UPDATED ----- Questions on KMG clone??

C Craft

Well-Known Member
I got one I built and till today it was fairly quite for a step pulley with an adjustable belt! However today I was grinding something and as the grinder winds down I hear this tick, tick. noise!

So pulled the belt and put on a new one. Still hear it! Stopped and pulled the new belt and put the old belt back on. Still hear the tick tick and now it is getting louder. So I don't think it is the belt but, checked the seam and it appears OK!

I am beginning to think it may be a Square Flanged Mounted Bearings


I also am beginning to see a wear pattern on the left side of the drive wheel! That is another thing that has me thinking the bearing be going. It appears that the shaft may be slightly forward and thus turning the drive wheel juuuuuust enough, that it is putting more pressure on one side of that drive wheel!!

So has anyone else had one of these bearings go?? What did it sound like when it started. The more I run this one like this the louder the tick tick is getting and it also appears now to be getting a vibration. Anyone got any thoughts on these questions??
 

KenH

Well-Known Member
Bummer - yep, a tick tick along with a tad of vibration surely can be a bearing. Does the bearing get warm at all while running? Oh, the tick tick sound isn't there with just the motor running and no belt is it? If so, then could be a motor bearing.

Now would be a good time to turn loose of $300 or so and put a 3 ph motor with Chinese VFD - you'll wonder what took so long! Of course, replacing the bearing is only $10 or so for each bearing. Big difference there.

Good luck.
 

EdCaffreyMS

"The Montana Bladesmith"
Probably the best way to locate the problem bearing is heat..... a bearing that is "going out" will usually produce far more heat then a "good" bearing... that means running the machine for a while, then as soon as you shut it down, start feeling the various bearings on the machine for heat. If you come across one that is obviously hotter then the others, it's a good bet it needs replacing. You likely know this, but all bearings are not created equal. Over the years I've learned to stay away for "cheap" bearings, usually the import variety. You might save a couple of bucks out of the gate by buying import bearings, but in my experience it seems they simply don't last....and many times they are "bad" straight out of the box.

I've also heard a motor bearing described as you did.....and again, if you're motor is a "bargain" brand, a failed motor bearings isn't uncommon.
 

C Craft

Well-Known Member
Ken, I would love to do an update but the $1600.00 I just spent for plumbing repair negates any chance of that for now!

Ed, the grinder is one thing I did not skimp on! I already know that import bearings suck. Almost hard to find good ones.

The shining side of this, that I still have some memory left. :eek: Got to thinking this over in my head last night and I have another set of Square Flanged Mounted Bearings in the shop in my cabinet! I accidently due to a (PC glitch at the time), ordered two sets! When the credit card statement came I almost sent them back. However figured it might not be a bad idea to keep them and now glad I did!!

I have tried to see if there was play on the bearing but when I checked it last, I was unable to feel it by pushing and pulling on the shaft! However now that it is getting worse, I may. It don't take much to get noise and vibration so may not be able to detect it by feel. Usually if you can feel it the bearing has already disintegrated! Gonna run it and see where the heat is today some time. I am also gonna try running the motor without a belt. I am pretty sure the noise is in the bearings! That's my baby and I usually can listen to the sound of a machine and I can say before it breaks down, something it wrong!!!

Thanks for the advice guys. Sometimes it is just good to bounce something off others in the know!!!!
 

EdCaffreyMS

"The Montana Bladesmith"
BONUS on having the spare bearings! It's frustrating when something breaks down and ya gotta wait for parts...... like I'm still waiting on the press cylinder. :) Hopefully it will be as simple as identifying the offending bearing and replacing it! Keep us posted!
 

KenH

Well-Known Member
Cliff, with spare bearings on shelf, it's a no brainer to repair bearings - good luck. Let us know how the test without belt goes.
 

C Craft

Well-Known Member
OK so here is what I know for sure. Today was a busy one, we keep 2 of our Grand kids during the weeks from early morning till about 5 PM. They were both here today as today is a planning day for the school. Planning for what I don't know but, the two year old was sick and the five year old was taking the day off from school and good behavior! :eek: I shouldn't say that because she wasn't bad just aggravating at times! :rolleyes: Between them and my sick wife somedays I just have to write-off shop time till late!! Like from 9 -10 PM tonight!!


So I didn't get a chance to even fire it up till after supper tonight, and a quick nap in the recliner! :( OK Pop needed a nap, so there!!

One thing I am pretty sure of my 220V 2hp motor is OK. Without a load, nothing but, hum out of the motor. I did find a couple of loose components. Just tightening those helped but, did not eliminate the gremlins! The last time I was working on the grinder I was out of Locktite so got to go back and loosen, hit them with Locktite and re-tighten them! Vibration is the master at loosening things.


I am beginning to think it may be another loose component, as I could not find a hot bearing in the bunch. So glad it is not the motor. Going to start at one end and work my way over every bolt and nut till I check everyone of them.
I will post more when I know more!!
 

Frank Niro

KNIFE MAKER
Have you ever used the rod or piece of broom stick for sounding? place one end of the rod on or near a spot to be tested and the other end on your ear. Usually sound magnification will soon tell you where the trouble spot is.
Frank
 

C Craft

Well-Known Member
Frank I know of what you are saying, I have really bad hearing as it is and it makes it hard for me to locate where the sound is coming from. I started going over the machine the other day and have tightened some bolts. Which seems to have lessened the sound some. Still looking for what the cause is yet. When I get time I am going over every bolt on the machine, as I suspect that may be the culprit!!
 

C Craft

Well-Known Member
Well I finally found the problem! I kept looking every time I used the grinder and still could not put a finger on where the noise was coming from. I unbelted the motor no problem without a load no problem,........ . I changed sanding belts in case that was the problem,.......no problem. It seemed no matter what I tried I could not find where the noise was coming from.

Then a couple of nights ago, the noise begins to get real bad and I am not getting vibration. So I shut it down and pull the sanding belt off, I am looking and still have not spotted the problem.

The next morning in daylight I look at the floor under the grinder and I see this! 2-2-2018 004 by Clifton Craft, on Flickr

This is the rubber off of the bottom roller of my platen. I made a 12" platen with a 2" wide strip cut from a granite tile.

Here is a pic of the new platen with the 12" granite being epoxied to the back.

8-20-16 005 by Clifton Craft, on Flickr

This next pic shows a bit more, even though it is a little blurry!



If you look closely at this pic you can see the debris building up on shaft this wheel runs on! Not sure what this is but I believe it may have started the problem!

2-2-2018 002 by Clifton Craft, on Flickr

I am thinking some of this debri got into the bearing and slowly destroyed the bearing. The bearing going bad has been the noise I have been hearing, and when the bearing finally failed, it froze enough for the heat to build and cooked the glue holding the rubber on the wheel!

So now I am down till I get one of these! I have yet to pull it off. It is possible that I may be able to put new bearings in this and re-epoxy the rubber!
Moral of the story, if you start hearing a noise check all the parts with bearings!!!

OK, here is the strange part. I just went and pulled the bottom wheel off of my platen. It appears the bearings are OK. They seem to be fine, spin without anything noticeable. So did the glue fail on the 2" contact wheel. Or was it something else?????????????

I am wondering if the debri bound the wheel just enough to heat it and the glue failed!! I think I may contact Rob @ Beaumont for a bit of advice.

If any of you all have an opinion or idea I am open!!!
 
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KenH

Well-Known Member
Glad you found the problem, but can't imagine debris piling up enough to lock the bearing. You are saying the bearing spins freely now? Hey, at worse case, remove the platen and put the belt across the aluminum core of the wheel - it's 1" diameter now? That might allow running enough to see if bearing is running as it should, OR perhaps building heat? Perhaps it's "possible" (?) the bearing was running hot, locked wheel enough to spin the rubber loose, then as bearing cooled, allowed it to turn free again?

The platen couldn't slip down and catch on the rubber?

I'd try gluing the rubber back on for sure - epoxy or perhaps contact cement? That's how I put rubber covers on my small wheels, glue them on with contact cement.

Ken H>
 

Drew Riley

Well-Known Member
Do you do a lot of contact grinding on that bottom wheel? Could just be heat from that. Then again, sometimes rubber coatings just come loose.
Also, and forgive me if this is a stupid question, but are you sure the bearing is spinning free, and that you're not just seeing the inner race spinning on the shaft?
 

C Craft

Well-Known Member
Glad you found the problem, but can't imagine debris piling up enough to lock the bearing. You are saying the bearing spins freely now? Hey, at worse case, remove the platen and put the belt across the aluminum core of the wheel - it's 1" diameter now? That might allow running enough to see if bearing is running as it should, OR perhaps building heat? Perhaps it's "possible" (?) the bearing was running hot, locked wheel enough to spin the rubber loose, then as bearing cooled, allowed it to turn free again?

The platen couldn't slip down and catch on the rubber?

I'd try gluing the rubber back on for sure - epoxy or perhaps contact cement? That's how I put rubber covers on my small wheels, glue them on with contact cement.

Ken H>
Ken,
OK, so now looking at your reply, I am giving this more thought!! Thinking on what I said about debri, locking the bearing. I am beginning to re-think that and I doubt it too. Perhaps I was just reaching for a quick answer.

The bearings are turning free. I have pulled what was left (the inner aluminum wheel). What you said about, "the bearing was running hot, locked wheel enough to spin the rubber loose, then as bearing cooled, allowed it to turn free again"! I suppose that is possible. I will say I can slip the tip of my finger in the bearing on both sides and although free, it doesn't feel right when I turn the bearing!! It seems to have a rough spot!!

The platen couldn't have slipped there is a keeper top and bottom! Only way it could contact the wheel if for it too come loose!

It appears they may have used contact cement to glue the rubber. Although from my experience and I have glued a blue mile of formica counter tops. to adhere properly contact cement is applied in an even coat and allowed to tack. Once tacky if you touch one part to the other part it has to be in the proper place, cause once it sticks you ain't gonna move it!! So I don't see how they used contact cement unless they put the two together wet and hoped for a bond when it dried!!

Do you do a lot of contact grinding on that bottom wheel? Could just be heat from that. Then again, sometimes rubber coatings just come loose.
Also, and forgive me if this is a stupid question, but are you sure the bearing is spinning free, and that you're not just seeing the inner race spinning on the shaft?
ARC,
I haven't used the contact wheels in a while. About the only time I do use then is contouring a handle or working a radius. Thinking about that I did recently use the wheel to contour a piece of metal for something I was fabricating!!

As for the bearing spinning freely, it does but I feel a rough spot ( not a definite bad spot but a spot that just don't feel right) when using the tip of my finger to turn the bearings.

Back to the piece I was contouring for whatever I was fabricating. It runs in my head that is about the time the problem started.

__________________________________________________________________________________________________________

So here is my newest theory!!:confused: The piece I remember fabricating was from 3/16" or 1/4" steel and I remember working the radius. The radius had to be just right, and it suddenly came to me that I needed to move the piece back and forth instead of working in one area and destroy the grinding belt!

I am wondering if staying in one place to long I cooked the glue in those areas! Once the bond is broken on contact cement, it won't rebond and heat is something that will do that. Seen it happen on counter tops where someone set a hot dish from the oven!!

So subsequent uses of the grinder heated the wheel again and again. The noise was from the wheel running with loose areas!

So anyway while I got this wheel off I am going to replace the bearings, (I don't like the feel of them) and re-glue the rubber. Now all I have to do is figure what is the best for re-gluing it!!
 

KenH

Well-Known Member
Cliff - I know when using contact cement for best bond you let it get tacky 'n almost dry before putting the pieces together. When I glued my rubber on the axles to make the small wheels for the grinder, I sprayed the inside and axle good, then slid them on to dry. while that doesn't make the best bond, so far it seems to be holding ok. Realizing a small wheel grinder doesn't get near the stress nor heat buildup that a larger wheel would when grinding.

While many folks will say skateboard wheels don't work at all for a grinder, I've been using them for several years with success - the set I've got on the grinder now have been in use for 3 or 4 (more?) years. They're long board wheels, 2" wide by 3" diameter.

Good luck
 

C Craft

Well-Known Member
Yep on the contact cement we used to use slider strips, (sraps of formica to put under the counter top till you get it slid in place). When you get it where you want it you start from the center out and pull the strips and work any air from the middle out!!

I got my new bearings ordered! Beaumont has them but heck I can order four quality bearings for what I would have to pay for two thru Beaumont, and that includes shipping to the door!

I figure this way I will have a couple of backups should I start to hear noise again!! o_O:D
 
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