Kity 612 Bandsaw help needed.

[Tad-blody]

I was wondering whether any current or former 612 owners could advise me.
I've had the saw a couple of years now but I keep snapping the blades, when they go they crack either from the gullet or from the back of the blade (I've managed to stop a few before they've actually snapped).
I've checked the bearings and wheels to the best of my ability for play/true running and run the blades with the teeth overhanging the wheels as per the instructions for the machine.
I've tried several quality brands of blade between 1/2" and 3/4" wide, for straight cuts, most end up with several cracks which show as a jump in the blade.
I guess therefore that I must be either making a tensioning error or that the wheel 'tyres' have gone hard (if this is possible)
I've had a Burgess bbs20 (previously) and a Jet jwbs9 (currently) and haven't suffered the same problems.

 

[OscarG]

I was wondering whether any current or former 612 owners could advise me.
I've had the saw a couple of years now but I keep snapping the blades, when they go they crack either from the gullet or from the back of the blade (I've managed to stop a few before they've actually snapped).
I've checked the bearings and wheels to the best of my ability for play/true running and run the blades with the teeth overhanging the wheels as per the instructions for the machine.
I've tried several quality brands of blade between 1/2" and 3/4" wide, for straight cuts, most end up with several cracks which show as a jump in the blade.
I guess therefore that I must be either making a tensioning error or that the wheel 'tyres' have gone hard (if this is possible)
I've had a Burgess bbs20 (previously) and a Jet jwbs9 (currently) and haven't suffered the same problems.

Firstly may I recommend Tuffsaws, brilliant blades > https://www.tuffsaws.co.uk/

Secondly I have a Kity 513, where you're also supposed to run the teeth off edge of the wheels. I was struggling to keep small blades on the wheels with the teeth hanging off. After speaking to Ian at Tuffsaws (another Kity owner) he didn't think it mattered where the blade was, if the blade was happy and tracking well in middle of wheel then so be it. I've followed that and not had any problems since.

 

[Tad-blody]

Thanks for the reply.

 

[Steve Maskery]

I think I've earned my stripes on the subject of bandsaws, and although I've asked several bandsaw manufacturers why they suggest hanging the teeth off the front of the wheel, not one of them has been able to tell me why.
It is the position of the blade on the wheel which governs now true to North the blade actually cuts. I've explained it using the analogy of a beer barrel before now.
Don't worry about where it sits, just get it to run True North.
If you are breaking blades, then either the welds are poor or they are being over-tensioned.

 

[Tad-blody]

Thanks for the input.

 

[Beau]

I had snapping blades early on with my Kity. I changed blades supplier to one who did thinner blades and the problems stopped. They were fatiguing due to the thick steel on the tight radius.

 

[Tad-blody]

Interesting, was yours a 612 also Beau?

 

[Beau]

Think it was the 613. Not especially small wheels but the supplier normally made blades for big industrial machines hence the overly heavy gauge steel blades.

 

[Tad-blody]

Thanks Beau the 612 takes a shorter blade than the 613 so still feasible.

 

[Engineertopi]

I use this old thread for my question about Kity 612 bandsaw. I have not been able to adjust my machine to cut straight without drifting. The machine drifts so much to the left that I have not been able to use the fence for the parallel cuts. Is it possible to adjust the machine to make straight cuts without drifting? I have tried various blade widths, blade alignments and blade tensions without breakthrough.

According to the manual, the saw blade should be aligned by that way that the teeths are aligned out of the wheel and only the blade body lies over the wheel. I have understood the blade body should be aligned to the centerline of the wheel only if the top of the wheel is slightly curved (not flat).

It feels difficult to align to blade with the flat wheels. The blade jumps off the wheel very easily if the blade is set by the manual and if the are any backward forces applied from the work piece to the blade.

Is there something possible wrong in my machine or should I plan to replace the original flat wheels with the curved ones?