Band saw blade keeps coming off

Band saw blade keeps coming off

Post by Chri » Sat, 28 Jan 2006 05:47:40



I feel an idiot for not being able to get this damned thing fixed myself,
but I have a smallish bench mounted metal cutting bandsaw of good quality.
OK, she's done a bit of work before I got her, but there's no wear in the
bearings and the cast iron wheels run true. I have played with blade
tension (tighter seems more reliable) and with the top (none powered wheel)
tilt, which is adjustable, and the blade guide ball bearings, which are
adjustable, but STILL the blade will suddenly jump off one of the wheels. 3
things look less than perfect. the wheels had some sort o gritty coating,
when new, like coarse carborundum paper, this is now quite worn. The blade
makes a noticeable jump as the welded part passes through the work piece.
Nothing much, but when worked hard it is audible and can be felt. Finally
the blade is quite old and not as sharp as it might be. Cutting alloy makes
the blade come off more than steel.. Can anyone with experience of these
machines point me in any directions to look to? Thanks!
 
 
 

Band saw blade keeps coming off

Post by Tom Gardne » Sat, 28 Jan 2006 06:01:44


The blade


Quote:
>I feel an idiot for not being able to get this damned thing fixed myself,
> but I have a smallish bench mounted metal cutting bandsaw of good quality.
> OK, she's done a bit of work before I got her, but there's no wear in the
> bearings and the cast iron wheels run true. I have played with blade
> tension (tighter seems more reliable) and with the top (none powered
> wheel)
> tilt, which is adjustable, and the blade guide ball bearings, which are
> adjustable, but STILL the blade will suddenly jump off one of the wheels.
> 3
> things look less than perfect. the wheels had some sort o gritty coating,
> when new, like coarse carborundum paper, this is now quite worn. The blade
> makes a noticeable jump as the welded part passes through the work piece.
> Nothing much, but when worked hard it is audible and can be felt. Finally
> the blade is quite old and not as sharp as it might be. Cutting alloy
> makes
> the blade come off more than steel.. Can anyone with experience of these
> machines point me in any directions to look to? Thanks!


 
 
 

Band saw blade keeps coming off

Post by Stephen Youn » Sat, 28 Jan 2006 06:40:58


Quote:

> I feel an idiot for not being able to get this damned thing fixed myself,
> but I have a smallish bench mounted metal cutting bandsaw of good quality.
> OK, she's done a bit of work before I got her, but there's no wear in the
> bearings and the cast iron wheels run true. I have played with blade
> tension (tighter seems more reliable) and with the top (none powered wheel)
> tilt, which is adjustable, and the blade guide ball bearings, which are
> adjustable, but STILL the blade will suddenly jump off one of the wheels. 3
> things look less than perfect. the wheels had some sort o gritty coating,
> when new, like coarse carborundum paper, this is now quite worn. The blade
> makes a noticeable jump as the welded part passes through the work piece.
> Nothing much, but when worked hard it is audible and can be felt. Finally
> the blade is quite old and not as sharp as it might be. Cutting alloy makes
> the blade come off more than steel.. Can anyone with experience of these
> machines point me in any directions to look to? Thanks!

Install new tires on the wheels.
 
 
 

Band saw blade keeps coming off

Post by Tom » Sat, 28 Jan 2006 06:48:54


Quote:

> I feel an idiot for not being able to get this damned thing fixed myself,
> but I have a smallish bench mounted metal cutting bandsaw of good quality.
> OK, she's done a bit of work before I got her, but there's no wear in the
> bearings and the cast iron wheels run true. I have played with blade
> tension (tighter seems more reliable) and with the top (none powered wheel)
> tilt, which is adjustable, and the blade guide ball bearings, which are
> adjustable, but STILL the blade will suddenly jump off one of the wheels. 3
> things look less than perfect. the wheels had some sort o gritty coating,
> when new, like coarse carborundum paper, this is now quite worn. The blade
> makes a noticeable jump as the welded part passes through the work piece.
> Nothing much, but when worked hard it is audible and can be felt. Finally
> the blade is quite old and not as sharp as it might be. Cutting alloy makes
> the blade come off more than steel.. Can anyone with experience of these
> machines point me in any directions to look to? Thanks!

Replace the blade.

Tom

 
 
 

Band saw blade keeps coming off

Post by John Marti » Sat, 28 Jan 2006 07:14:53


Line up the wheels.  Make sure they are in the same plane.

Crown the tires.

Install a blade with a good weld.

Back off the guides and adjust the wheel tracking so the blade tracks
on the wheel crowns.  Adjust the guides.

John Martin

 
 
 

Band saw blade keeps coming off

Post by Chri » Sat, 28 Jan 2006 07:21:53



Quote:
> Line up the wheels.  Make sure they are in the same plane.

> Crown the tires.

> Install a blade with a good weld.

> Back off the guides and adjust the wheel tracking so the blade tracks
> on the wheel crowns.  Adjust the guides.

> John Martin

Thanks for the replies, what do you mean by "crown the tires" please? The
wheels are flat on the blade running surface and seem to have glued on
abrasive coating, not something that looks to be (easily or cost
effectively) renewable. Cheers.
 
 
 

Band saw blade keeps coming off

Post by Glenn Ashmor » Sat, 28 Jan 2006 07:26:19


First check blade weld and make sure it is straight.  Next check the ***
tires.  They should have a slight crown.  If it has worn flat you need new
tires.  Sort of counter intuitive but the blade seeks the high spot as it is
running.  Next check the wheel alignment.  Both wheels should be parallel
and in the same plane.  Lay a straight edge against both wheels.  It should
touch the top and bottom rim of both wheels.  If not there should be a set
***or bolt next to the top wheel axel that adjust the angle and the
powered wheel can be slipped in or out on its shaft.

The blade tension should be just tight enough that it makes a musical note
when plucked and it is good practice to back off the tension when the saw is
not being used.

The Bandsaw Book by Mark Duginski is primarily  aimed at wood cutting
bandsaws but the tuning chapter applies to both wood and metal.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at:  http://www.FoundCollection.com/
Shameless Commercial Division: http://www.FoundCollection.com/


Quote:
>I feel an idiot for not being able to get this damned thing fixed myself,
> but I have a smallish bench mounted metal cutting bandsaw of good quality.
> OK, she's done a bit of work before I got her, but there's no wear in the
> bearings and the cast iron wheels run true. I have played with blade
> tension (tighter seems more reliable) and with the top (none powered
> wheel)
> tilt, which is adjustable, and the blade guide ball bearings, which are
> adjustable, but STILL the blade will suddenly jump off one of the wheels.
> 3
> things look less than perfect. the wheels had some sort o gritty coating,
> when new, like coarse carborundum paper, this is now quite worn. The blade
> makes a noticeable jump as the welded part passes through the work piece.
> Nothing much, but when worked hard it is audible and can be felt. Finally
> the blade is quite old and not as sharp as it might be. Cutting alloy
> makes
> the blade come off more than steel.. Can anyone with experience of these
> machines point me in any directions to look to? Thanks!

 
 
 

Band saw blade keeps coming off

Post by Glenn Ashmor » Sat, 28 Jan 2006 07:44:23


Sounds like the tires have been removed.  They are thin *** bands that
are glued to the wheels.  They have a slight crown in the center.  The crown
forces the blade back to the center of the wheel when it gets off to one
side.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at:  http://www.FoundCollection.com/
Shameless Commercial Division: http://www.FoundCollection.com/


Quote:

>> Line up the wheels.  Make sure they are in the same plane.

>> Crown the tires.

>> Install a blade with a good weld.

>> Back off the guides and adjust the wheel tracking so the blade tracks
>> on the wheel crowns.  Adjust the guides.

>> John Martin

> Thanks for the replies, what do you mean by "crown the tires" please? The
> wheels are flat on the blade running surface and seem to have glued on
> abrasive coating, not something that looks to be (easily or cost
> effectively) renewable. Cheers.

 
 
 

Band saw blade keeps coming off

Post by Tom » Sat, 28 Jan 2006 07:52:34


Quote:

> Sounds like the tires have been removed.  They are thin *** bands that
> are glued to the wheels.  They have a slight crown in the center.  The crown
> forces the blade back to the center of the wheel when it gets off to one
> side.

> --
> Glenn Ashmore

> I'm building a 45' cutter in strip/composite. Watch my progress (or lack
> there of) at:  http://www.FoundCollection.com/
> Shameless Commercial Division: http://www.FoundCollection.com/




> >> Line up the wheels.  Make sure they are in the same plane.

> >> Crown the tires.

> >> Install a blade with a good weld.

> >> Back off the guides and adjust the wheel tracking so the blade tracks
> >> on the wheel crowns.  Adjust the guides.

> >> John Martin

> > Thanks for the replies, what do you mean by "crown the tires" please? The
> > wheels are flat on the blade running surface and seem to have glued on
> > abrasive coating, not something that looks to be (easily or cost
> > effectively) renewable. Cheers.

It's a metal cutting bandsaw, they don't have *** tires and the
wheels don't need crowning.
The blade needs replacing before anything else.

Tom

 
 
 

Band saw blade keeps coming off

Post by John Marti » Sat, 28 Jan 2006 08:47:20


Quote:

> It's a metal cutting bandsaw, they don't have *** tires and the
> wheels don't need crowning.
> The blade needs replacing before anything else.

> Tom

You sure about that, Tom?

John Martin

 
 
 

Band saw blade keeps coming off

Post by Tom » Sat, 28 Jan 2006 08:55:28


Quote:


> > It's a metal cutting bandsaw, they don't have *** tires and the
> > wheels don't need crowning.
> > The blade needs replacing before anything else.

> > Tom

> You sure about that, Tom?

> John Martin

Yes
 
 
 

Band saw blade keeps coming off

Post by Tom Gardne » Sat, 28 Jan 2006 08:51:27



Quote:
> It's a metal cutting bandsaw, they don't have *** tires and the
> wheels don't need crowning.
> The blade needs replacing before anything else.

> Tom

There's probably some political thing going on here,  if one faction want's
to believe in tires and crowning, who are you to burst the bubble and
suggest the obvious?
 
 
 

Band saw blade keeps coming off

Post by Hexhe.. » Sat, 28 Jan 2006 08:52:11


What is the size of this bandsaw, is it two wheel or a smaller three
wheel. Does fly off when cutting wood or metal, well it stay on when
cutting wood but fly off when you try to cut metal?
 
 
 

Band saw blade keeps coming off

Post by Tom » Sat, 28 Jan 2006 09:14:29


Quote:



> > It's a metal cutting bandsaw, they don't have *** tires and the
> > wheels don't need crowning.
> > The blade needs replacing before anything else.

> > Tom

> There's probably some political thing going on here,  if one faction want's
> to believe in tires and crowning, who are you to burst the bubble and
> suggest the obvious?

Ya right, better retread the wheels, crown them, fit new bearings,
guides, possibly rewind the motor and replace the switch.
To actually suggest replacing a consumable before overhauling
the machine was unthinkable.
Thanks for the headsup Tom, I withdraw all previous suggestions
as totally inappropriate. Hang on a minute, didn't I read somewhere,
that you suggested replacing the blade?

Tom

 
 
 

Band saw blade keeps coming off

Post by John Marti » Sat, 28 Jan 2006 09:30:26


Quote:



> > > It's a metal cutting bandsaw, they don't have *** tires and the
> > > wheels don't need crowning.
> > > The blade needs replacing before anything else.

> > > Tom

> > You sure about that, Tom?

> > John Martin

> Yes

You might want to write to DoAll and Grob and a few others, then, and
tell them that they're wasting money by putting tires on their wheels.
Oh, wait, those must be woodworking saws.  Silly me.

It probably is the blade.  But there are a lot of other things he
should be checking.

John Martin