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+-- Thread: Bandsaw making some expensive sawdust (/showthread.php?tid=7303089)
Re: Bandsaw making some expensive sawdust - jteneyck - 06-19-2016
alnandy said:
We rarely use a full fence by itself for resawing, preferring a point fence.
The reason is blade drift. I've gotten 2 brand new resaw blades from Highland and both drifted substantially. For ripping, we adjusted the flat fence to account for drift and it was good to go. For resawing however, if the flat fence orientation is even slightly off from the drift direction, and you try an resaw 10-14" stock, the results won't be good.
First, we mark a line on the wood's edge where we want to resaw, then we actually do a bit of both: We adjust the flat fence for drift, attach the point fence to the flat fence and resaw along the line. Since the flat fence is already close to the correct orientation, we only need to make very minor adjustments using the point fence.
Blade drift is a sign something is wrong. People go to single point fences or skew their tall fence as a way of accommodating blade drift, but that's the wrong approach. I'm not saying it won't work, but fixing blade drift is a better solution and resawing and especially cutting veneer is far easier if you do.
Blade drift can be caused by several issues, but the leading three causes I've found is a dull blade or a blade with unequal set, a blade that is not adjusted correctly on the wheels, or misalignment of the saw itself, specifically the wheels. My 14" Delta with riser wouldn't cut a straight line parallel with the miter slot for the life of me until I took the time to figure out why. In my case, the wheels weren't even close to being even in the same plane, much less coplaner. Once I got them as close to coplaner as I could, and put a good blade on it, it cut like a dream after I got it adjusted correctly on the wheels. The fence is parallel with the miter slot, and I can rip or resaw with no drift. If I get drift that tells me the blade is getting dull. Change blades, get it adjusted, and I'm back cutting straight and true again. And I'm using a dinky, under tensioned 14" Delta. It's much easier on a beefier saw that can run blades at higher tension.
John
Re: Bandsaw making some expensive sawdust - Steve N - 06-19-2016
I agree with John's summation except that I would suggest the leading problem in blade drift is improper tension on the blade. Instead of calling it blade drift I've always felt blade drag would be a better explanation. If you look at the blade as a very thin, but long piece of material going through the wood under power you can see what I'm going to suggest. With proper tension the blade can only follow the leading edge where the teeth are. With poor or low blade tension the blade can start to turn sideways against the cut, which is the drag I mentioned before. John saying a sharp blade is quite true, and is a second requirement to achieve a good resaw.
You should be able to slab off flat slices if you have:
1) A properly set up saw
2) Guides that are properly adjusted for the blade you are using
3) Proper tension
4) A blade that is right for the work you are doing. IOW correct size and tooth count
5) Sharp teeth on the blade
6) Your fence, or saw point needs to be 90* to the table.
If you assume any of these are "factory fresh" you will likely not get a good resaw, In most cases these need to be adjusted not just when the saw is new, but any time you swap blades, and sometimes while sawing.
Re: Bandsaw making some expensive sawdust - MidwestMan - 06-19-2016
This is a great topic and I'm glad it was brought up. I have a Rigid with riser installed.
I have set my bandsaw up as best I know how. (blade centered on wheels, proper tension I think, cool blocks guides and the little wheels that hold the blade from being pushed back) and no matter what, I need to feed at about a 2° to compensate for drift.
I don't need to resaw that often, but when I do, I plane one edge flat and draw a line on the top edge and just guide it through manually, without any fence at all.
If anyone has suggestions for me, great. I'm not real happy about it, but it gets the job done.
Re: Bandsaw making some expensive sawdust - Joe Connors - 06-19-2016
MidwestMan said:
This is a great topic and I'm glad it was brought up. I have a Rigid with riser installed.
I have set my bandsaw up as best I know how. (blade centered on wheels, proper tension I think, cool blocks guides and the little wheels that hold the blade from being pushed back) and no matter what, I need to feed at about a 2° to compensate for drift.
I don't need to resaw that often, but when I do, I plane one edge flat and draw a line on the top edge and just guide it through manually, without any fence at all.
If anyone has suggestions for me, great. I'm not real happy about it, but it gets the job done.
I have used the same method as MIchael Fortune for three decades with great success. His method involves using the same blade for all cutting - 1/2 in 3 TPI skip tooth. It involves centering the blade. You do it by eye initially then you adjust position slightly using tilt adjustment. Google "Michael Fortune bandsaw setup". There is a video on Fine Woodworking done by him that details the setup.
Re: Bandsaw making some expensive sawdust - Steve N - 06-19-2016
Fortune came to the first WIA held in Cinci. He had a class on just this. All I can say is I always did ok on a BS before that, but my life in relation to a BS changed that day. That was using a POS HF 14" clone. On a better quality BS it just explodes from there.
Fortune via FWW
Article
Someone else agrees
Fortune offerings at FWW you may need to pay their "online membership fee" to view these.?
Re: Bandsaw making some expensive sawdust - jteneyck - 06-19-2016
MidwestMan said:
This is a great topic and I'm glad it was brought up. I have a Rigid with riser installed.
I have set my bandsaw up as best I know how. (blade centered on wheels, proper tension I think, cool blocks guides and the little wheels that hold the blade from being pushed back) and no matter what, I need to feed at about a 2° to compensate for drift.
I don't need to resaw that often, but when I do, I plane one edge flat and draw a line on the top edge and just guide it through manually, without any fence at all.
If anyone has suggestions for me, great. I'm not real happy about it, but it gets the job done.
What kind of spring is on your saw? I don't know if anyone makes a high compression spring for that saw but if they do I'd put one on it and adjust it to the 1/2" tick mark for a 1/2" blade, or maybe a little higher. Don't go nuts but make sure there's enough tension on the blade.
What blade are you using? A 1/2", 3 tpi blade is about the best for resawing on a 14", two piece cast iron BS. If you have been using a 3/4" blade, get rid of it. A 14" cast iron bandsaw can't tension it adequately. It can't even tension a 1/2" blade adequately, but it can put on enough tension (around 12,000 psi) to do a good job. For reference, BS blade manufacturers recommend around 25,000 psi tension, so you can see how we are already at a disadvantage with these small, cast iron saws.
Guides and blade bearing adjustment are the least important factor in sawing straight. People have resawed on large saws that can apply a lot of tension with no guides or bearings. I don't recommend it, but it demonstrates those things aren't all that important for sawing in a straight line.
OK, are you sure the wheels on your saw are in alignment? Take the wheel covers and table off and put a straight edge across the wheels. Adjust the tilt of the upper wheel so it's in plane with the lower wheel. Now, are the two wheels coplaner, or close to it? By coplaner I mean the straight edge should lay flat across all four points of the wheels where it crosses them, on both sides of center. If not, shim, adjust the riser block, etc. until they are as close as you can get them.
Any better now? No. OK, are you using a sharp blade? Are you sure? Just because it's new doesn't mean it will cut straight. Yes, OK, where is the blade on the wheels? Centered? Forget that. If the blade wants to cut left move the blade further back on the upper wheel, and further forward if it wants to cut right.
If none of the above works, your saw is cursed and you should sell it to some unsuspecting soul and move on.
John
Re: Bandsaw making some expensive sawdust - MidwestMan - 06-19-2016
thank you for the link to his setup of the bandsaw
Re: Bandsaw making some expensive sawdust - Steve N - 06-19-2016
MidwestMan said:
thank you for the link to his setup of the bandsaw
No problem, just hope they can help you navigate through setup. Like riding a bike, once you get it down, you will be good to go. I'm pretty sure this is the spring John was talking about I believe it will work on any of the 14" Delta's or the many clones of that design. Most folks using the factory spring go to 5/8" for a 1/2" blade, sometimes more. I'm not sure if this heavy duty spring is needed. I would go past the 1/2" indicator on a 1/2" blade, and see if that will make it tight enough. Plenty of time to spend $$$$ later, see if you can make what you have work first. If you feel the need to spend some $$$$ I'd suggest a good custom made blade, and some "cool blocks".
Something else I'm not sure if it was added. When buying a blade for a 14" saw, the book says it will support a 3/4" wide blade. The wheels will not fully support the wider blade. At the crown of the wheel you don't want overhang of the blade. A 3/4" will overhang. Most folks, and Fortune also will suggest never going wider than a 1/2" blade, and some folks will even use a 3/8" blade to resaw. For a 14" clone I like the 1/2" width. I find the 3/8" a bit fragile for resaw, unless you have the patience of Jobe. Realllllllllllly slow resaw.
Re: Bandsaw making some expensive sawdust - MidwestMan - 06-19-2016
Thank you Steve for all the added input. I've been using timberwolf blades. I just looked at timberwolf and they don't sell the "Skip Tooth" band saw blades that the video recommends using. Unless Timberwolf calls it something else.
Where do you personally purchase the blades that the video recommends? The guy said to use a ½" blade with 3 TPI and it to be a "skip tooth" type blade. I might as well get some "cool" blocks too.
Re: Bandsaw making some expensive sawdust - MidwestMan - 06-20-2016
John... I just noticed your response. Somehow I missed it earlier... I am using a Timberwolf blade, that is 3/4" wide and 3TPI. I am using the original spring.
I'll go through the things you mentioned and check it out..... thank you.
