Ceramic bandsaw guides - advantages/opinions????

[ian maybury]

Hi guys. To float the topic in a broader sense than the individual feedback that's been around so far. Do ceramics deliver substantial real benefits, or have real disadvantages? Why? Are some layouts/types better than others? Does the choice of ceramic grade matter a lot? i.e. are there cheap types/poor layouts that don't work well?

There's several types about:

(1) 'Lagunas' (now also offered by band saw makers ACM from Italy - not sure who the originator is, but they are also optional on some larger models of Startrite in the UK)
(2) Ceramic faced Euro style rotating disc guides.
(3) Cool block like inserts for smaller saws.
(4) More?

Eiiji F has posted elsewhere of fitting a set of the Laguna guides to his (600mm/24in?) Felder bandsaw, and reports a significant improvement in finish when resawing with a Woodmaster CT. He's also reporting rapid wear when resawing on the OEM thrust guides.

I've meanwhile just coughed up for a set of replacement stock European style thrust guides for my recently bought but as yet unrun used Agazzani - which despite not having done much work were badly grooved. They were not turning freely either though, and the blade was in poor shape and needing lots of force to get it to cut - so the high wear rate may or may not be typical. I certainly saw nothing like that on my 10 year old previous saw, but then it never did any deep re-sawing.

Ceramics to my mind may have two potential advantages:

(1) The option to adjust them in to touch the blade without overheating to damp out the sort of (largely invisible) small amplitude vibration in the blade that was giving my previous saw fits.

The double contact points top and bottom on the Laguna layout may conceivably enhance this effect.

(2) The ceramic may last much longer.

Against that I seem to be picking up a view that non-rotating ceramic thrust blocks can groove fairly quickly and cause tracking problems. Which if true may suggest that the Euro style rotating disc format in ceramic might be the better bet.

Bottom line. Do ceramics in general and any one guide format in particular offer substantial real world advantages/disadvantages? Or as somebody local suggested when asked (based on zero knowledge mind you) - are they just more gilding of the lily/bolt on bandsaw bling/another opportunity to spend money on tools that don't necessarily deliver much??? The conventional wisdom has it that guides are only incidental, that it's really blade to wheel set up that determines performance....

ian

[Dennis Ford]

The ceramic guides are much better for cutting green wood as they don't accumulate sap and dust like the bearings do. I don't know how well they compare when cutting dry wood but can say that they will last longer than the bearings.

[Eiji Fuller]

Ian,

I am obviously sold on the laguna ceramics.

I don't see wear on the ceramic thrust pad being an issue. I just ripped 100 - 3/16" x 5" tall 6' long cherry strips for some laminations with no wear. Rick K at laguna even mentioned they carried replacement ceramics but haven't yet sold any for wear out replacements but have sold some for breakage when people have dropped them.

I also don't think its a great idea to have the ceramic guides actually adjusted tight to the blade. Think brake pads. I had them against the blade and when I went to raise the guide post the blade moved with it. I felt that extra friction ie hp loss wasn't worth it. I now adjust them to .002" clearance and love it.

The driftmaster fence will be my next laguna purchase. Then the slider add on for my unisaw. Despite all the bad press customer service, especially with Rick, has been excellent.

[Van Huskey]

It is all about support.

The reality is that for resawing or ripping with a wide blade and a saw that can tension it correctly guides are more or less a non-issue. I can resaw 12 inch veneer with the guides completely backed off and can MAYBE tell the difference if I try hard. Countour cutting with narrow blades is where guides it becomes a big deal. For a cut that does not fair well using a Carter Stabilizer (best thing for tight curves) then you want a guide that sits VERY close or in contact with the blade AND gives a large support area AND is as close to the stock top and bottom as possible. The Laguna guides beat pretty much everything on all of the above. All bearing guides loose points because they are circular and this alone reduces the surface area and distance from the stock to the fully supported areas behind the blade, in fact I would rather have solid wood or ceramic guides than ANY bearing guide for narrow blades.

In my mind the single best guide for a bandsaw is the Laguna guides. However, if a saw is limited to straight cuts and is a high quality saw (like I know the OP and Eiji have) I don't care what guide is on the saw, I have decided to keep the Euro guides on my MM since they are so easy to set and like I said aren't really an issue. When one starts cutting contours is where guides make the biggest difference in this application a solid guide (lignum vitae, cool blocks and retrofit fixed ceramic) are right behind the Laguna guides with any of the ball bearing guides bringing up the rear. Ball bearing guides are better than solid guides if they will be on a saw with a wide variety of blades though.

BTW all of the above is OPINION and everyone has a different view, I do think my opinion is right though since if I didn't I would change mine!

[jerry cousins]

i'm using a mm16 - it's one of the older generation saws - i use it primarily for resawing exotics for veneers - started out with the stock euro guides - they were very sloppy and would fill up with dust and not spin freely - the sloppiness seemed to continue to get worse. i bought a set of carters but found them pretty cumbersome to adjust - then moved on to laguna ceramic. i found the difference in accuracy dramatic. the guides are not set to touch blade - but provide great stability when sawing. i've not noticed any wear of the ceramics after about 18 months. highly recommend.
jerry

[ian maybury]

Thank you guys. It sounds very much like (a) ceramic doesn't wear anything like as fast as metal, and (b) that being able to run with the guides very close to (albeit not touching) the blade does damp vibration, improve accuracy and help when curve cutting.

I guess in hindsight the latter is what the square cool blocks seek to do on small bandsaws too. It makes sense that bearings don't do so well on both counts - line contacts to each side of the blade are not necessarily going to stop vibration. European style disc guides are probably pretty good in this respect I imagine, the issue there is probably more damage to the contact faces.

Your original report got my attention Eiji, so it's great to hear others confirm your experience as it shows it's not a saw model specific improvement.

That's one to park in the knowledge bank to bring out when the time comes to replace guides again....

ian

[Mike Wilkins]

I have a 2001 model LT18 bandsaw from Laguna. This model came with the standard Euro-type guides, but the thrust bearing wore out quickly. I upgraded to the ceramic guides without a problem. Great support on all sides of the blade. But there is one thing that may un-nerve you but is not a problem: sparks that fly from the guides. This is the result of a hard material (blades) coming in contact with a harder material (ceramic). These sparks are not a problem but some have expressed concern in the past. It is a worthy upgrade that provides fantastic results.

[John Shuk]

I personally don't care for the Laguna ceramic guides on my saw(LT16). I find setting them to be a pain and I don't think I've gained anything over good roller guides. I also have to reset my guides if I raise or lower the blade guard. I'd rather have a little flexibility on my bandsaw. I don't like the sparks either. On the other hand, Laguna may have tweaked the guide system in the past few years.

[John Nesmith]

I use blocks made of lignum vitae, and run them right up against the blade. Seems to work, but of all my shop machinery, the BS is the biggest mystery to me.

[Van Huskey]

One thing to note about the Laguna guides is they recommend running them right up against the blade with no set off, which gives excellent support and makes them very easy to set. I do know quite a few people with these guides that choose to run them with a "standard" offset which will BTW reduce the number of sparks you get.

I didn't mention it but I do think guides may be the least important factor in the "system". If the saw is tuned really well and the proper blade and technique is used the type of guide won't make a noticeable difference in the cut unless the "system" is being pushed to the very limits. So short of those "special" cuts my favorite guides are the ones that are easiest to set and take the least number of tools. From this standpoint the Laguna guides do very well and the Laguna saws tend to have lots of room to access the guide, one area that a lot of particularly lower cost bandsaws come up very short.

[Scot Ferraro]

I have the Laguna Ceramics and love them -- they are easy to adjust and provide much better support than the older Euro-style guides I used. I second Eiji -- Rick is a great guy to deal with at Laguna and is very knowledgeable.

Scot

[Greg Portland]

Like Mike I had a Laguna LT18 that came with the typical thrust bearings. I have since upgraded to the ceramic bearings which have made a significant improvement. Two major points:

- If you want to use thin blades for scrolling work then you'll need to swap the ceramics with wood (lignum vitae, maple, etc.) or phenolic rods (Laguna's solution).
- Cool-block solutions can provide support as good as the ceramics but they wear out faster. The cool blocks have the advantage of you not having to swap the guides when you change blade widths.

I have the Laguna guides and my only complaint is that it takes -3- different hex wrenches to adjust the guides. Maybe Laguna has addressed this issue with their recent versions. I use lignum vitae blocks for the side supports when using narrow blades. I keep the ceramic block for the rear blade support because it can't come into contact with the blade teeth.

[Scot Ferraro]

The new guides have little thumb screws to adjust the side guides. You do need an allen key to adjust the thrust bearing, but that is not too big of a deal. You might call Laguna to see if you can get a set of thumb screws.

Scot

[Chris Fournier]

One thing to note about the Laguna guides is they recommend running them right up against the blade with no set off, which gives excellent support and makes them very easy to set. I do know quite a few people with these guides that choose to run them with a "standard" offset which will BTW reduce the number of sparks you get.

I didn't mention it but I do think guides may be the least important factor in the "system". If the saw is tuned really well and the proper blade and technique is used the type of guide won't make a noticeable difference in the cut unless the "system" is being pushed to the very limits. So short of those "special" cuts my favorite guides are the ones that are easiest to set and take the least number of tools. From this standpoint the Laguna guides do very well and the Laguna saws tend to have lots of room to access the guide, one area that a lot of particularly lower cost bandsaws come up very short.

Guides are criticial to optimal BS function. Remember that your blade deflection is determined by its beam strength, a short beam deflects less than a longer beam for any given load. Your BS blade guides, the thrust bearings in particular determine the length of your "blade beam" length. Guides are essential for optimal BS operation. Having used some rather large BSs for resawing I can tell you that given the same blade and a 36" BS with no lower guide or my 18" with upper and lower guides I would take the small saw with the lower guide every time. This personal experience is on saws that I have tuned up to my satisfaction and used for pretty heavy resawing of domestic and exotic lumber used for musical instrument building. Once I made a lower guide for the larger saw, the performance of any given blade on either the large or small saw was the same.

[Van Huskey]

Guides are criticial to optimal BS function. Remember that your blade deflection is determined by its beam strength, a short beam deflects less than a longer beam for any given load. Your BS blade guides, the thrust bearings in particular determine the length of your "blade beam" length. Guides are essential for optimal BS operation. Having used some rather large BSs for resawing I can tell you that given the same blade and a 36" BS with no lower guide or my 18" with upper and lower guides I would take the small saw with the lower guide every time. This personal experience is on saws that I have tuned up to my satisfaction and used for pretty heavy resawing of domestic and exotic lumber used for musical instrument building. Once I made a lower guide for the larger saw, the performance of any given blade on either the large or small saw was the same.

The equation is simple if you think about it. If the blade tooth profile, drift angle, feedrate and tension are correct the blade never touches the guides in a straight line cut even the thrust bearing. All of the above have to be correct but if they are the guides never even enter the equation, therefore I maintain they CAN be a non-factor in ripping or resawing BUT all the other factors have to be optimized. I have on occasion done 12"+ resawing with the guides purposefully backed off completely and the results are visually and palpably essentially the same. I have done this on two admittedly middle of the road saws (LT18 and MM20) and I was more careful with my feedrates than I normally am. I understand this may fly in the face of conventional wisdom and certainly marketing hype but I think it is fair to say that, no matter whether one buys my assertion above, guides are a far more important factor when it comes to contour cutting than straight line cutting. The lateral deflection is higher and coupled with the much lower beam strength of a more narrow and likely thinner blade with a resulting lower beam strength means they rely on the guides much more to keep them from going wonky.

[Chris Fournier]

Van, I think that your observations have everything to do with reducing the forces via reduced feerates upon the BS blade to below the threshold that causes appreciable beam deflection but they don't really say much about guides and how they affect the beam strength of a BS blade by adjusting the beam length. Slow feed rates increase blade temperatures and reduce blade life which is not really that good. I think that your experiment would be more useful if you kept the feedrate constant with both guide and no-guide conditions. Remove your variable feedrate and I think that guides will prove their worth every time. I am limiting my comments to the thrust guides for the most part.

[ian maybury]

Here's one take on how that circle maybe gets squared guys.

As the other thread it seems to me that a decent and well set up band saw operates within a sweet spot - a zone where potentially a very large number of variables find some sort of (perhaps uneasy?) balance. A decent saw/working within its limits ensures that there is a viable set-up in there somewhere, while set up expertise finds the sweet spot/zone.

Band saws (at least the example I've put time in on) don't perform very consistently unless the band and wheels are correctly aligned/the blade is tracking right, and the blade is tensioned enough. This I suspect is the basic. But that's not to say that the guides or indeed other less fundamental variables can't play an important part in specific situations. Some possible examples (which won't be news to most of you):

A sharp hook toothed blade is probably close to being self feeding, but a blunt one needs a lot more feed force - and in the latter case the thrust guides may be what prevents this excessive feed force from eventually overcoming the self centering effect of cambered wheels. This (and differences in work type) may be why some report very heavy wear to thrust guides, and others don't too. The side guides may likewise prevent blade twisting under feed forces.

Some saws that can't apply high levels of tension and have non-optimised wheel weights may depending on the blade fitted likewise suffer from blade vibration issues (waves running up and down the blade - many of us will have seen the 'harmonic' patterns this can produce and heard their noise, especially on lighter saws), plus various rotational oscillations. (try carefully touching a stick to the side of the blade and see what you feel, especially in deep cuts) Close fitting ceramic guides/cool blocks could in that case possibly produce big improvements - by preventing these vibrations/oscillations from getting going. Blade tension adjustments may (or may not - especially if the available tension is limited) move the system into a zone where these resonances are tuned out too.

So to put it in more general terms. There's maybe basics like using a decent blade, having correct wheel alignment and camber, having enough frame rigidity and blade tension, and having guides to prevent derailing of the blade in extreme circumstances etc. that are essential if the saw is to have the potential to work well. Then though there's a gazillion other variables which depending on your specific saw, blade and application enable a better or worse set-up that extracts more or less of this potential.

Some of these 'others' may deliver good results if set according to fixed guidelines/rules of thumb, while others may need tuning depending on the precise situation.

Which I suspect is why (while there's good and not so good saws, blades and other parts) that band saw set up remains a bit of a pernickety art - and why there's so much seemingly contradictory information about. Put simply it's very easy to conclude that what works in one situation is universal - when in reality it's maybe just a set up that works in that specific situation....

Ian

[Chris Fournier]

I too find that the BS can be a treat to use or a real bear to contend with depending on the day. I've learned to take the time to set it up for the type of cut I'm preparing to take but even then things can go a bit sideways at times. I do find that a fresh blade is as close to a sure thing as you can get.

I wish that it behaved more like the TS where you turn it on an all expectations are met with no fuss.

[Greg Portland]

The new guides have little thumb screws to adjust the side guides. You do need an allen key to adjust the thrust bearing, but that is not too big of a deal. You might call Laguna to see if you can get a set of thumb screws.

Scot
Thanks Scott. I had complained to them a few years ago about the adjustment methods on the original guides... I'm glad to see that they did something about it. I will give them a call...

[Van Huskey]

Van, I think that your observations have everything to do with reducing the forces via reduced feerates upon the BS blade to below the threshold that causes appreciable beam deflection but they don't really say much about guides and how they affect the beam strength of a BS blade by adjusting the beam length. Slow feed rates increase blade temperatures and reduce blade life which is not really that good. I think that your experiment would be more useful if you kept the feedrate constant with both guide and no-guide conditions. Remove your variable feedrate and I think that guides will prove their worth every time. I am limiting my comments to the thrust guides for the most part.


Certainly my observation has to do with reducing the feedrate, in this case it is reduced below the level that the blade deflects enough to touch the thrust bearing if it were there. I should have been clear by pointing out the feedrate I used was NOT reduced below an acceptable level. The blade I was using was a Laguna Resaw King which is a self limiting blade. It has a tooth profile to prevent overfeeding and keep the chip load correct. I was using a feedrate that is close to that limit and one that was known to me to give the best finish with that blade. The blade was tensioned as best as I can tell in the 25,000 PSI range and at a resonable feedrate just doesn't contact the thrust bearing. I am not saying guides don't have uses even in straight line cuts BUT I am saying that a proper blade, proper tension and proper feedrate reduce the actual use of the guides to a minimum. That said my hypothesis is that for straight line cuts any decent set of guides adjusted properly will produce an indistinguishable cut from another set of decent guides properly set up. Stated another way for straight cuts on a bandsaw I don't care if the guides are Laguna, Euro, Carter type ball bearing or any of the solid guides. Now when it comes to contour cuts I feel these are an entirely different equation and one can produce the best cuts with the guide that has the most/closest blade support and that support is provided as close to the top and bottom of the stock as possible. This formula leaves the current Laguna ceramic guides at the top of the guides I have used. Also note I am not advocating resawing or ripping without guides properly setup, because even in my example above the blde could be deflected with a small (or large) local increase in density in a board such as a knot.