noisy mill motor

[stirlinglad]

The motor on my mill has done virtually nothing ever,, yet when i connect the belt and apply the slightest sideways tension it rattles like   
an old clockwork toy... is there any point in opening up the casing of the motor as i thought these brushless ones had no maintainable parts,,or am i wrong(again).. the motor is'nt yet a year old so should i try to contact SPG tools to see if they will help?
It really has done virtually nothing as the vibration made it practically unusable..I'm not very keen to open up the motor as elictrickery scares my witless   what do you guys and gals suggest i do? I'll be glad of any help and advice you can give...
ps its an sx2 clone i think, but ive heard it called an xj12 type too???

...Mike...

[Alan Haisley]

Are you sure it's the motor and not the spindle?
Could one or both pulleys be crooked?
Could a pulley be loose?
Is the belt free of any defects?
With the belt off, use something like polyethylene (Tupperware lid, etc.) to apply side pressure on the motor pulley and see what happens.
With the belt off and motor stopped, can you get any side to side or up and down wiggle out of either pulley?

Any other things anyone can think of that can be quick, cheap tests?

Alan

[stirlinglad]

Hi  Alan,
yep, tried that .  that was my process of elimination.. its only noisy when i put a slight pressure on the pulley on the bottom of the motor, with no pressure at all or even with the belt off its almost silent which is what makes it so annoying as it gives me an idea what it should be like

..M.

[b.lindsey]

Mike, if it is still under warranty I would contact the manufacturer or wherever you bought the mill. I can understand your frustration with the noise.

Bill

[stirlinglad]

 Hi Bill, yep I think thats the best course of action,,I'll try dropping them a line tomorrow...
I just tried it out on a very slim cut of a lathe tool holder,with the belt floppy,,absolutely no tension on it at all..and it worked ok.
it seems the v shape of  the belt and pulley cause enough grip to operate,,but i don,t yet know if it would still work on say, a thicker cut 
or would the belt slip ? i'll give it a little test tomorrow and see. but i think your right bill,,,send it back cos i've never heard a motor rattle like that before..but if i open it to have a look they'd probably deny any liability then. :thinking:but i'd love to see what is rattling about in there though

cheers
..mike..

[Stilldrillin]

Mike.

Have you checked if the pulley is slightly loose, on the motor shaft?   

My lathe pulley made a racket, way out of proportion to it's wobability factor! 

Perfectly quiet, now that it's grubscrewed and loctited.......... 

David D

[stirlinglad]

hi David,, i'll check that out this evening,, oh it would be great if it was something so simple...

..m..

[stirlinglad]

Well the motor pulley was solid,, but what was strange was that there was no rattling tonight at all?  I think i've got gremlins...   The other night it would'nt stop rattling unless I let it run totally free but tonight it's quiet even when i put some side load on it, on either top and bottom pulley's.. i'm going to let it run for a while today to see if it happens again after it's had a chance to get hot...All i wanted was a mill for occasional use,,if i knew it was going to be such a load of mince i'd never have touched it and just kept saving for a grown up's mill.... as i just don't have time for this nonsense,,ah well,, i've got it now so i'd better get on with it i suppose...

thanks for listening guys and sorry about the moan..

...Mike...

[Allen Smithee]

Two possibilities spring to mind - it may have been a dirty bearing which has now thrown the offending bit of crud from the track. But it could also be a loose magnet. Unlike conventional brushed DC motors, BLDC motors have fixed "coils" and rotating magnets. It's possible that one of the magents has become unglued, and is sometimes moving to a position where it snags on the rotor. Neither problem is difficult to fix, but as it's under warranty I'd get the supplier to sort it out!

AS