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Wavy Bandsaw Cut – Advice Needed
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Author:  John Killin [ Sat Feb 05, 2011 4:07 pm ]
Post subject:  Wavy Bandsaw Cut – Advice Needed
I just got my bandsaw up and running in the past couple of weeks. I’m getting a wavy pattern with the saw when I cut. This is my first bandsaw so I’m a bit green as far as the troubleshooting goes.

The saw is a 14” delta. I have not added a riser block.
I have installed a high tension spring. I had the same results with the old spring. I get the same results if I use the gauge on the saw for the tension or if I max out the adjustment for tension.
The blade is a Bosch ¼” blade – These are the blades sold at Lowes. This could be part of the problem. The weld on the blade looks Ok. And I don’t see anything odd with it.

I haven’t seen any tips on troubleshooting this specific issue on the net or in books. I believe my setup is Ok. I’m posting some pics below to show the cut. Any advice would be greatly appreciated.

Thanks,

John
Author:  SteveCourtright [ Sat Feb 05, 2011 4:45 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
It's likely your blade. My cuts improved a lot when I installed a Timberwolf blade.
Author:  Alain Moisan [ Sat Feb 05, 2011 4:53 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
John Killin wrote:
I believe my setup is Ok.


Double check with the info on this site:

http://home.vicnet.net.au/~pwguild/i-bndsaw.htm

I greatly improved my cuts once I went over it.
Author:  klooker [ Sat Feb 05, 2011 4:56 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
How thick is the wood - looks like about 3" ?

How many tooth per inch (TPI) is the blade?

I have a 6" Delta also but with a riser block. I like using 1/2" or 3/8" 3 or 4 tpi blade with a skip pattern. They don't feed as easily as a standard hook tooth but I find them more predictable. Here's one from Woodcraft
http://www.woodcraft.com/Product/200083 ... -Skip.aspx

Anyhow, I suspect your blade is too fine & better suited for scrolling. You may also be trying to feed at too fast of a rate for the blade which will cause it to twist.

You also need to make sure your guides are set well. Ideally, you want to the guides & thrust bearings as close to the blade as possible but not tight against the blade which will cause it to bind. It's tedious to set the guides because as you tighten the set screws, the guide blocks will move a little and result in them being either too close or far from the blade. As I adjust the guides, I turn the wheels by hand to check how close the blade is to the guides.

Kevin Looker

edit:
I meant to say I have a 14" Delta also with a 6" riser block...(not a 6" Delta)
Author:  Edward Taylor [ Sat Feb 05, 2011 8:31 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Its your blade. I highly recomend the little ripper blade from http://www.tufftooth.com/, nearly cuts as well as my 1" Woodmaster CT and at 5/8" should not be a problem for your 14".
Author:  Michael Smith [ Sat Feb 05, 2011 8:45 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
like the others said it could be partly your blade. 1/4" blade isn't really suited for that kind of cut. Also you likely need to tune up your saw. There are several how tos online. I have a delta 14 and it was way way off when I got it.
Author:  Edward Taylor [ Sat Feb 05, 2011 8:57 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
I can still get some pretty nice cuts with a quality 1/4" blade in thick hardwoods. I remember hearing those bosch blades are garbage. He should still use something probably at least 1/2" for that type of work though.
Author:  jmanter [ Sat Feb 05, 2011 10:37 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
almost looks like you are feeding too fast. Try it again with a slower feed rate (but not too slow!)
Author:  Ti-Roux [ Sun Feb 06, 2011 1:40 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
1/4'' blade is not really suitable for straight cut, especially with pieces that high. The blade is then exposed enough to be flexible and create those waves. If you only have 1 bandsaw and don't want to change the blades often, you should go with 3/8''. It will be better at straigh cut, and it's still small enough to cut tight curves. I have the chance to have acces to a nice machine room, and we have two bandsaws. A 18'' equiped with a 1/2'' blade for straight cut and a 14'' with a 1/4'' for curves. I also have a 3/4'' cardbide blade that I mount on the 18'' when I have major resawing to do.
Author:  JasonMoe [ Sun Feb 06, 2011 2:42 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Feed the wood in slow when you start the cut. If you go fast at first, the blade will angle outward. Check the blade for tightness too. If the blade starts off crooked, it will never get better. Check for squarness too. Sometimes I do a double take, i'll go in, then pull back and go back slow to settle the blade down.
Author:  brenbrenCT [ Sun Feb 06, 2011 8:42 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
i'd guess that your rear guides are too far away from the blade, your feed rate is too fast, and your blade tension is not right.


i'm not buying the "it's the blade" argument. i can get perfect slices with an 1/8th in blade when i'm too lazy to change blades, i just go slower and double check my guides.
Author:  TonyKarol [ Mon Feb 07, 2011 5:11 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
I can buy that its the blade - not all baldes are created equal .. I too have a Delta 14 with riser, 10 years old, only a 3/4 HP .. and have never had anything but blades from my local bandsaw shop (www.tufftooth) as mentioned above on it since I added the riser .... I resaw with either a 3/8 3t or 1/2 3t industrial hardened tip blade, and get excellent results. BTW .. I could never seem to get a 1/4 6t to work right -if I simply took that off and put on a 3/16 10t, reset the guides and started her up, the cut was superb, so I have never had a 1/4 6t on it ever since ....
Author:  Howard Klepper [ Mon Feb 07, 2011 5:23 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Could be that the wheels need to be made more coplanar. Could be something else, but I'd check that.
Author:  nickton [ Mon Feb 07, 2011 5:34 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
This may sound funny to some but I could swear I can cut straighter with my smaller blades. Seems to be less friction perhaps. A skip tooth blade works best, even though mine is now broken. I had previously thought a real fine tooth blade would make better cuts but learned that is not necessarily the case because they wander more.
Author:  John Killin [ Tue Feb 08, 2011 12:00 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Have I spent a bit of time going over the saw. Not much time, but I checked some basics. I'll spend some more time this weekend to see if I can nail it down.

The wheels are coplanar, the guides are set properly. I have tried feeding at a slower rate (really slow) and get the same results. I also get a wavy pattern on wood that isn’t as thick as what I showed in the picture. I don't feel any vibration when the saw is running.

I’m going to try a better quality blade. I think that is likely the cause.

Thanks everyone,

John
Author:  the Padma [ Tue Feb 08, 2011 12:56 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Dude ...its all in the sawdust

You gotta make sure the sawdust is A1 first class perfect consistency in size.

Now the other dudes been telling you what to do to get the sawdust perfect.

So go for it.

blessings
duh Padma
Author:  Bobc [ Tue Feb 08, 2011 2:37 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Have you tried cutting a slice following a pencil line and no fence?
Author:  John Killin [ Tue Feb 08, 2011 11:01 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Bob,

That is how this cut was done. I get the same results usign a fence.

Padma,

This thing makes some really sweet sawdust.
Author:  Michael Lloyd [ Tue Feb 08, 2011 1:00 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
This cut makes no sense to me. Please don't get me wrong and no disrespect intended but that's an odd cut. I'd almost think you pushed this board through without turning the saw on. How fast is the blade turning and how many teeth per inch. idunno
Author:  Bobc [ Tue Feb 08, 2011 5:46 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
John Killin wrote:
Bob,

That is how this cut was done. I get the same results usign a fence.

Padma,

This thing makes some really sweet sawdust.
Bobc wrote:
Have you tried cutting a slice following a pencil line and no fence?


Well if that's the case I'm inclined to think it's the blade.
Author:  jmanter [ Tue Feb 08, 2011 6:16 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
laughing6-hehe Todd! I once bought a Vermont American blade with the teeth backwards.... I couldn't turn it inside out, ended up cutting and rebrazing it... i don't buy those anymore...
Author:  cphanna [ Tue Feb 08, 2011 8:35 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Hey, John,
You've received lots of good advice so far, and, in my opinion, a few pieces of advice that might or might not be relevant to you situation.

Every blade tracks a bit differently. Some want to cut straight. Some want to cut a little this way or that. EVERY blade tracks a little bit differently. This factor is called "drift."

Try this with some scrap: Take a straight, flat stick of scrap, and draw a pencil line parallel to the edge you would normally push against your fence. Let's say you draw a line one inch from the edge of your stick, all along its length. Then do a free hand cut until you find the slight angle that gives you the straightest cut. You just found the "drift" of the blade. Without moving the stick any farther, quit pushing and turn off the saw. Using your stick as a guide, draw a pencil line on your saw table along the straight edge of your scrap stock. This marks the angle of your blade's ideal drift. Next, set up a resaw fence parallel to your pencil line. Doesn't matter whether you're resawing something an inch thick or an eighth of an inch thick. Just make sure your fence is parallel to that line you drew. That line is the ideal drift of your blade, and that's the angle your blade wants to follow.
Now....if your blade is skip tooth, and your rate of feed isn't too aggressive, and if your blade tension and guides are properly set up, you should notice MUCH improved performance. You will be able to feel the correct rate of feed. Your saw will just gobble it up if your feed rate is right, and it will resist you if you rush it. Go with your senses here. You don't need a wide blade for this. A 1/4-inch blade ought to be fine, if it is a skip tooth blade. Wider blades are fine, if they are also skip tooth. Wider blades will also have their ideal "drift."

Just my two cents worth. Try it. I don't think you will be disappointed.

Good luck!
Pat
Author:  Bobc [ Tue Feb 08, 2011 10:06 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Pat good advice on blade drift. Something I consider to be the most important part of saw set-up. That's the reason I asked if he tried cutting to a line without the fence. That would take drift out of the picture for now.
Author:  John Killin [ Tue Mar 15, 2011 6:33 pm ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
Well I thought I would report back on the final outcome on this one.

It turns out it was the blade. I was able to make it to a Woodcraft last week 10 minutes before they closed and picked up a 3/16" 10 tpi timber wolf blade. I was going for something with less tpi but this is what they had in 3/16" and the guy said it would work.

So brought it home, put it on, set everything up and the waves are gone. The cut is smooth and working like I expected.

In hindsight I'm thinking if I ever wanted to reproduce that wavy texture on a future project there be now way to pull it off with just a bandsaw. I'd need to build several jigs and break out some files. Unless Bosch starts selling those blades with that as a feature. laughing6-hehe It was a neat cut.

Thanks for the tips everyone.

John
Author:  Brian Forbes [ Mon Mar 21, 2011 1:00 am ]
Post subject:  Re: Wavy Bandsaw Cut – Advice Needed
I have the same bandsaw, no riser, got it from Lowes, and the blade is also from Lowes. The onyl time I have any weird blade action, from wavy stuff, to creeping in one direction, to not cutting straight, it's usually the fault of the guides. Double check your guides and see if it helps. You want almost contact on all the small blocks on the sides of the blade, and you want to adjust the rollers on the rear of the blade to just touch the blade on the rear when its moving at full speed. One thing to do when you start is to release all the guides, and pull the bearings back about an inch so everything is completely out of the way. Run the blade for a few seconds to make sure it is centered on the tires where it naturally wants to be. That's another thing that can cause bad cuts is the blade fighting to ride on a different portion of the tire than the guides are allowing. Once you have the blade adjusted so it runns naturally on the center of the tires, go ahead and snug up the guides with the saw off obviously. You may be up the creek already with that blade though. The waves might be happening because a portion of the teeth got bent over during a cut and smashed against the guide. This can cause a portion of the blade to cut fine and another to pull or drag in one direction. Either way, its the result of poorly adjusted guides when you mash teeth against them. If adjusting the guides doesnt do it, you may have destroyed the blade, and I'll agree with the member who said to buy a nice one. I had a blade from a wood working store for a LONG time before it went bad, and I bought the lowes blade to save some $$ as a temorary fix. Once it's shot, which will be far sooner than the nicer one I had, I'll go back to the better blade.
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