Bandsaw fettling

[pike]

Can any seasoned bandsaw users help me with some perhaps beginner questions about my new BS400?

I've aligned the blade with the table (with an engineers square from the side of the blade) but should I also be aligning it front to back e.g. if it's not square when putting the square up against the back of the blade?

It's slightly out, maybe it doesnt matter?

Secondly, I was hoping when I set the location of the upper guide assembly e.g. side guides just behind the blade gullet and thruster not quite in contact with the back of the blade, that I'd then be able to use the rise and fall to set height without needing to readjust the guides basic position. However the whole rise and fall and guides is closer to the blade at the top of its height compared to when its down near the table, which means I have to loosen and move them every time. I had thought I would not need to unless changing blades.

p.s. I've watched the snodgrass video and have Mr Maskerys DVD on the way.

Cheers!
Carl.

 

[PAC1]

Closer would be fine pushing the blade forward would not be so good. So if it does not cause an actual problem I would leave well alone. If it affects the blade adjust the mechanism a touch

 

[pike]

If I set the guides up with the rise and fall say 6 inches above table, then I try to bring the height up, the thruster/rear guide hits and starts to push the back of the blade when I get to about 60% of the way up. It's not good as it means I need to adjust more than I was led to believe I'd have to.

That's with a 3/4 inch blade on, I suppose it would be less likely with a half inch blade.

Is the alignment of the whole rise and fall in relation to the blade something which can be user adjusted?

 

[Alexam]

Hi Pike,

I have the BS400 and setting up the bandsaw in the way Alex Snodgrass suggests should work exactly.

Let me run through how I do it from the blade on the wheels, widen top and bottom guides and set the thrust bearing well back, so that the blade runs clear without touching anything.

Check the position of the blade on the top wheel. It should be situated with the lowest part of the gullet in the centre of the top wheel. Close up and run the machine briefly, then check the blade position again. If it does not remain centred, then you need a slight adjustment on the wheel at the back of the machine.

This only needs small adjustment - (as with a clock, 10 mins at a time) Unlock it and turn it clockwise to move the blade backwards on the tyre, or anticlockweise to move it forwards on the tyre. Lock it off and try running the machine again. REPEAT UNTIL STABLE, which may take several attempts.

Once stable, then move the side guides into place, just off touching and then the thrust bearings likewise, just off touching. Run the machine again. Nothing should be touching and the blade shold be centred.

If you still have problems, PM me with your phone number and I will be pleased to call you.

Alex

 

[pike]

Thanks again Alex,

I will do some more tests. I might not have checked tracking enough by actually putting power through the machine before setting the guides up.

However I'm not clear what impact your good advice will have on the rise and fall not going up and down in line with the back of the blade? My main issue is just that if I set the thrust bearing nearly touching the blade with the rise and fall in one place, then if I move the rise and fall height (for example to go from cutting 25mm wood to 200mm+), I have to move the thrust away first as the whole rise and fall and guide assembly doesn't go up and down perfectly in line with the blade.

Hope that makes sense
Carl.

 

[Alexam]

Definately sounds like you have not set the blade correctly in the centre and it is drifting forward and back and only being maintaind by the thrust bearing. That blade position should not change no matter if the height is high or low. Sounds like it is moving simply because the blade is moved by the thrust bearing, when it should be static. The above should help. Let me know what happens.

Alex

 

[ajayre]

I have the same issue with my BS250. What Carl is describing (or at least as I understand it) is this:

1. Center blade perfectly. Turn machine on. Blade doesn't drift forwards and backwards.

2. Set guidepost to highest position and set thrust bearing to just behind blade per Alex Snodgrass.

3. Operate machine. Everything fine.

4. Turn machine off. Lower guide post. Now the thrust bearing is touching the back of the blade.

The blade hasn't moved because the machine was not turned on. Nothing is drifting. The problem is that the guidepost is not perfectly aligned with the blade. As the guidepost is lowered it is ever so slightly out of alignment with the blade, which means that as it is lowered the thrust bearing moves closer and closer to the blade.

As I said, I have this problem with my BS250 but I set the thrust bearing so that regardless of the guidepost position it isn't touching the blade. This means that in some guidepost positions the gap between the blade and the thrust bearing is more than I would like, but it doesn't seem to be critical and therefore doesn't seem to cause a problem.

HTH, Andy

 

[pike]

Andy yes exactly. You put it better than me I had hoped not to need to adjust the thrust bearing just because I wanted to change height.

Carl.

 

[Alexam]

Pike,
check the settings first of all to make sure they are correct, then if the problem still arrises, ask RECORD ( or the people you bought through) to send an engineer out to correct the fault, as it is under guarantee and this should not be happening.

Bear in mind that if the blade can move back too far, then the teeth of the blades will get damaged by the guides, THis is why you should not move the thrust bearing back and Andy should pewrhaps ask RECORD to look into this as well .

Alex

 

[woodbrains]

Hello,

Can't you shim one of the mounting bolts of the blade guide post, to bring it parallel to the blade? I'm not familiar with your particular machine, but I should think a thin washer between the BS case and the blade guide mounting plate would do the trick.

I would not pay a great deal of attention to the Snodgrass video. The bit about guide set up is OK and pretty universally applied anyway, so nothing new. The bit about tracking the blade gullets at the centre of the wheel is incorrect. Set the blade to run centrally. His assertion that the blade needs support from the wheel directly behind the teeth makes no sense. He doesn't even tell us why he thinks this should be the case. If you think about it, why does it? About 75 percent of the blade just hangs about in mid air, so why worry about supporting the blade around the teeth when on the wheel? But there are a few reasons why it shouldn't be done. You limit the blade width you can use, you'll probably start tearing up the tyres with the gullets contacting the wheel and physics says the blade naturally want to run at the highest point of a crowned wheel. Setting the tracking control so it runs off centre is fighting against forces here and may likely cause bearings to fail quicker.
Mike.

 

[tomasg]

Guidepost mounting holes sounds misaligned to me ...
if your saw is plumed on ground and wheels coplanar after that
and then your blade is consistently tracking on center of crowned wheels.....
You SHOULD be then ABLE to have guides close and running without any noise WHATSOEVER.
If so... then retract thrust guide . At this point ,
" The guidepost should be PARALLEL with the blade and this will be more noticeable when
your guideposts are as low to the table as you can adjust it
Hope this helps
Tom

 

[woodpig]

I have the same issue with my BS250. What Carl is describing (or at least as I understand it) is this:

1. Center blade perfectly. Turn machine on. Blade doesn't drift forwards and backwards.

2. Set guidepost to highest position and set thrust bearing to just behind blade per Alex Snodgrass.

3. Operate machine. Everything fine.

4. Turn machine off. Lower guide post. Now the thrust bearing is touching the back of the blade.

HTH, Andy

I suppose we all do things slightly differently but can I ask why you're setting the thrust washer position with the post right at the top (as a matter of course) rather than setting it with the post at the height you intend to use it? I'm guessing maybe it says this in the manual?

I'm pretty sure you'll be able to adjust the post so that the thrust washer setting remains the same at all heights but it's not a bad habit to check it at the height you're working anyway and adjust if required. Only takes a couple of seconds. Let us know how you get on, it all adds to the library of information available on these machines. :wink:

 

[Alexam]

Hello,

Can't you shim one of the mounting bolts of the blade guide post, to bring it parallel to the blade? I'm not familiar with your particular machine, but I should think a thin washer between the BS case and the blade guide mounting plate would do the trick.

I would not pay a great deal of attention to the Snodgrass video. The bit about guide set up is OK and pretty universally applied anyway, so nothing new. The bit about tracking the blade gullets at the centre of the wheel is incorrect. Set the blade to run centrally. His assertion that the blade needs support from the wheel directly behind the teeth makes no sense. He doesn't even tell us why he thinks this should be the case. If you think about it, why does it? About 75 percent of the blade just hangs about in mid air, so why worry about supporting the blade around the teeth when on the wheel? But there are a few reasons why it shouldn't be done. You limit the blade width you can use, you'll probably start tearing up the tyres with the gullets contacting the wheel and physics says the blade naturally want to run at the highest point of a crowned wheel. Setting the tracking control so it runs off centre is fighting against forces here and may likely cause bearings to fail quicker.
Mike.

Interesting concept Mike. Which bandsaw do you run presently?

 

[woodpig]

I've just checked the manual for my RP BS300E and it clearly says to "recheck the upper bearings once the height is set for any slight adjustment required". I've upgraded the bearings on my machine so I can't recall what's required on the standard ones but it's only one bolt to adjust mine.

In spite of any marketing hype it's best remembered that these are hobby machines not professional ones.
Record Power sell the Startrite range for that purpose.

 

[pike]

I should add I am so far pretty pleased with the cuts I'm getting on the BS400. It's just when it's the first bandsaw I've ever had and I've not been on a course or anything, there are things I'm not sure are by design or faults.

I can do 2mm veneers and square cuts so its not so bad. Rips would need a run on the planer but that is fine by me.

I heard in a couple of places that once I set the upper guides to be just back from the blade gullet, that I shouldnt have to do it again. I guess that depends on what bandsaw you have, and as others have said, its not actually that big a deal to reset for a different height.

I could maybe shim the guide post as suggested, but thinking about it, the whole guide post has some play anyway so maybe I'm being picky as I learn whats what.

Cheers.

 

[woodpig]

Unless we're talking about several mm I wouldn't bother. If there is a slight change in the position of the guides depending on whether the post is fully up or fully down just make sure the side bearings remain behind the gullet at all heights, Then adjust the rear bearing as required for the height you've set.

 

[pike]

It is several mm actually. I haven't measure it but I'd say over 10mm. I'll have another play tomorrow and see if I can get to the bottom of it, or get used to it.

 

[woodbrains]

Hello,

Can't you shim one of the mounting bolts of the blade guide post, to bring it parallel to the blade? I'm not familiar with your particular machine, but I should think a thin washer between the BS case and the blade guide mounting plate would do the trick.

I would not pay a great deal of attention to the Snodgrass video. The bit about guide set up is OK and pretty universally applied anyway, so nothing new. The bit about tracking the blade gullets at the centre of the wheel is incorrect. Set the blade to run centrally. His assertion that the blade needs support from the wheel directly behind the teeth makes no sense. He doesn't even tell us why he thinks this should be the case. If you think about it, why does it? About 75 percent of the blade just hangs about in mid air, so why worry about supporting the blade around the teeth when on the wheel? But there are a few reasons why it shouldn't be done. You limit the blade width you can use, you'll probably start tearing up the tyres with the gullets contacting the wheel and physics says the blade naturally want to run at the highest point of a crowned wheel. Setting the tracking control so it runs off centre is fighting against forces here and may likely cause bearings to fail quicker.
Mike.

Interesting concept Mike. Which bandsaw do you run presently?

Hello,

At home a Kity 613 and an Axminster AP5300. In school I run 2 Startrite 352's, 2 Record Power BS 250's and a couple of horrible draper mini bandsaws for the pupils. The Kity doesn't run on crowned wheels, so is a different setup.

Mike.

 

[woodpig]

It is several mm actually. I haven't measure it but I'd say over 10mm. I'll have another play tomorrow and see if I can get to the bottom of it, or get used to it.

Wow, that is bad! Something seriously wrong there. Contact Record.

 

[pike]

Yeah it doesn't seem good but as I say I'm happy to be patient, maybe I'm doing something wrong. Perhaps my floor isn't level, not sure if that would do this though.