tapping in SQTmsy lathe

[kendo]

we have the live tooling tappers, but they're old and the T/C spring mechanism gets hung up sometimes. The clamps that hold the square end of the tap are worn out, as well as the rubber collets. Replacing and servicing these components is extremely expensive. Plus, changing taps in these holders is such a pain compared to the bilz-style quick change adapters.

I'd like to look into switching over to the quick-change bilz-style tap holders that would be held static in a boring bar holder, but this would entail tapping with the spindle instead of live tooling.

Would this be inherently slower, and less productive?
What method do most of you guys use?
Is there live tooling for these lathes that uses quick-change style tap holders?
If so, I'm having a hard time finding it.

anybody out there using these I just found?: http://www.techniksusa.com/metal/cnaftc.htm
it doesn't look like it's quick-change, as its got set screws to clamp the square end of the tap
now THAT would be a dream come true, a bilz style quick-change T/C tap adapter that nestled right into an ER collet chuck...

[jimiscnc]

the teckniks heads you show at your link are really a floating tap holder in the profile of an ER collet (ER-25? ER-32?) the end of these on the I.D. are rectangular with one or two grub screws to lock on the square at the holding end of the tap. (the square of most taps does not vary per size. It's the same rectangle for one range of sizes, then steps up as tap size increases. Where you could have a hundred different tap sizes, the rectangular size is only about 3 to 5 possibliities for the range of taps these machines accept.

Not very quick change at all. But they can use standard ER collet holders, which is a benefit.

The jacobs style rubber collets you have are excellent in that they are very very small and use a much smaller "head" than a similar range ER Collet. Quick change they aren't!

A bilz type quick change head would take up a lot more clearance in the work area and would create interference problems where the jacobs type would not.

A simple ER collet extension with an ER head, that would accept the techniks ER collets would be a good thing for main spindle tapping. Just mount it like a boring bar on the turret.

Solid tapping has been commonplace on turret type Mazak turn-mills for perhaps the last 7 or 9 years? Prior to this technology becoming standard, driven tools had to have float, just like older m/c's before solid tapping.

SOLID TAPPING at the lathe spindle is still an option to this very day! It is a seldom bought option, however. So you still need an old fashioned floating head if tapping on center using the lathe spindle. However, if you can find a cylindrical shank collet extension that accepts a bilz style head, you will be in biznez for floating taps at the main spindle, using a fixed/lathe style holding arrangement at the turret.

Lastly, if your taps are all the same brand, sometimes there is an adjustable backstop inside for the tool to locate on axially (to the tap) when it's pulled down by the action of the ER collet. This has some decent repeatability, so once you dial in the offset of one tap, it can be swapped out for the exact same brand/part number WITHOUT the need to re-set the tool. The length of the tap is, in concept, a "pre-set" tool!

-90% Jimmy, the Mazak internet fairie

[kendo]

thanks for the reply jim,

none of the machines have solid, or "rigid" tapping so I'm stuck with float holders no matter what

I ordered one of the techniks float collets today, for ER32, and no, they're not quick change so they won't save me any time, but at 100 bucks each, I could buy 3 complete sets for the price of replacing ONE of the mazak float tappers. Parts for those things are so dang expensive! and they're so old mazak doesn't even know what components I'm talking about unless I take pictures and email 'em.

I didn't realize the tappers I currently use were considered "jacobs" style - heres one of 'em on ebay:
http://cgi.ebay.com/Mazak-Live-Tool-...item19bc0f2d79

to me, they seem to take up plenty of room in the workspace, but this shop is my first experience with cnc lathes.

[jimiscnc]

I could be misinforming you about the name of this type of collet. I call them jacobs type because they are pretty unusual in their design. and when you dig through bins of old collets, the "rubber ones" do seem to come in a box marked "jacobs" vulcanized rubber to steel segments is pretty wierd, but hainbuch/microcentric/hardinge all do it with their quick-change lathe spindle collet systems. but these are much bigger than the tiny collets we're discussing here.

i dont quite see how the jacobs design would work at all? I would think that the steel segments would "fold over" or do something wierd to induce run out, but, in the field they are proven and seem to work great. the built in float in the head you link at ebay probably doubles the cost of the head. I think standard heads with floating collets is the way to go. especially with costs and flexibility.

i like ER collets because they are a very common easily available standard. rego-fix in Indianapolis does a great job with ER variations. they have lots of cool solutions for collet type stuff.

i recall daewoos from the late 90's came with at least one floating tap holder ER type collet for their mill-turns.

i think almost all machine tool builders get their tool blocks from german vendors? eppinger, exsys, trudex, Zettl mimatic, edwardandrews.com, usshoptools.com.chevintools.com are some that come to mind. koma, parlec and smw (chicago chuck company, not the old barfeed people) are also in the arena.

-jim

I learned about VDI tools from ten years at Index 1985 to 1995. The VDI tool block was a standard developed I think in the mid 70's by all the German CNC lathe builders of the era. Standards are good!

[Captdave]

I use Maritool floating tap holders ER16, ER20 style with great success.

http://www.maritool.com/Tool-Holders...duct_info.html

I also use a Hardinge TT style floating tap holder where tap depth tolerances are required. They pull out and free wheel while the spindle stops and the reengages once the spindle reverses. They use specific collets with a square drive for the tap.

http://cgi.ebay.com/HARDINGE-TT-3-4-...item53e16d6677