctly.

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 09:05:39 pm
content: cut some aluminum with it, it seems to work fine. No noise.The other problem I think that might have lead to this, is not fully seating the burrs in there. I think the last burr I used in it was not fully seated (wanted to get a little bit of extension, i think the proper way is to get long neck burrs).

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2020, 10:55:20 pm
content: ok, so I was cutting the edge of something in a precarious position and it caused the tool to bounce around and it made that noise again. So, this time I struck it gently with a 3 pound lead mallet on the top and it seemed to fix the issueIt does not compress tightly enough is my guess. Its not a magic stick like a 'finger belt sander', you need to plan your cut and follow through on your plan and not do anything spontaneous with this die grinder. I am more used to things that sand/abrade, and generally you can stick those in however (so long its not a stone tool (sharpening stone).. these are sensitive to damage in their own right).I was being hectic with it to try to vary the cutting position on the burr, but I believe that this just increases the risk of 'bounce' and you should instead be more willing to wear the tool out faster as a beginner. I call it surgical. Grinder feels like a pressure washer in comparison.Did 3 feet of aluminum weld cutting with it, to flush, and it still does not make noise.

author: tautech
author_rank: Super Contributor
timestamp: August 16, 2020, 07:56:14 am
content: My 2cIf it's a brushed motor the com end of the armature is sometimes only bushed and they'll squeal if they get too dry.Typically they might use a porous bronze bush that will hold some lube yet you want very little in close confines to the com for fear of contamination.High speed ball races of the output end can be C3 rated bearings that offer better life at higher RPM's and loadings. The C3 markings can be easy to miss so inspect them with care.

author: coppercone2
author_rank: Super Contributor
timestamp: August 16, 2020, 08:02:05 am
content: nah its brush less and its been working fine. the maintenance procedure is to tap it with a lead hammer until you need to buy a new oneI am not dealing with that complicated spindle assembly, i have things to do that are actually useful/fun. It has to be some kind of stupid alignment problem. If it develops a different type of squeaking or bearing noises that I am familiar with, I will try replacements.. but this noise was too strange for me to think about it anymore other then hammer time, and as of right now it seems to be holding up very well.

author: Ian.M
author_rank: Super Contributor
timestamp: August 16, 2020, 08:13:40 am
content: You've dropped it, so you may well havebrinneledthe bearing, and possibly lost any spindle preload its supposed to have. How could it come and go? Well if the indentation damage is to the race(s) and is just to the side of the normal track of points of contact for the bearing balls, it might not cause any vibration till axial play in the spindle permits the balls track to wander into the pits. If the bearings are suspect, the only certain cure is a spindle rebuild with all new bearings. If its still under warranty, get a video clip of the malfunction, and see what the manufacturer's service department has to say.

author: tautech
author_rank: Super Contributor
timestamp: August 16, 2020, 08:22:07 am
content: Quote from: coppercone2 on August 16, 2020, 08:02:05 amOK, so probably ball race at each end.QuoteDon't discount it's an axial load issue. You say when it gets a hard time the squealing starts which suggests the output end bearing housing or inner bearing surface is a shade lose so the armature moves axially and the bearing moves on the shaft or in its housing resulting in axial loading on the bearings which with a tap of youradjusterhelps neutralize the axial loading.Ball race bearings in general are not suitable for axial loads although there are some that have higher axial ratings than others.More 2cIf it were mine I would disassemble and check bearings are reasonably tight on shafts and in housings and if not address it with Loctite or prick punching of the shaft if needed.Even if the bearings are sealed or shielded pop one side out with a very fine screwdriver and either add light oil to revitalize any remaining grease or add just a little low viscosity grease.Good luck.

author: KL27x
author_rank: Super Contributor
timestamp: August 16, 2020, 08:32:18 am
content: QuoteGeneral rule I have learned over time doing any sorta grinding with a bur is to always conventional cut, but climb your way in sections. Start at the finish, sorta, then climb your way up a bit grinding back to where you started, blending that in, then take another step ahead, ad infinitum.

author: KL27x
author_rank: Super Contributor
timestamp: August 16, 2020, 08:34:42 am
content: And my other post about the stand probably didn't make any sense. I thought you had dropped your angle grinder.

author: coppercone2
author_rank: Super Contributor
timestamp: August 16, 2020, 08:36:56 am
content: its a good idea for both but I need to finish making a metal working table (i do everything on top of a cast iron table saw or in a vise).I need to reinforce the bottom with more flat bars, and I need to get ground flat bars for the top. Its expensive to finish. That table was supposed to have magnetic drill capability, and holders for all the different metal working tools. I can use all the magnetic things on the table saw anyway.. just need to be careful not to drill into the motor or something.that table turned into a freaking money hole. I prefer having the tools that can be used to most of their capacity without the table then a monster table without anything on it.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 28, 2020, 11:17:18 pm
content: One of the things I've learned about repair, is that it's often not possible to logically deduce the error from the symptoms.If your grinder squeals like a hog, there id definitely something wrong with it, but from the outside you can not deduce what part has failed, or in what mode it has failed.It may be a cog, maybe you have a cheap version and it's a dry bushing instead of a ball bearing.Pouring WD40 in it is not a good idea without first figuring out what part has failed and how it failed.It may well turn an easy repair into completely unrepairable.One of the failure modes of ball bearings is to lock up completely. For example from a broken ball or ball cage that wedges itself between the raceway and other balls. In such a case the squealing can be caused by the axle slipping inside the locked up bearing. If this is nod addressed promptly and adequately, the axle wears out very fast and the thing is ripe for a ground fill. In this case if WD40 seems to help, it just hides the problem and your grinder WILL fail a day or week later.

author: coppercone2
author_rank: Super Contributor
timestamp: November 08, 2020, 09:11:19 am
content: my new rotary tool fell on the ground and it became extremely loud when run on the highest speed settings, to the point where I wanted ear protection. I took it and tapped it against the side of a metal table gently the compress the stack, and it went back to normal. I got the collet finger tight and used it like a small battering ram.This appears to be common between the milwakee rotary tool and the dewalt die grinder. It seems like it could be a common thing. I did not use a hammer for this one because its small. It is similar to making a good sandwich where it needs a little bit of compression.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: November 08, 2020, 09:16:00 am
content: Quote from: coppercone2 on November 08, 2020, 09:11:19 amI don't think it's normal for any power tool to require the user to 'do the Fonz' to keep it operational.

author: coppercone2
author_rank: Super Contributor
timestamp: November 08, 2020, 09:20:56 am
content: well it took an impact from a table onto cold concrete while it was fairly cold, but fortunately without a insert. I don't know what the manufacturers can do to make it stronger, given the low price.What I should do is stop sitting them upright with the battery as a base. Chances are the same happened with my dewalt tool.Tools that stand up right on batteries are a total double edged sword. Maybe the proxxon can take it for 3x the price.