Bandsaw Issues

[gary wParticipant @garyw]

I wonder if anyone can help give me some advice. The blade in my horizontal bandsaw keeps coming off the internal 'wheels' whilst its cutting through the last few mm's of a cut. I have tried to take the pressure off the blade by holding the saw body up but it still pops off annoyingly which then requires me to remove the thumbwheel, open the cover, slacken the tension wheel, slide the blade back on the guide wheels and then re-tension etc. The blade is fairly new and its not tensioned too tightly when I re-fit it. So any suggestions would be welcome as I am getting pretty fed up with having to re-fit the blade for what appears to be a pretty straight forward cut.

[gary wParticipant @garyw]

Bandsaw blade keeps coming off

[john fletcher 1Participant @johnfletcher1]

There is an ALLEN screw in the hub (axle) on the wheel nearest you when operating the saw. This screw needs adjustment to alter the tracking on that wheel, then every thing should be OK. I have the details some where but I've put it safe and can't find it. I seem to remember that you have to slacken the large nut which is in the centre, then tweak the ALLEN screw which is on the inside just a little bit. I'll get back to you later today.Ted

[gary wParticipant @garyw]

OK, many thanks for giving me an idea what is causing it. Its strange really, as it cuts fine until its about to finish the cut then it pops off. I will look for the tracking adjustment after work tonight.

[Neil WyattModerator @neilwyatt]

Hello Gary,

> fine until its about to finish the cut then it pops off.

One cause of this is over-supporting the bit being cut off. As the bit holding it on gets thin, the off-cut lifts of its support and pinches the blade, causing it to be thrown. Cures – don't support the outside part of the material, or make sure any support is flat. I have added a (easily removable) short piece of 2" angle to provide a support table dead level with the base of the vice.

If that isn't the cause, try the tracking. I upset the tracking on mine recently, and it can take a fair bit of fiddling to get the tracking right.

> The blade is fairly new and its not tensioned too tightly when I re-fit it.

This could be also an issue – let's say it's hard to over-tighten a bandsaw blade.

Neil

[Ian S CParticipant @iansc]

The blade requires to be tightened quite tight, The instruction book that came with my 4 1/2" saw said tighten until a musical note when band plucked (did not say which note). As said above, there is adjustment on the front wheel, but I found that the two plates that guide the wheel when tightening were very loose, 4 mm plates in 5 mm slots, replacing those helped no end. Ian S C

[Howard LewisParticipant @howardlewis46836]

It might be worth checking that both pulleys have minimal or no end float, or runout.

My Warco Bandsaw sent the very thin steel tube bearing spacer through the bottom ball race and oil seal.

As part of the new bearings/oil seal exercise, the spacer was replaced by an accurately made, thick, brass spacer, the pulleys skimmed to run true, and then the blade was tensioned (Roger Warren advised "as tight as possible&quot. The tracking was then set so that the back of the blade just touched the flange of the idler pulley.

As long as the feed is not too heavy, it will cut discs about 1/16 inch (1.5mm) thick from round BMS bar.

Forcing the feed, causes the blade to run off in a curve as the cut progresses.

Somewhere I saw an article on replacing the plain bearing in the idler pulley with ball races.

Am tempted to do this to improve the location of the Idler.

Has anyone else made this mod? If so, how did you get on?

Howard

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