Recommendations for replacement bearings for KMG (besides Beaumont)

East Branch Knives

East Branch Knives

Joined
Feb 5, 2014
Messages
169
One or both of the 4 bolt flange bearings on my KMG (the bearings through which the drive shaft passes) have gone bad (I think) because the drive shaft and drive wheel get incredibly hot pretty quickly, and it looks like grease is leaking out of one.

Does anyone have recommendations for good quality replacements and where to get them? I realize I can get them from Beaumont, but I'd like to see what else is out there. And assuming my alignment is true, I thought it was a little early for the bearings to be failing after only three years of occasional weekend use, so if there's a higher quality available I'd like to get it.

I know they need to be UCF-204-12.

Thank you!
 
Not sure on the bolt hole centers but as far as bearing quality, I have ALWAYS used Timken bearings for anything severe duty. AKA race cars I've built or 4 wheel drive trucks with serious horse power. Never had a bearing failure using them, unless I neglected on maintenance.

https://www.zoro.com/timken-flange-bearing-4-bolt-ball-34-bore-ycj-34-sgt/i/G8416527/

I plan on putting them on my grinder down the road, as the cheap ones I have get real hot.

Either that or look into SKF. They are the two world leaders in bearing manufacturers as far as I'm concerned.
 
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East Branch Knives said:
I thought it was a little early for the bearings to be failing after only three years of occasional weekend use
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Yeah, I think something may have gone wrong. I'm still on my original set, they have over a thousand hours run time.
 
I have had problem with the bearings on the rotary platen. The first set failed far too soon. I replaced all of them at Beaumont and the new ones didn't last even 50 hours before they started making noise. I will run them until they go completely bad and try to fined a better bearing.
 
12345678910 said:
Try to find a cause.

Excessive V belt tension ?
Misalignment ?
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+1 but I honestly think it will be more in a misalignment than tension or just being cheep bearings from my experience. Even the cheap ones have a static load in the 1000 - 1500 lbs static load and 2500 - 3500 lbs Dynamic load, but those numbers don't take into account poor manufacturing. I've been replacing bearings for over 25 years, and you really get what you pay for. I can with 100% certainty tell you if you take a $12 bearing and compare it's performance and precision to a $70 bearing you are going to get much more quality and precision from the $70 bearing as well as longevity if properly maintained. I'm already looking into replacing the ones on my grinder and I have't even finished building it yet. They are priced about the same as the Beaumont bearings and the quality is sh!t. A lot worse than I expected.
 
I replaced a bunch of mine with SKF. The ones that came in my KMG were cheap garbage, and were one of the first things I pointed at when addressing all the issues my machine had.

Make a point of confirming that all your wheels and attachments are as square as they should be - since offering the direct drive kit for these machines, I'm hearing tales from a bunch of folks saying that they found the older pulleys on their platens weren't drilled and tapped square from the factory. ..
 
Stacy E. Apelt - Bladesmith said:
I have had problem with the bearings on the rotary platen. The first set failed far too soon. I replaced all of them at Beaumont and the new ones didn't last even 50 hours before they started making noise. I will run them until they go completely bad and try to fined a better bearing.
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yea I got a buddy who's grinder did the same thing..Way too soon for the bearings to go bad..
 
East Branch Knives said:
One or both of the 4 bolt flange bearings on my KMG (the bearings through which the drive shaft passes) have gone bad (I think) because the drive shaft and drive wheel get incredibly hot pretty quickly, and it looks like grease is leaking out of one.

Does anyone have recommendations for good quality replacements and where to get them? I realize I can get them from Beaumont, but I'd like to see what else is out there. And assuming my alignment is true, I thought it was a little early for the bearings to be failing after only three years of occasional weekend use, so if there's a higher quality available I'd like to get it.

I know they need to be UCF-204-12.

Thank you!
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go to eBay and search. a Browning VF4S-212 is $30. a Dodge: F4B-SC-012 is $40. a SKF: FY-3/4-TM is $35.
scott
 
Bearings are made in a variety of grades, I expect the manufacturer trying to save a dollar.
Replacements are widely available. Any bearing supplier can cross-reference your existing bearings for size and should be able to help you choose a bearing better suited to the speed & load of your machine.
As far as alignment, I doubt thats a problem, I would be shocked if those flanged blocks dont carry self aligning bearings.
 
Lieblad said:
As far as alignment, I doubt thats a problem, I would be shocked if those flanged blocks dont carry self aligning bearings.
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My mistake - for some reason, I skipped right over that he was specifically referring to the flange bearings. Sorry!
 
Lieblad and Pleasanthill are on point--with a background in mfg. I can tell you that bearings are a part that widely vary in cost--and often mfgs. try to save a buck or two with their selection--better bearings are always that--better--and like many things, you tend to get what you pay for. I would take these gentlemen's advice and purchase new ones from one of the sources Pleasanthill recommended.
 
Lieblad said:
As far as alignment, I doubt thats a problem, I would be shocked if those flanged blocks dont carry self aligning bearings.
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Misalignment can still very well be an issue. Even though they very well are self aligning bearings. If you read the spec sheet they most probably only have a certain degree of mis alignment that is recommended by the MFG. In my experience with these bearings although those of the higher grade with access to the spec sheets it's usually only a couple of degrees. Here is a link to a video that shows the procedure for checking the alignment of this type of bearing with the shaft installed. Although the video shows pillow block bearings the same procedure can be used for flange style.

http://youtu.be/OSYN5wLB67k
 
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For y'all having problems with the bearings on your rotary platen, I noticed mine had a bolt too long that was preventing the adjustment block from sitting all the way down, causing that wheel to sit at an angle. I had to grind it flush to sit right.

For folks with wonky holes in their flat platen assemblies you can also have a wonky bolt, nut or the platen assembly itself can be wonky. I may have got lucky and got one where all the errors canceled out because mine works well considering the lack of precision in the design, but I've heard of folks who's belts won't run straight, won't track in reverse and has uneven wear. If you're having trouble, try swapping bits around?
 
Here is a link to a video that shows the procedure for checking the alignment of this type of bearing with the shaft installed. Although the video shows pillow block bearings the same procedure can be used for flange style.]
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To split hairs & confess I really dont know what type of selfaligning bearing a KMG may use, my comments were not with selfaligning dual rollers in mind, but a regular ballbearing made for a selfaligning block.
Assuming a shaft is not bent, (what can kill any bearing quick...) those can run at greater misalignment as the alignment is not created via its rollers & races.
 
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Thanks guys for all your help. I ended up buying two SKF bearings off ebay. I'm not sure if they need grease or not (I know the ones that came w/ the KMG did not, despite having zerks), but I suppose I'll find out when they arrive. I downloaded a guide on bearing designations and honestly I think I could attain reasonable fluency in Mandarin before figuring that designation system out completely.

Matthew, where did you buy your bearings? I'm sure I'll have to replace the others at some point.

Pleasanthill, thank you for that video. I will try and check my bearing alignment per those instructions to make sure it's on point.

Nathan, trying to get the platen, wheels, drive shaft, etc., all squared up and aligned with one another was pretty daunting, and I'm sure there are some things out of whack. I notice that my belts run at a slight angle to the platen, probably only 3 degrees or so off center but still noticeable. Now I'm guessing it could be the bolts/holes, but it may also be that I didn't properly align everything. When I set up the grinder, I fumbled around with a couple carpenter's squares and some string trying to get the wheels aligned before throwing my hands up. I'll have to post another question re: getting all the wheels aligned on the same plane(s) because I couldn't figure out a good method. Btw, I finally got around to setting up my platen chiller and it is AWESOME! The platen is actually cold to the touch even after 30+ min of grinding, which is pretty amazing.
 
Beumont oh boy.

I had a 2" wheel and the rubber was wearing into a cone. I had a devil of a time trying to figure what the cause was and then I noticed.

They had mill the hole to deep for the bearing so the entire wheel drifted to one side causing uneven wear.

Their customer service is horrible so I just cut off the rubber, made a correct size spacer for between the wheel and remounted it.

I buy elsewhere now.
 
So I left a belt connected to my KMG for about 2 months last winter and when I fired it up the next time I noticed a clacking sound at decent speed. I didn't think that should have been enough to fry the bearing but now I see I'm not the only one that has dealt with this. For the record I wouldn't normally neglect a tool like this but my shop is forty minutes away and I planned on heading back the next day and found out my sister was very sick so that was my last trip out for the winter. I have other grinders, only have one sister!

EBK do you need a bearing press to pop these out of the flange? And if you don't mind could you post or email me a link to the bearings you picked up?

-Clint
 
East Branch Knives said:
Thanks guys for all your help. I ended up buying two SKF bearings off ebay. I'm not sure if they need grease or not (I know the ones that came w/ the KMG did not, despite having zerks), but I suppose I'll find out when they arrive. I downloaded a guide on bearing designations and honestly I think I could attain reasonable fluency in Mandarin before figuring that designation system out completely.

Matthew, where did you buy your bearings? I'm sure I'll have to replace the others at some point.

Pleasanthill, thank you for that video. I will try and check my bearing alignment per those instructions to make sure it's on point.

Nathan, trying to get the platen, wheels, drive shaft, etc., all squared up and aligned with one another was pretty daunting, and I'm sure there are some things out of whack. I notice that my belts run at a slight angle to the platen, probably only 3 degrees or so off center but still noticeable. Now I'm guessing it could be the bolts/holes, but it may also be that I didn't properly align everything. When I set up the grinder, I fumbled around with a couple carpenter's squares and some string trying to get the wheels aligned before throwing my hands up. I'll have to post another question re: getting all the wheels aligned on the same plane(s) because I couldn't figure out a good method. Btw, I finally got around to setting up my platen chiller and it is AWESOME! The platen is actually cold to the touch even after 30+ min of grinding, which is pretty amazing.
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get a big square, some magnetic levels, and a 36" piece of PGFS and just start. i would use the drive wheel as my initial reference point. sounds like a nightmare. is there any drawings so you can make a plan? as far as the new bearings, they should come in a box with instructions including grease requirements. most bearings that size are sealed, permanently lubed. if it comes with a zerk, i would grease whether bearings are sealed or not just to keep grinder dust out of the works.
scott
 
Sorry for the late reply - I bought the replacement bearings I used from McMaster Carr.
 
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