I have purchased a DELTA Shopmaster bandsaw. A table top but ideal for what I do. My question is that when I start cutting along a straight line I have to move the work off parallel about 15 degrees to follow the line. This is my first bandsaw. I went through the adjustments again. Have I miss something obvious?
TIA
Ken
First things first: since this is your first bandsaw, you should get yourself a copy of "The Band Saw Handbook" by Mark Duginske, ASAP.$12.57 at amazon.com.
Are you using a rip fence to guide the stock, or just cutting freehand? If you're using a fence, is it adjusted dead parallel to the blade?
Is the blade tension high enough? A loose blade will deflect, and cause the cut to drift.
Is the height of the upper guide adjusted properly (just above the wood)? The farther apart the guides are, the more the blade can deflect.
Are the guide rollers and blocks adjusted properly? They should be just a hair away from the blade; check your owner's manual for adjustment procedures and recommended clearance. If there is too much slop in this adjustment, the blade can deflect far enough to cause the problem you're seeing.
Are you using a good quality blade, or the one that came with your saw? Factory-supplied blades are of notoriously mediocre-to-poor quality. I use mostly Timberwolf blades from Suffolk Machinery, which are of noticeably better quality than the Delta factory blades. There are other good brands out there, too. Do a Google Groups search -- there was a discussion here a month or so ago IIRC about different brands of bandsaw blades.
Might the blade be damaged? If the teeth are sharper on one side than the other, or if the set of the teeth is greater on one side than the other, it won't ever cut straight.
Finally, since this is your first bandsaw, consider the possibility that it's your technique. :-) If this is the problem, the only cure is practice. :-)
Good luck!
-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
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Ken - I have that bandsaw too. A nice little unit. The blades that come with it (or the ones that came with mine) are OK, not great, but OK. An investment in a quality aftermarket blade is a good idea.
I also had no idea how to set the guide blocks and tension on it, since it was my first bandsaw too. Do some googlin' on these topics. And try increasing the tension on the stock blade, it helped me some.
Finally - there is a well known phenomenon called "drift" when using ac (some, but not all) bandsaws. Do a google on Bandsaw Drift and you'll find the way to compensate for it. According to many, drift is inevitable and just a fact-of-life with a bandsaw. Doesn't necessarily mean anything is wrong.
Ken in addition to checking to see if your fence is parallel you might also want to check your upper and lower guides. Often we get calls here at Carter from people with the same issue on 14" saws. It seems that many of the offshore manufactured machines are not exactly built to perfect specs. As such many seem to have the groove in the upper post machined slightly off center. The guide assemblies which sometimes use this groove to lock into place are then skewed slightly off center. This in turn causes the upper blocks or bearings to guide the blade in whatever director the skew is towards.
If the groove is way off, the skew is noticeable, but typically it's only slightly off and thus even proper guide adjustment will seem correct visually, but the guides will be forcing the blade off parallel. Unfortunately if you have this problem and the only attachment screw that secures the guides fits into the groove then your basically of luck, short of drilling and tapping a new set screw hole on the side. However if your guides do have a secondary set screw not used in the post groove ,which many do, then your all set. Basically you need to loosen all attachment screws, make sure the guide blocks or bearings (upper and lower) are parallel, then secure the guides with the non groove attaching set screws first. When they are secure you can snug up the grooved set screw, but don't over tighten as this will cause the guides to skew.
Lee Carter Products Company
Doug Miller wrote:
Ayup. If it's cutting but leading to one side, compensate. It doesn't happen with all blades, but with any bandsaw, because it's a blade problem.
As to fences, hang it up somewhere to gather dust and resaw against a pivot block. Parallel means nothing, in spite of other posters. Less than nothing with lead. If you want to use the fence because it by-God came with it, try a modification similar to
Me, I'm right handed, so I put my pivot block on the right, so my clumsy left hand maintains pressure against the block as my right keeps things aligned and moving.
The bandsaw book that Doug Miller recommends is worth every penny you spend for it. Not only will it tell you how to setup the saw, it is a great guide to technique. I found that in addition to the right pitch and width, "tension" is extremely important for straight line cuts (ripping and resawing) and that some blades, particularly from cheaper sources may be longer than the specs (usually 93 1/2" for a 14" saw) and therefore you can't tension them properly. Go with top quality blades from reliable woodworking supply sources. Steel is good enough, don't spend money on carbide unless you are running a production shop.
To measure a bandsaw blade, take some non-stretch string and make knots that are exactly the recommended length (93.5") apart. Leave some extra outside the knots to serve as handles. Then lay the blade on a flat surface and stretch the string around the outside circumference and see if the two knots intersect. Allow plus or minus 1/4" tolerance for this rather unsophisticated measuring technique.
Dustmaker
Thanks to all for your assistance. It was very helpful. And I am ordering the book. Regards,
Ken
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