Horizontal bandsaw not aligned

[tig lover]

Sorry if this is posted in the wrong section.

I am having issues with my 12inch bandsaw.. as i can't get the blade to be square to the table. The guide rollers from what i can tell seem to be set up square. But if i loosen nut that locks the whole guide rail on the opposite side to the motor side guide rail it moves as i tighten it. The blade is probably 2-3 degrees out of square to the table. i have uploaded two pictures to help you see what i am talking about. One has coloured markings but ignore the square as the vice has been lined up to the bandsaw blade its self and not the table which is not something i want to do. Can anyone help me as to what is going on? I can try upload a you tube video if that helps? In the second picture with the markings the green gap is bigger than the blue gap to give you a idea of where its out of alignment

 

[tig lover]

Also the guide rail that is next to the blue marking.. it twists out of position a bit as i loosen the locking nut. I don't know if that is normal

 

[Seadog]

The blade can only follow the arc of the pivot. If the pivot is not square to the base it'll never cut true. Myself and @windspent an interesting hour or rwo trying to puzzle out why his one didnt cut true. I think that we ended up shimming the pivot to base join on one side to correct it.

 

[roofman]

Would it not be easier to adjust the vice face to the blade...the generic chinese bandsaw i owned had me in tears over trying to get the blade running true, in the end it was the 0 degree mark was not true to the blade and i then just squared it up and scribed a new mark on the table...Or am i barking up the wrong tree here?

 

[fizzy]

An overall picture would help - arm could be bent or something.

 

[tig lover]

The blade can only follow the arc of the pivot. If the pivot is not square to the base it'll never cut true. Myself and @windspent an interesting hour or rwo trying to puzzle out why his one didnt cut true. I think that we ended up shimming the pivot to base join on one side to correct it.

if you talking about the pivot that moves the whole thing up and down.. no it is square but if you look closely. you can see the two guide rails do not line up. How can i correct this? The machine its self looks flat and nothing looks bent.

 

[tig lover]

Would it not be easier to adjust the vice face to the blade...the generic chinese bandsaw i owned had me in tears over trying to get the blade running true, in the end it was the 0 degree mark was not true to the blade and i then just squared it up and scribed a new mark on the table...Or am i barking up the wrong tree here?

I could do that but i want to fix the issue as even when did line it up like that. it did cut a lot better but it was still 0.5-1mm off square i know the machine is capable of being far better than that.

 

[roofman]

Those 4 roller guides/bolts have eccentric adjusters on them and you can move the blade over by slacking the nuts and turning the guides

 

[grim_d]

Move the vice.

Forces you to check square every time you set up for mitres and back again. I never use the marks.

 

[tig lover]

Those 4 roller guides/bolts have eccentric adjusters on them and you can move the blade over by slacking the nuts and turning the guides

The guides are square to the blade. but the blade its self is not square to the table mate. If I loosen the locking nut for the guide rail it does start to swivel out of square

 

[bricol]

The guides are square to the blade. but the blade its self is not square to the table mate. If I loosen the locking nut for the guide rail it does start to swivel out of square

I think he means loosen the nuts holding the guide bearings - leave the quide themselves alone. Turn the square end on the bearing to rotate the eccentric the bearing is on to move the blade across, then adjust the other bearing similarly on the other side of the blade so the blade is again running nicely between them.

 

[roofman]

I think he means loosen the nuts holding the guide bearings - leave the quide themselves alone. Turn the square end on the bearing to rotate the eccentric the bearing is on to move the blade across, then adjust the other bearing similarly on the other side of the blade so the blade is again running nicely between them.

You have explained it better

 

[bricol]

You have explained it better

I thought you explained it concisely and accurately - made perfect sense to me despite never looking that closely at how a proper bandsaw blade guidance is done - I just added extra verbage to pad it out a bit.

Last time I used, or in fact even got close to a decent proper band saw must be close to 20 yrs ago - every place of employment since has fenced them away with only "authorised" people allowed to use 'em.

 

[tig lover]

Right.. I have tinkered with the saw and it now has a accuracy of 0.5mm square with the vice jaws aligned to the table which is a massive improvement. However its still not a true cut. i cut 12mm off a bit of 80x80 box section and i measured it as the following.. 12.19mm at the top.. 12.60 ish at the bottom.. I've lined up the blade using a 2 3 5 block and a square but its still not right. Does the blade have to be perfectly 90 degree to the table bed or does it have to have a very slight angle? because at the moment its likely 89 ish. Also i have had to tighten things on the saw and i am wondering how tight could i have it? I can still rock the blade back and forth when the machine is off by a cm and the bearings do roll with the blade.. is that enough or should it be more loose?

I do thank the help you have given so far guys

 

[grim_d]

It's a bandsaw, not a milling machine. They are used to rough cut material before further processes. If your using it to chop up box for fab projects then welding them will make them move more than the bandsaw is off by.

Chopping up material for machining? You surface/face it anyway.

No harm in getting it close but these small machines are built to a price. Close is close enough.

 

[roofman]

ditto

 

[tig lover]

It's a bandsaw, not a milling machine. They are used to rough cut material before further processes. If your using it to chop up box for fab projects then welding them will make them move more than the bandsaw is off by.

Chopping up material for machining? You surface/face it anyway.

No harm in getting it close but these small machines are built to a price. Close is close enough.

yeah i finally got it to cut perfectly square now though even with small box section. took a lot of tinkering haha

 

[roofman]

yeah i finally got it to cut perfectly square now though even with small box section. took a lot of tinkering haha

Would you like to share...it might help others