Aligning The Bandsaw Blade Central To The Table Slot

[pollys13]

I loosened up the bolts holding the table to the trunnions. I've lined it up quite well by eye but I don't think is precise.See attached screenshot.
Any ideas please on how I go about lining up the blade dead central with the slot in the table insert?
Cheers.
Peter.

 

[pcb1962]

What difference would that make?

 

[pollys13]

What difference would that make?

I need it to reference to the measure scale on the fence mount, not stuck the measure down in position yet, waiting until I get it exactly aligned.

 

[Alexam]

Hi Peter, What you have in the photo looks quite OK to me and as long as the blade is verticle 90 degrees both sideways and front to back, then it will not matter if it is running a smidgen off centre of the slot.

As you may already know, getting the blade in the right position on the top wheel is the key and various methods are regularly used. I prefer the method shown by Alex Snodgras in the attached video, which again, you may have seen.

THE BEST FROM A BANDSAW 'Alex Snodgrass of Carter Industries has an excellent video https://www.youtube.com/watch?v=wGbZqWac0jU on a tune up method that works well, but if you want to get the best use of your bandsaw on an ongoing basis, then the Steve Maskery DVD's will show you far more and they are a real investment. http://www.workshopessentials.com/shop/ '.

For checking the tension of your blade - A Flutter test Video - https://www.youtube.com/watch?v=z8zZuDosSy0

Malcolm

 

[Steve Maskery]

I don't think that getting the table any more central will be that great a help, TBH. You get different widths (slightly, anyway) just by changing the blade for one of a different kerf, for example.

If you really do want to use a scale, I'd suggest making the cursor for the scale adjustable by mounting it through elongated holes. That way you can stick down your scale as close as you can, make a test cut, measure it and then adjust the cursor so that it reads the same as reality.

But personally I think you are better off just cutting to a pencil mark.

 

[Lons]

I might be missing something obvious but to my mind depending on whether the table tilts or not and how that mechanism works could be an important factor in where the blade runs in relation to the slot.

I rarely use that feature on my old Startrite but tilting the table does of course reduce available clearance which if the blade was too close to an edge would mean a catch.

Does that make sense or am I talking b******s again. :lol:

 

[Steve Maskery]

I've taken a closer look at the picture and it looks fine to me. In which direction do you want to move it? Are the guide bearings pushing it one way or the other (they should not be making firm contact).

You will find that the insert wears anyway, especially if you do any amount of curved work, and you will soon be making you own zero-clearance inserts, in which case the slot will be where the blade is anyway.

Lons - tilting the table will alter the position of the cut in the insert a little. For bandsaw ZCIs, fitting one for an angled cut is a little more complicated anyway., you have to be able to drop it in vertically, even though the hole is now slanted.

But I don't think that just because the table can tilt, that of itself changes where the blade runs. The blade will run in a straight line tangential to both wheels, come what may.

 

[rafezetter]

I would possibly suggest making a zero clearance insert now to get the blade reference if it's that important for accuracy.

 

[pollys13]

......Uum, OK thanks for all the input guys. Have just collected the table from a machinist mate who tapped a pair of holes in side so I could attach the fence mount correctly and I've only just attached to the table. As I understand now, having the blade dead central in the slot is not crucial. So I can stick the scale down on the mount so lines up with the side of the blade. I am familiar with the procedures for setting up the bandsaw.
I think I will be alright but if not will get back to the forum and ask.
Cheers.

 

[Lons]

Lons - tilting the table will alter the position of the cut in the insert a little. For bandsaw ZCIs, fitting one for an angled cut is a little more complicated anyway., you have to be able to drop it in vertically, even though the hole is now slanted.

But I don't think that just because the table can tilt, that of itself changes where the blade runs. The blade will run in a straight line tangential to both wheels, come what may.

Thanks Steve.

I guess what I meant was that when the table is at maximum tilt, the clearance available in the slot is much less, has to be surely? So if the blade in normal position is close to one side or the other then there is a possibility it will rub on the side of the slot.

My 352 slot is 8.6mm wide and blade almost dead centre so roughly 4mm clearance each side, without physically setting the table at 45 deg to check I guess that clearance will be halved so if the blade wasn't central it would be very close to the side. Or am I misreading that as I often do. :? :lol:

Bob

PS: Mine doesn't have a provision for inserts which is a pain as the previous owners damaged the slot. Any clever ideas apart from taking it to a machine shop to be altered? The area around the blade is thinner so I could I suppose file it out and make something up but fixed from above but it's a bit daunting and I don't want to ruin the table.

 

[Steve Maskery]

Your analysis is correct, I think. Which is why you need different ZCIs for flat cutting and angled cutting.

If you post a picture of your setup it might trigger a few thoughts.

S

 

[Lons]

Okydody Steve will do though i can't get into the workshop for a few days

thanks
Bob