OPTIMUM D 240 x 500 DC VARIO

[ARM]

Hello there
Has any of U kind Folks had any experience with this machine. 'Tis made in China with German (precision) Engineering support and partnership. A bit more costly than the usual Far Eastern Equipment, but with much more enhanced and accurate Toolmaker's precision features. And the nicest part, this particular Model has speeds in the 4.000 RPM range. BTW am not in any way promoting their stuff. !!!
As a tyro and rookie we need advice on whether a 5C COLLET CHUCK or an ER25/32 System is better.
Personally would prefer the 5C. However, as this lathe has European foundations and is geared (forgive the pun) for our hobbyist market, this particular Model utilises an ER Collet system and the Spindle Mountings are in Metric measurements, as opposed to the 5C Collet Chucks available in the USA in imperial co-ordinates. As an example Toolmex, who stock good quality 5C Chucks don't stock Flanges/Adaptors in these Metric measurements. Ideally, we would like an 4" 5C Chuck.
Now the numerous questions to resolve our quandary.
Would we be able to purchase a 5C Collet Chuck for this Model ???
Does any one know of where we may be able to acquire ADAPTOR PLATES for this Lathe ??? Please don't ask or suggest we turn our own. Wouldn't know where or how to start.
Will we be able to work up close to the ER Collets since we intend turning very small items ???
The 5C Collets have a nice convex shape which will permit one better access to stock with, say 8mm Cutters.
If these Adaptors are not commercially available then how difficult would it be for a good, experienced Toolmaker to make one ??? We looking at Cost here, as well.
And finally, we accept that SPEED would be important to be able to work efficiently with COLLETS.
But, and that is a BIG BUT, how critical is speed in this equation ???
For the record, permit us to say that it is only through the benevolence of U kind Folks that Forums like these flourish to the betterment of one and all, and we are indeed immensely grateful for that.
Thanks in anticipation.
ARM

[swatson144]

I have no experience with this brand of machine. I did look it up to see if I saw anything at odds to your desired goals.

It claims to have a #4 Morse taper in the spindle. I doubt you will be able to run a 5C in it, using the conventional through spindle draw bar and adapter. A 5C draw bar measures 35mm so a little big for the spindle bore (throat). For most collets you'll likely be affixing the holder on the spindle vice in it because of the small spindle bore leaves little room vor a hollow drawbar.

I wasn't able to determine the spindle threads and I'd certainly want to make sure that they were fairly standard, most in this class are 1 1/2" by 8TPI or 1 1/4-8. Yes even the Chinese lathes. If you don't have access to a larger lathe you'll be wanting to buy partially machined back plates, flanges etc. It's vexing to try and cut a 6" backplate on a 4" chuck, but it's easy if you can thread it on the spindle and cut the spindle register then flip it and face it to cut the chuck register.

If finish is important most of these machines with a single lead screw cut on the 1/2 nuts and therefore are simply cutting a fine thread. Not an insurmountable problem as swapping position of the gears on the lead screw will have it cutting at a slow feed but you have to swap again to thread.

As to speed, Cutting speed would be determined by the material and diameter. If you will be making lots of the same parts you will defiantly want to use a work holder that will allow a length to pass through the spindle. Machine, Part, then advance the stock.

I'm not sure why you are all twisted o'r the axles about collets. Personally I only use them on my machine when I'm using precise stock of small diameter and need a precise product without turning the OD.

Hope that helps somewhat. You may also want to look at some of the 9x20 lathe sites. Just google 9x20 and you can see much more info on this class of machine.

Steve

[stevec]

Steve, I'm with ya on most of your reply. I just don't understand "I'm not sure why you are all twisted o'r the axles about collets."
Steve

[swatson144]

Oops sorry, "Twisted over the axles" or making something a bigger concern than it perhaps needs to be. By all means it is better to plan ahead, but often we find ourselves overly preoccupied with tooling that just isn't required for the use.

Generally the little 3 jaw works great.

Steve

[swatson144]

The major concern I had for my 9x20 was to get a 4 jaw on it. After installing a decent 4 jaw if collets are needed then the holder can be setup in the 4 jaw and dialed in to perfection. There is little point in chucking a holder in the 3 jaw as it will only be less accurate than the 3 jaw.

I never really looked for a 4MT holder/adapter, "hollow drawbar" collet arrangement since my 9x20 is only 3MT. There may be one out there that meets your need. I have a 5MT-5C on the 12"x36" and stumbled onto every thing but the drawbar for 25W.

Pretty much my collet planning was to find the costly answer that would work if required. In the case of the 12x36 it was about a 1200$ answer. Fortunately in the mere matter of a couple weeks I came up with most of 2 collet sets holders and all but 1 drawbar for less than 100$ the bulk of which was the 5MT-5c adapter from grizzly for 51.20$ delivered. Plan for the worst and hope for a lucky break.

There are always things needed more than collets IMHO and it's a goodly expense in them, and I am on a budget. So I always get what I have to have, and hold off on the rest until I have to have it, or stumble into a very good deal.

Steve

[ARM]

STEVE
Hi and thanks for Your comments.
The only reason we are making a big deal about these COLLETS is that we want to turn these small Thumb Bobs and other parts for our Custom knives.
Attached is a pic of one of our Folders with the neat Thumb-Bob on the blade.
And we think it would be a walk in the park to turn this from small diameter stock with Collets. You are looking at a 2.4 mm recessed shank, body around 2.9 with a head of 3.5 mm. We do have a much bigger Lathe, a 14 x 40 to be exact, which is really intimidating to work on. Remember we are rookies.
We are definitely not thinking of getting a DRAW-BAR collet system like Your Hardinge's etc. What we had seen and are getting from Toolmex for our bigger machine is a SPINDLE-MOUNT BISON Collet Chuck. And we were hoping U Guys would be pointing us in that direction with an ADAPTOR compatible for the OPTIMUM.
However, we appreciate Your input and will think over what U have just highlighted.
Thanks once again and take care
kindest regards
ARM

[swatson144]

Ok that explains it! You are planning on production runs of small parts which is exactly where collets shine. The other reason would be for extreme accuracy, which would require a whole different, more costly setup.

I'd perhaps even be looking at some of the smaller ER collets like the 8 11 or ER16 thinking that the holder would be less in the way. Something like this one http://www.ebay.com/itm/New-C3-4-ER16A- ... 2566fa6c02 with a bit cut off and a bushing on the back end of the spindle to support the stock. ER16 will hold up to 10mm which should be plenty for most folding knives. You could just fit it up in the machines chuck and use it. Not particularly recommending that one but it's the idea I'd be heading on a budget with a definite purpose in mind. If you are only going to be running a few sizes of stock then you can buy good collets in the size you need foe about the same money as a cheap set.

Steve

[GlennW]

Hello ARM,

Since there are two fairly similar threeads going that you are posting in, I'll add my reply here as well as the other thread.

5C are work holding collets and come in just about any size you would ever need, but the deviation from the designated collet size is minimal for accuracy. ER are tool holding collets and have more size flexability. ER don't like to grip short parts. 5C come in "blanks" which can be machined to accept and locate short or stepped parts, or threaded to grip threaded parts. 5C are also available in square and hex as well as round. If you are clever, they can even be shaped to grip just about any shape part with a bit of EDM work. They make expanding 5C collets as well for gripping the ID of parts, some actuated by the collet closer system.

5C are, or it seems, designed mainly to be used with some form of quick operating draw bar system, which speeds up part loading, unloading, or stock movement, which is superior to ER. The ER need to have the nut backed off to break the grip which is very slow by comparison.

Two different animals...

I use ER for tool holding in my CNC mills, but 5C for work holding in my lathe or fixturing on my mills or grinders. I find 5C far more versatile for work holding than ER.

YMMV depending on your application.

You mention that you are only rookies.

You won't be a rookie forever, so what seems appealing presently for your needs right now, may not be a suitable in a few months or a year...

[ARM]

I'd perhaps even be looking at some of the smaller ER collets like the 8 11 or ER16 thinking that the holder would be less in the way. You could just fit it up in the machines chuck and use it. Not particularly recommending that one but it's the idea I'd be heading on a budget with a definite purpose in mind. If you are only going to be running a few sizes of stock then you can buy good collets in the size you need for about the same money as a cheap set.
STEVE
Hi
We do have the ER 16 Collet chuck set with the straight shank and would indeed give it a shot on the 3 Jaw chuck. Would also have to get some small shank Tooling in the 6-8mm size. thanks for taking the time.
kindest regards
ARM

[ARM]

GLEN WEGMAN
Hi
That was a very good background to the application of these Collets. Would look at both, try them out and really experience them for ourselves. Otherwise it would all remain theory.
Do forgive our ignorance, we did not hear about this before - "YMMV"
Is it You must make verification ??
We did see 5C Universal Stops on a Catalogue. However, the Salesman said these were only necessary if we were machining multiple parts and would not be needed for single parts. Now that U mention it won't we have a problem holding small items of a given stock which have very little recess into the chuck itself ?? We accept the gripping force on either the 5C or ER 16 would be tremendous at the face. Won't speed now compensate for the minimal removal at each pass of the cutting tool ???
Once again a gracious Thank You for taking the time to enlighten us.
LORD BLESS
aRM

[Harold_V]

Do forgive our ignorance, we did not hear about this before - "YMMV"
Is it You must make verification ??

In Glenn's absence (he's not online as I type), YMMV means "your mileage may vary". In other words, you may experience a different outcome, but in this case, you can take Glenn's comments to the bank.

We did see 5C Universal Stops on a Catalogue. However, the Salesman said these were only necessary if we were machining multiple parts and would not be needed for single parts.

Such stops are not very reliable unless you hold the diameters that will be gripped to exceedingly close tolerances. Because a collet closes by collapsing, a function of drawing the collet deeper in to the closer, holding lengths can be troublesome. You can stop a part reliably by using a stop that mounts in the internal spindle taper. You can also hold lengths very reliably by the use of soft jaws in lieu of using collets. That isn't quite as convenient for small work, however.

You have not asked my advice on selecting collets, but Glenn's comments are worth their weight in gold. Using an ER series collet for varied sizes is a recipe for long term problems. When you use the collets through their full range, they are flexed excessively, leading to collets that are in pieces instead of one piece. You are far better served to use a single taper collet, and use the proper (nominal) size. Single taper collets are rather restrictive, although they will grip through a slightly larger range than may be apparent. The problem is, when you go beyond nominal size, the collet grips only at the rear, and when you go below nominal size, they grip only at the front. That permits parts to be loaded misaligned axially (they can be less than perpendicular).

Harold

[ARM]

HAROLD
Hi
OK !
We would now formally ask Your advice, please.
What would U suggest, as the bottom line in finalising this problem of ours.
Which Collets to get and which Collets to utilise permanently ??
To be or not to be...............that's the ultimate question, so what's it gonna be ??
We await Your esteemed further comments.
thanks and kindest regards
aRM