You are here

60 posts / 0 new
Last post
woodsmith
woodsmith's picture
ceramic guides vs. rollers lm29

My lm29 is around a year old now. I always a have trouble with the roller guides freezing up, or sawdust building up on them. The blade wants to ride up on the edge of the roller when pressure is applied and you end up with wavy cuts. I'm debating on buying the ceramic guides, but was wondering if their worth the 300. Anyone have any experience with them? In my opinion the roller guides was a poor design.

Baron
Baron's picture

I've never had rollers so I can't compare. My ceramic guides work well when adjusted but they constantly go out of adjustment. When they are out it doesn't seem to affect the quality or accuracy of the cut. You know they're out of adjustment when you hear a slight hissing sound constantly and see more more sparks than normal. upon inspection you find that the guides have rotated and are touching the blade constantly. I then re-adjust them but I'm afraid if I tighten them more I might turn off the nuts. I'll be trying loctyte this season.

Post Oakie
Post Oakie's picture

The main issue is that the blade wants to ride up on the shoulder of the roller.  This could be a problem with the tracking, blade tension, or not enough down pressure on the blade.  Ceramic guides may not be much help if there are other problems.  Roller guides shouldn't be freezing up all that often.  How heavy a water flow do you use?  I mill dry unless there is a problem with sap build-up, and even then, I use just enough drop to keep the blade clean.  Are the bearings sealed or is there a grease zerk?

I like the ceramic guides on the HD36 for a couple of reasons.  First, no moving parts.  Mainly, though, they take up less space and allow a wider cut.  As Baron says, they do need adjustment now and then, and you should keep some spares.  I use blue Loctite on the threads, and it does help.  If I had a sawmill with rollers, I'd put on the ceramic guides.

eddiemac
eddiemac's picture

I've never had ceramic guides but did think about getting some when Timberwolf came out with theirs for the Norwood.  The price dissuaded me, but also the fact that I'd never had very many problems with the rollers that came on my LM2000.  The roller surface eventually wears down and bearings will lock up when they run out of lubrication.   But that takes a long time.  Many sawmill makers use roller guides, so it must not be such a bad idea.  (In fact, I remember reading that Woodmizer had tried ceramic guides and abandoned them, with no plans to go back).  I make sure there's a 1/16" space between the back of the blade and the raised rear edge of the rollers and use a slow drip, drip, drip of water lube.  If a bearing goes bad before the roller wears out, I press them out and replace both after prying the side seals off and adding extra grease.  The bearings are very cheap and readily available.  Ceramic guides may be superior when working correctly, but rollers are practical and economical. 

eddiemac
eddiemac's picture

Note:  the Timberwolf guides I mentioned above are actually not ceramic, but instead use bearings to support the blade above, below, and behind.

Bill
Bill's picture

I used the ceramic guides for 1 day then took them off and put the rollers back on . In over ten yrs. I'e only had to replace 1 bearing in a roller guide.

jmanatee
jmanatee's picture

Bill, in your 1 day of ceramic use did you have to replace them?  Why didn't you like them?  Or is it just a case of being use to bearings and how to adjust them?

Bill
Bill's picture

One of the ceramics came chiped maybe fractured because after a few hrs. use it broke and jamed up the blade. I was told I tightened it to much which may or may not have been the case. Also sparks fly and I was thinking if I made a cut in dry wood and forgot to turn the water on I could have a fire. Mean while I made a new block for the guide out of very hard wood which I'll use if I ever put them back on. In theory they seem like a very good idea because they hold the blade stable . It's been a while now but some thing else was budding me also maybe I found them hard to keep adjusted properly ?? I just can't remember any cons that I had at the time now.

farmerjohn
farmerjohn's picture

Woodsmith, I've had my LM29 for two years and haven't had any trouble at all with the roller guides.  Well, I did jamb a piece of wood on the back roller and bend the bracket that holds it, but was able to straighten it out and it works fine.  I have mine placed about an eighth of an inch behind the blade as it normally tracks without a load on it.  As for it locking up, that seems strange. 

machamillion
machamillion's picture

Also no problems here with rollers on my lm29. Tighten up the blade if its riding up or change it may be dull.

Bill MacLellan
Bill MacLellan's picture

LM 29 here and no issues with the rollers, I have had them build up a bit with gum during the winter and I simply give them a wipe once in awhile to keep them clear, but nothing. I did pop the bearings out and hand pack them with some good high speed grease just as a preventative measure. (not much in there from factory)

Does anyone else out there trailer and find that there tracking moves from time to time. I find mine does once in awhile and I am not sure if it is temperature changes or if things move when I am transporting. Not a big issue I can reset it in minutes, just curious.

Baron
Baron's picture

Hey bill my HD 36 had the tracking change plus I had one blade that rode funny somehow. 

Like u said its a quick fix. 

Bill
Bill's picture

I put jam nuts on the bolts for tracking shortly after I started sawing and only adjusted once in ten yrs. when I tried out the sparker guides.

Post Oakie
Post Oakie's picture

Checking tracking should be part of the blade change procedure.  On the 36, changing tension affects tracking, so I always bring the band saw blade up to tension and give the wheel a quick spin by hand before putting the shield back on.  Adjusting the ceramic guides is also part of my blade change procedure, since they can get knocked out of position, plus my older blades are considerably narrower than the newer ones.  It takes less than a minute, if you have an allen wrench handy.  I keep some extras in the tool box, but small chips don't seem to affect them.  If they get a larger chip, I just turn them over & use the other side. In three years, I've replaced one round guide and one back guide.

Baron
Baron's picture

Is anyone using a tension meter to check blade tension? How common is it to break blades due to high tension? I recently increased my tension and it cuts much more nicely but out of 15 used blades two broke.

Post Oakie
Post Oakie's picture

Baron, did the blades break at the weld?  I'd also be concerned about the bearings if you crank in a lot of tension.  Used blades can sometimes develop micro cracks that don't show up until you use them.

Baron
Baron's picture

I'll check. I'm pretty sure the latter is the case but I'll check. 

wayne busse
wayne busse's picture

Baron, it sounds like you're breaking every third resharpened blade. When the  blades were resharpened was the gullet cleaned up ?  Micro cracks form first in the bottom where the blade is the most  narrow. Grinding removes those micro cracks. On the tension side, if you bottom out the spring and continue to add tension you are adding extra stress on bearings and compressing the belts and stretching the band blade. Something has to give . The first blade on my HD 36 , lasted 5 hours before it broke. Being a newbie , I kept going long after the blade was dull and kept adding tension to try to improve the cut.  The blade had a half dozen cracks over 1/4" deep along with the complete break.

 

 

 

Baron
Baron's picture

Hmmmm! I'll be checking tomorrow Wayne. Maybe it is overtightened but I want to see if there are cracks in the gullet.  

Bill
Bill's picture

This was happening to me after I switched to the gold line blades so I've really slacked off on the tension compared to the previous blades I used . I'm not sure yet what brand I'll buy next batch.The blades were new so I had them re welded now I have a set up to weld my own. Tee original blades I used I was getting 12 to 15 sharpenings before trouble struck. They were .032 I prefer the heavier blades for most sawing.

Baron
Baron's picture

Bill that is a great photo. I checked a couple blades and they aren't cracked yet. I just went through the process of re-checking all the guides settings. I tightened the set screw on the main shaft, re-aligned the ceramic holder reset the top and bottom ceramics.  I used a matchbook for clearance top and bottom. Then is backed in the rear ceramic and tightened all set screws. By the time I had squared the fisrt can the ceramics were rubbing the blade and the housing was crooked (below). Still turns out nice lumber but its noisy when the guides rub.

 

Notice that the guide is askew and the upper ceramic is rubbing. This is after squaring only one cant (below). Before I adjusted this guide the upper ceramic was was clearing the blade ad the lower was rubbing. 

 photo photo 5_zpsxwdopub9.jpg

 

 photo photo 3_zpsooejotnq.jpg

r.garrison1
r.garrison1's picture

One thing I would wonder is how the blade tracks at speed and under load, relative to the blade sitting still. Any way to set up a camera on the frame and watch that spot as it starts the cut?

I think of this because of when I was a finish carpenter; using a 10" miter saw. When I was cutting a joint I wanted to keep neat, I would take a small cut just outside, then move to the cut I wanted. If I didn't, there was a little bit of a rough right on the part where the sawblade first hit the wood. This is because it tracked slightly differently when under load from when it was free spinning.

Post Oakie
Post Oakie's picture

Nice close-up photo.  So... the set screw that goes against the flat on that holds the arbor in place is slipping & allowing it to twist.  The next question is whether the set screw is backing out due to vibration, or is it just inadequate?  You might try some thread lock compound (blue) to see if that holds the set screw in place better.  If that doesn't work, it might be time to do some reengineering and hold the arbor with a bolt that has a little more meat on it.  Beautiful log sitting on the sawmill, by the way.  Did a tree service drop it off?

R. Garrison's point is good.  Blade can be doing something different when under a load.

Jeff Lee
Jeff Lee's picture

I have not got my mill yet but it is ordered. smiley

I am hearing mixed advice about the ceramic guides and keeping them adjusted.

Would I be over thinking it if I replaced the factory set screws with some more aggresive set screws like these from McMaster Carr 

Knurl-Grip Cup Point Set Screws     

http://www.mcmaster.com/#set-screws/=zcmjah

Or will blue loctite do the job?

Also, what about all the bolts that hold the bunks together. Should we take the time to use loctite on them as well ?

Does anybody know the size fasteners that are used for the ceramic guides?

Thanks

 

 

 

Blackbeered
Blackbeered's picture

While the ceramics on my one year old HD36 are the biggest headache, I can't imagine going with metal rollers [noise, quicker metal fatigue?].

The ceramics need constant attention, maybe a tweak every sixth log.  The sparks come from the blade contacting the ceramics ... with or without blade lube.

My mill came with the brackets which hold the guides out of plumb, i.e. the gap between the ceramics cannot be made parallel to the blade in the front-to-back direction.  [Sent off drawings and pix to Norwood but they never showed any interest in resolving].  I'm sure there's a way I can pitch the bracket the few degrees it needs, but for now I leave the gap wider than it ought to be.

The guide which takes the worst beating is the block behind the blade; you've got four surfaces to work with but I need to find a way to 'resurface' those faces rather than buy a net set of ceramics $$$$.  If anyone has any ideas on how to grind down the faces, my I'd sure like to see them.

Jeff, I've never had the first problem with any of the bolts holding the bunks together.

Bill
Bill's picture

Jeff you can't over tighten the c. guides I had one split just installing them it looked like it had a flaw in it and it was also chipped when it arrived. Norwood told me I tightened it to much. Their all self locking nuts on the frame so I don't imagine they'll come loose , loctite on the guide screws may not hurt I made a replacement guide out of some very hard wood but put the roller guides back on so not sure how well it will work but see no reason why not.

Baron
Baron's picture

Jeff,

I don't like second guessing the design of these mills because I think they're great all-in-all. However in every manufactured item there are apt to be a few things that are less perfect. While not in all cases, things requiring LocTyte are less perfect as that is the reason for applying LocTyte.  If the design was flawless you wouldn't be asking about it or considering LocTyte. That being said I've never used rollers. I know many swear by them. I suggest that you get into it for a while and see how things work out for you. Adjustments or replacement parts are readily available and can always be considered later. For now get some sawdust happening.

Baron,

PS  I'm a new guy too! I have the HD36

 

 

"Where do you stand? Are you riding with the brand... or are you running scared? " Conagher 

Post Oakie
Post Oakie's picture

"Also, what about all the bolts that hold the bunks together. Should we take the time to use loctite on them as well ?"

Any bolt held with a nylon insert nut, lock washer, or grooved flange nut should hold without Loctite.  Vibration is the biggest problem for everything else.  The backing ceramics can be rotated, and the top & bottom disks can be turned over to get a fresh surface, but it doesn't hurt to have a spare or two in the tool box.  The spring action of the metal holding the ceramic disks seems to be enough to keep the bolts from slipping, but the back bolt is against the rigid ceramic guide, and I've lost a couple before I used Loctite on them.

The idea of a hard wood guide is interesting.  I may have to give it a try.

I agree, the Norwood portable sawmills are good, but I've made a lot of tweaks on mine, and finding new ideas all the time.  Keep 'em coming!

Baron
Baron's picture

Jeff,

I would like to have two more bunks and 6-8' more track and corresponding extra bunks. I cut so much odd-ball stuff that I like allot of bunks. Most responsible Sawyers won't be following my trail. If you find yourself cutting allot of short stuff you may want an extra bunk or two. An extra set or two of dogs in a nice luxury that will save you time. I also use the optional Dogging Assist Devise.

Once you cut for a while you'll develop likes and dislikes in the way you approach your work. That experience will drive your purchases.

 

Best!

Baron
Baron's picture

You might as well know that I'm say'in nothing about the great pleasure with which I now mill. I am being careful not to cause a "run on the bank"(manufacturer). I received a set of roller guides from the factory on Saturday and what a difference from the previous guides.

7 Degree Blades and Rollers baby!!!!!!

 photo IMG_9576_zpsdddfp6rz.jpg photo IMG_9575_zpswkkibeeo.jpg

Post Oakie
Post Oakie's picture

Baron, you've almost convinced me.  That's some crazy grain in the log.  Red oak?

Pages