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dsc
21-10-2013, 06:12 PM
Hi all,

curious what's the view on lowering stepper motor mount vibration, do you normally mount them against a plate via some sort of vibration cancelling material? I've seen cork 'gaskets' used for this and I even have some fancy rubber / cork / other 10mm thickness vibration mats at home which I could use, but I'd rather double check to see what's the standard solution. Of course there's the bolts as well, which will need fancy washers, or something similar?

Second thing is vibration against torque'd bolts, I'm using a mixture of M4 and M5, the M4s are torque'd to 3Nm (stainless into ali) and M5s will be 4Nm. With those torque values in mind, is there a risk of the bolts un-doing themselves under vibrations from the motor (Nema 34) ?

Regards,
T.

JAZZCNC
21-10-2013, 07:03 PM
Over complicating the job.!!. . . . Just tighten the buggers up and they will be fine, never had one fall off yet.!!

No fancy washers needed Spring washers work fine.

EddyCurrent
21-10-2013, 08:35 PM
I used to work with a fitter called Dick, when it came to nuts & bolts people used to say there's 3 kinds of tight, "There's tight, f***king tight and Dick tight", I'm assuming tight is enough ?.
I read somewhere about stepper motor mounts to reduce resonance similar to the rubber spider of some couplings but would it introduce backlash ?

Jonathan
21-10-2013, 11:51 PM
Over complicating the job.!!. . . . Just tighten the buggers up and they will be fine, never had one fall off yet.!!

No fancy washers needed Spring washers work fine.

That's alright for some - i.e. the people who use AM882 drives or others with resonance damping algorithms. However if you're using a more generic drive it can help if you're having problems with resonance to use some sort of 'anti vibration' mount. Some stepper motors I got from a large plotter (nema 34 and 23), were mounted with a piece of thin neoprene rubber between the front face of the motor and the mount, with the screws inside small rubber bushings which pushed into the motor flange.

It's worth remembering that stepper motors can conduct a significant amount of heat from the mounting face, so it's a good idea to bolt them to a reasonable size piece of aluminium. Clearly putting neoprene in between is not going to do the thermal conductivity much good, so the motors will run at a higher temperature.

JAZZCNC
22-10-2013, 12:23 AM
That's alright for some - i.e. the people who use AM882 drives or others with resonance damping algorithms. However if you're using a more generic drive it can help if you're having problems with resonance to use some sort of 'anti vibration' mount. Some stepper motors I got from a large plotter (nema 34 and 23), were mounted with a piece of thin neoprene rubber between the front face of the motor and the mount, with the screws inside small rubber bushings which pushed into the motor flange.

Well they should dump the shity drives .!!. . . . But anyway I Wasn't talking about the gasket was meaning the tightening.!!! . . . But how many resonance problems have you come across caused by motors mounted directly to mount with no gasket.?. . . Personally None and I've help sort many a resonance problem.!

dsc
22-10-2013, 10:46 AM
I simply thought this sort of vibration can effect how the machine works, but if it doesn't, I'm ok with it as adding any mats / gaskets would complicate the assembly anyway.

I'll go simples on this and use normal bolts / washers.

Cheers,
T.

EddyCurrent
22-10-2013, 11:36 AM
Obviously smaller motors
Stepper Motor NEMA 17 Cork Gasket 4-Pack - RepRap.me (http://reprap.me/Stepper-Motor-NEMA-17-Cork-Gasket-4-Pack/en)
Silicone Rubber might be a choice as it transfers and stands the heat, wife has some cheap baking trays made from it.
Thermal Interface Material - OSCO (http://www.osco.uk.com/products/thermal-interface-material)
http://www.ebay.co.uk/itm/SILICONE-RUBBER-SHEET-200MMSQ-1-1-5-2-3-4-5-6-8-AND-10MMTHK-/330788411590?pt=LH_DefaultDomain_3&var=&hash=item4d048698c6