Thread: New chuck

Originally Posted by Anorak Bob

I bought an 80mm 3 jaw Griptru for about a hundred bucks 5 or so years ago though in all honesty I reckon a 4 jaw is easier to use .

I thought the advantage of the Griptru was on multiple pieces....sure a little painful to set up but once done you have the speed of a self centering chuck with(close to) the accuracy of a independent chuck(at that diameter). A lot like(if you lathe is big enough) using a small 3 jaw mounted in a 4 jaw.

Stuart

While I had the test gear out I thought I may as well check the 5" Chinese no name brand scroll chuck that came with my CQ9325 lathe for runout.

0.02 mm at 20 mm diam and 0.04 mm at 10 mm diam not too shabby for a 10 year old lathe that's done a heap of work.

So if I can get that out of my old clunker, I should be able to get similar from a new chuck. Well you would think so

Rob

Originally Posted by nearnexus

So I think I will look closely at the ER avenue.

The existing Schaublin collets I have only go to about 15 mm or so, and are imperial, but the biggest bug bear is that they only have very small pull down tolerance.

Since you've the small stuff covered I'd look at ER40 or whatever size goes up to the max spindle bore plus a bit.

Originally Posted by nearnexus

General Tools did offer me a 100 mm TOS for about $350 which was tempting, but that's about as much as the lathe cost.

Bad comparison. It's not really relevant what you paid for the lathe, what is relevant is what you want to do with it. I once bought a lathe for $100, does that mean you think I should never buy a tool costing more than the machine cost me?

PDW

Originally Posted by PDW

Since you've the small stuff covered I'd look at ER40 or whatever size goes up to the max spindle bore plus a bit.



Bad comparison. It's not really relevant what you paid for the lathe, what is relevant is what you want to do with it. I once bought a lathe for $100, does that mean you think I should never buy a tool costing more than the machine cost me?

PDW

Yes, ER40 is a good way to go.

And yes, I agree on your last point.

Something to think about.

Rob

Hi Rob,

What's the spindle bore size on the Schaublin 120? ER40 goes up to 1"

In any event, I think you should show some respect for the Schaublin brand by sticking with W20 collets, ( or is it W25? ) of course they are probably three times the price and unobtainable...

Ray

Originally Posted by PDW

I just use a good quality 4 jaw. 3 jaw chucks are for repetition work where the workpiece is pretty much going to be machined in a single setup so slight runout doesn't matter. Bellmouthing definitely does though.

If I want runout less than 0.01mm and the work diameter is less than 40mm I use a collet. Over that, a 4 jaw. The 3 jaw chucks I just use for rough work. I even have one P-B chuck with a set of 'soft' jaws welded to the original jaws - just skim it or bore to diameter as required.

Yes, I'm a metal butcher.

Having said that I'm not knocking you for buying a good 3 jaw chuck. I just prefer to buy good 4 jaw ones myself as they can *always* be set to have the workpiece run concentric (or offset if required) and they hold a lot more rigidly than any 3 jaw chuck ever made which makes parting off & facing much less problematic. I just don't use a 3 jaw enough to warrant spending serious money on one.

PDW

I absolutely agree with you. I didnt buy the bison because it would have so little runout, its just a nice side effect. Mind you, it gives you a bit of flexibility when things didnt go to plan. If I had collets, id probably use them, but for 90% of my work, the new chuck is plenty good enough. I do have a 4 jaw, but recently, the only time ive justified getting it on is when the bison doesnt have enough reach. I do have a pratt burnerd that came with the lathe, but whilst it runs true, the bell mouthing in it is so bad that all its good for is turning precision rounded triangles as the workpiece flops around. And dont even think about parting.

But back to the original point, I dont see why anyone would want to own such a fine machine and foist a below average chinese made chuck on it. Im also from the school of thought that I dont have lots of money and that the best way to waste it is to cheap out and buy the option that might not do the job to my satisfaction. After reading reviews of the bison, there was no mystery as to what I was getting. The fuerda could have gone either way in my experience.

Originally Posted by RayG

Hi Rob,

What's the spindle bore size on the Schaublin 120? ER40 goes up to 1"

In any event, I think you should show some respect for the Schaublin brand by sticking with W20 collets, ( or is it W25? ) of course they are probably three times the price and unobtainable...

Ray

As someone with a saved searches for Rivett collet, Schaublin Collet and Hardinge Collet on ebay i can tell you the W style collets are far more common then the 4C i am after, and not that expensive. Schaublin gear is only made from unobtainium, Rivett gear is made from weapons (or maybe surgical?) grade unobtainium....
Since i paid zip for the lathe i don't feel the need to scrimp on chucks and collets, if it costs me $1000 in gear then i still have a cheap lathe for what it is (will) be.

Ew

Originally Posted by RayG

Hi Rob,

What's the spindle bore size on the Schaublin 120? ER40 goes up to 1"

In any event, I think you should show some respect for the Schaublin brand by sticking with W20 collets, ( or is it W25? ) of course they are probably three times the price and unobtainable...

Ray

It's 22.5 mm by my measurement.

Ray I can't believe the prices Schaublin collets bring now.

I saw a dead centre collet for the headstock listed on fleabay at over $70 recently. I have one of those and probably 30 others, which is rather mind boggling when you add it all up.

They work OK but ER has better capabilities IMHO.

Rob

Originally Posted by nearnexus

According to the guy at General Tools where I got it, they've sold a lot to precision machinists in all sizes, and the feedback has been 100% good.

makes one wonder if its now 50%?

Originally Posted by eskimo

makes one wonder if its now 50%?

Ha Ha - good one.

Rob