CL1 damping

[That would work]

Hi
Have recently aquired a Record CL1. I have a fair bit of experience using a graduate and then a Jubilee so apart from bolting down not much more was needed there. Change of circumstances now with a CL1. (With the Record stand)
I was wondering what members with one of these have found to be the most effective way of damping any vibration. I am thinking about making a box from 3/4 mdf that 'hangs' attatched to under the bottom shelf and nearly touches the floor and filling that with concrete. Thanks in advance,
Tim

 

[Steliz]

If you have a concrete floor to bolt it to then use hard rubber washers to absorb vibrations. I like the idea of a suspended weight but a heavily loaded shelf will also work.

 

[Mark Hancock]

If it's the same stand as for a CL4 I got the technician at College to box in the upper section of the stand and fill it with sand bags. I would have liked it bolted to the floor as well but this wasn't allowed :roll: Anyway it works a treat as it is.

 

[That would work]

Hi Guys
Yes have concrete floor so will be bolting.... I wish record made the feet (part with hole) of the stand from heavier gauge steel! It is the same stand as the CL4.
OK was wondering about using rubber between.
Yes going to really beef up under the bottom shelf with heavy boxing, bracing and concrete.
Also will be putting a leg under the bowl turning attachment.
Quite impressed at how smooth and quiet it is though. Picked it up for £270 on an eBay flash sale (minus £30 off the price)

 

[Phil Pascoe]

Be careful you don't drill through a DPM.

 

[That would work]

Good point... currently it's on patio paving slabs which are under a very temporary shed!
Will soon be building a new workshop though. Yes will be aware of dpc... galvanised bolts :?

 

[MusicMan]

The hard rubber washers (both below and above the feet, with no part of the bolt touching the lathe legs directly) will help to minimise vibration transmitted from the lathe to other workshop machines, and vice versa, which in your case is not really necessary. It's used when there is sensitive equipment running at the same time, but this isn't your concern. A plain bolt will do.

What you want is a way of absorbing vibrations generated on the lathe.
Putting a heavy box under the lower shelf, not touching the floor, is a good way. You should make sure that the box is firmly affixed to the legs/shelf of the lathe (ie not dangling loosely below it). And don't use concrete; plain sand (slight preference for sharp sand) is much better than concrete, since the vibration between particles of sand damps the vibration, whereas concrete itself vibrates. You can make a very good bell out of cement, but not out of sand.

This isn't speculation but experience of running a metrology lab, making very sensitive measurements, in some cases with amplitude far below an atomic diameter. We got a bit paranoid about isolating vibration. Once we had to turn off a water pump 200 metres away, as vibration going through the water supply affected the results!

 

[That would work]

Interesting, makes sense about a material that does not resonate.
Going to make a very substantial structure around bottom shelf incorporating a box to hold sand underneath.
I'll post details once I've done it.

 

[MusicMan]

It may not be practical but the best place to attach your box would be the middle of the legs, but the lower shelf is probably the only practical place.

I have a similar lathe, the Coronet No. 1 precursor. A good, reliable and useful model. I have it mounted on a heavy wooden bench.

One important point is to pay attention to the alignment of the bars and tailstock. When you bolt the lathe down, check with a good spirit level that the mounting points for the lathe itself are level. Then when the lathe is assembled, check that the bars are straight, and horizontal both along and across the bed. (They should not be twisted). Finally, using a centre in the tailstock and a centred point in the headstock (make this yourself using any piece of wood e.g. on the faceplate), check that the headstock and tailstock centres meet accurately. Any defects cam usually be rectified by shims under one or both of the bar supports.

 

[That would work]

I've decided to box in the space between the top and bottom shelves (so the mid section) completely and fill with sand. I'll loose the bottom shelf but would rather have a vibration free machine. And of course sand would be easy to remove if needs be