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View Full Version : Royal 5C collets...accuracy??



krems
12-30-2006, 02:28 PM
I have a 13" clausing lathe w/ a 4 1/2mt spindle. Included w/ the lathe is the collet closing attachments. My lathe is set up for the 5C collets. I have a few of the Royal 5c collets. Mhat kind of accuracy should I expect when turning rounds in the collets. I took a pin guage and put it in one of my collets and it showed .002" difference from high to low or +/- .001" ....Is this normal or should I expect the collet closing system to be more precise than this?

Anyway to true up the collet closing system..???

Thanks in advance......Krems

lazlo
12-30-2006, 04:10 PM
I took a pin guage and put it in one of my collets and it showed .002" difference from high to low or +/- .001" ....Is this normal

No, that's not normal! You're getting a TIR of 0.002". Good collets are spec'd with a total runout of 2 tenths.

The first step would be to determine if most of the runout is in the collet, or in the chuck/closer.

The Royal 5C lever closers (which I'm guessing you have on your Clausing) have a large bearing at the back. When the bearing
goes bad, you'll get really bad runout. Another potential problem is if the previous owner didn't take the time to properly fit the closer nut to the back of the spindle.

nheng
12-30-2006, 06:47 PM
Lazlo, I hate to disagree but I believe the 2 main ingredients to 5C alignment are the 5C taper and the register area toward the rear of the collet (whose diameter and tolerance Hardinge is sorta tight lipped about).

I would check the spindle taper for any nicks or dents. You can put bluing on the spindle adapter, place it in the spindle by hand firmly and then pull it out, checking to see where the blue rubbed off. You may need to very carefully use a round stone ONLY on the area of the nick or dent. It might be a good idea to search for less agressive methods. Remember that you want to touch ONLY the damaged area, if any.

Whenever I install my 5C adapter, I insert it into the spindle taper and indicate the 5C taper. I then gently tap it in as needed to coax it by a few tenths if necessary.

AFAIR, Hardinge TIR for standard accuracy is 0.0004" and "special accuracy" versions are 0.0002"

Den

Virgil Johnson
12-30-2006, 07:43 PM
Use a dial indicator to check your adapter without a collet in place noting the runout. Remove the adapter and rotate 45 deg or so then check again. I was able to get my adapter running within .0003. I marked the location to the spindle with a die grinder so I can out it back in the same relation. Royal 5C's should run less than .001 day in day out providing the adapter/spindle is running true.

J Tiers
12-30-2006, 07:52 PM
Need to know if you have "parallel runout", or "wabble".

The first is the same all along a pin, the other is worse the farther out you go.

Collets are pulled-in hard by the closer. If the threads are out of kilter, the drawtube not on-axis, etc, then the collet can get in there cocked, and have wabble.

Parallel runout would indicate a different type of problem.

Check for crud or dings in the taper, inside the adaptor, and outside it, and inside the spindle.

Check that the drawtube rear bearing centers up.

Check that the threads are not dinged up and the drawtube is not bent.

Royal is a half-step under Hardinge..... maybe..... A Royal closer and collets ought to be very good, if the closer system was made for that machine.

If it was adapted by Bubba and Joe-Bob, who knows?

Per your last question (posted as I posted) about 1/64 range, centered on the collet size is best. They are stepped by 1/64 increments typically.

krems
12-30-2006, 07:52 PM
Thanks guys, I thought that they mere supposed to be more accurate than that. The spindle runs true. I suspect that the 4 1/2mt-5c collet closer is the source of the problem. I'll try alligning it up first then try again.

One more question about collets: If I was using a 1/2 " (.500") collet what range of diameters would be acceptable to use in it...ex......490-.510"...plus or minus 10 thousandths or less / more. Thanks again

Krems

Frank Ford
12-30-2006, 07:58 PM
And, it's always possible to get a dud. Admittedly, one shouldn't expect the greatest accuracy with imports, but last year I bought a 3/16" Lyndex from McMaster that was way off - more than .020" if you can believe that. A quick phone call got me a new good one.

Cheers,

Frank Ford
FRETS.COM (http://www.frets.com)
Gryphon Stringed Instruments (http://www.gryphonstrings.com)
My Home Shop Pages (http://www.frets.com/FRETSPages/Machining/index.html)

nheng
12-30-2006, 08:09 PM
Krems, Technically, they shouldn't be used beyond 0.002" either way. The further you get from nominal the more distortion gets introduced and the accuracy and holding power goes down. Whether or not the collet gets any permanent damage from being "sprung" will depend on the brand and how far it's been stretched. I've gone +/-0.005" many times and a bit more once or twice. Den

Rich Carlstedt
12-31-2006, 01:06 AM
When you talk collet accuracy, first you have to mention.
Lathe spindle condition/runout
Collet holder condition/runout ( Note ! also does it still have a key ?)
Collet condition.
Assuming all are new, then you should expect about .0005 or better.

My lathe is old, but has new bearings.
The collet holder is in good condition BUT I must mount it in only one location (Paint marked !) to get .0001 reading on a .0001 indicator.

I bought about 80-100 5 C's from a guy quitting busines. they were all used and many duplicates, so i sorted them out by running them in my 5C holder in my Clausing lathe. I used dowel pins and was sort of shocked at the results.
I found used Hardinges with upto .002 runout, but the average was .001<
I found like new imports with .005 runout.
I found the average on all was at .0012 runout. (used)
I found almost all Imports to have wobble (non-parrallel runout)

I found most of the Hardinge collets to be more accurate than the others.
I had Royal, Southbend,Hardinge,Elliot,Lyndex, and others.

Follow what Evan said about runout mearsuring and check some other sizes.
Royal is pretty good and I rate them just below hardinge also.

I do not use Oversize work (over+.001) in a collet, thats how they get damaged.( the larger radius causes the forces to be unsupported ..draw it up on a piece of paper) You are bending the "jaws"
They will go down to -.005 without hurt ( no jaw bending!). But you may see wobble as parallel holding on the work axis is tapered!
For odd size work, Thats what the old collets are used for. got a lot of them!

Rich

krems
12-31-2006, 01:37 AM
As was expected on a used piece of equipment the collet closer has a slight dent in it and I'm sure it';s causing the poor accuracy. Spindle runs true but when indicating in the collet closer /holder (4 1/2"mt) I'm not able to get it to run true. I'll have to see if I can smooth out the dent. I think the collets are all new. I'll try one thing at a time. Even if I can get it lined up to run true in one location I can mark it for reference. Good idea

Once I get everything runing true then I can test each collet for accuracy.

Rich:...nice buy on the used collets. I just looked through a catalogue and these could get expensive if you wanted a complete set.

Happy New Year from Montana................Krems

HTRN
12-31-2006, 01:49 AM
Royal guarantees all it's collets to be .0005 TIR or better. Note that not all of their collets are made in China - only the ones marked "Tuff Pro" are... Although that's now most of the entire line..:( As recently as 10 years ago, Royal offered a real first class product, even offering special 5C grinding collets that haven't been spread that offer really tight accuracy for sharpening endmills... Guess that era is now over..

Does Anybody besides Hardinge and Lyndex make a quality collet anymore?

HTRN

DR
12-31-2006, 02:12 AM
Does Anybody besides Hardinge and Lyndex make a quality collet anymore?

HTRN


Lyndex doesn't make quality collets, at least not quality enough to be mentioned in the same breath with Hardinge.

Next time you buy a Lyndex collet, check the box, it'll say made in Japan. Then check the collet, likely it won't even have the Lyndex name on it, much less the notation that it's made in Japan. Maybe only the box is made in Japan?

J Tiers
12-31-2006, 02:27 AM
If it was Japanese it would probably be good.....

I bought one, a 3C, and I think it was from china....... it is ok for runout, but the threads are slightly different from a Hardinge.

HTRN
01-07-2007, 04:36 AM
Lyndex was bought out by Nikken, and I can tell you that the Nikken Stuff is $$$$. I worked at one place that had a coupla Nikken integral shank Cat 40 boring heads, and They paid something like $700 each for them back in the early 90's. That same shop used Lyndex and Parlec Cat 40 toolholders(mostly Parlec's), and Lyndex collets - All DA's, mostly 180's.

We never had a problem with the Lyndex collets, aside from occasionally having to replace a couple of them.


HTRN

Alistair Hosie
01-07-2007, 04:07 PM
If there is a dent in it can't you send it back for an exchange?Alistair

Alistair Hosie
01-07-2007, 04:09 PM
Happy new year from Scotland Krems regards. Alistair

nheng
01-07-2007, 06:16 PM
I have 3 Lyndex collets, purchased new from MSC for a job. The faces were heavily segmented (difficult to photograph), perhaps ground late on a Friday afternoon with a loaded wheel. The OD threads were a bit on the rough side also. The Hardinge, by comparison has a jewel-like appearance and accuracy to match. In my recollection, the Lyndex box said Japan. They also had sloppy radial slotting and heavy entry chamfers. Both collets shown are 3/32 although the Lyndex looks a bit larger due to the chamfer.

http://img.photobucket.com/albums/v319/nheng/misc/hardinge_lyndex_collets.jpg

HTRN
01-08-2007, 05:25 AM
Your experience is unusual. Nheng. We never got chewed up collets, and they were always problem free. But then, We ordered them direct from Lyndex.


HTRN