New Breed of Bandsaws, a 14" Bandsaw Comparison Article

[John Martin]

Tensioned based on the saw's scale, true, but then confirmed by finger pressure. Which implies that it was OK.

We agree that the scale is miserable. It's based on the deflection of the tension spring, which may be a worn-out old one, a brand new one, a brand new higher-rate die spring, whatever. Not the best setup, but I'm not sure that any of the others are any better. Like you, I've found that the best way to set the tension is to start with the gauge, go higher, then try the saw and see if you need to go even higher.

The belt vibration may not have been due to a cheap belt, but just to an old one. A belt that has been sitting tensioned in one position for some time can take a set, which can then cause vibration. A new belt - even a cheap one - will usually make it go away. As will, obviously, a link belt.

On the setup, tuning and documentation, again we agree.

If I had done the test, I think I'd have ordered the saws anonymously, but then invited reps from each of the manufacturers in to set them up and observe the testing. Documenting the steps, tools and time required to bring each saw up to its best. As a prospective buyer, that's something I'd want to know.

John Martin

[Frank Boettcher]

I didn't read the article nor am I likely too. However, when the changes to Delta band saws ( 1.5 hp 3450 rpm motor and associated drive train changes to drop the output blade speed, new tensioning spring, new quick release and presets for various width blades, larger table, multiple presets for the pattern makers to set their casting drafts, new stand with much better dust collection, etc..) that preceded and were incorporated into the 28-475X, I personally observed similar tests with that unit pitted against the best that Jet, Powermatic and several others had to offer at the time. All machines were set up properly and used the same blade. Set up included tension gage on the blade because one of the things that was measured was overarm deflection, and the tension had to be equal for all units. All this occurred about 2001 plus or minus

The Delta won the resaw test easily but certainly not by a factor of nine. It won the dust collection test, overarm deflection and motor overload tests also. And these were lab controlled tests by product engineers that had an average of 25 years experience with the design of woodworking machinery. The tests, if anything were judged conservatively, as the final results would be given to marketing for use in ads and selling, and it is important that you can back up what you say.

Since that time each of those manufacturers has had their own upgrades for the most part matching but not exceeding the motor hp that the Delta has.

And Delta has, I believe changed motor manufacturers from Marathon to whomever, but not changed HP (except that the Marathon could legally be rated 1-3/4 HP, probably who they are with now, could not). And the cast iron may be coming from China by now, if they have used up the batch that me and mine made for them before shutting down.

But even with the changes, I would be a skeptic about the results of the FWW testing, particularly a 9 times thumping in resaw. In the old days, I would expect something like that to be challenged. But in the world of B & D with folks with big box mentality and no industrial experience, I don't think there is anyone capable of challenging.

Frank

[B A R R Y]

Excellent suggestion.

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[dpb]

John Martin wrote: ...

Suspect it would be unlikely for a manufacturer to spring for doing that on their nickel given the number of reviews done. But, one would hope that the reviewer is experienced and expert enough to do the tuning and report what was done as you note. I suppose there's some value in also knowing how a tool performs "out of the box", but unless the potential buyer is one who won't tinker on their own, it would be far more valuable to know which can be made to perform well relatively easily, which require more effort, and which are basically a lost cause or at least require significant effort.

Sorta' a case in point -- in looking up manufacturers' spec's for the blade speed to see if there was any chance that might be a correlating factor on the timed test disparity, I found several reviews for the subject saws. One had several where the riser block attachment pins were badly misaligned so that the saw wheels were drastically non-coplanar if installed as manufactured. The solution from the manufacturer was to remove the pins on one end of the block and just set the block in place where needed to align the wheels. This was, coincidentally, one of the saws with a high misalignment value in the test, but nothing mentioned in the review other than the measurement.

Space constraints, of course, mean not all can be reported, but it seems that much of significance wasn't in this particular review...

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[dpb]

Frank Boettcher wrote: ...

You didn't miss much... :)

It's clearly fraught with some unexplained problem in that half the population fell into one of two widely disparate groups, the Delta just happened to be the worst of the poor for some unexplained reason. There's certainly little to suggest it really is or would be such a poor performer in the report that one could reliably hang one's hat on.

It seems there must have been some uncontrolled factor to cause the measured resaw times to be so split into two groups, but what that could have been is, of course, impossible to tell from the published story...

For comparison, for the 5-lb test, there's this overall comparison --

Group Average/Std Dev

Slow 3:45 +/- 1:15 Fast 0:58 +/- 0:01.5

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[Chris Friesen]

This is only valid information if the manufacturing is consistent enough that the results hold true from unit to unit.

Given that one of the common complaints about cheaper imports is that there is relatively little quality control, it would seem that testing a single unit and reporting the results is always going to end up generalizing from a single datum.

Chris

[dpb]

Yep...

And, of course, that's always true of any testing unless it is replicated (and I know of no circulating magazine that does that kind of reviews).

It really doesn't matter whether it's a descriptive comparison as in "fit and finish" or the detailed measurements of (since this is on the FWW BS article) how close to coplanar the wheels are, there's an open issue of what the next unit of the same model would have measured and how well does the tested unit represent the one you might receive.

One can speculate that QC is better on higher-priced units, but unless reviewers either get corroborating data from the manufacturers or run tests on more than a single unit, there's nothing that says the test unit isn't representative of the average, the median, the mode, the 5th or 95th percentile of the manufactured units. It is, of course, less likely that a randomly purchased unit is at one extreme or the other, but not out of the question...

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[Markem]

What you have not heard about end user Quality Control.

Stopping myself before this ends in an endless rant.

Mark

[B A R R Y]

Ahhh... I know that feeling...

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[John Martin]

I too would hope that the reviewer would be experienced and expert enough. I'd expect it too - at least I would have until this review. If I were the marketing manager at one of the manufacturers/importers, I'd consider spending $1,000 or so to send one of my tech guys to a product test to be an easy decision. Especially if I happened to be the Delta marketing manager after seeing that review. Doesn't take too many lost sales to pay for that - and can you imagine how many sales that review may have cost them?

I'm guessing that blade speed wasn't the main factor in this test, as (I'm guessing that) the speeds are likely in the same general range. Although maybe that's the reason the Jet, with the smallest motor, tied for fastest at the lower feed pressure but stalled at the higher.

The fastest saws were all either 2 HP or 230 volt. Any significance there? Maybe, if the slower saws were bogging down to the point of stalling. Not too likely, though.

In my own experience, slow resawing often means that a stringy chip is dragging in the throat plate. Or that the blade is too loose and is vibrating in the cut. Who knows?

John Martin

[dpb]

Yes, I went and found manufacturers' spec's and posted them for all except the Laguna -- they are all 3000 sfpm except for the Rikon which was 2950 so blade speed isn't the explanation at all.

No, it's 3000 sfpm just like all the others (with the possible but unlikely exception of the Laguna for which I didn't find a spec.)

No, that's not true, either. The Jet was as fast as any for the 5-lb test and it had the smallest motor.

All the motors w/ the exception of one which wasn't noted are dual voltage, so the 115V rating was simply as shipped. Doubt it is a factor. The one motor spec no data for is torque.

Not possible to tell, of course, as we've already concluded from the data, but the two groups of fast/slow and the same saws falling in the same group on the two tests means it has to be consistent. The blade tension problem seems certainly up there as a likely candidate. I don't think the consistency of the results could be attributed to something like the chip in the throat plate...

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[Swingman]

Jumping in late, but that's my take on the reason for the published results also.

Because I lucked into an "Iturra Blade Gage", I'm keenly aware of just how different the "finger pressure deflection method", the "pluck method", "the flutter method", and the least desirable of all, reliance on the default built-in marker gauge, can be from an actual measured tension.

IME, use of any but the blade tension gauge usually resulted in my under tensioning a blade.

[dpb]

I agree completely.

What baffles me is that nobody in editorial seemed to pick up on the gross difference and ask when the article was submitted for publication. Or that the reviewer didn't think it really odd and at least futz around a little to figure out what went (obviously) wrong...

A nice bandsaw has been on my wish list for a long time, but this article surely won't help much in making the decision, methinks, even if were to jump in the near term...which ain't likely, anyway, unfortunately. :(

[dpb]

While I agree in another response w/ the tendency to under-tension w/o a good measurement, what I intended to add in context of the published results is how, if the same reviewer set the tension and checked for "ok", even if the builtin guide was the initial reference he would end up w/ such a discrepancy between saws where there were these two groups that performed so nearly identically within the subgroups but so grossly differently between...

'Tis a puzzle still and one can only hope enough questions were raised that there's a follow-up to the article eventually that sheds some light on the issue.

I've undoubtedly gone on far too long on it, but being an analytic type I like futzing around w/ numbers and trying to find underlying patterns and failing that, tend to get obsessive... :)

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[Leon]

What no one has considered or mentioned is that these guys that publish these articles are first, journalists, and second, woodworkers. If you watch the news, you will find the fact that the high temperature for today this year has been over 85 degrees "x" number of times, setting some kind of record. So and So has hit the base ball straight over the pitchers head "x" number of times on the second Tuesday of each month, setting some kind of record. There is certainly some kind of record being set this year with the lack of hurricanes and or tropical storms. The fact that there have been darn few actual storms does not stop the weather bureau and all its journalists/meteorologists from naming every cloud cover to hide the egg on their faces. They have quota's you know and they have to justify all that expensive equipment. The guys conducting the band saw tests don't care about accuracy, they are interested in selling magazines, and when you throw in some hard to detect flaw in the testing procedures you get sensational results that excite the readers. ;~)