Bandsaw table alignment

[neolitsia]

I have just bought a Hammer bandsaw. The table bolts onto to the trunion assembly in the usual way and it is not precisely located (there is some play in the horizontal axis before the bolts are tightened). I can’t find any information on how to align the table with the blades' cutting axis. There are various suggestions on how to align a fence with a blades individual ‘drift angle’ but nothing on how to align the table in the first place.
Any suggestions?
Thanks in advance

Murray

[China]

Set the base of the nachine on a level surface, and the use a spirit level to set the table level

[ian]

set the base on a level surface

get the blade running true on the wheels

then use a set square to square the table with the blade. The table doesn't have to be exactly horizontal, but at the zero mark it must be at 90° to the blade.


ian

[neolitsia]

Thanks for the replies, however it is the alignment with the vertical cutting axis of the blade that I am trying to do. This is the same thing as setting a table saw fence parallel to the blade.
In the Bandsaw Book Lonnie Bird describes a procedure for setting the fence parallel to the blades' drift angle. It involves getting a short (50cm or so) piece of stock and marking a straight line down the centre parallel to the sides. You the carefully cut to the line for about half the length then clamp it in place. The work piece should now be parallel to the blades cutting axis and the fence is set parallel to it. Apparently this angle varies from blade to blade.
With the mounting bolts loose, if you grab my table and try to rotate it in the horizontal plane there is play of several degrees, so I need to position it square to the blade cutting axis.
Thanks again
Murray

[silentC]

It's not important. Just set it so it's square to the chassis of the saw and lock it off. You do your adjustment with the fence and/or the blade tracking.

[joe greiner]

I've used this procedure.

Use a set square to get close to a precise alignment, then for tighter precision:

With a board reasonably flat, and of sufficient area, cut half way through (straight, with no side load on the blade), and back out of the cut.

Rotate the board, and cut similarly to meet the previous cut.

Examine the meeting point. If both cuts are aligned (i.e. no wedge between them), the table is perfect. If not, adjust the table tilt.

Repeat as necessary, until satisfactory. Then reset the pointer on the table protractor to zero.

This may need to be repeated after any bevel cuts. "Satisfactory" is in the eye of the beholder/user.

Cheers,
Joe

[derekcohen]

As others have stated, first get the table parallel to the floor. Hopefully you have a perfectly horizontal floor!

Now you can use the table as your reference for verticle for the blade.

You have a choice: use a square to align the blade to the table, or (what I do) use a Wixey gauge to do so. The Wixey can get you absolutely spot on.



Regards from Perth

Derek

[Jack E]

Can you clarify whether you are trying to set horizontal or vertical?

Vertical: just sit a square on the table, adjust the table until it is square with the blade.

Horizontal: it doesn't matter as you will not get it accurate, just adjust as you cut.

[Peter36]

Hi Murray
I use the technique described in FWW No 173 "Five tips for better bandsawing" The author suggests using moderate blade tension and using the bandsaw tracking adjustment to eliminate the drift . Works for me . I could email the article to you .

Regards
Peter

[neolitsia]

Can you clarify whether you are trying to set horizontal or vertical?

Vertical: just sit a square on the table, adjust the table until it is square with the blade.

Horizontal: it doesn't matter as you will not get it accurate, just adjust as you cut.

Its horizontal, thanks for the tips.

Murray

[silentC]

See, no-one understands your question (except Jack).

It doesn't matter if the table is not square to the blade in the horizontal plane because you will adjust the fence or the blade tracking to get it cutting parallel to the fence. If the table is a few degrees off square, it wont make any difference. Try to get it as square as you can by eye but you're unlikely to be able to get the fence at 90 degrees to the front of the table anyway due to drift - and every blade will have different drift, so if it's 90 degrees for one blade, it wont be for another.

[pjt]

I think what neo is asking about is alignment of mitre guage (table) slot to blade, if u have your mitre guage set at 90 it needs to travel past the blade and be paralell to the blade to achieve a 90 deg cut on your piece of wood, u can of course set your mitre guage at the amount of misalignment and achieve a square cut by trial and error. The table also needs to be 90 to the blade vertically as others have said.

To set the blade paralell to the table slot this is what I would do...
widest blade on machine and tensioned up fully
guides set as per normal
good straight steel rule butted up to side of blade (a rule the length of the table is more accurate) need to make sure rule is not level with a tooth with set i.e.level with gullet, a little bit of judgment is required here and make sure rule cant move
measure from end of rule to slot at each end of table and make this distance the same and lock it up.
It also doesn't mean anything if u dont use your table slot like others have said
As far as drift goes I'm not sure how adjustable the oem fence is but... others have said enuff there.
Is this what u where after??
Peter.

[silentC]

u can of course set your mitre guage at the amount of misalignment and achieve a square cut by trial and error.

That wont work because the direction of travel is still off centre. For the mitre gauge to be of any use at all, the slot has to be perfectly parallel to the line of the cut. That's probably why I never use mine.

I doubt you could align the table based on measurements off the blade either. The drift is rarely parallel to the sides of the blade.

There are two schools of thought on catering for drift: 1) you adjust the fence as described above or 2) you set the fence at 90 degrees to the table and adjust the tracking. If you move the blade further back on the wheel, it points away from the fence; if you move it forwards it points towards it.

If you do it the second way, you will probably be able to get the blade cutting parallel to the mitre slot. If you do it the former, you haven't got a hope unless you jag it.

[Skew ChiDAMN!!]

The only times I use the mitre gauge on a BS is when I'm docking the ends off narrow(ish) pieces, such as pen blanks or picture frames.

It won't get the cut 100% at 90°, 45° or whatever but it's certainly more accurate than free-handing. (If precision is necessary, then the freshly cut face is introduced to the mitre gauge on my linisher. )

The best you can do is determine the "average" of the drift over several blades and set the table to that... but as you need to make allowances while cutting for the wandering of each blade anyway, (ie. trimming the fence, etc.) it's really a rather pointless exercise.

[Jack E]

I may be wrong and I am not at home to check but I don't think my BAS350 has an adjustment to get the table square.

I don't even know why a bandsaw table has a mitre slot.