Startrite 14-s-1 Bandsaw - Problems!!

[Perry]

My dear old startrite (running on single phase 240v) is starting to play up - it will run fine for 4 or 5 minutes & then stops. It will nor re-start unless I wait a few minutes.
I have heard it may be the danfoss overload switch, and after re-wiring the main connections this does make one hell of a buzzing noise whilst the motor is running! Before I only heard the buzz on startup.... It also hums very slightly when the machine is not running but connected to the mains.

I'm thinking about gambling & stumping up the £50 for a new switch but was wondering if there are any members who have had any experience with these units or could offer advice before I part with my hard earned wedge.

Thanks in advance

 

[9fingers]

Hi Perry,
I have an 18-s-1 (well actually 18-s-2 because I have added a second speed)

You need to diagnose the problem a bit before shelling out any cash.

The fault could be the NVR/overload relay or the motor.

First slip the belt off. The motor should spin freely by hand and continue spinning for a while. there will be a slight rubbing noise from the centrifugal switch.

With the belt off the driven pulley should turn smoothly but with a bit of effort.

Put the belt on and run the saw under power till it cuts out. Disconnect the power. Is the motor hot to the touch or gently warm? Too hot to touch is bad.

If the motor is cool/warm then I would suspect the overload relay.

One thing that concerns me is that you says the relay buzzes even when the motor is off. Unless the NVR is separate from the on off switch (unusual) then this should not be happening. When the motor is off then no current should be drawn and so no reason for any noise what so ever.

Do you have any way measuring motor current?

hth
Bob

 

[Perry]

Thanks for the reply Bob,

I checked the motor & pulley and they spin as you mentioned, and since the re-wire I haven't experienced to motor stopping (although it has had only very light use) - I did run it for about 20 minutes & checked the motor which was just warm to the touch. I also put the dial on the overload unit to max after talking to someone at A.L.T saws & spares, so maybe this has had an effect, but I'm keeping my fingers crossed until I have given the saw a thorough workout!

The 'standby' buzzing is still present but it really is very gentle, sort of like the hum you can hear from a fluorescent light or an old amp which has been left on a while. I am disconnecting the machine when I leave the workshop as a precaution though.

Perry