Breaking bandsaw blades

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Breaking bandsaw blades

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  • #439863
    Oxymoron
    Participant
      @oxymoron

      I seem to be breaking bandsaw blades too frequently and wondering why.

      I've got an Axminster engineering series band saw. Using axcalber blades. 1440mm x 1/2" 10TPI. Blades seem to break along the welded join long before the blade becomes blunt. Generally the saw starts to 'jump' when the join passes over the cut metal and if I look at the join it shows a crack starting to form. Shortly after it will break. Its hard to guess how long I've used a blade, maybe an hour total time.

      I wonder if I'm doing something wrong. I tend not to release the tension when its not being used, is that bad practice? Should I be using a different manufacturer? any ideas please?

      This is the blade that broke this afternoon.

      unadjustednonraw_thumb_4604.jpg

      Thanks

      Dave

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      #26987
      Oxymoron
      Participant
        @oxymoron
        #439868
        jimmy b
        Participant
          @jimmyb

          I can't help with any advise, other than to say I leave my bandsaw tensioned all the time, with no ill effects.

          Jim

          #439869
          Emgee
          Participant
            @emgee

            Try a different make and type of blade, I had the same problem before changing supplier.
            Like Jim I leave my blade tensioned.

            Emgee

            #439870
            Oxymoron
            Participant
              @oxymoron

              Thanks guys, interesting re leaving blade tensioned, so that's probably not what I'm doing wrong.

              Dave

              #439872
              Douglas Johnston
              Participant
                @douglasjohnston98463

                Don't throw the blade away, you can silver solder it back together again. Plenty advice on youtube. I have also noticed the jumping as a blade is about to break and wonder if badly adjusted guides may cause this.

                Doug

                #439874
                Clive Foster
                Participant
                  @clivefoster55965

                  Something very wrong going on there. A professionally made blade shouldn't break at the join like that until its very old and well past its use by date.

                  I've had them go in a similar manner, including the jump, when I've cocked up the joining using the welder on my Startrite saw but that was pure operator error. Either poor welding technique or not getting the blade straight so there is a step on the back at the join. I rarely have problems when making the 112" blades for my Startrite vertical saw but my old Alpine horizonta/ / vertical is much more demanding.

                  Best guess is that the blade tracking is well out with the balde not sitting properly back against the rear bearing and / or not properly held parallel between the the side bearings.

                  The common small horizontal / vertical bandsaws are notoriously hard on the blades due to the small wheels, short wheel centres and rapid twist betwixt wheel and guide. Being made to sell at an economic price the various alignments and adjustment arrangements are not as well controlled as one would ideally like.

                  Best to make sure that the blade is sitting true on the rear roller and properly held between the side rollers with minimal tension applied. Then make sure that the blade is tracking ture on the main wheels without touching any flanges. (The drive on my big Startrite can be disconnected allowing the wheels to be spun by hand which makes life much easier. No flanges on the wheels either but setting up from scratch isn't trivial.) Once the balde is running true in its natural position you can then carefully crank the tension up re-adjusting as needed to keep the blade running free.

                  Being one of the early imports my Alpine moved all over the place as tension was applied. I had to run it with the cover open to see what was going on.

                  Clive

                  #439878
                  T.B
                  Participant
                    @t-b-2

                    I too had the same problem and was getting frustrated enough that i was considering buying a new bandsaw as i was getting through blades at an alarming rate

                    In the end i found these people online **LINK** and after a quick phone conversation they recommended i try one of their M42 series bi-metal blades and to be honest i've not looked back since.

                    Usual disclaimer : i have no connection with the above company , just a satisfied customer !

                    #439879
                    Mike Poole
                    Participant
                      @mikepoole82104

                      The blade welder on the workshop bandsaw had an annealing operation after welding, perhaps this was not done or cooled too quickly and hardened again. Might be worth annealing the joint if it has been butt welded, a pencil flame torch should manage it without affecting too much of the blade.

                      Mike

                      #439880
                      Oxymoron
                      Participant
                        @oxymoron

                        Douglas, thanks for the silver soldering tip. I'll fish the blade back out of the bin! I'll try silver soldering it as you suggest.

                        Clive, some things for me to check on the tracking. I'll take a good look at that tomorrow. I have a vertical wood cutting band saw. 88 1/2" blade and I've never had any problems with that but the wheels are bigger diameter and the blade is not being tested through the guides to turn the blade vertically.

                        I've got a couple of spare blades but if anyone could recommend a different supplier that would be great for my next purchase.

                        Dave

                        #439881
                        clogs
                        Participant
                          @clogs

                          I have a 12inch SIP band saw (14 years old) and until I found TUFFSAWS I used the original manuf….

                          same result as u but I did get a mile or two of cutting heavy mild steel….mostly 50 mm dia n 10mm plate….

                          i now use Teff saw Cobalt loaded blades never a prob ever…tensioned all the time….and similar money, even by Machine mart prices…

                          blurb say's can be used without coolant but I still use it….don’t like the mess but when I run out of the milk goop gonna go straight to hydraulic oil only….plus all my lathes n mills will get the same treatment….

                          as for ur prob blades I'd be sending em back for repair or replacement…..

                          it wont be tracking that’s causing this problem…they are flexible…..more likely to be from a bad batch….

                          try another supplier or TuffSaw….

                          wouldn't bother tryin to fix em…just not worth the trouble …..

                          never buy cheap brands off ebay. They work to hard …..

                          good luck…

                          just to add a very happy customer of TSaw…..

                          #439882
                          Oxymoron
                          Participant
                            @oxymoron

                            Just what I needed, thanks T.B.

                            Mike, annealing is an interesting idea. Might give that a try. Cheers

                            #439883
                            nigel jones 5
                            Participant
                              @nigeljones5

                              Chap who makes blades once told me, if it breaks on the weld then its a badly made blade – avoid! Ive been down the braze them back together but unless your desperate its just not worth the effort. I used the cheap Silverline ones off ebay with varying success. Then I bought one from a local shop….had it years…its a lot thicker than my previous ones and the box said Cobalt tipped (anyone know how this is even possible?). Anyway, vutting up to 1/4" brass and copper with only SIX tpi I ddnt expect it to hold out for long – best blade I ever used by a mile. Still using it! Even kept box somewhere so I gan try to source another.

                              #439884
                              Nigel McBurney 1
                              Participant
                                @nigelmcburney1

                                I have "Do All " type bandsaw made in uk under licence by Alexanders, it has a built in butt welder,with a follow up anneal. I have found that if i am a bit too quick with the annealing the weld will break,changing supplier may be the answer.

                                #439885
                                Oxymoron
                                Participant
                                  @oxymoron

                                  Thanks Clogs, will check out TSaw.

                                  #439887
                                  Oxymoron
                                  Participant
                                    @oxymoron

                                    Thank you to everyone, some things to check on my saw and some ideas on different suppliers.

                                    #439893
                                    Ex contributor
                                    Participant
                                      @mgnbuk

                                      Send it back.

                                      Our supplier at work (KR Saws) have a lifetime warranty on their welds – if a blade breaks at the weld at any time, the cost of the blade is credited to our account. On the very infrequent occasions that a blade has broken on the weld, I sent a picture to the rep who then called in & picked up the broken blade when he was next passing.

                                      If no one contacts a supplier to inform them that they have a QC issue, they will just keep on sending out defective products.

                                      Nigel B

                                      #439896
                                      Ray Lyons
                                      Participant
                                        @raylyons29267

                                        I have been making my own blades for years to fit a 6"x4" horizontal bandsaw. Going back a bit now but I bought my silver solder from Wiston, it looks like a thick fuse wire. I use a small pencil blow torch for heating and after repair and cleaning up, the joint is annealed to remove the stresses.

                                        #439898
                                        Dalboy
                                        Participant
                                          @dalboy
                                          Posted by T.B on 02/12/2019 18:24:17:

                                          I too had the same problem and was getting frustrated enough that i was considering buying a new bandsaw as i was getting through blades at an alarming rate

                                          In the end i found these people online **LINK** and after a quick phone conversation they recommended i try one of their M42 series bi-metal blades and to be honest i've not looked back since.

                                          Usual disclaimer : i have no connection with the above company , just a satisfied customer !

                                          I also use them and if unsure about the best one for an application then a quick call and Ian will give great advice. Sometimes he may not answer the phone straight away as he may have machines running while making blades.

                                          I am a very satisfied customer

                                          #439900
                                          Oily Rag
                                          Participant
                                            @oilyrag

                                            Looks like numerous others have pointed out, poor quality welding. I have a Chincom cheapo bandsaw which uses 1/2" x 0.025" x 64 1/2" blades. The originals supplied with the mahine (3 with various tpi's) lasted about halfway through their first cuts! Since then I have only ever used Starrett bi metal M42 vari-tooth blades – never had a problem with these, track well, cut well, and last an amazing time! Only time they ever struggled was when I had some copper berylium stock to cut – but then anything struggles to cut that stuff!

                                            Cost was about £15 per blade from J&L (now MSC) in Wednesbury about 10 years ago, worth every penny.

                                            #439906
                                            Brian Wood
                                            Participant
                                              @brianwood45127

                                              Oxymoron,

                                              I haven't seen anyone blame other than poor welding but there are other reasons for frequent blade breakage as I know to my cost and those were professional blades as well..

                                              I recommend you test the guide alignment/wheel alignment. My guides were both very bad, simply cast surfaces clamped together.

                                              The method is easy with a stretched wire round the blade wheels and through the guides, it will show those faults as in no other way. When I had put my guides right, blade breakage stopped as if a tap had been turned off.

                                              Regards Brian

                                              #439909
                                              Dalboy
                                              Participant
                                                @dalboy

                                                This is a vertical bandsaw mainly for woodworking but the setup applies to many bandsaws worth watching.

                                                #440000
                                                larry phelan 1
                                                Participant
                                                  @larryphelan1

                                                  Could it be that the blade is too course for the job ?

                                                  The standard or common pitch for these saws over here seems to be 14tpi and this works well on my Chinese cheapy.

                                                  I find that Bi Metal blades perform much better for the extra cost. And yes, I keep the blade tensioned all the time.

                                                  #440002
                                                  IRT
                                                  Participant
                                                    @irt

                                                    I seem to remember hearing somewhere that the biggest cause of breaking blades was over-tensioning them.

                                                    #440009
                                                    Clive Foster
                                                    Participant
                                                      @clivefoster55965

                                                      Ians comment about over tensioning reminds me that my old style, UK built, 14" throat Startrite vertical bandsaw requires a noticeably lower tension on 1/2" blades than the Alpine 6" capacity horizontal / vertical saw. The Startrite uses a spring to apply tension via a big knob on a screw with a nifty viewing window showing the size of blade that tension is appropriate for. Much nicer than the "heave it up and hope" system used on the Alpine.

                                                      Was told that the small horizontal vertical saws had to have the blade over-tensioned to work correctly due to the combination of small, relatively closely spaced wheels and savage twist between wheel and guide. Allegedly you want wheel diameters approaching 30 times blade size on centre spacing approaching 45 to 50 times blade size if a smallish two wheel saw its to work really well. I imagine it all gets easier once you have enough wheel size and spacing so larger saws have different rules.

                                                      Wish I'd known about Brians wire trick 30 odd years back. Would have made setting mine up so much easier. As I recall matters the killer wit mine was one wheel twisting a bit when fully tensioned so the flange kicked the blade out of line as it came off the wheel. Which took a deal of sorting to generate appropriate clearances and blade support once I'd figured the problem.

                                                      Clive

                                                      Edited By Clive Foster on 03/12/2019 13:26:34

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