How to reduce the vibration of a bench lathe ( Emco Compact 8 )

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compact8

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It's my EMCO Compact 8. The noise level is very acceptable at 500 rpm but then it would step up to max at 850 rpm and then reduced by a bit at 1700 rpm. Obviously some kind of resonance is happening. May I have some suggestions on how to cut the noise down at 850 rpm ? Thanks in advance and Merry Christmas


 
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Turn up the tunes? Mounting to a somewhat dampened surface (wood, hard rubber), and add weight to the base, are two methods. Mike
 
Your video link shows, "unavailable", so Im making a few assumptions.

What type of motor does it have?

Switching from a single phase motor to 3 phase reduced my lathes noise by about 3/4.

Especially the gear noise from the headstock.
 
The video should be visible now. Somehow it was unintentionally marked as private in Youtube so only I could see it.

The lathe is belt driven so it is not gear noise. The power feed gear train in the picture is disengaged as I rarely use power feed. The belt was kept in tension by a spring and a wheel. I believe the noise is due to the resonation of the spring. I could feel by my finger that the shaft of the wheel pressing on the belt shakes a lot more when the noise level is high. Just have no clue how to fix it, if it can be fixed at all.

It's not the noise but vibration that bothers me. The vibration may make the machine wear out more quickly.

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Could be the tensioning wheel that presses on the belt. There is a large amount of pressure on that wheel in use and I wonder if the bearing in there is going.
 
mikey said:
Could be the tensioning wheel that presses on the belt. There is a large amount of pressure on that wheel in use and I wonder if the bearing in there is going.
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The metal of the wheel runs directly on the shaft without any ball bearing. I oil the shaft quite often and as far as I can feel it, the rotation is silk smooth.
 
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compact8 said:
The metal of the wheel runs directly on the shaft without any ball bearing. I oil the shaft quite often and as far as I can feel it, the rotation is silk smooth.
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I stopped oiling it and replaced with a new pulley out of 6061 and 2x 6001-2RS bearings pressed-fitted in that, vibrations did go down but isn't fully gone because my 1-ph ac motor is the major source of vibration in my lathe.
 

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Fermic said:
I stopped oiling it and replaced with a new pulley out of 6061 and 2x 6001-2RS bearings pressed-fitted in that, vibrations did go down but isn't fully gone because my 1-ph ac motor is the major source of vibration in my lathe.
Click to expand...
Nice mod. I believe the aluminium wheel is much lighter than the original steel wheel so the resonating frequency of the spring+wheel system is changed ( to a higher frequency ) resulting in less vibration ?

Secondly, what's the diameter of the new wheel compared with the original ? if the new wheel is larger, the length of the spring hence the tension will be changed. That may change the resonating frequency as well. I think I will try things out in that direction. Thanks.
 
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