Replies

1. 
   JohnWW | Sep 02, 2009 06:24pm | #1

   On most modern band saws the tires aren't glued on and the tires are made out of synthetic rubber called urethane.

   John White
   Shop Manager for FWW Magazine, 1998-2007

2. 
   PeteBradley | Sep 03, 2009 03:39am | #2

   I'm not sure all of the "problems" you're seeing are really problems. John started to separate the wheat from the chaff, and I'll continue. Forget how long your lower wheel spins. It's a new machine with new bearings, they're good for a few years no matter what they are.

   Now you have a motor that sits still when running on a board, but you can feel vibration when you touch certain parts of it. Not as good as some, but entirely acceptable for a band saw.

   It sounds like you were running ok on 120, if so there's no need to change to 240. The only way I can think of that you could get more vibration from rewiring alone would be to mess up the start circuit somehow.

   Now you may still have too much vibration. My top suspects would be:
   1. Bad or improperly tightened belt. Try swapping in an AX belt and watch it run. If the free parts are blurry, tighten or loosen until they aren't. Good quality AX belts are available from McMaster and other machienry suppliers, don't buy the lumpy hardware store belts.
   2. Bad pulley, particularly the motor side. Try running the motor with and without the pulley.

   Good luck!

1. 
   Don01 | Sep 04, 2009 07:10pm | #3

   Pete, "Now you have a motor that sits still when running on a board, but you can feel vibration when you touch certain parts of it. Not as good as some, but entirely acceptable for a band saw."I would argue that a new motor, like new bearings, does not vibrate. It will certainly hum, but any vibration is not acceptable especially when not under any load. Pulleys, blades, belts can be out of balance but the driver itself must run true.We need OKAHUN to clarify vibration, and to report on his no load operation once the 120V conversion is done.Don

1. 
   PeteBradley | Sep 05, 2009 04:34am | #5

   Put any motor on a balance machine and you'll find it vibrates. The only question is how much. The OP can only detect vibration by putting his hand on the motor. Probably not as good as some, but it wouldn't be anywhere near my top suspects to cause meaningful vibration on a band saw. On the other hand, the vibration of an improperly tightened belt will be noticeable on my 700lb old iron band saw.

   Edited 9/4/2009 9:35 pm ET by PeteBradley

1. 
   Don01 | Sep 05, 2009 07:22am | #6

   I guess we are in opposition.
   When most who operate powered machinery detect vibration it is in response to an abnormal condition. User observable vibration is plain not acceptable to any of us whether it is in the belts, the blade. Even putting a hook & loop disk on a ROS slightly off will introduce noticeable and sometimes quite unacceptable vibration into a tool that is suppose to vibrate.
   The vibrations the OP has reported are significant and fall far outside your "Not as good as some, but entirely acceptable for a band saw." assessment.
   I am assuming that you have followed the full story which started July 25. In the recent post dated Sept 2, the magnitude of the vibration does not appear to be as significant as in the past, thus my request for clarification.Don

1. 
   PeteBradley | Sep 05, 2009 04:40pm | #7

   Read my past posts and you'll find I don't do web forum "opposition", and that I've been rebuilding vintage woodworking machines for some time. As you point out, characterizing the vibration (is it vibration or hum?) is important, but the fact that it's not noticeable without touching the motor and the fact that he's on his second motor suggests it's minor. I might not like that motor, but the odds of that being the cause of major vibration at the machine are lower than other possibilities. More information will help.

2. 
   okahun | Sep 05, 2009 06:37pm | #8

   Hi everyone sorry it took so long to get back. Let me clarify a few things. This motor was my second one from Steel City and it was never run at 120v. I got the motor out (my son actually) and changed voltage to 120v it had the same vibration as at 240v. The vibration is not a hum but I feel my fingers move when placed at it's worst point on the motor between the start and run capacitors. As to belt tension I've set it from loose to tight and no change. SC recommends 1 inch deflection at midpoint. I've set it under, at and over their recommendation. I don't remember who brought up I don't need to check the bearings because their new, I learned a long time ago NEVER #### U ME anything. I've discovered that I need to shim the upper wheel out about .005" to be coplanar with a 1/2" blade at tension. I use an Iturra gauge and set the tension at approximately 14000 psi, I replaced the stock spring with his also. In addition I have to shim at the inside of the column to line up my guides. In a vertical plane the upper wheel at it's tire edge would be out of plumb leaning to the right. I've checked both pulleys they seem to be okay. Last year when I installed this motor the Bandsaw was so smooth that I thought this is one great tool. I'll realign everything so it's better than when it came from the factory. If realigning solves my problem I'll be a happy camper. If I still have problems and SC won't help, I'll buy my own motor, a good one, and life will go on. The only difference will be I'll never buy another SC product. Thanks again to everyone for helping and I'll keep you posted.
   okahun

1. 
   okahun | Sep 06, 2009 01:01pm | #11

   I don't recall if I mentioned this earlier but after I took the belt off and ran the motor still had the same vibration. The motor was hanging from the swing mount against the cabinet side and transferring the vibration the same as if the blade was turning with the belt on. The whole cabinet shook enough that you felt it on the table. I tried clamping the motor away from the cabinet side still felt the same vibration, must have been through the pivot point and clamp. I'm going to try and engineer something where I can isolate the motor from the saw and the only connection would be the belt. I think the belt would absorb most of the vibration. I can use this motor till it quits. Anybody know if I'm on the right track?
   okahun

1. 
   PeteBradley | Sep 06, 2009 03:55pm | #12

   Did you do this experiment with the pulley off? I'm just wondering if your pulley is out of balance. It's interesting though that you say the motor started out smooth. One possibility that was so remote I didn't even want to mention it was that SC got a run of motors with bad bearings which fail quickly. A related explanation is if you whacked the shaft and damaged them (e.g. dropped it, excessive mallet usage, etc) though you'd know that. A bad motor bearing would also be the best explanation for the "howl" from the first motor. It's a long shot, but you should try turning the motor by hand with no belt to check for smoothness, and also check for excessive heating after it's run.

2. 
   okahun | Sep 06, 2009 07:31pm | #14

   It ran with the pulley on and off, no difference. The pulley slides on the shaft so no mallet use there and didn't drop it either. It howled twice when I turned it on without the belt, hanging from it's mount. And that was back in July I think. Since then no howl. I tried rotating the motor by hand and it's smooth except for a consistent ticking, which is very faint. SC told me why it ticks but I don't remember the explanation. With the first motor I remember being on the phone with the tech guy and after I pulled it out he had me spin it by hand, with the same ticking back then. What do you think of my idea to isolate the motor from the cabinet.
   okahun

3. 
   JerryPacMan | Sep 06, 2009 04:29pm | #13

   What state are you located in?  It looks like an interesting problem and I would look at it for a beer and repair it for a 6 pack.  If you have an IR thermometer check the motor end caps after running 5 or 10 minutes.  A bad bearing should be easy to determine.

    

   Life is what happens to you when you're making other plans.

   When your ship comes in... make sure you are not at the airport.

   Edited 9/6/2009 10:27 am ET by JerryPacMan

4. 
   okahun | Sep 06, 2009 07:32pm | #15

   I live outside of Chicago, IL.

5. 
   okahun | Sep 06, 2009 07:36pm | #16

   I forgot to mention I ran the motor solo for 20 minutes and it was hot when I touched it.
   okahun

6. 
   JerryPacMan | Sep 06, 2009 07:56pm | #17

   It is too far for me to travel for a beer or six.  Did you touch just the end plates and if you did was one end hotter than the other?  The hotter end would indicate a possible bad bearing. 

   Life is what happens to you when you're making other plans.

   When your ship comes in... make sure you are not at the airport.

7. 
   okahun | Sep 06, 2009 08:40pm | #18

   I think I touched the side. I have an instant read cooking thermometer and I can run the motor again for twenty minute and touch each end with the probe. It's a good idea thanks.
   okahun

8. 
   okahun | Sep 06, 2009 09:20pm | #19

   Just ran the motor for a little over 20 minutes. Tested the temp on the side it read 116 degrees, the end with the pulley 102, on the side between the capacitors it was 112. I give up, I'll finish setting up the saw, hook up the motor and use it until it pucks. But I will isolate it and that should remove the vibration from the equation.
   okahun

9. 
   PeteBradley | Sep 07, 2009 05:14am | #20

   Modern motors get hot. In the old days they couldn't get a HP or more out of a 56 frame. Your temps sound ok. The ticking is almost certainly the centrifugal switch, which energizes the start windings until the motor spins up.I've had some luck with rubber washers to help isolate motor noise and they might eat up some vibration too. You need them under the motor base and under the mounting bolt heads so there's no "hard" connection to the machine. I agree it's time to set it up and run it.

10. 
    SARGEgrinder47 | Sep 07, 2009 04:42pm | #21

     

    "I've had some luck with rubber washers to help isolate motor noise and they might eat up some vibration too. You need them under the motor base and under the mounting bolt heads so there's no "hard" connection to the machine.

    I agree it's time to set it up and run it".... Pete B.

    Agree in both cases. I do believe you will find a rubber cushioned motor mount on automobile engines and for a reason. You have to use all steel mounts on race cars as the enormous HP will torque bonded rubber off of the steel base it's applied too. But... if I have to take a stock motor off a WW machine for any reason.. I will drop a rubber washer back on the bolt to separate metal to metal.

    Regards...Sarge..

    Woodworkers' Guild of Georgia

2. 
   okahun | Sep 05, 2009 06:39pm | #9

   What is an AX belt, brand name or type?
   okahun

1. 
   PeteBradley | Sep 05, 2009 09:03pm | #10

   AX is the designation for a cogged machine belt. They're designed to go around small pulleys more easily than a solid belt, but they have the side effect of being more limber and in some cases, less prone to vibration.Just a reminder that the length of belt designations can be confusing. A 4L300 belt has a 30" outside circle, but to get an A or AX belt with a 30" outside circle, you have to order AX28. Best to measure your outside circle and match that up rather than go by the number.Pete

3. 
   Don01 | Sep 04, 2009 07:44pm | #4

   OKAHUN,
   Can you put clarity around this vibration?
   The motor will hum. Vibration to me suggests that something is out of balance or otherwise causes the motor to shake.
   The vibration you refer to when the motor is out of the frame running freely. Is it comparable to what you experienced when the motor was mounted in the saw? According to your original diagnosis, this saw was shaking enough to loosen the blade tensioning handle.
   If this is at that magnitude then you probably have a bent rotor. If the motor did not vibrate at 120, but does at 240, then is it at all possible that the shaft was damaged when you made the voltage change? I'm thinking that that motor was removed to do the voltage change only because I would have to do this with my saw.
   Lastly, I would suggest getting the motor over to a repair shop for an evaluation. Then you will know and perhaps that evaluation will help you deal with Steel City if the findings support a defective motor.
   Did you perhaps pay for the saw via credit card. If so, your card may have extended warranty coverage for up to 1 year from date of purchase. If the seller will not make good on the defect, they (the cc company) will cover the repair. A lot of people overlook this feature. Buy all of your tools on credit card.

   Don