I am using 19 inch bandwheels with 1 1/4 blades does any of the forum members have a preference between sealed bearings or greaseable bearing on the guide rollers? thanks Fathead.
Hey Bob,go for the grease-able guides and get a good grease gun,too.
albert
Never had sealed bearings for that application. I can naught conceive of not being able add grease to the roller bearings regularly. They take a lot hard use and heat.
Sealed bearings on my LT40shdd51 have 500 hrs no problems so far.
Pete
Greasable is way better, might get by with sealed if using diesel for lube. Steve
I got 1150 hours on my lt40 before the first guide bearing went out. I squirt some ATF on the back side of each guide bearing each day. Don't know if it helps or not but it can't hurt.
I always had greasable bearings until I got this mill and I fully expected that I would change them out for greasable ones at the first sign of trouble, but I got 2500hrs out of the moveable side and the fixed side is still good at 2650 so far. That's at least twice as long as I thought they would last, and they change out in 5-10 min. They do get hard use but they never got hot to the touch until the first set went out. So I'd say use which ever you want, but I like the sealed ones.
We've worn out more than a few sets of blade guide rollers on our LT40 that have had sealed bearings. The bearings have been in good shape. In the "old days" when they had zerks, it was common to for the bearing to go before the guide was worn out.
(https://forestryforum.com/gallery/albums/userpics/10034/888/wsguiderepace20110331b.JPG)
The old guide was 1/10" smaller in diameter than the new. Bearings still good.
Make mine without zerts.
I changed my blade guide rollers last winter when the mill was parked in the garage.
I now have the sealed bearings and they seem to be doing good. I'm still not used to the fact they don't get greased! :-\ I'd give the old ones 1 shot of grease every 4 hours, and they were still tight as new when I sold them.
I was a little skeptical about the sealed bearings at first, but I'm getting over it. ;)
Sealed bearings on my lt 40 spr. I have to change the moveable side about every three to four months. hours very, I shut down probably more through the day than most might. I am at 3/4millon bd/ft with 2150 hrs. This has been mostly a one man operation. the days I have had off bearers the footage goes up. This being said, I have thought about going to the greasable one too. At least the moveable side, lots of coolant going on.
A local distributor has the R8 2RS bearing for 4.15 each, I keep a small supply on hand. It is a 20 minute fix for me.
Me too ,I where them out before the bearing gos out, all sealed bearings :D I buy them from WM by the box full :D :D :D
Started out greasable. Went sealed and haven't looked back.
I have used both, but the advantage goes to the sealed bearings. Pumping grease into the bearing blows out the seal, the water from the lube finishes them off. Plus, regular old grease don't work very well in a high-speed bearing. Ever calculate the rpm those rollers turn ??
Quote from: Peter Drouin on September 27, 2012, 08:06:43 PM
Me too ,I where them out before the bearing gos out, all sealed bearings :D I buy them from WM by the box full :D :D :D
Bearings or guide rollers by the box full? ???
Good sealed bearings will last,hong kong harry brand mayby.basically your belt tensioner on your truck uses the same bearings and many will do over 100,000 miles.For the few bucks the bearings cost I'll stick with sealed. Frank C.
Sealed. They last longer and require less maintenance.
I don't do alot of sawing but mine are sealed.
Mine where greasable when I bought my mill. I changed that over to sealed as soon as they wore out. Then a few years after they where being sold with the sealed bearings. :)
Very interesting, I would have thought the greaseable ones would have wore a lot longer.Keeping the contaminates out most play a big part in the life of them. It is great to be able to pull on the experience of you guys. I am making a lot of progress on my mill I am going to ask my boy to help me post some pics thanks for all the advice.s
This is almost making me rething, I have redressed my rollers only once, the moveable side had close to .030 wear front to back, the fixed side inside .010 but worn on the flange side. I have changed the fixed side twice, and the moveable side 4 times mostly just the front bearing. I know I need a new felt bob. This said it is cutting great, no sign of misalignment. so how can some of you folks get 2500 hrs on one set of bearing? just asking,
I havent replaced mine so far in just over 500 hrs. Mine are sealed at this point and I dont think I will swap over to zerks when they do go. Not exactly sure on this but those apear to be a 6204s (someone correct me if I am off a few numbers)
I know when I go to BC Bearing here in Alberta they want to know speed, temp and chemical/moisture environment for the bearing and I get the the hi temp hi speed ones for a few other apps that use that bearing The price is a fair bit higher for them but they do last a LOT longer in the high speed high temp, high thrust application bearings than the basic normal use idler type application.
There is a slighty wider "double race" high thrust high speed bearing in that size too. has almost 3 X as many rollers in 2 rows instead of one and has significantly better thrust and cooling specs. Wonder how it would A) fit and B) wear? Think it is about 3/16 wider but I would have to measure to be sure.
2100 hours with sealed bearings.
Mine are greasable and just out of habit I grease, so far so good I have three bearing's that require grease every two hours I'm not a high production operation so I probably over grease if thats possible but it does keep me professional in front of customer's while greasing I also check the mill out, for this and that's and get a break! 8) http://www.ehow.com/facts_7766563_greasable-vs-sealed-bearings.html
Just some info .On high speed precision CNC type metal cutting machinery on a rebuild most use sealed bearing .They remove the bearing seals ,wash out every bit of lube then repack the bearing .Then blow every bit of it out with compressed air .Sounds stupid but here's the catch .That bearing will never pick up any more lubrication except that which clings to the balls in the bearing .
They then replace the seal and continue to rebuild the component .Now this type machinery will make millions of precision cuts to micron tolerances before it needs rebuilt again .For those who don't know a micron is 1/1000 of a millimeter .---bearing trivia ---
Al brings up a good point the only usefull grease is whats in the bearing.Many folks pack grease everywhere and say the bearing will pull it in, not so.Really if bearings could run in light oil just dipping their feet in it their most happy.Grease is a default lubricant not as good as oil but will stay put and is better than nothing. Frank C.
The sealed bearings don't let in any contaminents, as where the greased one will and that will kill it every time. They where not well designed to begin with, having the felt backing made for having an opening as soon as one over greased them and sawdust , and dust in general got in there . Wear was the only outcome to come of it.
By definition and in truth grease is merely oil with a thickening agent .Contamination is what kills bearings not generally lack of lubrication .
On the subject the mill I am building but can't seem to find the time to finish is 100 percent sealed bearings salvaged from discarded new industrial stock . The track rollers ,blades guides etc are hardened sealed units designed to run for years in a hostile industrial environment .I doubt I have any problems with them .
I could never get more than 3 months out of sealed bearings untill I started greasing them, now I get 3 years. It's not needed to pump in so much grease you blow the seals out. Steve
On my little TK 1220 mill, the guide rollers consist of double /sandwiched ball bearing roller bearings for the blade to roll on and a single horizontal bearing for the back of the blade.
I have grown tired of replaceing them as the water lube destroys them, even thru I take em' off , greae em' up almost each use if there is much down time between uses.
I found some roller guide bearing on Cooks website I am going to use. They are very much like the WM rollers.
I have a sealed bearing on the fixed side and a greaseable on the moveable side. I find that when I replace the blade and try to get it between the grease zerk and the guard it is a tight fit and I often scrape the blade against the guard. I'm sure it sometimes takes the sharpness off some of the teeth when I do that. I will replace that guide soon with a sealed bearing.
Nick
Nick, you know you can change only the bearing and pull the zerk out and put a plug in there eh eh :)
or you could grease the zerk just a thought!
I prefer sealed ball or roller bearings.
Most folks who use greasable bearings either don't grease them at all :( or put in way too much grease way too often :o. And a lot of folks don't bother to wipe off the top of the zerk fitting with a clean cloth before and after they grease them ::).
Need your opinion on bearings for my roller guides. I can buy two no-name (probably made in China) sealed bearings for less than the price of one name brand bearing. Which would you buy?
I have found that using either bearings, regardless of brand will not last too long if not taken down and greased internally a bit. Mainly due to the amount of water I use, if not maintained they will foul and bind up.
I bought a box full of the no-names at 2+ bucks a pop. They have lasted as well as anything else so far, as long as I don't let them set too long without a bit of grease.
I have yet to modify my mill to accept the cooks 2" rollers, yet.... ::)
Quote from: Ga_Mtn_Man on October 30, 2012, 05:38:26 PM
Need your opinion on bearings for my roller guides. I can buy two no-name (probably made in China) sealed bearings for less than the price of one name brand bearing. Which would you buy?
I tend to stick with the brands I have known and used for years. thats what BC bearing carries any way. they do have the cheap stuff now too but they dont even offer it to me any more. I like SKF and Timken and one other western europe one that i cant remember the name of.
I buy and use what my sawmill manufacturer recommends. In 6,000 hours, I have only had one sealed bearing to fail. I knocked an old bearing out of a worn roller guide, tapped it in, and away it went. I don't off hand know how many roller guides that I have worn out. If it is sealed, contaminants can not get into the bearing. WM and probably others have a felt and then a metal washer that effectively isolates the bearing from the normal sawmill activities.
Quote from: Magicman on October 30, 2012, 05:55:48 PM
WM and probably others have a felt and then a metal washer that effectively isolates the bearing from the normal sawmill activities.
TK does not have that felt and metal washer and that's the reason for short bearing life on the TK.
I plan to fabricate a metal washer shield similar to WM, but I didn't know about the felt washer. If anybody has a picture it would help. If no picture a description of the assembly would work.
Maybe WM is using something like this:
http://www.astbearings.com/catalog.html?category=single_row_felt_seal
I don't know because I did not understand the illustrations.
WM has felt washers that are next to the sealed bearings and are captured in front of and behind the roller guide.
From the manufacturer's website:
"The felt sealed ball bearing falls within the product category of deep groove ball bearings. The characteristics of this group are wider inner or outer rings and the original production designs used a metal shield with a felt ring on one or both sides of the bearing. However, most of the designs in production today have switched to a heavy duty rubber seal to replace the felt."
So probably not what WM is using.
WM's bearings are regular over the counter sealed beatings. The felt washers surely protect them from the soapy water lube mixture, etc.
The felt washer sounds like a good plan, Larry send me a couple when you get them made. Steve
humm,. felt washer, good info ! did not know WM used them.