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Crescent Machine Co. Bandsaw (Patent 1905) Advice

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  • Crescent Machine Co. Bandsaw (Patent 1905) Advice

    Hi, I am eyeing off an old bandsaw (I think it's about 32") and have thrown a few queries to Matty (L.S. Barker1970) but thought I would stop pestering him and share my questions here in the event it may help others. The saw is about 350klms from me so to daylte I have relied on pictures and a multitude of questions to the owner.

    Q1. From the pics I have been provided it looks like at the very least it'll need new vulcanized rubber on the idler and drive wheel. Through a query a year or two ago someone mentioned a place in Goodna (Brisbane) that charged about $250, but can't find the info anywhere. Does anyone know where I may be able to get the wheels re-done in Brisbane?

    Q2. I am told it was working fine last time it was used but has just been sitting in a shed for a while (it belonged to an ex-boat builder). With that said, I may need to repour the babbitt bearings, I did a quick Google and there doesn't seem to be a shortage of people in Australia who can supply the lead based babbitt metal. But who in Brisbane could someone recommend?

    Q3. The motor on the saw is a Crompton Parkinson 2.75HP Three Phase motor. On the motor plate it has 940RPM. This sounds pretty slow? I would be replacing the motor with a Single Phase 3HP motor (Cheaper than a VFD) which looks very straight forward given the foot mounting assembly. What RPM would I seek in a motor as a replacement? I have read anything from 1400RPM to over 3000RPM!
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  • #2

    Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

    We like pictures if you have any!
    1. Is it a flat belt pulley that drives it fromm the motor?
    2. Lots of help here with babbitt and can be a interesting , challenging and fun job to repair babbitt bearings. There are shims in most babbitt bearings that are meant to be adjusted so may not need replaced but some general care.
    3.Not sure what your standard single phase motor rpm would be to keep the cost down. Here it is 1725 rpm. May need to calculate the bandsaw rpm and change the motor pulley size to get the saw running the same rpm with the new motor. If you Google pulley calculator to can figure out the rpm exisiting and what pulley you need when to do the calculation with the new motor rpm. Its easy , if you know 3 of the 4 items to calculate . EG Motor rpm, The pulley on the motor, and the driven pulley size will give you the rpm of the machine.
    Don't forget we like pictures!


    • #3

      Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

      i have a 1915(approx) crescent 20, us made, i assume its the same manufacturer!

      i did enquire about new babbitt but that was 5 years ago and i never did have it done! everything seems fine. the machinist i spoke to, does babbitt quite regularly, he fills the entire cavity them bores the hole for the shaft

      my saw doesnt have tires, there is a machined lip on the rim for tooth clearance. i've been using it like that for 5 years, no problems
      my shop is a beaver lodge
      steve, sarnia, ont

      1940's Craftmaster Lathe


      • #4

        Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

        Thanks chaps. See pics attached. I am fairly sure it's identical to: but might be the 32" version.

        - I think it may have had a conversion at some point regarding the pulley (see pics) and is driven by 2 x V-belts.
        - I found the people today I was looking for regarding vulcanized rubber services. They are called Queensland Rollers & Liners (Cobalt Street, Carole Park QLD) over near my part of the world and advised me that it would cost between AUD$265 - AUD$300 ex GST. There are blue or orange polyurathan options but think from America only which with postage may end up nudging the price up.
        - 1725rpm looks to be a 3 Phase motor speed. I've got the choice out of 4 Pole (1400rpm) or 2 Pole (2800rpm) both 50Hz for a Single Phase motor. OR I get a VFD and I make use of it being variable speed and can add in soft start, etc. Once I pick it up I'll look at doing the RPM calculator.


        • #5

          Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

          1725rpm isn't just a speed for 3 phase motors, it's the speed of a 4 pole motor on 60hz. The motor thats on it now must be a 6 pole motor, which is 1000 rpm on 50hz.

          If the motor is in good shape, it might be easier to go vfd to get the machine running at the proper speed opposed to messing with pulleys. Might be expensive though if you need a transformer for the voltage? Good luck!


          • #6

            Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

            Yes Jason is right, as we had a 6 pole motor, 380 Volt, 3Phase, 50 cycle, motor on a mechanical metal cutting hacksaw, it ran about 900 rpm as I remember (yes long time ago in The Netherlands) the 6 pole was used to have aa slow enough speed on the saw without having to go with a jackshaft.

            The 4 pole motors run 1440 rpm on 50 cycle net and the 2 pole motors run 2880 rpm, HTH.

            Have fun and take care
            Leo Van Der Loo


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            • #7

              Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

              Thanks guys, perhaps I re-visit the VFD idea. A VFD is about $50 more expensive than a motor replacement BUT am keen on gentle startup. Is it purely just two variables you need to set:
              • KW
              • Full load current
              I found these guys here in Australia;


              • #8

                Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

                The VFD would be very good as the motor setup looks great! Keep us Informed!


                • #9

                  Re: Crescent Machine Co. Bandsaw (Patent 1905) Advice

                  Motor speed isn't related to whether your motor is single phase or thrree-phase. It's related to Hertz (Hz), also known as cycles, which is the frequency of the "alternating" in Alternating Current (AC).

                  Originally posted by Leo Van Der Loo View Post
                  ...The 4 pole motors run 1440 rpm on 50 cycle net and the 2 pole motors run 2880 rpm, HTH.
                  As Leo says, on our 50hz system a two pole motor runs at ~2880rpm; and a 4 pole motor runs at ~1440rpm. A six pole motor runs at ~960 rpm - and cop a load of this motor that drives my 30" bandsaw...

                  Click image for larger version  Name:	Pres12.jpg Views:	0 Size:	1.08 MB ID:	1267653

                  Click image for larger version  Name:	Pres13.jpg Views:	0 Size:	1.34 MB ID:	1267654

                  Click image for larger version  Name:	Pres11.jpg Views:	0 Size:	1.52 MB ID:	1267655

                  ...yup, that's 480 rpm, which I believe makes it a 12 pole motor. As this is a direct driven bandsaw, it needs the low rpm.

                  In Canada and USA they have a 60hz system, so all their motors run 20% faster.

                  What a VFD does (among other things) is vary the Hz, which varies the speed the motor runs.

                  One source of VFDs is Jack Forsberg. He imports VFDs direct from China, and knows the requirements of old woodworking machines. He's reputed to be very helpful with setting them up (I don't know - the one I bought from him two years ago is still sitting on a shelf in my workshop, waiting for me to finish the machine I bought it for ).

                  Cheers, Vann.
                  Last edited by J Vann; 01-24-2020, 02:15 AM. Reason: Typo corrected.
                  Proud member of the Wadkin Blockhead Club.