New Kity 613 Owner, needing advise

[k4kris]

Hi all, I am a bandsaw Newbie, and have just purchased a secondhand Kity 613. It seems in pretty good shape though it was set up badly when I got it. I have replaced the worn guides with some sapele, aligned the table, and given it a general clean. However I am having real trouble with the tension and alignment, I have fitted a new 1/4" blade, but whenever I try to tension it, it jumps off of the wheel. I can get it to run on a slightly slack tension, and align it, but as soon as I try to tighten it, it jumps. I am aware of running it on the edge of the wheel.But I notice that if the teeth are aligned with the edge (1/3rd over hanging) of the top wheel, then the blade is almost hanging off of the bottom wheel, I am just not sure of the sequence to tighten, should I tension the blade, and then try to align it?
I also notice that the motor doesn't freewheel, is there brake on the motor or is it binding?

Any help is much appreciated.

 

[Paul Hannaby]

I used to have one of these and I found the blade position was a result of both tracking and tension. It sounds like you need to reduce the tension slightly to get the blade tracking on the bottom wheel correctly. With mine, once it was set up, when changing blades I used to leave the tracking alone and just wind up the tension until the blade was running on the edge of both wheels.

 

[k4kris]

Thanks Paul, do you have a way of knowing when the tension is about right on these, as I feel I may have messed with the alignment adjuster too much, so need to start from scratch. Some people seem to see "As tight as it will go" but as you say, thi results in the blade coming off the wheel, but it seems a fine line between not tight enough and too tight. Any tips greatly appreciated.

Kris

 

[xraymtb]

With mine recently I found I was using too much tension also. Simplest test I have found was to raise the guides as high as they will go then push the blade sideways above the table - looking for a deflection of between 1/4" and 1/2" without too much pressure (i.e. push hard but not so hard your finger turns white). Once I got that right, I was able to adjust the tracking correctly.

Another point I noted, unlike a crowned wheel, when I adjusted the tracking the blade tended to not react then very suddenly run away off the wheel so you need very fine adjustments on the tracking and with mine I sometimes had to use my finger to guide the blade towards the rear of the wheel a bit when I overcorrected to stop it coming off with a bang and having to start over again.

 

[Paul Hannaby]

If the blade is running too far off the bottom wheel, reduce the tension until the blade overhang is the same on both wheels. It's that simple!