Vibration problem
Vibration problem
(OP)
Hi
We are trying to machine a left handed & a right handed thread each thread is 500mm long and the total shaft lenght is 1500mm long, there is a 100mm long section in the middle which is left stock 30mm . The material is EN24T we are using carbide insert tips ,speed has been tried at 500 & 250 rpm ,feed is non adjustable as set by cnc lathe
Pitch is M30 x 2mm , Passes are 15 , Spring passes are 2 , plunge angle is 29.5 degrees. The problem is we are getting alot of vibration and can't get rid of it , net result the thread looks rough
Anyone got any good ideas
Regards
Henry
We are trying to machine a left handed & a right handed thread each thread is 500mm long and the total shaft lenght is 1500mm long, there is a 100mm long section in the middle which is left stock 30mm . The material is EN24T we are using carbide insert tips ,speed has been tried at 500 & 250 rpm ,feed is non adjustable as set by cnc lathe
Pitch is M30 x 2mm , Passes are 15 , Spring passes are 2 , plunge angle is 29.5 degrees. The problem is we are getting alot of vibration and can't get rid of it , net result the thread looks rough
Anyone got any good ideas
Regards
Henry





RE: Vibration problem
When was the machine last leveled?
How long is the tool?
How old is the machine?
If the center of the part is left as stock is the length causing a off balance whip?
.....
Fill what's empty. Empty what's full. And scratch where it itches.
RE: Vibration problem
RE: Vibration problem
The other approach is to roll the thread.
RE: Vibration problem
thanks for the replys
We have now manufactured a new type of support for this job
It is mounted just infront the cutting tip and is basically a large ultrawear bush that is 0.1 clearance on thread od and about 50mm long . The bush completly surrounds the shaft so it hasn't got any chance but to do what its told ( so to speak ) The support for the bush is made from 40mm thick mild steel and the whole thing is bolted to the saddle so runs up and down nicely.
i must admit the whole thing works great and we can easily remove the bush and replace for bigger sizes
Regards
Henry