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Crescent Machine Co. Bandsaw (Patent 1905) Advice

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Charlie_6ft

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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!
 

heimlaga

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Q1: The rubber is most likely not and does definitely not need to be vulcanized onto the wheel. When the local rubber shop in Vasa put new tyres on my bandsaw they vulcanized the ends of the rubber band toigether to form a continuous loop and then glued it onto the wheel. Ready made tyres for theese larger bandsaws are hard to find but any decent rubber shop can cut them from standard industrial rubber sheets. Unfortunately I am not local to your area so I cannot tell you where to go.

Q2: I have repoured babbit bearings and it isn't too difficult. You will get a better result if you have a slightly undersized mandrel made from a piece of steel shafting, let's say 0,3 mm underdiametre and then pour the babbitt around it and then scrape the bearings to fit. Unfortunately I am not local to your area and cannot recommend a supplyer.

Q3: It all depends on the size of the pulleys. If the belt drive is made for a 900 RPM you must put a significantly larger pulley onto the saw to maintain the same cutting speed when shifting to a faster running motor with the same size pulley on it as on the old motor. A 32 inch saw would certainly require an awkwardly large pulley if powered by a 3000 RPM motor. It is the cutting speed of the blade that matters and from that you calculate RPM f the drive shaft and from that you calculate the gearing
 

Charlie_6ft

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Thanks chaps,

Q1. 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.

Q2. Thanks for the babbit bearing advice. It may not be required BUT will find out in about 3 weeks when I pickup the saw.

Q3. 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'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. BUT regardless I'll get all the figures and then run it through an RPM calculator to figure out the speed.
 
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