Bandsaw not cutting straight

[Jans husband]

I have a reasonably priced bandsaw-Titan, but I suspect this may be a common and straight forward problem to solve.
I can't get the saw to cut in a straight line, leaving me with blank ends which are not 90 degrees.

I have seen a suggestion to buy a slightly shorter blade (5mm shorter) to make the blade more tense, because the adjustments on the machine are at their limit.
Does a blade lengthen or stretch after time and use, if not, what other factors are at play here?
Any advice appreciated.
Thanks
Mike

 

[Dehn0045]

Alex Snodgrass shares a lot of useful information in this video. Blade, tension, guides, tires, wheel alignment, table alignment all play a role. Never heard of a titan bandsaw - by "reasonably priced" do you mean "inexpensive"? Size? (9, 10, 12, 14, 17 inch? or equivalent). Not sure you will be able to find blades that are 5mm shorter than standard specified.

 

[leehljp]

Major tension does not make for straighter cuts; the right amount with alignments and adjustment in the above video will. The major factor in straight cuts begin with the alignments of the wheels and then the guides. The Alex Snodgrass video above is the best help I ever had for bandsaws.

 

[Jans husband]

Thanks Sam, and Hank
Titan are inexpensive-bought without much research on my part. Works very well for what I ask of it.
I'll look at the video in detail tomorrow
A mate told me about Tuffsaws who he says make bandsaw blades to order.
I've not looked into that aspect yet.

Mike

 

[Gary Beasley]

Trying to drive a piece of wood through the bandsaw faster than the blade can easily cut it can result in crooked cuts. If you know the blade is reasonably sharp slow down and see if it gets any better.

 

[Alan Morrison]

Mike, Tuffsaws gets my thumbs up as well.
Let the blade do the cutting!!!

Alan

 

[Mortalis]

I do not rely on my bandsaw to cut off the blank square. Too many factors involved. I have my bandsaw tuned and it cuts straight within reason but I still depend on a solid holder with pin that is square and level with that holder and square to the belt of the sander. I then place the cut section(s) of the blank on the pin, move it toward the belt on the belt sander and then rotate the blank about the pin as it is slowly sanded square even with the tube(s).
Band saws have to have a decent, sharp (on both sides) blade with the guides adjusted so that it more supports the side of the blade and doesn't encroach upon the teeth. The back guide wheel needs to be adjusted just so it spins when pressure is applied to the teeth of the blade. The table should be checked with a machinist square to be sure the blade is running perpendicular to the table. That is just the beginning.

 

[rherrell]

I've never had a bandsaw that cut straight, it's up to the operator. You can adjust the fence at a slight angle to make up for the blade drift but a bandsaw is really not made for straight cuts...IMO.

Here's a warning label I have on my machines...

 

[SpiritRider]

I am fighting the same thing on a new powermatic bandsaw

 

[jttheclockman]

Rick said it all. Blade drift. There is this big argument that it does not exist if well tuned but not true. Bandsaw blades are like scrollsaw blades. They are stamped out and will have a leading edge side. Tuning the saw is key and there are many people that have their methods. Here is one that works well too.

http://www.bing.com/videos/search?q...422330467471E4046D2F422330467471E40&FORM=VIRE

 

[SpiritRider]

The first thing I did was order a new blade, but I haven't put it on yet.

 

[Bats]

I've never had a bandsaw that cut straight, it's up to the operator. You can adjust the fence at a slight angle to make up for the blade drift but a bandsaw is really not made for straight cuts...IMO.

Or, in the case of my bandsaw (a Taiwanese Delta 14 knockoff), the fence is the source of the problem. The damn thing's a degree or two off from the blade & miter slot, and it's not adjustable. I keep meaning to fab up some sort of sled to get around the issue, but somehow it hasn't quite happened yet.

Here's a warning label I have on my machines...

Love the jeweled panel/knobs behind it... did it come that way, or did you do it yourself?

 

[bmachin]

Michael Fortune has been around a long time. Take a look at his video to avoid a lot of unnecessary gyrations.

Side note: I haven't tried this, but if he has saws that he hasn't needed to adjust for 46 years, then there must be something to it.

Bill

 

[Fred Bruche]

I had a similar experience with a cheap-ish bandsaw, I was mostly using it to resaw blanks with the idea to waste less material than on my table saw but since it wasn't cutting straight that wasn't working so well. So I took the time to understand how that saw was working, squaring this and tightening that, it was doing better but not quite there. What really fixed it was to get a 4tpi blade (6tpi works well too) instead of the 14tpi (?) blade that came with the saw. It now works like a charm even on hard material like ebony, ironwood, or rosewoods
I buy the blades from this site

 

[Jans husband]

Thanks to all for your help. A lot to think about here. Excellent video help.
First, I hadn't realised that the set up of the blade guides was so crucial to the operation, so I will start there.
Also, I was surprised to see Alex Snodgrass handling a blade without wearing gloves. I would have thought that to be a first lesson in safety!
Mike

 

[rherrell]

Or, in the case of my bandsaw (a Taiwanese Delta 14 knockoff), the fence is the source of the problem. The damn thing's a degree or two off from the blade & miter slot, and it's not adjustable. I keep meaning to fab up some sort of sled to get around the issue, but somehow it hasn't quite happened yet.


Love the jeweled panel/knobs behind it... did it come that way, or did you do it yourself?

I made them myself. All I had was aluminum and I'm not happy with how it turned out, aluminum is too soft for engine turning IMO. I'm going to replace them with stainless steel so it will SHINE!!

 

[jttheclockman]

Thanks to all for your help. A lot to think about here. Excellent video help.
First, I hadn't realised that the set up of the blade guides was so crucial to the operation, so I will start there.
Also, I was surprised to see Alex Snodgrass handling a blade without wearing gloves. I would have thought that to be a first lesson in safety!
Mike

Do not compare yourself to him. He has done this so many times he can do it in his sleep. He is at every woodworking show and then some.

 

[MyDadsPens]

I have been a cabinet-furniture maker for 30+ years. I have also made a lot of picture frames and they require perfect joints. In that time I have never once been able to cut or sand anything straight. I think any tool that has drift is probably better suited to cutting curves. IMHO pens need to be exactly 90 to the tubes. For me I use a small cutoff saw to get blank to within 1/16 of tube and then a few seconds with a carbide pen mill. Occasionally I need to sand finish off the ends of pens - and it scares the hell out of me because I have never seen anything sanded straight. I use a sanding device that looks like a pen mill with sand paper, some guy on here makes them.
My mini cutoff saw probably cost less or similar than 1 custom band saw blade. Before I came across the small chop saw I was going to use a mini saw for cutting arrow shafts. I do use my band saw too (if its plugged in an closer than the chop saw) but would never expect the cut to be square enough to the blank without also using the pen mill

 

[MyDadsPens]

Oh I forgot to add, in miter joints for picture frames the best joints are created by cutting the 45 with a chop saw and then shaving a very small slice with a razor miter trimmer. I have thought about trying a similar approach for trimming pen blanks. but never thought about it long enough to work out squaring to the tube instead of the blank, but still hold it strong enough to trim with a plane

 

[jttheclockman]

Oh I forgot to add, in miter joints for picture frames the best joints are created by cutting the 45 with a chop saw and then shaving a very small slice with a razor miter trimmer. I have thought about trying a similar approach for trimming pen blanks. but never thought about it long enough to work out squaring to the tube instead of the blank, but still hold it strong enough to trim with a plane

There is no reason to have square ends when cutting pen blanks. I see too much effort in making all kinds of jigs to match tubes with blanks and so forth. (segmenting is a different game so do not get that mixed up) If the tube is inserted and is about 1/16" from the ends then you win. Any cutoff tool will do this, (scrollsaw, bandsaw, chop saw, table saw, hand saw. Miters saw. You can use a mill to trim but the prefered method is to sand. I take blank to my belt sander and freehand the end just till I get close to tube. This saves sanding on the lathe. Then with a transfer punch the correct size as inside the tube I put in my jacobs chuck in tailstock of lathe. In the headstock I have a flat plate with sandpaper stuck to it. Now you can sand those ends flat perfectly 90 degrees to tube. There are examples here in discussion topics so a quick search will help. Good luck.