Quantcast
  • We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

A source for Ceramic disks for bandsaw guides

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

Derek Cohen (Perth Oz)

Established Member
Joined
2 Mar 2005
Messages
2,723
Reaction score
56
Location
Perth, Australia
I have a Hammer N4400 bandsaw. This uses steel European guides. Felder do sell a replacement set of ceramic guides, but they are very big $$$ in Oz. Ceramic guides would reduce heat and be capable of being set closer to the blade for reduced movement/better stability.

It occurred to me that it would be possible to simply epoxy ceramic disks over the face of the steel bearings to achieve the same result. I am struggling to find parts that can be used.

Ideally, the disks need to have a diameter of 35mm and be around 1-2mm thick. The reason for this thickness is that there is not a lot of depth available at the sides. If this is not thick enough to minimise heat, please comment.

Here are pictures of the guides to illustrate. Note that there are two sets of guides, one above and one below the table ...





Any idea whether such disks can be purchased in small quantities? (I only need 6).

Regards from Perth

Derek
 

Derek Cohen (Perth Oz)

Established Member
Joined
2 Mar 2005
Messages
2,723
Reaction score
56
Location
Perth, Australia
Mike, I could purchase new guides, but they would be costly. The point of this exercise is to save bucks and get the results. The original Euro guides work fine, but not great. I get good results, but likely could get better. I cannot justify the cost of Felder replacements for the possibly small improvement.

Regards from Perth

Derek
 

deema

Established Member
Joined
14 Oct 2011
Messages
2,171
Reaction score
26
Location
chester
A little confused how ceramic discs will ‘close the gap’. My understanding (GL456) and the way I set mine is for the discs should to be toe’d in such that the front is touching the blade and the back isn’t. They then rotate with the blade. The back should also just be touching the blade......that’s according to the manual anyway!
 

Inspector

Nyuck, Nyuck, Nyuck!
Joined
18 Jun 2006
Messages
1,702
Reaction score
119
Location
Saskatoon, SK., Canada
I poked around a little and found this company in China :shock: :wink: that might have what you need.
What concerns me with your plan is if the discs get hot from friction the epoxy will fail. You are going to have to hunt around for some good high temperature epoxy.

https://www.machiningceramicparts.com/s ... wafer.html

An alternative would be to find carbide discs and have them braised/silver soldered on.

Pete
 

Derek Cohen (Perth Oz)

Established Member
Joined
2 Mar 2005
Messages
2,723
Reaction score
56
Location
Perth, Australia
The side guides are circular, face on to the side of the blade. Only a section of the guide face touches the blade (from behind the teeth). Hopefully the rear guide is obvious.

As I understand, even 2mm thick ceramic will insulate against heat. Please comment if you know differently.

Regards from Perth

Derek
 

MikeJhn

Grunkel
Joined
2 Sep 2014
Messages
4,047
Reaction score
53
Location
Kent mostly and France the rest
As far as I understand these things, at rest none of the guides should touch the blade, but only just, your rear disc looks too far away from the blade at rest, what you should be able to do is manually turn the blade wheel without the disc rotating, when you introduce a workpiece to the blade it should touch the rear guide, but and IMO it's a big but, the orientation of the rear disc is engineeringly completely wrong, to rub on one side/face of a what is supposed to be a support will move the blade towards one side and throw off the whole set up, I really can't justify why manufactures put these disc's on what is supposed to be a bearing support other than cost savings.

You may be interested in this : https://www.google.com/search?q=snodgra ... e&ie=UTF-8

And maybe this: new-bandsaw-guides-from-axminster-t104943.html

And page eight here: axminster-hbs350n-bandsaw-advice-t105064-105.html
 

Derek Cohen (Perth Oz)

Established Member
Joined
2 Mar 2005
Messages
2,723
Reaction score
56
Location
Perth, Australia
Mike, I understand that you are trying to be helpful, but the photos are NOT from my bandsaw. They are there to illustrate the placement of the ceramic. I am pretty decent at setting up a bandsaw. I have been doing so for many years. What I am after is information to locate suitable ceramic material.

Ceramic guides differ from metal guides in that they are able to be set touching the blade. Since they do not wear, either the blade or themselves, they offer greater stability. This translates to better resawing.

This is what Felder write: Ceramic guides guarantee excellent cutting results and maximum blade stability with four guiding blocks positioned directly on the saw blade. With reduced friction and less heat generation, ceramic guides are practically wear resistant and enable an extremely long usable life and consistent cutting quality when compared to conventional roller guides.

Regards from Perth

Derek
 

toysandboats

Established Member
Joined
23 Apr 2006
Messages
307
Reaction score
0
Location
Eastleigh, Hampshire
Derek, the only thing that came to mind was ceramic tap discs. I know they come as a valve assembly, but perhaps you can take them apart. A plumber might have some old ones to experiment with.
Good luck and I like your idea,
David
 

Inspector

Nyuck, Nyuck, Nyuck!
Joined
18 Jun 2006
Messages
1,702
Reaction score
119
Location
Saskatoon, SK., Canada

Trevanion

Greatest Of All Time
Joined
29 Jul 2018
Messages
3,775
Reaction score
555
Location
Pembrokeshire
Derek, can you get ceramic washers in Oz? I think one of those would be ideal if you could get one in the right size.

I don't want to start a "what's the best blade guide" argument but I cannot for the life of me see how anybody can say those Carter-style guides are any better at guiding a blade than any other method. If they were any good more manufacturers would have been using them years ago or at least offering them as an optional extra.
 

MikeJhn

Grunkel
Joined
2 Sep 2014
Messages
4,047
Reaction score
53
Location
Kent mostly and France the rest
Trevanion

The only reasoning I can see behind not offering Carter type guides on all bandsaws is cost, just look at the machining involved in having the a thrust bearing oriented the correct way compared to putting a disc at the back of the blade face on, this obviously applies to the side guides as well, using bearings instead of rubbing blocks makes the whole assembly more difficult to make, hence comparatively expensive, in engineering principles rubbing blocks are a last resort.

For my part, I can't see how having a disc of any type permenatley rubbing on both sides of the blade will not introduce friction and therefore heat into the blade, thence expansion and slackening of the tension and eventually de-tempering.
 

Derek Cohen (Perth Oz)

Established Member
Joined
2 Mar 2005
Messages
2,723
Reaction score
56
Location
Perth, Australia
Trevanion":3mx4y42d said:
Derek, can you get ceramic washers in Oz? I think one of those would be ideal if you could get one in the right size...
That was my first though, and I ordered these on eBay ...



They are 26mm in diameter and 4.6mm thick (which is likely too thick for the sides). They may work, but this is also the reason I am looking around. It would be so nice to find a simple ceramic disk of about 2mm in thickness, which I can glue to the existing bearing (which are quite worn, anyway).

I've looked at some of the Chinese offerings, but feel awkward asking for 6 items when they want to deal in thousands.

Regards from Perth

Derek
 

Trevanion

Greatest Of All Time
Joined
29 Jul 2018
Messages
3,775
Reaction score
555
Location
Pembrokeshire
I haven’t read so much nonsense in a while!

Of course cost factors into it but if they actually performed that much better than any other guide system like Carter claims they would definitely be offered as an optional extra on the Felder and Centaro machines as at that level of machine that kind of money is pennies, they’re an American hobby gimmick and nothing more. I know several very experienced craftsmen that swear by rubbing blocks for bandsaws as they support the blade far better and I agree, having all the pressure of the blade on one pinpoint on the sides or back is just going to stress and warp the blade in minutes of actual work rather than little cuts you might find hobbyists doing. Your idea of blades heating up from the friction and losing temper is just absolute nonsense, you would never get a blade hot enough to lose its temper even in extreme use, by the time the blade as done a full revolution any heat accumulated would’ve dissipated. Plus you should never have the guides “permanently rubbing” as there should be a minute gap between the blade and any guides, the machine should work well with a sharp blade without any guides at all.

If you use “engineering principles” in woodworking you’ll never actually get anything done :lol:.
 

MikeJhn

Grunkel
Joined
2 Sep 2014
Messages
4,047
Reaction score
53
Location
Kent mostly and France the rest
Rubbing blocks are a nonsense I agree, cheap, nasty and so old fashioned, plus Derek and deema both say they set up with the guides touching the blade so the nonsense is compounded, I know an equal number of very experienced craftsmen who would never consider using anything other than a bearing guide, any friction on a blade is going to create heat, your supposition that the blade will loose its heat on a full revolution does not work out in practice, grab one of your blades that has had a rubbing block permenatley on it after use, don't blame me for the burn. :wink:

I use engineering principles in everything I do. (hammer)
 

Trevanion

Greatest Of All Time
Joined
29 Jul 2018
Messages
3,775
Reaction score
555
Location
Pembrokeshire
MikeJhn":38kc4p6q said:
your supposition that the blade will loose its heat on a full revolution does not work out in practice, grab one of your blades that has had a rubbing block permenatley on it after use, don't blame me for the burn. :wink:
It does work in practice as I've put hundreds of meters of wood through a blade and never had a burn from touching the blade afterward, even on the old Startrite 352 with the thrust rods which constantly rub the back of the blade when cutting. Trying to over-engineer blade guides is a totally pointless and expensive exercise and is purely a money-making scheme, they don't prolong the life of the blade at all as the teeth go dull before the guides could do any damage and they don't improve cut quality which in all just makes them a pointless American gimmick to add to the pile of other pointless gimmicks.
 

MikeJhn

Grunkel
Joined
2 Sep 2014
Messages
4,047
Reaction score
53
Location
Kent mostly and France the rest
Trevanion we will have to beg to differ on this, as a retired engineer, I can't even look seriously at rubbing blocks being a good idea, it goes against all engineering principles that I have been taught and brought up with, but each to his own.
 

Trevanion

Greatest Of All Time
Joined
29 Jul 2018
Messages
3,775
Reaction score
555
Location
Pembrokeshire
MikeJhn":1v5pr1wd said:
Trevanion we will have to beg to differ on this, as a retired engineer, I can't even look seriously at rubbing blocks being a good idea, it goes against all engineering principles that I have been taught and brought up with, but each to his own.
But you still haven't shown me anything to say 100% that the Carter guides are any better than just a plain old block of steel other than what you've been told by salesmen (That's all Snodgrass is, a glorified Carter Salesman) and what you've conjured up in your mind. As a non-retired industrial wood machinist, I've got hundreds upon hundreds of hours clocked up in front of bandsaws of all different sizes and manufacture from the little Burgess three-wheelers all the way up to the big Stenner Resaws, they all cut wood exactly the same no matter what guides are put on them.

"They reduce friction" - The friction was never a problem in the first place, a dull blade is always the problem.

"It's a better design" - It's only a better design if it actually improves anything, All I can see is that they turned the rear bearing 90 degrees so that there is pinpoint stress on the back of the blade rather than a nice amount of support offered by a disk or bearing surface.

They're utterly pointless, and as I've said several times, nothing more than a gimmick to get hobby sales because "You need these guides to actually make the bandsaw work properly" when in actuality it's "Put a good blade in the machine and you don't even need guides". It's the exact same thing as those daft Knew Concept coping saws, over 10x the price of a new Eclipse frame and they offer absolutely nothing over the Eclipse other than a fancy colour on the frame and the fact it's "over-engineered". Put the same blade in both saws and they both cut exactly the same no matter what frame you have.
 

MikeJhn

Grunkel
Joined
2 Sep 2014
Messages
4,047
Reaction score
53
Location
Kent mostly and France the rest
And you have not shown me anything to prove that having a rubbing block on a blade does not involve friction, any friction will produce heat and that is inefficient, a scientific fact, a bearing on the back of the blade will produce far less stress than a disc oriented the wrong way and turning in opposite directions on the blade over its contact area instead of following the path of the blade.
 

Latest posts

Top