Blade guide setup -- a question
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On Tue, Mar 1, 2022 at 03:22 PM, Mark Kimball wrote:
I didn't pick that up in the Pitkin bandsaw setup document; but perhaps that's a consequence of the described adjustment method?? Inquiring minds want to know :)This was my video. Yes "blade neutral" is an excellent way to describe this. To me this was a very logical and proven method of setting up the saw but I did confirm this with other saw manufacturers. I have not seen Pitkin's setup doc but I suspect it may get the same result using a different method. I also found a video from Jet on setting up one of their industrial saws that said the same. Let me see if I can find the video. Also, please note: There are two other videos following my video you referenced. My saw was impossible to set up correctly. Some of these saws were made wrong and some are not. I put the original guard back in place and used an elevating plate to resolve the issue. I've been running the same blade for about a year now and I've cut a LOT of steel!? Here's part two: |
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I looked for the video but didn't find it. The method I described just makes setting up the guides a little easier. The horizontal position of the guides isn't super critical. I think mine is deflected about an 1/8" but what is critical is the back bearings that rides on the back of the blade. Ideally they should not touch the blade until the saw is cutting. Again, this is ideal and there can be some pressure but not very much. On my saw Harbor Freight had the blade deflected over 1/4" downward. They did this to make the saw complete the cut instead of fixing it right. When I set the blade up close to being correct I encountered other problem. The head would not drop far enough to complete a cut. John Vreede is very good on these saw. He might explain this concept differently but I'm fairly sure he will agree that less blade deflection is always best. Hopefully your saw is not like mine. I sell a plate to correct this problem. I have one left but don't plan on making more unless there is a significant interest. Let me know if you need it and I'll send you a link,?
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Good that the new blade did fix your tracking problem Mark. I've read many times in wood bandsaw setup, that the positioning of the rear support roller is THE most important thing to set correctly (just skimming the back of the blade) for optimal cutting in wood, especially resawing (splitting a workpiece?along the grain). but I've found it's not so critical for a 4x6 - anywhere from just touching to ~0.040" clearance will work OK so long as the roller touches the blade back when the weight comes on in the cut. My recommendation for setting the rear support roller is that the blade should aim for touching at some points?in the revolution of the blade and not in others, sort of hit&miss around the blade (subject of course to it being able to complete the cut!). The blade back doesn't move about much on a wood bandsaw, so much that there is at least?one youtube clip saying you should use a die grinder to dress the back of the blade so there is absolutely?no variation for best cutting,? The blade back doesn't move about much on a 4x6 without?its guides either, just what variation is there from less than perfect?alignment?when it was welded, but it does change quite a lot when the guides are installed with upto 0.040" being quite normal.?? As Mark2 points out the saw will still work acceptably if it pushes the blade forward upto 1/8", but this does start to affect the tracking on the wheel nearest the forward guide.? Over 1/8", esp.on the bottom guide closest to the drive wheel, and the blade comes off the near wheel when you put any sort of bow weight (>3-4 lb) on in the cut, so it seriously slows down how fast the saw will cut. You should not have to do this unless it has been mis-manufactured and it won't complete the?cut. Unfortunately mis-manufacture?when drilling the holes in the sawframe and pivot arm, or base pivot holes is distressingly common. It must vary by manufacturer, according to how much emphasis they put on the quality assurance around the drilling processes. but I estimate from what I've seen?that between 1 in 3 to 2 in 3 (!) are in some way out badly enough to cause setup issues, and?maybe none are truly correct to the?engineering drawings.? They just don't seem to get it. I believe this is because there are so many adjustments available in the standard way these saws are made, that literally ANYTHING can be made?to cut, albeit not accurately or well. It's a sad fact?that if they were made accurately, I doubt there would be much need for this group - jv? On Wed, Mar 2, 2022 at 11:04 AM Mark <mark21056@...> wrote: I looked for the video but didn't find it. The method I described just makes setting up the guides a little easier. The horizontal position of the guides isn't super critical. I think mine is deflected about an 1/8" but what is critical is the back bearings that rides on the back of the blade. Ideally they should not touch the blade until the saw is cutting. Again, this is ideal and there can be some pressure but not very much. On my saw Harbor Freight had the blade deflected over 1/4" downward. They did this to make the saw complete the cut instead of fixing it right. When I set the blade up close to being correct I encountered other problem. The head would not drop far enough to complete a cut. John Vreede is very good on these saw. He might explain this concept differently but I'm fairly sure he will agree that less blade deflection is always best. Hopefully your saw is not like mine. I sell a plate to correct this problem. I have one left but don't plan on making more unless there is a significant interest. Let me know if you need it and I'll send you a link,? |
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On Wed, Mar 2, 2022 at 05:18 AM, John Vreede wrote:
Unfortunately mis-manufacture?when drilling the holes in the sawframe and pivot arm, or base pivot holes is distressingly common. It must vary by manufacturer, according to how much emphasis they put on the quality assurance around the drilling processes. but I estimate from what I've seen?that between 1 in 3 to 2 in 3 (!) I suspect they make these saw in batches and dismantle a lot of the jigs when they move on to another product. If they get setup wrong for the next batch then they may make 200,000 saws (totally guessing on the amount, maybe way more) with a miss aligned pivot point. What a shame!? My approach to fixing this problem was the elevate the stock by putting a 1/4" thick steel plate under the vice. I sell these plates but if somebody want to make there own here is a template.? NOTE:? Make the part under the saw blade longer (red line) and cut through it after mounting the plate. |
开云体育Mark,Just had a chance to see your video, do you still have any plates for sale? Wayne Sent from far far away On Mar 2, 2022, at 8:48 AM, Mark <mark21056@...> wrote:
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Mark
John Vreede