BandSaw blade-to-table Square, or no

keakap · Post by **keakap** » Fri Dec 28, 2012 6:16 pm

Trying out some mortise/tenon procedures on the band saw, came to an alignment controversy, wonder if it's only me what sees a question.

The blade side should always be square to the the table, for normal 90 degree cutting, of course. But its normal, factory-set position as measured at the rear of the blade to the table is not 90 degrees (on mine it's off ~1.2 degrees). Normally this doesn't bother me, too much, but for some operations it is a PITA.
One such situation is cutting the cheeks of a tenon, or a bridle joint, where you definitely want the cut to be equal at top and bottom of the workpiece (flat bottom). Any stopped cut that I can think of at the moment is endangered.
The obvious b/s workaround is shimming the trunnion bolts. As romantic as that may sound, it screws up all kinds of alignments and is far easier to do than undo, well.

So, how do you all deal with this, if at all? Either way it is left, there is a chance the other cuts will suffer.
Any "quick fixes"?

Gene Howe · Post by **Gene Howe** » Fri Dec 28, 2012 7:06 pm

It REALLY becomes a PITA when cutting 5" thick curves as for a band saw box.
My fix was to add the washers between the trunnions and the table.
I couldn't think of a faster/easier fix. Worked, though.

charlese · Post by **charlese** » Fri Dec 28, 2012 9:01 pm

keakap wrote:Trying out some mortise/tenon procedures on the band saw, came to an alignment controversy, wonder if it's only me what sees a question.

One such situation is cutting the cheeks of a tenon, or a bridle joint, where you definitely want the cut to be equal at top and bottom of the workpiece (flat bottom). Any stopped cut that I can think of at the moment is endangered.
The obvious b/s workaround is shimming the trunnion bolts. As romantic as that may sound, it screws up all kinds of alignments and is far easier to do than undo, well.

So, how do you all deal with this, if at all? Either way it is left, there is a chance the other cuts will suffer.
Any "quick fixes"?

My bandsaw used to saw through the upper part of the wood before the lower. I recently fixed this by shimming the trunnion bolts above the trunnions.

I just went to my washer collection and found various thickness of washers and by trial and error installed the shims (washers). The operation wasn't too chore-some. only took about 1/2 to 5/6 hour. just tilted the table to install the left hand washers.

I checked the vertical position of the blade with an engineer's square. And yes - now the blade will POP out of a cut that's 1 1/4" thick.

P.S. Haven't yet tried this on re-sawing yet but am confident the vertical alignment will still work out with a POP out of the blade rather than top first.

To solve the tenon issue - saw the cheeks before sawing the tenon face.

heathicus · Post by **heathicus** » Sat Dec 29, 2012 12:40 am

I shimmed my table so it is square with the blade too. I understand the factory reasoning behind it not being square, but I'm not sure I agree. Now that it is shimmed square, I'm not sure why I would ever "undo" it. I resawed some ~6" wide cherry recently and it did just fine.

eagleta2 · Post by **eagleta2** » Sat Dec 29, 2012 12:18 pm

I also had to shim my table under the trunions to make the table square to the blade.

After doing so, my band saw performance increased greatly... I resaw better and experience less blade drift...assumable because the blade enters the stock at the same time top vs bottom.

The only disadvantage I have seen from shimming the table is that when mounted on my ss the band saw table isn't coplanar with my ss table system. This usually doesn't come into play since I am not normally band sawing very long stock. When resawing, its just my preference to resaw several shorter pieces than one longer one. It just works better for me.

Thanks
Geo

keakap · Post by **keakap** » Sat Dec 29, 2012 12:41 pm

Gene Howe wrote:...My fix was to add the washers between the trunnions and the table...

The remaining question then is whether to leave the shims (washers- and I'm assuming very thin washers) in. If you've done so has it given you any grief- enough to bother about? I imagine it means that you have to be a wee more cautious with the big cuts or resaws?

Thanks.
I've needed to lay in a decent supply of varied shim-washers anyway.

keakap · Post by **keakap** » Sat Dec 29, 2012 12:52 pm

charlese wrote:My bandsaw used to saw through the upper part of the wood before the lower. I recently fixed this by shimming the trunnion bolts above the trunnions. ...
To solve the tenon issue - saw the cheeks before sawing the tenon face.

Hm, mine hits lower first. A curiosity from a manufacturing perspective.
But the fix doesn't sound too awful.

Tenon issue-- of course! Why didn't I think ...
...and I checked- done carefully the cheek and face cuts come together within the space of the kerf, which is .030 with this blade, and that works, on small stuff.

And I messed around with mortise cuts yesterday, cleanup with a sharp chisel a PITA all right, but not too awful, either, unless there's a lot of 'em.
So it's a toss up almost, but I'm gonna try the shims.

Thanks.

Gene Howe · Post by **Gene Howe** » Sat Dec 29, 2012 12:53 pm

I used washers but you can find "U" shaped shim stock at most auto parts stores. Mine came as a graduated set. I think there are 12 in the set and all together they equal about 3/8". But, they do sell them individually.
I have not noticed any changes in the way it saws and I resaw 5 1/2". If anything, it might be better. It sure is better for thick curves. No more bellies.

keakap · Post by **keakap** » Sat Dec 29, 2012 1:04 pm

So in keeping with my usual practice of doing things backwards, I finally read ALL of the replies, and there is no more question. I'm goin with the shims.
Onliest thing I'll have to be careful with- real careful with- is any large cut with my perfect (almost) Mystery 1/4 blade, which can get gullet-bound.

Thanks every one.

Oops- and there's Gene's latest-- shim stock at auto parts stores: thanks again, I was going to ask about that.

Shopsmith Forums- made my day, again.

charlese · Post by **charlese** » Sat Dec 29, 2012 1:15 pm

keakap wrote:The remaining question then is whether to leave the shims (washers- and I'm assuming very thin washers) in. If you've done so has it given you any grief- enough to bother about? I imagine it means that you have to be a wee more cautious with the big cuts or resaws?

Thanks.
I've needed to lay in a decent supply of varied shim-washers anyway.

My washers measure anywhere between 1/16" to 3/32". They are standard washer stock. They will stay in place for ever, installed on the bolts, between the trunnions and the table. Very solid mounting.

Over the years I've collected a plethora of bolts, washers, nuts, etc. and stored them in file boxes.