Vibration

[docusk]

I just bought a new Record CL 36. Had to discard the old bench (from an old fabricated Sanders lathe which was working fine up till I ditched it.)
Built a new one, fastened to breeze block wall of garage with 2" X 2" battens at left end and along back. Bench bed is a 38mm kitchen worktop cut to 1.5 m X 0.5 m. Three legs left, centre and right, that on lhe left is made from an old 3" X 3" newel post from a very old (100 years or more) building secured with a 3 " coach screw down through the bench and bolted to concrete floor with angle bracket. The other two are 2 X 2 screwed with (centre) 2 1/2" coach screw and (right) with a 3" X 8 wood screw and both these also fixed to the concrete floor.
I found the workpiece vibrated excessively using the woodscrew in the Record Scroll chuck, managed to cut a dovetail hole for the main work which will be a clock. The workpiece is a circle of Beech about 8" dia and 1" thick.
When I put it on to the scroll chuck the vibration was almost as bad, even using all four speeds.
Have I done anything wrong by the look of what I've told you all?
I can reduce the vibration by holding on to the headstock (motor) assembly.

docusk

 

[PowerTool]

Hmm :-k
Nothing obvious,assuming the worktop is fastened to the wall battens.
I have a benchtop lathe - the bench is 6' x 2',supported on 3 "H" frames made of 3" x 2".It is only fastened to the wall at each end,but has cupboards underneath,and doesn't suffer much from vibration.
Perhaps the ballast in the cupboards underneath makes the difference - do you have any way of adding something heavy under yours ?

Andrew

 

[woodbloke]

I read somewhere a very good tip for dampening vibration. I have a Coronet Elf which is mounted on a very substantial wooden base, but which also has space for a long rectangular box, made from 15mm melamine faced chipboard (which gives an waterproof surface). The box is completely filled with builders sand mixed with engine oil to form a thickish goo - this concoction pretty much absorbs most vibration. The top of the box is the same chipboard and is secured with screws. All internal joints are sealed with silicone as is the top before being screwed into place - Rob

 

[Oldflyer2]

I think I might be checking the chuck and screw assembly with nothing in it and turned by hand. It is possible (dare I say it) that something is not quite right with the machine. Is there an adapter in the chuck and if so is it in straight?

Tighten the jaws of the chuck closed and turn on the machine. Does it still vibrate? If so, there is a definite problem.

Good luck

Tom

 

[paulm]

Following on from Tom's line of thought (and sorry if this is a bit basic as I don't know your level of experiece ), have you made sure the headstock is seated firmly on the bars and tightened adequately ?

Likewise, ensure the bars are located correctly and tightened properly on the end spacers.

Lastly, make sure the whole thing is adequately bolted and tightened down to the worksurface.

May need to add some horizontal bracings underneath the worksurface running the length, with perhaps one or two at right angles for cross bracing, to help stop any bounce or flexing in the worksurface.

Let us know how you are getting on.......

Cheers, Paul.

 

[Taffy Turner]

With the lathe turned off, mount the chuck, and then get a good grip on it and try moving it up and down.

Any movement at all is not good. I can't remember if your lathe has roller bearings or a plain bearing. If it has roller bearings and you are getting any movement, it needs to go back (call RP's customer service - they are pretty helpful). If it has a plain bearing, you can adjust it to take out the slack - instructions on how do do it are supplied in the manual, or there is a more detailed description on RP's website.

Good luck.

Regards

Gary

 

[docusk]

Latest update. I tried just about everything with limited success so I called upon an old friend who is a first class mechanical engineer running his own business with more lathes, mills, grinders and so fifth than you could shake a stick at.
So he took a hard look at the setup and told me all I needed were two pieces of 1/4" steel plate, 7" X 3" with a central hole to match the bolt and then pull all the fixings up tight.
These he made this morning and I did what he said this afternoon.
Also the belt pulleys were about 1 degree out of line - just loosened the grub screw and tapped the motor pulley till it came right.
Once it was all done I switched on and it was like a sewing machine! No vibration of the bed bars or the headstock.
He's so smug!
Mind you, he is absolutely rubbish at wood turning.

Thanks all of you who went to so much trouble to help me. I really appreciate it.
Can I mention that Record Power have a detailed Vibration run down on their website which you can print out. One of the goodies in there is, with a swivel head like mine, get the head lined up by putting a centre in both head and tail stocks then bring them together and adjust till the points meet properly. Good eh? Course I bet you all knew that anyway.

Regards to all docusk

 

[Anonymous]

get the head lined up

Ask your engineer mate to turn up a 1 MT at each end of a steel bar :wink:

 

[docusk]

Aha, methinks I see the glimmer of a jolly good wheeze here.
Clever old soke (not soak I hope) Thanks.
docusk

 

[docusk]

Other problems arose when I was trying out solutions. First off, I hadn't allowed for the rotation of the headstock for large bowl turning so I finished up with a bench made of 8" X 2" wood, battened together with 2" X 2" battens. There are three sets of legs 36" in height which are coach screwed into the leg at the top and into wooden blocks rag bolted into the concrete at the bottom. I also found the two steel plates excellent and the lathe doesn't suffer from vibration at all. Mind you I haven't tried anything longer than a bowl so might need more advice when I've tried some long spindle turning eh?

docusk