[OP]
Member
Recently I saw a bandsaw setup video which very definitely did not support the necessity for co planar wheels on a bandsaw. The gentleman on the video related his many (20-30?) years of experience in the tool industry as the basis of his advocacy for non co planar wheels. My question is - has anyone else seen this video and have a link to it? I thought I had saved it but can't find it. Senior moment?
Peter Leyden
Contributor
Is this the one?
http://www.youtube.com/watch?v=wGbZqWac0jU
Guest
Is this the video you’re referring to?
http://www.finewoodworking.com/ToolG....aspx?id=34055
Member
Wow, that guy should appear on an episode of myth busters! If I had a nickle for every time I've heard the coplaner argument I'd have at least enough to buy a new BS blade! Nice video there.
Well, let's not get silly. A properly designed and built machine that can tolerate the stresses caused by blade tension would certainly minimize the effects of non-coplaner wheels with flat tires. I am pretty sure the guy is not trying to say that given crowned tires, that running on the forward side of the crown on one wheel and the rearward side of the crown on another wheel due to planer differences would not be impactive to the blade path. Given the reality that many shops run 14" and smaller machines, many of which run crowned tires, the statement that co-planer wheels are important on this forum is certainly valid. With flat tires, it really would not make any difference given a properly designed and otherwise aligned machine, eh?
Another great video for myth-busters would ruffle the feathers of those folks who like to argue guide type. This guy runs a saw with the guides taken out of play, what looks like 16" of re-saw height, and cuts anything and everything he wants. The machine is large and tuned to the nines but, it certainly does show another method of obtaining a straight cut other than expensive "drift correcting" fences and brand X guides. ;-)
Last edited by glenn bradley; 08-13-2012 at 12:59 PM.
"A hen is only an egg's way of making another egg".
– Samuel Butler
Contributor
Glenn: The guy in the video is from Carter Tools. He is specifically talking about band saws with crowned tires when he says that co-planer is an non-issue. Before mentioning that, he talks about where to place the blade on the upper tire and he explains that he does it his way owing to the crown on the tires. He shatters a lot of the conventional wisdom in is demo.
Grant
Ottawa ON
Guest
Which video are you referring? I am confused about who’s the guy you’re talking about.
I've seen this guy before. He can take a Ridgid CI saw and make it cut like a Laguna. I hear what you are talking about at about 3:40 in. Doesn't prove to be correct in many folks experience but, it is always interesting to see someone do or say something that a lot of other people feel differently about. For example; I do not experience blade drift. Even my 12" Craftsman saw from days gone by could be aligned to cut true. I currently change blades frequently on my 17" and my 10" saw and I never have to readjust or compensate for "drift" whatever that is. Many other people have drift and have all sorts of methods or add-ons to take care of it. Seems like Michael is one of the few who is not troubled by no centering the blade on both crowned wheels. Vive la diference.Originally Posted by Grant Wilkinson
"A hen is only an egg's way of making another egg".
– Samuel Butler
Guest
First, he says the saw's built-in tension scale depends on blades being cut and welded to a precise length. He says a blade that is 1/8" short will throw-off the tension scale. On almost all saws, this is untrue.
Then he says the coplanar doesn't matter, and to demonstrate, he indicates the blade is running in the middle of the top wheel, but slightly forward of center on the bottom wheel. If you read the Duginske book, you will see that this is an indication that your wheels ARE coplanar. The blade never rides on the crowns of both wheels. That is because we separate the wheels enough (by raising the top wheel, to apply tension) that the blade is no longer long enough to ride on both crowns. So we apply tension, and then use the tracking to position the blade on the top wheel. Then the blade finds a sort of equilibrium on the bottom wheel, which MUST BE somewhat forward of center.
There is a point where the wheels are close enough that getting them any closer won't matter. I consider this point to be "coplanar enough." And I suspect that 99% of bandsaws shipped have wheels that are aligned close enough at the factory that performance will be satisfactory.
The Carter guy needs to be perceived as an expert, to keep people in their seats and have a chance to sell them stuff after the presentation. What he says may seem to make sense to people that don't think it through. But if he doesn't understand how the spring-based tension scale works, are you going to trust him on coplanar?
All just my opinions.
Last edited by Phil Thien; 08-13-2012 at 7:19 PM.
Member
Phil has a good point about the tension scale. I used to own the PM BS in the carter video, and the scale doesn't start rising until there is tension on the blade regardless of length. Hmmmm.
But on the fussy coplanar thing, I'm with the guy in the video. You can make a guide or jig that jumps the tables and touches both wheels, a sort of wide stick with cut out in the middle section (piece of plywood or MDF works well) to set the two wheels exactly coplanar. I did this once, saw it in a book or magazine or some such thing long forgotten. I set my wheels exactly co planer under tension, and the saw did not cut great. I started ignoring the coplanar thing, set the blade with the teeth just ahead of the center of the crown on the top tire (so the set of the teeth doesn't wreck the rubber), let the bottom tire take care of itself, saw cut great.
That guy claims to have 30 years experience specific to the bandsaw. Thats a lot more than I do. Of course my geriatric neighbor has more years experience than Greg Lemond riding a bike yet has never won a tour de France, so i guess not all experience is equal. My point is I know a lot of professionals that get great results from the BS and never even stopped to consider if the wheels are even vaguely coplanar. They set the saw up so it cuts well and move on. I've read many posts here by frustrated noobs trying to get a new saw to cut, the almost Borg like advice comes "You must set your wheels precisely coplanar, Resistance is futile, you will be assimilated) and I start feeling like I'm in a cartoon. Please don't tell my saw she isn't coplanar, or like a cartoon character floating in thin air, we will both plummet to our demise as soon as the fact we are defying physics is realized. I've seen at this point at least 5 BS experts offer some what contradictory advice regarding set up, can they all be right?
Member
I have a 1988 ? SCM 24" bandsaw with flat tires.. The wheels are not even close to co-planar.. Open the doors, you can see it .. I bet the bottom wheel is 3/16" out to the top one ... It works like a champ, resaws whatever I put in front of it . .
Guest
3/16" for 24" wheels doesn't seem like that big a deal.
I can tell you I had an Inca with 9" flat wheels, and 3/16" would have been a problem on that saw.
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