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View Full Version : A collet question? (Probably dumb)



torker
02-21-2008, 07:43 PM
Hey guys! I finally took a few minutes to play with my lil' Weiler turret lathe.
Got some collets delivered yesterday(Thanks for the tip Willy), reversed the old repulsion induction motor (that was easy) and put a collet in the collet closer. Was monkeying around adjusting the collet closing pressure when it dawned on me...should put oil on the collets..right?
Then... if you're doing a long production run, do you stop every now and then and put a bit of oil on the collet again?
Thanks!
Russ

wierdscience
02-21-2008, 07:47 PM
Won't matter one way or the other since both the collet and the spindle are hardened.Besides whatever coolant you use will take care of getting things good and messy:D

torker
02-21-2008, 07:53 PM
OK...Thanks Darin. Right... coolant...I hadn't thought of that. This thing has the pan but no system.
Time to buy another cheap 3 gallon parts washer I guess.
Russ

Oldbrock
02-21-2008, 10:38 PM
Torker, how in the hell do you have any time to clean up and get on the computer.You did a gazillion things in an afternoon, put some posts here and must have spent another 8hrs after supper. Are you one of these guys who doesn't sleep? ( must be a young buck) Peter in Glade BC

DR
02-21-2008, 11:31 PM
Yep, it's a very good idea to put some lubrication on the collet or in the spindle. We use a can of anti-seize grease (because the can has been around for ever and it has a nice dobber brush built in to the screw top).

I run long production runs on my 5C machines. I know for a fact coolant is not enough lubrication. Collets begin sticking after a few hours if not lubricated.

The amount of stick-ness of a collet is inversely proportional to it's cost. Hardinge collet have less tendency to stick than offshore imports.

torker
02-22-2008, 12:27 AM
Thanks guys! Yaaa... I made my first chips with the lil' Weiler tonight. Holy smoke is that a stout little bugger. Makes my china (note lower case) junk 14X40 look like a pile o' crap.
Didn't do a whole lot. I mounted up a (dull) 1/2"sq HSS lathe bit just to make a few light chamfers and dig the point in to make a little groove or something.
Funny... the little chamfer ended up as wide as the bit was ground .About 1/2"... zero chatter...no gunting..nothing but a steel ribbon rolling off.
Dig the point in and feed it in with the hand lever...prolly coulda used it for a cutoff tool...lol!
OK.. enough bragging...got another question...
How the heck do you know if the collet is adjusted tight enough?
The first cut I made... the piece spun in the collet. I think i over tightened it after that but it didn't spin.
So is this just experience? After awhile can you feel the closer lever when it closes and feel if it's tight enough or is there something a little more to it?
Thanks!
Peter...ya I get a few hours sleep every night. Cut it short tonight.. my back is raisin hell again and i'm choked at a customer (see new post)
Russ

JRouche
02-22-2008, 01:59 AM
I put a lil light oil, doesnt matter what type really. I do it not so much as a corrosion preventative but mostly so I have a good sliding, lubricated surface for the taper. You know, when you are pulling the taper up snug it just helps me to think Im not draggin dry tool steel against tool steel. And it helps to give a better feel for whats tight and whats just friction. Then, I basically apply a strong pull on the handle. I mean leaning against it abit. I try to make sure Im pretty darn close to the collet size to the work size too. I have 64ths collets so it works out there is always a right sized collet.. I may be over tightening but after too many slips which I really dont like I crank it down. Again, Im not over springing my collets, right sized collet helps. JRouche

GKman
02-22-2008, 07:14 AM
I put a lil light oil, doesnt matter what type really. I do it not so much as a corrosion preventative but mostly so I have a good sliding, lubricated surface for the taper. You know, when you are pulling the taper up snug it just helps me to think Im not draggin dry tool steel against tool steel. And it helps to give a better feel for whats tight and whats just friction. Then, I basically apply a strong pull on the handle. I mean leaning against it abit. I try to make sure Im pretty darn close to the collet size to the work size too. I have 64ths collets so it works out there is always a right sized collet.. I may be over tightening but after too many slips which I really dont like I crank it down. Again, Im not over springing my collets, right sized collet helps. JRouche

I just started using 5-C collets (1/8" To 1-1/16" by sixteenths) and was surprised at the lack of size range. They seem so rigid that they only fit the size listed within a few thou. I bought them thinking that that they would be flexible enough to cover the range. Guess that's what I wanted to think. How are they supposed to fit?

J Tiers
02-22-2008, 07:54 AM
You obviously want ER or Jacobs collets....... Just a few cover the whole range of sizes.

Not only won't a 5C cover THAT gap between sizes, they actually won't cover the space between the 1/64 sizes either. Or they should not be forced to, anyway.

If you do, you end up holding only by the edge at the back or front of the thru-hole, and it will be wobbly. That can be cheated a bit, but may permanently distort the collet.

I have some 3C collets (got used from Sobel) that are so "spread" that it takes a hammer to get them seated in the closer. And that is just to "slip them into place". obviously that "spread" will take a toll on the gripping capability also.

torker
02-22-2008, 08:14 AM
JT.. I hear you about the ER collets. Sir John has long recommended them over a 5C.
I got my first taste of 5C shortcomings last night. I thought I could just pop a piece of 1/2" hot rolled round in the collet and go to makin a few chips. You know that didn't work. Ended up putting the pieces in the other lathe and turning them down to near perfect size(had to get within a thou) just so I could play a bit.
JR.. That's about what I ended up doing. I had to sort of lean on the closer lever to set the collet. I was thinking that may have been too tight... maybe not.
My machine takes 3/4" tooling but I'm betting I could make the 5/8" work. In fact.. a few guys here said I'd have a more accurate setup by doing that. Ya.. we'll talk about that.
So.. oil it is.
I have sooo much to learn about this thing!
Russ

DR
02-22-2008, 08:45 AM
JT.. I hear you about the ER collets. Sir John has long recommended them over a 5C.


It all depends on what you're doing. Use cold draw stock, 5C's have no comparison. Slip the work into the collet and go. For multiple part jobs you can't beat the 5C.

Hot rolled stock isn't recommended for any kind of collet. It's not perfectly round, among other problems.

5C's are so far more versatile than ER's there isn't any comparison. 5C's are available in square, hex, expanding style, soft (emergency style) for machining to size, oversize step chuck style, plastic and brass for non-marking. One style of collet, 5C, will span the entire size range from tiny to up to several inch diameter. All sorts of indexing heads and spin indexers are available to take 5C's, we transfer jobs from the lathes to the mills all the time taking the collet with the job.

This whole ER as work holding device only exists in the hobby world. Don't waste your time or money.

Also, you guys who buy the cheapo, offshore 5C collet sets are being short changed. Half the time the collets are so poorly made an on-size piece of stock won't fit into the collet without you having to spring it open. Buy quality as you need them rather than a complete set of junk.

Russ, consider yourself very lucky your Weiler is setup for 5C, it's the best you could ask for.

RobbieKnobbie
02-22-2008, 09:22 AM
I just started using 5-C collets (1/8" To 1-1/16" by sixteenths) and was surprised at the lack of size range. They seem so rigid that they only fit the size listed within a few thou. I bought them thinking that that they would be flexible enough to cover the range. Guess that's what I wanted to think. How are they supposed to fit?

The rule of thumb I've always went with is this: slide the piece into the collet, then squeeze the collet with your fist. Twist the stock with your other hand. If the collet can lock down on the material with just hand pressure then it should hold pretty well once mounted in the machine.

If you can't get the collet to close down enough with hand pressure then the machine wont be able to generate enough pressure to resist cutting forces.

pcarpenter
02-22-2008, 12:46 PM
I am no expert, but I would definitely keep lubricant on the back side of the collets. Hard surfaces rubbing on hard surfaces are a recipie for galling. Gall up a spindle and you will be really sad as it won't be round.

I figured the "by 64th's" set is the way to go coupled with perhaps a few of the u-turn-em soft collets to make anything else you need. A few square collets could be big time savers too. Now I need to go get my collet closer made.

Paul

GKman
02-22-2008, 02:50 PM
It all depends on what you're doing. Use cold draw stock, 5C's have no comparison. Slip the work into the collet and go. For multiple part jobs you can't beat the 5C.

Hot rolled stock isn't recommended for any kind of collet. It's not perfectly round, among other problems.

5C's are so far more versatile than ER's there isn't any comparison. 5C's are available in square, hex, expanding style, soft (emergency style) for machining to size, oversize step chuck style, plastic and brass for non-marking. One style of collet, 5C, will span the entire size range from tiny to up to several inch diameter. All sorts of indexing heads and spin indexers are available to take 5C's, we transfer jobs from the lathes to the mills all the time taking the collet with the job.

This whole ER as work holding device only exists in the hobby world. Don't waste your time or money.

Also, you guys who buy the cheapo, offshore 5C collet sets are being short changed. Half the time the collets are so poorly made an on-size piece of stock won't fit into the collet without you having to spring it open. Buy quality as you need them rather than a complete set of junk.

Russ, consider yourself very lucky your Weiler is setup for 5C, it's the best you could ask for.

At what price does cheap start. Where and when did you find those poorly made collets. Are Swiss offshore? What if they are German but made on Chinese machines by Armenian green card workers? You know that all dark haired Armenians are descendants of Attila the Hun's army? Makes 'em chinks right? We need to know these things.

RobbieKnobbie
02-22-2008, 06:02 PM
damn good point. And what of BMW's made in the Carolinas by immigrant mexicans? I can't take this intermingling anymore, I need something more concrete to be prejudiced about.

JRouche
02-22-2008, 09:43 PM
I just started using 5-C collets (1/8" To 1-1/16" by sixteenths) and was surprised at the lack of size range. They seem so rigid that they only fit the size listed within a few thou. I bought them thinking that that they would be flexible enough to cover the range. Guess that's what I wanted to think. How are they supposed to fit?


Yup, yer right. They are very stiff, not much spring designed into them compared to say a ER collet. Less slices is they way I see it. I have a 64th set so it covers what I need. Then it still can become a pain to fit the stock into the collet cause I am so close to the OD of the stock. If there is a burr or anything forget it. JRouche

JRouche
02-22-2008, 09:45 PM
My machine takes 3/4" tooling but I'm betting I could make the 5/8" work. In fact.. a few guys here said I'd have a more accurate setup by doing that. Ya.. we'll talk about that.

Just lemme know, I give you what I can and what you can use.. JR

JRouche
02-22-2008, 09:53 PM
You obviously want ER or Jacobs collets....... Just a few cover the whole range of sizes.

Thats funny.. Dunno why but I never really thought to use the ER collets in the lathe. I have a full set of ER-40, 32 and 25. I use them on the mill. Well sometimes. On the bridgeport I use Acura-flex (nuther flex collet design similar to TG collets) collets.

The 5C is very versatile in my shop. The two lathes take them. The horizontal mill takes them.. And my cutter grinder takes them. Not to mention the fixtures for the vert mill that use them. They are here to stay.. Guess you really need all types.. Hmmm, a TG set??? LOL JRouche

clutch
02-23-2008, 02:03 AM
This whole ER as work holding device only exists in the hobby world. Don't waste your time or money.


Gee, just about every cnc we have, that is holding a rotary tool is using an ER series collet.

Clutch

DR
02-23-2008, 06:32 AM
Gee, just about every cnc we have, that is holding a rotary tool is using an ER series collet.

Clutch

Mine too.............so what's your point?

I have 5 CNC machines, every one uses or has the ability to use ER's for tool holding. Not a single one has ever used an ER to hold a workpiece.

The majority of my workholding is by power assisted closers, air or hydraulic. That's the only way my machines can be run efficiently. To date I've never seen a power closer I could use with ER collets.

GKman
02-23-2008, 09:07 AM
Mine too.............so what's your point?

I have 5 CNC machines, every one uses or has the ability to use ER's for tool holding. Not a single one has ever used an ER to hold a workpiece.

The majority of my workholding is by power assisted closers, air or hydraulic. That's the only way my machines can be run efficiently. To date I've never seen a power closer I could use with ER collets.

If I had 5 CNC machines, I think I'd let them pay for a plumber to fix my house full of obsolete plugging up piping instead of trying to patch it up with information requested here but each to his own.

torker
02-23-2008, 09:25 AM
Whoa! What's that all about?
Anyway...
Yes I just bought cheap collets. Just a 17 piece set. I didn't want to spend a bunch of loot on good ones to find out my new(to me) lathe was a POS.
And I was very happy to find it was a 5C machine. I've been reading what I can find on these Weiler turret machines. I lucked out. They come with 5C and also some special German (or Euro) collets that are hard to find.
Someday I'll probably end up with every 5C collet made as I have the turret machine now and I already have three Spindex's that'll be used for various things.
Good thing for cheap collets I guess. I'll maybe end up wrecking a few while I'm learning this turret black magic stuff :D
Russ