Info on Indexers?

[DocsMachine]

I have a compact Trak mill, and I have several projects on the table that could use an indexer. I am quite ignorant of such things, apart from the general concept of how they work. (For example, the difference between an indexer, and a 4th axis.)

I'm told that both Haas and Hardinge indexers will basically plug right in- I assume others will, too, but those have at least been confirmed by the factory.

I'd like to have a better handle on what I'm after, before I drop the coin on one. Looking around at used ones online, I see some listed as 7-pin or 14 pin (which I assume is just the generation of the controller) with and without brakes, and either servo or brushless motors.

My table size is limited (2Op machine, about a 14" square table) and given my usual parts, a 5C indexer is fine. If I had my druthers (whatever those are) I'd prefer a Hardinge taper nose rather than threaded, simply because I have a 3-jaw and a couple pot chucks to fit. Threaded is not a deal-breaker, most of my pieces will be in a standard 5C collet.

Recommendations? Brands, models or generations to look for? High-number production isn't a key issue, so I don't need the latest-and-greatest, lightning-fast version. Affordable is more important.

Thanks in advance.
Doc.

 

[mhajicek]

I don't know about controlling them directly with your Trak mill; it would need to have drives and wiring for a fourth axis, and I don't know about compatibility. Haas rotaries can be bought with a standalone control box, which you can use a number of different ways. You can program a series of moves, and cue it either manually or with a signal pulse from the machine, or you can connect it via RS-232 and send it commands with DPRINT. Here are a number to choose from:

Rotary Tables
Indexers

All are capable of full 4 axis. I have an HA5C-T on my CM-1 (12" x 10" travels), but I had to take the collet closer handle off for clearance.
HA5C-T | Single Spindle 5C indexer | Rotaries and Indexers – Haas CNC Machines

One good thing about the Haas rotaries is you can find used ones and their control boxes easily on auction sites and at used machine dealers.

 

[PROBE]

This TOUCHDEX - KAWATATEC CORP. is worth checking. They are additional suppliers of this type of mechanically operated indexers. No interfacing problems, no cabling.

Stefan
Cogito Ergo Sum

 

[DocsMachine]

I don't know about controlling them directly with your Trak mill; [snip] Haas rotaries can be bought with a standalone control box, which you can use a number of different ways.

-That's my understanding of it. The mill software just issues an index signal or pulse, and the standalone controller is what actually moves the indexer spindle. And one has to program a delay in the mill's G-code so it 'waits' for the index to complete.

Supposedly that signal- and presumably electrical connection- is fully compatible between my mill and a Haas or Hardinge indexer- and presumably others, as I said, but those two are endorsed by the factory.

One good thing about the Haas rotaries is you can find used ones and their control boxes easily on auction sites and at used machine dealers.

Haas and Hardinge both. But that's my question- in looking around, I've found a handful of different versions of both, and I don't really know what I'm looking at. What features do I want, what capabilities am I looking for, is one better than another for certain uses, etc.

They are additional suppliers of this type of mechanically operated indexers. No interfacing problems, no cabling.

-That's a new one on me. I had no idea such a thing existed!

Doc.

 

[Mud]

-That's my understanding of it. The mill software just issues an index signal or pulse, and the standalone controller is what actually moves the indexer spindle. And one has to program a delay in the mill's G-code so it 'waits' for the index to complete.

Supposedly that signal- and presumably electrical connection- is fully compatible between my mill and a Haas or Hardinge indexer- and presumably others, as I said, but those two are endorsed by the factory.

The Haas boxes issue a cycle completed signal back to the Trak control, to tell it to proceed with the next command, no dwell needed. There are 4 wires in the interface cable, 2 for the signal to the box to "do it" and 2 for the signal to the control that "it's done". The cable is plug and play, available from Trak or I got one custom length from an ebay seller,

Haas and Hardinge both. But that's my question- in looking around, I've found a handful of different versions of both, and I don't really know what I'm looking at. What features do I want, what capabilities am I looking for, is one better than another for certain uses

a 4th axis is controlled by the machine;s control and synchronizes with the other axes. Prototrak doesn't do that, you need an indexer.

There are air operated indexers, like the Erickson 400 and 600 indexers. Those need an interface box built to work from the Trak control, I don't know of one to purchase. The Trak control will handle very little current , so the solenoids need to be operated by low current draw relays, and then you have to rig up a momentary contact for the completed operation signal for the mill to go on to the next operation. It's doable, but if you want to get up and running anytime soon I recommend buying a Haas indexer with a box. I ~think~ any box operated unit will work with your control,

 

[mhajicek]

I've found a handful of different versions of both, and I don't really know what I'm looking at. What features do I want, what capabilities am I looking for, is one better than another for certain uses, etc.

What do you want to do with it? A 5C unit will allow stock through the spindle. You can get 5c fixture mounts to make custom fixtures:

1x6" 5C Fixture Mounts

I got the HA5C-T with thrust bearings so I can use a tailstock with it, without fear of damage.

Haas calls the 5C units "indexers" and the platter units "rotary tables", though they have the same interface and control capabilities. A platter style "rotary table" is better for mounting large fixtures, like a vise trunnion:

Samchully CNC Rotary Tables and Fixtures - Martin Trunnion Tables

 

[DocsMachine]

The Haas boxes issue a cycle completed signal back to the Trak control, to tell it to proceed with the next command, no dwell needed. There are 4 wires in the interface cable, 2 for the signal to the box to "do it" and 2 for the signal to the control that "it's done".

-I'd inferred that from some of the pictures I've seen, thank you for confirming that. I'm assuming that's what Trak means when they say the Haas and Hardinge indexers are compatible- they presumably use the same 'start/stop' signals/wiring/polarity/whatever.

[...] but if you want to get up and running anytime soon I recommend buying a Haas indexer with a box. I ~think~ any box operated unit will work with your control.

-Why I'm here. I see a ton of indexers with different controls, different motors, different cable connections (between the motor and standalone box, presumably) and so on, just trying to get a better handle on what I might need before I blow the cash on something that, with my luck, would turn out to be the wrong one.

What do you want to do with it? A 5C unit will allow stock through the spindle. You can get 5c fixture mounts to make custom fixtures[.]

-99% will be, effectively, "second op" work, typically doing some cross-drilling to a part out of the lathe. Typically, 5C collet capacity will be all I need.

One question I had, though, was it seems most of the 5C indexers, even newish ones, appera to use the older-style threaded Hardinge nose, rather than the later 4-degree taper nose.

I have a 4 degree 3-jaw chuck, and a couple of "pot" chucks, that I have no particular need for on an indexer, but which would be nice to have the option in case something crops up in the future.

I'm assuming the indexers use the threaded nose because it's more secure against milling and drilling forces than the plain-taper is?

Kind of an irrelevant question, since as I said, the bulk of my need is for standard collet-sized stuff anyway, but definitely curious about it, if anyone knows.

I got the HA5C-T with thrust bearings so I can use a tailstock with it, without fear of damage.

-A few of my proposed pieces will indeed need a tailstock, which I assumed I could buy separately, if I can't find one that comes with one.

Are thrust bearings not necessarily a given?

Doc.

 

[Garwood]

CNC indexer protocol is basically standardized. The differences lie in how you have to interface it with the machine control. If you had a machine that lacked spare M-code I/O and had to make it work you would probably hook into some unused optional function and for that you may need extra relays to flip flop polarities, etc.

CNC indexers are usually made to be configurable for what your control wants to see- You set the parameters to determine what kind of signal the indexer sends to the control.

Haas indexers are user friendly. The control box is very easy to program once you get the hang of it. Outside of that they are not the best quality, but they work.

I've never seen a Hardinge CNC indexer/4th. I wouldn't expect much from them.

 

[mhajicek]

Are thrust bearings not necessarily a given?

Doc.

Correct. I think the platter style "rotary tables" will have them, but 5C's without the "T" will not. Thrust bearings add about $1k to the new price.

You can probably do light work with a tailstock on a non "T" model, just keep that tailstock pressure low. Could void warranty on a new unit.

Another option is instead of a tailstock, use a steady rest, which will not apply endwise force.

 

[DocsMachine]

CNC indexers are usually made to be configurable for what your control wants to see- You set the parameters to determine what kind of signal the indexer sends to the control.

-Makes perfect sense.

Haas indexers are user friendly. The control box is very easy to program once you get the hang of it. Outside of that they are not the best quality, but they work.

-Not makin' jet engine parts, here.

I've never seen a Hardinge CNC indexer/4th. I wouldn't expect much from them.

-All I know is Trak endorses them as being "fully compatible" with the machine's TMX control, and several of their demo videos show an indexer clearly labelled "Hardinge", so I can't imagine they'd be all bad.

But, I'm not stuck on any one marque. I don't care who makes it, as long as it works, is reliable, and doesn't cost me an arm and all three of my firstborn.

I'm assuming that Yuasa and other marques would be similarly compatible, but I'd also want to be a lot more certain of that before I drop a few grand on one.

Another option is instead of a tailstock, use a steady rest, which will not apply endwise force.

-There's an idea.

Thinking about it, I think I'd rather have a tailstock, so I don't need to worry about chips getting caught under a steady- rollers or otherwise- and maybe scarring the OD. But nevertheless, that's a good idea.

Doc.

 

[mhajicek]

Thinking about it, I think I'd rather have a tailstock, so I don't need to worry about chips getting caught under a steady- rollers or otherwise- and maybe scarring the OD. But nevertheless, that's a good idea.

Doc.

A lot of the ones I've seen have a bushing or bearing, rather than rollers, supporting the tail end of a fixture. So chips aren't a problem.

 

[Vancbiker]

I’ve seen more than one place just mount a limit switch near the edge of travel to bump with a tool to start the indexer. Some place an M0 immediately after in the program so the operator can verify the index is complete before continuing on. Others have just plugged in a dwell to give time to complete. A bit riskier, but eliminates work for the operator.

These were in situations where no external M code outputs and corresponding MFIN signal were available or the user lacked knowledge of how to wire into an existing interface.