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jefferson
3rd July 2008, 09:23 PM
I moved my Vicmark lathe yesterday into the warm end of my workshop. I had the sparky in who lowered the fluoro lights etc and put a pendant down for power.

All seemed OK, until the 450kgs of lathe started rocking when I pushed it. The concrete floor aint level!

I have the lathe sitting on rubber pads, so maybe the weight will settle.

But what if it doesn't? I don't want the lathe base shifting to accommodate the unlevel floor. I've thought about shimming the base but the sheer weight of the lathe means I won't get the weight flat across the base.

Suggestions please.

regards Jeff

powderpost
3rd July 2008, 09:28 PM
Drive some small wooden wedges under the feet t get it level, then mix up a tlie grout mix and work that under each foot. Don't forget to remove the wedges and fill the voids too.
Jim

rsser
3rd July 2008, 09:29 PM
Had (have) the same problem with my lathe.

One layer of rubber waffle mat at the uphill end, two on the downhill.

She only rocks with a decent lump at a given RPM though.

So when you say 'when I'm pushing it', what/when?

Rubber mat has this downside.

If it's just at one rpm then you can ignore it with a bit of up or down ramp. It's just a harmonic vibe.

If it's at a broader rev range, then, off the top of the noggin, try tightening your anchors, or changing your rubber type, or replacing the rubber with softwood packing.

DJ’s Timber
3rd July 2008, 10:07 PM
Shouldn't need to sit the lathe on rubber pads. Mine is sitting on the adjustable bolts on the concrete floor and it does not move unless I have it running too high for the size that I have mounted.

How thick and big are your pads? Can you sit say a 75mm or 100mm square by 6mm thick steel plate on top of them? If so drill a hole in the centre of the plates but not right through just a couple of mm so that you can screw the adjustable bolts into them so that you can level it.

Manuka Jock
3rd July 2008, 10:18 PM
Jefferson ,
How much does it rock , what thickness of shim will you need ?

orraloon
3rd July 2008, 11:19 PM
A shim under the short leg should be all it needs. If it is steel direct onto concrete then I would put a hardwood pad under all the feet.

jefferson
3rd July 2008, 11:32 PM
It seems DJ has the answers to all questions!

The rocking is really at the headstock end, it's maybe 4-5mm out. I thought about jamming a wedge under the low end, but have my doubts.

The idea that I use the adjustment bolts has some merit. That is, I place steel plate under the pads and adjust from there. But I would much prefer if the floor was level.

That said, the solid rubber pads under the lathe seem to have settled a little, and the rocking isn't as bad as it first was. I suspect the rubber has compressed under the 450kgs of weight. A sort of self levelling.

I haven't tested the lathe in its new position yet with anything substantial. There's a very hefty 600mm yellow box burl in waiting, but I'll probably cut it up into more manageable pieces on the bandsaw. (Unless DJ tells me otherwise!)

thanks again as always,

Jeff (novice wood turner)

DJ’s Timber
3rd July 2008, 11:46 PM
IMHO the rubber pads are an invitation for vibration, the Vicmarc lathes are well built and balanced that there is no vibration or noise to transfer to the concrete in the first place.

Here is a bit approx 550mm dia Yellowbox that I trued up on mine and it didn't even look like moving.

76973

Manuka Jock
4th July 2008, 12:04 AM
It seems DJ has the answers to all questions!

The rocking is really at the headstock end, it's maybe 4-5mm out. I thought about jamming a wedge under the low end, but have my doubts.

The idea that I use the adjustment bolts has some merit. That is, I place steel plate under the pads and adjust from there. But I would much prefer if the floor was level.

That said, the solid rubber pads under the lathe seem to have settled a little, and the rocking isn't as bad as it first was. I suspect the rubber has compressed under the 450kgs of weight. A sort of self levelling.

I haven't tested the lathe in its new position yet with anything substantial. There's a very hefty 600mm yellow box burl in waiting, but I'll probably cut it up into more manageable pieces on the bandsaw. (Unless DJ tells me otherwise!)

thanks again as always,

Jeff (novice wood turner)

Jeff , I don't know if your lathe stand has two long feet either end or 4 small ones at each corner , but the possibility exists for chipping away the concrete at the high end , just enough to allow the stand to sit level.
The task is not as big as it may at first sound , a cold chisel , a bolster , or even a big old wood chisel , and a hammer are all that is needed.
That way , there are no shims to slip out , and you can still bolt down to the concrete.

robyn2839
4th July 2008, 08:55 AM
all you have to do is jackhammer/chip out concrete where it is high,i had to do that with mine then i dynabolted mine .........bob

TTIT
4th July 2008, 09:38 AM
Drive some small wooden wedges under the feet t get it level, then mix up a tlie grout mix and work that under each foot. Don't forget to remove the wedges and fill the voids too.
JimAll that concrete chipping sounds like hard yakka :C. I reckon Jim's on the right track - but how about jacking the lathe up a little and just slap a bit of grout/render under each leg so that when you lower the lathe it will just level itself out :2tsup:

Manuka Jock
4th July 2008, 09:53 AM
There is a fair chance that the grout will turn to dust under the vibrating load . It is after all , just plaster , its not a structural product .
Shims are a better option , direct leg / concrete contact , the best .

jefferson
4th July 2008, 01:06 PM
I shimmed the lathe this morning with two gal plates and adjusted the bolt to suit as DJ suggested. Everything seems rock solid now but time will tell.

Thanks all for the suggestions and feedback.

Jeff

rsser
5th July 2008, 06:41 PM
Well, this is a bit behindhand, but FWIW I solved an unven floor problem with thick waffle mat under the old VM 175 and never had harmonic vibes.

Got them with the Stubby at one rpm setting since it has a wider base fore and aft than the VM and so two thicknesses of mat were used. I'd expect that were they replaced with conveyor belt rubber pads the vibe would go.

gtwilkins
6th July 2008, 02:52 AM
Bit behind too. I had the same problem with my 300, Vicmarc recommend rubber dampers but I read somewhere about using lead roof flashing, worked like a charm. Quished down and now everything is stable.

jefferson
9th July 2008, 04:09 PM
Out on the lathe turning spindles today - and to my horror the vibration has returned. Strange, as it was working OK for the last couple of days. And the vibration gets worse the faster it goes. Does that say anything?

There seem to be two conflicting opinions here about the Vicmarc lathes on whether to use rubber pads or not.

I intend to jack the 300 up (it has two base supports, not four legs incidentally) and sit it on hardwood beams, then try to adjust the level using the bolts provided as DJ suggested. That doesn't seem right to me, given that 450kgs will be sitting only on the bolts.

I'll report my frustrations back later. Any and all advice again welcome.

Jeff

rsser
9th July 2008, 04:42 PM
Well, all other things equal, the lump you are spinning Jeff will have its own effect.

Is it seriously out of balance? Did it improve when you trued it up?

Apart from that, I'd suggest you seperate out the two issues here: level, and vibration. The latter may not be caused by the former.

Unless the level is clearly wrong across two planes it might be worth ignoring it for the moment and addressing the vibration.

Are the legs equally tight all the way round? (If one or two are not you may just have harmonic vibes, ie. a resonance set up by an unbalanced lump).

That said, if the floor is unven and you have tightly bolted the legs down, you may in fact be putting twisting forces on the bed. I'm told that despite all a cast bed can be twisted. Put a drive spur in the headstock and a live centre in the tailstock and see if they line up.

jefferson
9th July 2008, 10:08 PM
Ern, DJ and all you other helpful ones, thanks.

I have now placed 70 x 35mm Vic Ash boards under the two "legs" on the Vicmarc - with gal plates under the adjustment bolts and have almost got it right. No vibrations at any speed using the method DJ suggested a few days back. Thanks DJ, I've got rid of the rubber.

The extra height, at first glance, seems more comfortable. I'm 6' 1" or thereabouts and guess that the correct height may be even be an inch or two heigher.

But the beast still has a slight "bearing" feel about it at all speeds when I put my hand over the drive end. It's so, so, so slight that it's probably not a problem. I'm thinking that the weight of the heavy VL 150 chuck on the outboard side has something to do with it. (If I put the VL 120 chuck inboard with the 150 outboard, the drive seems to be in better balance.)

In all, a much better day on the lathe. The 3/4" skew chisel, now freshly sharpened, is almost obliging. Only two dig-ons on maybe 16 practice beads. I will get there!

9 degrees max here tomorrow, so plently of opportunity for more practice with the fire going in the shed.

I seem to turn OK (left handed) going right to left with planing cuts using the skew, though exactly the opposite when rolling beads. Must be something there but I will work it out. I've been turning spindles out of qs Vic Ash, some tear out but not much.

You guys / gals are a a terrific help, so thanks again.

Jeff