Motor Vibration

[savarin]

I mean for the motor, something like this. The vibration in my motor sets up harmonics at different heights of the support pillar.

The idea being that the motor mounting plat is totally isolated from the drill head mount.
I'm unsure due to it hanging off in a vertical fashion rather than being horizontal like in a lathe.

 

[JPMacG]

I think that the soft mounts that I got from McMaster are intended to be used in compression, not in tension or in shear. I don't know how they would hold up in tension or shear, but I suspect not well.

 

[Ray C]

I went ahead with the soft motor mounts. These are neoprene rubber mounts from McMaster-Carr. They are 1 inch diameter, 3/4 inch tall and are rated at 50 lbs each. The cost was about $2.50 each. They definitely helped - I can no longer feel the 120 Hz motor torque vibration on the lathe bed with my fingers. I'm not sure how well they will hold up - time will tell. I probably "fixed" something that did not need fixing, but eliminating vibration makes me feel good.

View attachment 265345View attachment 265346

I once owned one of these lathes and the topic you mention has been discussed ad-infinitum over the years. Vibration is inherent in that design. All of those extended arms and brackets are prone to transmitting and/or amplifying all sources of vibration. The motor itself sits on a hinged plate and that hinged plate will rise and fall because one side of the pulley is pushing and the other side is pulling. That is the primary source of vibration driven by the mass of the motor. You could lock it down but then, even the slightest unevenness in the belt will be transmitted to all the brackets in that mechanism.

A long time ago, I was knee-deep in an Atlas TH42. I moderated a forum on a website dedicated to those machines. No One ever eliminated all the vibration unless they converted the machine to direct drive.

Ray

 

[brino]

Another thought is to try Link-Belt, like this:
http://www.leevalley.com/en/wood/page.aspx?p=30051&cat=1,240,41067

Apparently since each link can move a little with respect to its neighbour, in can help eliminate vibrations being transferred from one pulley to another. I believe it is available in different standard widths from other suppliers.

-brino

 

[Silverbullet]

I mean for the motor, something like this. The vibration in my motor sets up harmonics at different heights of the support pillar.
View attachment 265424
The idea being that the motor mounting plat is totally isolated from the drill head mount.
I'm unsure due to it hanging off in a vertical fashion rather than being horizontal like in a lathe.

They would isolate the motor vibrations but not the pulley and belt vibrations. Some but not all.

 

[wa5cab]

Nothing directly to do with rubber motor mounts, but I have to add one comment about hinged motor mounts. If doing an interrupted cut, under some circumstances, you can actually get the motor to bouncing rather badly if the only force tensioning the belt is the weight of the motor. Although some of the Atlas motor mounts were hinged for adjustment, once adjusted for the desired belt tension, they were supposed to be locked in place by either a bolt with adjustment and jam nuts (like on my non-Atlas 4X6 band saw ) or by two slotted arms with pinch bolts at each end. Once adjusted and locked, the entire assembly was rigid, at least within the limits of the strength of the parts.