Blades for Felder FB710

[Van Huskey]

TKS guys for your feedback. Vans, from the sources you listed above which from your experience does the best welding for these Lenox tried master blade? Also, I read somewhere that the FB710 would not be able to tension anything higher than 1" blade. Had these been your experience?

TKS,
Albert

I have not actually used a 710 but have crawled all over them on static display, the most recent was this years IWF, they usually only bring one or two bandsaws and this year they had a 710. I would expect to be able to properly tension a 1" Trimaster, no issue. They are lighter in build than the Centauro saws but the 710 is still a beast.

As for welds no matter the source when you have ordered enough blades you will get a bad weld sooner or later. I haven't had a poor weld from any of the three in several years but if I had to bet on getting a perfect weld it would probably be CT Saw. Statistically, I can't even say they are the best of the three and certainly can't include the hundreds of suppliers but they have been good to me as have the other two. Again, I do suggest you get a variable pitch Trimaster no matter what size you decide on.

BTW I noticed I referenced a 3/4" Trimaster in my other post, must have been a brain fart, the 1" 2/3tpi or 1" 3/4tpi would be my choice for that saw.

[Albert Chio]

Hi Denis,

What spring upgrade did you get? After market or one from Felder? What has been your experience with your FB710. I also replaced my old SAWSTOP with the Felder 700s and been really happy with it. Hope my experience with the FB710 is same. Haven't had a chance to use it yet but have un wrapped it and very impressed with build quality.

TKS

[John TenEyck]

I would be hugely disappointed to find out after the fact that a higher end Euro saw can't put 25K psi on a 1" resaw blade. Isn't that a common reason people buy these saws?

Anyway, as for blades, I've had great service from bandsawbladesdirect.com as others have noted. My one experience with Spectrum Supply did not go well. I bought a 1" x 1.3 tpi Woodmaster CT from them. It cut great until, after resawing/slicing veneer on less than 500 sq. ft. it broke at the weld. They offered me nothing other than being willing to reweld it, which might have been fine had it not wiped out half the teeth when it broke. I accept that you will get a bad weld now and then. I also expect a company to offer reasonable compensation when it happens since they were the ones who welded it. Spectrum Supply is now on my banned for life list.

FWIW, the Woodmaster CT 1" x 1.3 tpi blade is a wood slicing monster. It cut incredibly fast and smooth. I've never used another blade that cut that well, that effortlessly. But after the sour taste Spectrum left in my mouth I've gone to the other end of the spectrum (slight pun, I see) and am using Woodmaster GT and Woodmaster C blades. The 2 tpi Woodmaster C blades cut slower than the 1.3 CT, though still adequate, and the finish isn't as smooth, but I'm getting just as many slices of veneer / inch of stock. I can buy 6 of the C blades for the price of one CT, so if one or two brake it's no big deal. None have yet, however. Plus I can resharpen them myself though that's a process I'm still learning.

It is not the most pleasurable job changing out a big, stiff blade on a large bandsaw. Going to a narrow blade will require readjusting everything, making the job even less fun. OP, are you sure you don't have room for another bandsaw? I leave the 1" resaw blade on my larger bandsaw, and cut everything else on a 14" Delta with riser block. On that I leave a 3/8 x 4 tpi most of the time. FWIW, my experience with the Diemaster II was not as good as I expected. They cut fine until they didn't, and their life was no where near the 4 - 6X of a non bimetal blade as claimed.

John

[Denis Kenzior]

Albert,

i used an aftermarket spring. Choose a size that would fit in the housing. I ended up with 2x4.5” spring from Danly. See part number 9-3218-36

The FB710 was a perfect saw for my space. It is a good compromise between resaw ability and has ample table size for scroll type work. It was also the biggest saw I could fit into my space, which sealed the deal.

[marty fretheim]

I would be hugely disappointed to find out after the fact that a higher end Euro saw can't put 25K psi on a 1" resaw blade. Isn't that a common reason people buy these saws?

Where did this magic 25k number come from anyway? Not trying to be a wise ass but I have never seen any documented, recommended blade tensions from the manufacturers. Not doubting that number, just don't know where it comes from. The saw manufacturers don't seem to document tension capabilities of their machines either. Can somebody please post some? There seems to be a lot of people running oversize blades on their saws and getting away with it, although maybe not ideal. Now if you're in a production shop, resawing with a power feeder, that's a whole different story.

I've been running a 1-1/4" tri-master on my Felder FB 610. I should have bought a 1" but made a mistake. The experts keep telling me my saw won't tension it, but nobody told my saw that. My saw only tensions it to 20k. I don't know how the cut could get much better, but I don't use a power feeder ramming the wood through the blade, but I wish I did. When this blade dies I will replace it with a more appropriate blade, but I am surely not disappointed with the saw. There is more to a bandsaw than a stiff spine. I do understand the benefits of achieving maximum tension on a given blade. Because his high end Euro saw doesn't reach 25K means nothing. If the blade doesn't drift, weave or barrel through a cut isn't it tensioned enough? I bought my Euro saw because of the high quality cast iron, electronics/motor, fit and finish and the country that sold it to me (how's that for PC?).


20160401_184735.jpg

My Shelby has over 700 Hp, does that make somebody's new 500HP Audi/BMW/Mercedes disappointing? I think not!!

Just my thoughts, I'm still learning this enigma we call the bandsaw.

Merry Christmas!!

Marty

[David Kumm]

On my old cast iron saws the 25K came from experimentation. I put two tension meters on the saw to verify numbers and cut hard maple to .04 with a bandsaw cut on both sides. Using a planed edge on one side is much more forgiving but I tested sawing both sides. I could get decent cuts at 20K with my 3 tpi Trimaster but not good enough to stay within a few thou at .04 or less. I also want enough tension so the blade does not spin the back bearing. That does not mean that every saw or every blade needs that tension but 25-30000 is the sweet spot for my old Olivers. If buying a saw mainly for resawing, the ability to tension a 1" carbide blade takes a lot of the risk out of the purchase. There are other factors that can compensate and the extra stiff band on the 1.25" Lenox at low tension might be one of them. I've not experimented with that set up. Dave

[Van Huskey]

I've been running a 1-1/4" tri-master on my Felder FB 610. I should have bought a 1" but made a mistake. The experts keep telling me my saw won't tension it, but nobody told my saw that. My saw only tensions it to 20k.

Marty

That would be the equivalent of roughly 30k psi if you kept the same spring pressure and moved to a 1" Trimaster. The 1.25" is .042" thick.

To get the recommended tension numbers you have to corner a Lenox engineer and force it out of them. They want to discuss your saw, the material you are cutting (the on label uses for the Trimaster run from wood and aluminum all the way to titanium alloys) but when pressed they gave me the 30k psi number as the point for which you will no longer can expect any improvement from the Trimaster. If you are interested get on the phone to Lenox and have a conversation. I am not sure why they don't publish numbers but plenty of authors (ie Bird and Duginski off the top of my head) parrot the same figures and cite the manufacturers, I assume they have had the same conversations I have.

The only reason I think saw manufacturers may be reluctant to cite numbers is the fact the saw as it sits has nothing that reads in psi. The scales on Euro saws, especially the ones with remote scales on the spine) read notoriously low for the blade width. They have a lot more spring travel above the last blade listed, I reset them to be more aligned with the actual maximum.

BTW what size is the Kenne Bell SC? Based on HP I'm guessing 2.8L or 3.2L.

[Alan Lightstone]

Funny you ask. I have a 710 and live only a few miles away from Driftwood. My saw is about 3 years older than yours, so things might have changed, but when I was shopping for mine, I had Florian@Dallas give me the factory specs for the tension spring. The bottom line is that the spring will (barely) get a 1” Trimaster/Woodmaster to 25kpsi. It will be nearly bottomed out and unlikely to keep doing it after several compressions due to spring set. I installed an upgraded spring on mine.

Which spring did you get, and where did you get it? Any issues with warranty on a brand new saw upgrading the spring? Really not happy that a beast of a saw like this can't properly tension a 1" blade to 25k psi.

[Alan Lightstone]

Also, looking at the Lenox Trimaster choices on Bandsawbladesdirect. What are the advantages, disadvantages of the two thicknesses (0.035" and 0.042 inches) that they offer on the 1" 3/4 tpi blades? Is there a better choice between the two to use on the FB710?

[John TenEyck]

As David and Van discussed, you get maximum performance out of a carbide tipped band only when the tension is high enough to minimize deflection. David's empirical data clearly shows it. It doesn't mean you might not be satisfied running at lower tension, but to take full advantage of what the blade has to offer high tension is needed.

It is rather surprising that bandsaw manufacturers don't state what tension their saws are capable of achieving, at least the ones who make saws that can put 30 K psi on a certain band. When I look at the band sizes that manufacturers state their saws are capable of running I automatically conclude it's overstated by at least one size. So if they say their saw can run a 1" band, then 3/4" is likely all it can really use. In the case of the Felder FB710, the specs. shows it can run a 1-1/8" band, and that would make me suspicious that it can put 25 - 30K psi on anything more than 3/4".

I have two saws, a venerable old Delta 14" CI saw and a modern steel framed Grizzly. The Delta manual says it can run a 3/4" band. Maybe, but not with very much tension. On a 1/2" band I couldn't get more than 18 K psi with an Iturra spring nearly fully compressed. (Note: I don't recommend doing that because you could easily damage the upper wheel spindle.) For normal use, I run the 1/2" band at 12K psi. It cuts well enough for what I ask of it. I've even cut 10" veneer with it and as long as you have a sharp blade and are patient, very patient, it will do it. But it's nothing like what the larger Grizzly is capable of. That saw is rated for a 1-3/8" band. I run a 1" band on it and it easily puts 27K psi on it at the 1" tension mark, and there is a lot of spring left. I'm sure it could easily put 30K psi on that band, but whether it can put even 25 K psi on a 1-3/8" band is doubtful. But back to the 1" band at 27 K psi. It will resaw and slice veneer without wandering, barreling, or any other problem that can easily happen on the Delta, and do it at least 10X faster with a better surface finish (when using a carbide band). Both saws will get the job done but for resawing and slicing veneer the Grizzly is an easy choice that is a joy to use.

Bandsaws, unlike cars, are pretty simple machines. Sharp blade, plenty of tension, and enough power to pull the band through the wood is pretty much all there is to it.

Merry Christmas,

John

From Lennox: https://www.lenoxtools.com/Pages/FAQ.aspx

LENOX blades are designed to handle up to 30 000PSI. Please consult your machine manual for proper setting on your machine. Over-tensioning blades can cause premature machine failure.

[Denis Kenzior]

When I was shopping for my bandsaw no manufacturer would provide any actual hard numbers about blade tension. The only thing one could judge a bandsaw was actual owner's experience (which is quite subjective) and the physical weight of the machine. But that doesn't really tell you everything. I wanted a saw that that would handle a 1" carbide blade, so I had to dig a bit deeper.

John mentions trying to gauge the size of the blade a saw can realistically tension by looking at the maximum blade width and dropping down a size. This gets you in the ballpark, but not really an ideal way of judging a saw. There is also no direct relationship between wheel width and tension ability. The width of the wheel is what limits the blade width. How stiff is the frame, how stout is the tensioning mechanism and how stiff the spring is determines how much tension can be put on the blade. FB710 is rated for a 30mm blade. In reality it can probably easily accommodate 1.5-2" wide blades. But why would you want to?

Anyway, back to tension. Felder did provide me with the spring tension specifications. Minimax sales had no idea. So big kudos for Felder sales for being able to obtain this info. If anyone cares, Felder specified the FB710 spring as 330 N/mm with 20mm max travel, giving an effective tension of 6600N (~1500 lb of force). The FB740 (which is in theory a much stouter saw) was quoted as 320 N/mm with 15.5mm of deflection. The spring on the FB740 is only rated to 5000N. FB610 was way less.

So now I had to make sense of these numbers. We want 25kpsi tension on the blade. We need to know the cross sectional area to find the force required to stretch the blade to that tension. Typical Trimaster is 0.035" thick by ~.9 wide. So .035 * .9 * 25000 = ~787 lb of force. Unfortunately the force exerted on the band by the tension spring must be double that number. Think of the circular band as two separate segments of steel and both must be tensioned the same amount. So to tension a typical 1" carbide blade, you need 1600 lb of force on the spring. Go look at the Danly Spring or AS Raymond catalogs to understand the physical sizes of a spring that can accommodate such forces. They're not tiny.

Another issue to consider is how stiff the spine is. As you tension the blade, the frame of the saw will start compressing, in effect applying less tension on the blade. So that 1600 lb number is the bare minimum, in an ideal world with an infinitely stiff bandsaw spine. The stock Felder spring was barely adequate, but close. I liked the overall build of the machine based on spending a full day with a FB610 at another woodworker's shop.

Once I got the machine into the shop I went about measuring real world numbers. They corresponded closely to the above 'ideal' calculations. The FB710 stock spring did get a woodmaster CT to 25kpsi. But it was nearly bottomed out. This was confirmed with 2 Lenox tension meters and via stick + .0005 dial indicator. In my testing the 'clamp a digital caliper' over 5" was not accurate or repeatable compared to a dedicated tension meter. In comparison, the FB610 would get a 1" Trimaster to only 19k before bottoming out on a stock spring. The cut quality was comparable on 6" mahogany boards. I felt pretty comfortable putting in an upgraded spring as I felt the tensioning mechanism could take it. The Danly spring I put in my saw (9-3218-36) is rated at 2255 lb at maximum operating deflection and is about the same physical size as the stock spring.

In my testing I haven't really found a huge difference between 17-20k psi and 25k psi for 'typical' resawing. Sharp blade, properly setup guides, steady feed, fence alignment, stock straightness, downforce on the fence - all play a huge role. Once you start sawing dense woods and wide boards, then the tension starts to help out. So if you're trying to squeeze every bit out of a given board, tension helps. But you're also at the whims of the wood; every bit you take off releases tension and the stock can start to move and warp. So count on going to the jointer after a couple of rounds through the saw unless your stock is short or quite stable.

So my advice to anyone shopping for a new bandsaw is, go physically inspect the saw. Contact the manufacturer and see if they can point out owners in your area. Talk to them, take measurements and use common sense. Don't take the sales guys at their word.

[Denis Kenzior]

Alan,

I would stick to the thinner blade. Mostly because the kerf will likely be thicker on the .042 blade, and with a bandsaw you want to keep the kerf width to a minimum to maximize stock utilization. The .042 thick blades will also require 20% more tension force if you care about hitting the 25k psi (or more) magic number.

[marty fretheim]

That would be the equivalent of roughly 30k psi if you kept the same spring pressure and moved to a 1" Trimaster. The 1.25" is .042" thick.

To get the recommended tension numbers you have to corner a Lenox engineer and force it out of them. They want to discuss your saw, the material you are cutting (the on label uses for the Trimaster run from wood and aluminum all the way to titanium alloys) but when pressed they gave me the 30k psi number as the point for which you will no longer can expect any improvement from the Trimaster. If you are interested get on the phone to Lenox and have a conversation. I am not sure why they don't publish numbers but plenty of authors (ie Bird and Duginski off the top of my head) parrot the same figures and cite the manufacturers, I assume they have had the same conversations I have.

The only reason I think saw manufacturers may be reluctant to cite numbers is the fact the saw as it sits has nothing that reads in psi. The scales on Euro saws, especially the ones with remote scales on the spine) read notoriously low for the blade width. They have a lot more spring travel above the last blade listed, I reset them to be more aligned with the actual maximum.

BTW what size is the Kenne Bell SC? Based on HP I'm guessing 2.8L or 3.2L.

The SC is 2.8. Didn't want to replace the hood for the 3.2.

Marty

[John TenEyck]

A lot of good info. there, Denis. But your comment on the saw frame compressing and that resulting in less tension on the blade is not really correct. The frame will bend as spring force increases, but if it's stiff enough that you can apply 1600 lbs of force then it will be 1600 lbs on everything, including the blade.

I also was surprised that you have to rejoint your stock after taking a couple of slices. That was a problem for me with my 14" Delta, but driven mostly by the blade wandering due to the really low tension. When I got my larger saw I had much less problem with this happening, but it still did once in awhile which I attributed to me not being able to keep the stock tightly against the fence during the cut. To address that I built a tall fence and roller featherboard, modeled after one John Lanciani showed here a few years ago and have never had to rejoint stock since. If the stock is pressed tightly against the fence over it's full height the blade slices veneer of consistent thickness, slice after slice. Here's a link to what I built: https://sites.google.com/site/jteney...aw-rollerboard You might consider something like this.

I found your comment to inspect a saw before buying to be spot on. I would add, don't just inspect it, if at all possible run it, and at a minimum measure the tension you can apply to the blade. I've had no trouble using a set of Vernier calipers in getting accurate and repeatable results, but the cost of commercial tension meter is cheap compared to new saw and would be a worthwhile investment.

John

[Denis Kenzior]

John,

I'm no engineer, so if you say that frame flex does not affect the force applied, I stand corrected. I will say that when I was running my measurements, I would measure the tension on the band and since I knew the spring specifications I would also measure the spring compression. Spring travel (and thus force applied to the band) was always a bit higher than what the 'ideal' model was predicting.

I work mostly with Sipo and other Mahoganies, which tend to be a bit unpredictable. I had perfectly jointed / planed boards move significant amounts after ripping them. I observe the same wood movement after resawing as well, so I don't think it is the saw as my veneers come out with less than .006 variance between the four corners on a 6-8" wide board after feeding by hand. A setup that flattens stock against the fence would definitely help though. I have not needed to do enough critical resawing to invest in a dedicated setup similar to yours. It is on the TODO list.