Felder FB510

[Jim Becker]

If you are contemplating spending serious money on a new saw, and one of your objectives with that saw is to be able to resaw and slice veneer from wide stock, shouldn't the saw you buy be capable of doing that without compromise?

I agree with the point of this question. When we invest in tools, our intended purpose has to be achievable by the solution we choose. That doesn't mean that budget doesn't come into play...it does for sure...but within the available budget or by saving for a little longer, it's a good practice to focus primarily on that "what do you want to do" thing that John clearly asks about.

I do a little bit of resaw work on my MM16, but If I have something a bit more serious or just below or larger than my comfortable capacities, I ask a friend (who is also a 'Creeker) to assist with his larger machine with a stoutly tensioned 1" carbide blade. Like butta....

[Derek Cohen]

Well, we're talking about a Felder, not a Hammer of different size, but I like data so what tension have you measured on your saw?

John, I have been asked this question before and my reply remains the same: I do not use a dedicated meter. I tension by sound, and if this works ... well, it works. I do not need numbers to confirm this. The reason I responded to this thread was my belief that any Felder must be specced higher than a Hammer ... so if my N4400 (which is a 17 1/2” saw) can do it successfully ... and I am on my second CT blade ... then a FB510 should have no trouble.

off to Prague ..

Derek

[Jeff Monson]

Well, we're talking about a Felder, not a Hammer of different size, but I like data so what tension have you measured on your saw?

John, do you have any data on a FB610? I just read the thread you pasted, and I will say I'm surprised. I have a FB510 on order (set to deliver end of January) and now you have me thinking I chose the wrong saw. I do resaw quite a bit so I dont want to be disappointed. I could change my order to a FB610 but it would be an additional 1k

[John TenEyck]

John, I have been asked this question before and my reply remains the same: I do not use a dedicated meter. I tension by sound, and if this works ... well, it works. I do not need numbers to confirm this. The reason I responded to this thread was my belief that any Felder must be specced higher than a Hammer ... so if my N4400 (which is a 17 1/2” saw) can do it successfully ... and I am on my second CT blade ... then a FB510 should have no trouble.

off to Prague ..

Derek

Enjoy Prague, where the Pils is perfect but stay away from the Becharovka (sp), and the rest of your travels Derek.

I'm glad you are happy with the performance of your saw, but w/o measuring the tension you are just guessing. Perhaps it's perfect, perhaps it should be higher and you could enjoy even better performance, perhaps it's so high you risk breaking something.

John

[John TenEyck]

John, do you have any data on a FB610? I just read the thread you pasted, and I will say I'm surprised. I have a FB510 on order (set to deliver end of January) and now you have me thinking I chose the wrong saw. I do resaw quite a bit so I dont want to be disappointed. I could change my order to a FB610 but it would be an additional 1k

Sorry Jeff, I don't have data on the FB610. But you should be able to have Felder send you the data. If they don't have any, well, red flag, but I'd ask them to measure it for me with whatever width and gage blade you want to run. If they won't, a big red flag, but before I'd panic I'd ask if someone here has a FB610 and for any data they have or if they would be willing to measure it on their saw. Alternatively, if they have a showroom close enough to go to I'd ask if I could come in and measure the tension on a FB610, and FB510, too, for that matter. If that's a no go, well.....

I don't want to bad mouth Felder or the FB510. I'm simply pointing out another Creeker could not put 25 ksi on a 1" blade on his FB510 and the feedback he got from Felder wasn't what one would hope for.

John

[Mark e Kessler]

What I would like to see a comparison of tension from a homemade tension guide and a commercially available one like the Starrett. And and actual DOE of how this supposed testing is being done, I haven’t seen any of that in the “data” that has been published on the SMC, its all assumptions unless the tool/s doing the testing are calibrated and certified and the steel in the blade is known (meaning it was tested to confirm the manufacturer spec).

Now don’t get all bent out of shape this is not to say the “testing” isn’t worth while without doing it correctly, and maybe it was and it was not disclosed.

I am really only concerned with getting a parallel cut within a couple thou, sure I want the best I can get and obviously there are folks getting excellent results with less tension, hell my stupid laguna 14/12 does pretty good just by setting it flutter style.

[Mark e Kessler]

I think it’s just a matter of swapping the spring if the 510 for a stiffer one if it does not, i am not going to worry about it pretty sure it will be good enough if it ain’t I will swap the spring

[Doug Dawson]

What I would like to see a comparison of tension from a homemade tension guide and a commercially available one like the Starrett. And and actual DOE of how this supposed testing is being done, I haven’t seen any of that in the “data” that has been published on the SMC, its all assumptions unless the tool/s doing the testing are calibrated and certified and the steel in the blade is known (meaning it was tested to confirm the manufacturer spec).

Now don’t get all bent out of shape this is not to say the “testing” isn’t worth while without doing it correctly, and maybe it was and it was not disclosed.

I am really only concerned with getting a parallel cut within a couple thou, sure I want the best I can get and obviously there are folks getting excellent results with less tension, hell my stupid laguna 14/12 does pretty good just by setting it flutter style.

The so-called "home-made" tension gauges, using the calipers etc clamped to the blade, are based on the basic physics of the stretching of a beam. I would tend to trust them more than the commercial tension gauges, if they were properly set up.

[Mark e Kessler]

Oh I know, the properly set up part is the thing. Not so sure I would trust homemade to the Starrett... I work in testing lab and I can tell you for me to trust a home made gauge it would need to be cross checked against a known certified gauge and specific test methods, which none here have (could be, just never came across it). However does it really matter? probably not, it's woodworking not engineering so if its off +- who cares if the cut is right

The so-called "home-made" tension gauges, using the calipers etc clamped to the blade, are based on the basic physics of the stretching of a beam. I would tend to trust them more than the commercial tension gauges, if they were properly set up.

[Doug Dawson]

Oh I know, the properly set up part is the thing. Not so sure I would trust homemade to the Starrett... I work in testing lab and I can tell you for me to trust a home made gauge it would need to be cross checked against a known certified gauge and specific test methods, which none here have. However does it really matter? probably not, it's woodworking not engineering so if its off +- who cares if the cut is right

So use a better caliper? The iGaging unit is good enough, to within the usual estimates of what is good-enough tension. To quote Art Garfunkel, it won't make a dimes worth of difference. I wouldn't waste my Starrett calipers on this. You can measure everything else okay with the iGaging as well.

[Denis Kenzior]

John has given you a lot of good advice already.

You might want to check out http://www.solowoodworker.com/tools/resaw.html. The bottom line is that all steels behave pretty much the same, so no 'calibration' is needed.

I can only add that I performed the comparison you are speaking of. Had 2 Lenox Tension Meters and also tried the 'home made' method with a .0005 Brown & Sharpe DTI. Both were within 5-7% with repeated measurements. The home made method can be in theory a bit more accurate due to measuring over a longer distance: the commercial tension meters measure over 4-5", the home made method can do it over 12-16", depending on how much resaw height you have. Keep in mind though, that commercial units use good indicators, calibrated for the length of measurement needed and constructed not to introduce any cosine error.

You're measuring .004-.012 inches of stretch, depending on distance. I wouldn't trust any cheap digital calipers for this that are not even repeatable within .001 (check the specs if you don't believe me). Go get yourself some .0005 dial or test indicators if you go this route. Or just buy a commercial tension gauge.

[David Kumm]

For what little it is worth, I've had at least four tensions gauges over the years. Bought used and new. I would set up three on my Oliver 116 in a row and tighten the blade. It takes two hands and some effort to get to the 25K range. The most deviation between all of the gauges was about 1000. That is irrelevant to me as I only care about repeatability. On my saws, anything over 25K seems to give me the best cut but the increase in tension over that doesn't reflect in a better finish. I will increase the tension when sawing wider stock to keep the back bearing from engaging if possible but generally won't go over 30K because I can't see the spring on my saws and bottoming out a spring is a recipe for a broken blade.

The point of the gauge is not a specific number but to assess the range that tension improves the result. I measured some veneer I cut out of maple. Ranged from .0595 to .0585. I know I can get that result when I tension my saws to the same number and not risk screwing up my expensive blade. I kept two gauges and sold the other two. Dave

[John TenEyck]

I think it’s just a matter of swapping the spring if the 510 for a stiffer one if it does not, i am not going to worry about it pretty sure it will be good enough if it ain’t I will swap the spring

That's OK as long as the frame can handle the higher load without bending so much that the guides go out of alignment.

John

[John TenEyck]

Oh I know, the properly set up part is the thing. Not so sure I would trust homemade to the Starrett... I work in testing lab and I can tell you for me to trust a home made gauge it would need to be cross checked against a known certified gauge and specific test methods, which none here have (could be, just never came across it). However does it really matter? probably not, it's woodworking not engineering so if its off +- who cares if the cut is right

For what it's worth, which isn't much, I was an R&D engineer for over 30 years and was involved in all kinds of high precision mechanical properties testing. One thing I learned is that simple, direct measurement is usually the best approach if the situation allows it. Measuring the strain in a bandsaw blade is simple and direct, and very repeatable. Here's how I do it: https://sites.google.com/site/jteney...-tension-meter

As someone else reported, the Young's Modulus of steel is pretty consistent at 29 - 30 x 10^6 psi for the type used to make BS blades. Error measurement from a dial gage with 0.001" resolution is less than 0.001". At a 12" gage length and a Y of 30 x 10^6 psi, blade strain is 0.010" at 25 ksi stress (tension). So the max. error in that case from a dial gage with 0.001" resolution is 10%, half of that if you use a dial gage with 0.0005" resolution. In reality the error is much less. But you can go nuts and use other, higher level gauges with even lower error in the quest for greater accuracy.

So maybe the gods are against me one day when I put my shop built tension meter on a new blade and it gives me the max. error. So instead of getting 25 ksi I only have 22.5. I'm OK with that. What I'm not OK with is not being able to get an indicated 25 ksi because the machine isn't capable of generating enough force. FWIW, I've measured over 40 ksi on my BS with a 1" blade. I wouldn't want to run a blade that high, but it's nice to know the saw is capable of giving me 25 ksi w/o being at or near its limit. Equally important, the guides remained centered on the blade meaning the frame is rigid enough to keeps things in alignment.

[Denis Kenzior]

Using a dial or test indicator is the proper way to go. Cheapie .001 is sufficient but .0005 is easier to read.

I'd just caution against using dial calipers in this application (as has been suggested). One would be limited to (typically) about 6" measuring range and the accuracy / repeatability is poor. So one might measure 5.999 unstretched and 6.004 stretched, giving a theoretical 25k psi. But in reality the actual measurements were 6.000 and 6.003 respectively. So the blade is only tensioned to 15k psi instead of 25k. This is a worst case example of course, but even an inaccuracy of .001 equals 5k psi. No sense in using a measurement technique with a potential error rate of 20% or more when an almost fool-proof one can be done for $10 and some scrap.