Denford Cyclone, Loud buzzing Noise

Hi all,

My Denford Cyclone Lathe has started making a loud buzzing noise. Opened up the cabinet but cant quite identify where it is coming from...'

Does anyone recognise the noise?

https://youtu.be/BHNFS_2o02M

while I have not worked on a denford machine I have to ask

what motors are running ?

since the spindle and axis drives are stopped

I guess you have a coolant pump and either hydraulic or pneumatic compressor running ?

switch them all off and if the noise stops
then turn one on at a time to find which is making the noise

John

You have tried opening the electrical cabinet and having a listen?

Videos aren't that good at helping identify sounds, but it sounds like either a motor rattling (cabinet cooling fan?) or a relay chattering.

No noise coming from the electrical cabinet so don't think it is a contactor or relay. I took the side cover off and the noise seems to be coming from the spindle motor. Running the spindle doesn't affect the sound at all which seems strange, I think I am going to have to take the internal sliding covers off to have a closer look at the motor.

Could be the cooling fan for the spindle motor.
If it's similar to mine (mine was a denford controller version), the spindle motor will have a forced cooling fan fitted, which I think runs whenever the machine is powered up and no e-stop/limit triggered.
And having just checked the wiring diagrams I've got, it is controlled by the main MDC contactor (I can't find the diagram, but I'm pretty sure that's powered via the E-stop relay), and has it's own dedicated circuit breaker labelled SMF. Flipping the SMF to off will soon tell you if that's the problem.

Couldn't find that breaker in mine, don't suppose you could send me the wiring diagram that you have could you?

Think it is definitely the fan though, I can feel it vibrating when put my hand on it.

Attachment 22664

I wonder if the fan's fed from somewhere else on yours.

Fanuc OTA diagrams can be found at http://denfordata.com/bb/viewtopic.php?f=15&t=2337
However, I just looked at this set - http://denfordata.com/bb/viewtopic.php?f=15&t=2508 and the spindle fan is single phase powered via Fuse 4. However those machines appear to have 3 phase + Neutral input, whereas the older ones were only pure 3 phase. Do you know what power input your machine has?

I have the 3 phases and the neutral on mine, removing F4 fuse didn't stop the fan. But removing the F2 fuse did though. Now just got to find the time to remove those internal sliding cover/panels to see whats going on.

Thanks for your help so far.

Found the culprit, it is this spindle cooling fan, no obstruction and it only makes the noise at high rpm. Are these serviceable or do i need to buy a new one?

Attachment 22680

Attachment 22681

Searching the model, turns up the original on RS - http://uk.rs-online.com/web/p/axial-fans/2584718/ but it's discontinued, and they list this - http://uk.rs-online.com/web/p/axial-fans/6196860/ as a replacement.

Might be best to double check measurements though.

I bought the replacement that RS suggested, slight mismatch on the PCD so I opened up the holes on the metal ring that interfaces the fan and spindle motor, wired it up now no annoying loud noise. Thanks for helping me diagnose this problem.

a great result