Monster Resonance query

[Richard Kennedy UK]

Hi I was wondering if any one had had any issues with resonance I seem to be getting quite a bit and was wondering if it was common

Is there a fix? I tried tightening everything down but its still occurring

[Bill Bulloch]

Are you talking about vibration? If so, is it happening when there is nothing on the lathe?

[Randy Privett]

Is this one of my tools?

[Montgomery Scott]

What diameter is your piece and what speed are you turning at? Is this an inside or outside cut and what tool are you using?

[David E Keller]

The only time I get vibration is when going deeper than about 6 inches or if I haven't cleaned out the shavings... It's usually the shavings.

Edit: Please ignore this... I thought you were talking about hollowing with Randy's monster hollowing rig.

[Reed Gray]

Another second on getting vibration when going deeper. They do great for 6 inches or so, and beyond that they get a bit of chatter. More suited for clean up cuts than roughing at that distance. I have put my 3/4 inch McNaughton hollow form cutters in them, and it was too long of a lever. The 5/8 inch ones were no problem, unless I was reaching out too far.

robo hippy

[Steve Schlumpf]

Richard - I am going to take a guess that what you are referring to is vibration in your lathe that only happens at certain speeds. I have that in my Jet 1642 in the 700 rpm range. I have my lathe balanced as best I know how and have 280 pounds of ballast added to help counter vibrations.... but I still have them. Check to be sure your lathe is level and that your centers still meet after moving the lathe onto the concrete pads. I am willing to bet that the alignment it is off center just a touch.

Let us know what you find.

[Roger Chandler]

Do you suppose he is referring to the "monster" lathe........you know the white 3520b that sells in Europe?

I did not comment because I was not sure I understood completely his question..........now Steve speaks of lathe vibrations...........someone from over in the UK posted some pics of their "mayo colored monster" a few weeks back.......not sure who it was, maybe Richard?

I found this thread........Richard maybe referring to his white 3520b......

http://www.sawmillcreek.org/showthread.php?164684-May-I-have-a-tiny-gloat&p=1689473&highlight=#post1689473

[Richard Kennedy UK]

Yes Its to do with my white monster 3520B I was turning a small 10 inch platter only about 2 inches thick at about 8 inches from the centre I get a resonant hum I guess it could be the speed I haven't added any ballast yet would that make a difference? I guess it is vibration of some sort but I am not sure what! Vari speed is new to me having lived with belt speed adjustment for the last 8 years. I am not sure what speed I should be turning at I have discovered that you can speed up and vibration vanishes! wow very impressed with that! if I need to add ballast I can do it easily

Thanks for all the responses so far.

[Brent Grooms]

My mustard version has agood resonance that shows up about 1000 to1050 rpm and goes away by 1150. It doesn't matter what I'm turning, bowls or spindles. haven't heard of any cures

[Richard Kennedy UK]

Thats right where I was turning Its good to know its not just this machine! I will crank it a bit faster maybe and see what happens although given recent events I am wary of doing so! I know people like Terry Scott turn fast but I haven't had the opportunity to do so until now in fact I hardly ever went over 900 rpm before I made a hollow Spalted beech form yesterday and found being able to speed up over 1000 gave me a much better finish!

[Steve Schlumpf]

Richard - general rule of thumb that I use is to increase the speed until the blank starts to vibrate - then reduce that speed until the vibration disappears. Once you have the blank trued up (balanced) you should be able to increase your speed without vibration problems.

Also, if your lathe is level - then adding ballast may help somewhat but everything I have heard is that each lathe has a point where the harmonics will cause a vibration. With variable speed control - just dial it down until it goes away.

[David DeCristoforo]

I'm thinking that all lathes are prone to this. Unless, that is, you have a machine that is soooo heavy that it can absorb just about any and all vibration. Sometimes when you mount a chunk of wood on your lathe and start it spinning, you will discover a "harmonic sweet spot". Actually, in this case it's a "harmonic sour spot" where the vibration occurs. I have found that just a bit slower or faster will get you out of the vibration zone.

[Roger Chandler]

I'm thinking that all lathes are prone to this. Unless, that is, you have a machine that is soooo heavy that it can absorb just about any and all vibration. Sometimes when you mount a chunk of wood on your lathe and start it spinning, you will discover a "harmonic sweet spot". Actually, in this case it's a "harmonic sour spot" where the vibration occurs. I have found that just a bit slower or faster will get you out of the vibration zone.


Very true! Harmonics at work!

[Ken Whitney]

I get a resonant hum I guess it could be the speed

One other possibility, all four feet may not be in equal contact with the floor. Spinning an out of balance load can cause vibration on the foot that doesn't quite make good floor contact.

Good luck.

Ken

[Richard Kennedy UK]

Had a bit of an investigation the four adjustable feet seem to be firmly in contact with the floor the leg bolts needed tightening a quarter turn but still I have noise I can put my bowl gouge against the wood one handed get the noise going then adjust the vari speed it doesn't go Its not a big prob I just need to sort it out!