alcazar

iTrader: (2)

My little one (an Emco Compact 5), has started to vibrate badly when cutting, especially when using the parting tool, even AFTER the tool OUGHT to have cut the workpiece round.

Anyone else think the bearings might be done for?

Also, what makes an electric motor need a shove to get going.........same lathe, both directions?

TIA

addi monster

iTrader: (6)

could well be the bearing , may have colapsed hence the shove,, i have seen the sadle come loose before and that will enable the tool holder to vibrate,.

chocolate_o_brian

iTrader: (22)

I'd say bearings fubared Jeff. The little motor needs more oomph to get the lathe turning probably as said bearing's gone so metal - metal contact is occuring OR is siezing up. It could blow up and we call that at work - a catastrophic failure

Sure NSK or other makes would have the bearing required, metric or imperial. Any ideas on the type of bearing it is (assuming it is shagged?)

http://www.ebay.co.uk/itm/Emco-Compa...item43aaac7d47

Any good to you? physical copies available too but at a price from the U.S.

http://www.emcomachinetools.co.uk/Pr...9/Default.aspx

Random but had a look as I like stuff like that.

MMT WRX

Is it the chuck that's vibrating or the tool. It could be the saddle/carriage needs adjusting on the bed, if there is an adjuster. There does appear to be adjusters on the compound/cross slide on the link COB put up.

p1mark

Gib strip on the closs slide sloppy.
Saddle loose
Chuck loose (screw on type or bolt on?)
Tool height way above or below centre (i assume you have checked this)
Spindle bearings (easily checked with a clock)
Tool - not enough rake or clearance angle, edge gone etc.

alcazar

iTrader: (2)

Wow, thanks for the above.

Andy: I'd not seen that link to the importers before, yet I HAD seen their "shop". on ebay I've downloaded the service parts manual and can use it to strip the thing down, should it become necessary. When I bought it, I stripped it as far as I dared to clean it, re-grease it after respraying it.
I have the instruction manual somewhere, downloaded from t'internet years ago, and spiral bound for me.

MMT WRX: will check those two out before attempting to strip it down.

P1 mark: I'll look at those in order, thanks.

Don't suppose you have a dial gauge Andy? Or access to one?
Or could I use a dial vernier clamped down?

Just done a couple of searches: dial gauges seem to go for anything from £20 WITH a magnetic base, to around £40 WITHOUT.

Locally they are around £70 Far cheaper to just put in new bearings.

chocolate_o_brian

iTrader: (22)

Hmm, could have a look. My gaffer has a lieu day today so can't borrow one till he's back if there's one floating about. Would say a dial gauge is better than calipers in fairness. See the run out more accurately.

alcazar

iTrader: (2)

That's what I thought, but if I can't beg, borrow or steal one, I thought of clamping the vernier gauge with the depth probe against the headstock, and turning the headstock to see if there is any wobble?

Or failing that, buy a dial gauge with magnetic base off ebay for £20............ I DO like to own tools, as you know mate.

chocolate_o_brian

iTrader: (22)

I count that 7 digs you've had about me owning tools. I'll take a picture of my home tools which I own as well as my tool locker at work - again tools I own.

I just forget either where stiff is or to bring it home when required. See if I can get you a dial gauge borrowed. Gimme a couple days.

The Zohan

^^^would be my first thoughts

alcazar

iTrader: (2)

You're keeping count???

Well, except that it WASN'T a dig, or it would have had a smiley

It was simply looking for verification as to me liking to own tools.

I've just bought two more, btw, a biscuit jointer and a Bosch 2.6mm planer And I'm LOOKING for a table saw, a big'un, but not industrial size, about 2000W.

chocolate_o_brian

iTrader: (22)

Mmm-k

Been a shit couple weeks, apologies, 6 digs

terzoscooby

All the above plus cutting speed. Parting off is probably worst for vibration. Try dropping and raising chuck speed. A CNC machine increases speed as diameter decreases. Defo worth investing in indexable parting off tool if you haven't already.

mikef04

iTrader: (7)

Just a thought, i am only assuming that this is a hobby lathe? If it is 230V AC it will have a small capacitor attached to the motor windings. This is what will give a motor its starting "Shove".

May also be worth checking if its motor circuit runs on a capacitor start/capacitor run circuit. If it is, a possible problem with this could be a swtich usually centrifugal, which once motor is upto "X" speed it will shut then use the run capacitor.

Hope this is of some help.

ALi-B

iTrader: (1)

As above; there is usually a starter capacitor somewhere they are pretty big - a traditional starter cap is about the size of a spice jar on a 2kw motor, although modern ones can be a fair bit smaller.

Unless the lathe has a soft - starter circuit to gradually spin it up to speed (can usually tell by the noise it makes when you start it up, which is clearly different to a DOL started motor). Seeing the motor is bi-directional, I'm guessing it will have some sort of starting circuitry.

alcazar

iTrader: (2)

It has a mahoosive capacitor, yes, and about the size of a spice jar, yes, and it WAS OK when I removed the motor to have it rewound, as I managed to get a nasty shock off it

Got a few other things to try, then I'll check that. Wasn't well yesterday, so nowt got done

IS there a way to check a capcitor, other than replacing it with a known working one?