old-style taig spindle

[pepperwood]

I understand that the New taig spindle is threaded for the ER16 collets. While, if I have this right, the old style spindle was designed for a proprietary style by taig. If you were comparing them or using them what would be some, if any, of the other differences to note?? Would I be correct in assuming that it is the same spindle with a different threaded mount? When was this New change instituted? PW

[cameraguy]

old style was threaded 3/4-16 and took a simple collet and nut. decent, but not anywhere near the availability of collets and sizing. also, it wasn't as accurate for runout, nor did it have the clamping (compression) range of a decent er collet. you may never notice depending on what you are using it for.

you have a couple of options;
1) adapters are made to go from 3/4-16 to er16. looks kind of like a toolholder. you put it on the thread you have in place of the nut, you get er16. advantages; cheap and you get all the er16 collet sizes. disadvantages; you still lose out a bit on runout due to the adapter adding some, you also lose a bit of z due to its length.
2) replace the whole spindle, they are only like $100. advantages; lots. disadvantages; costs $100.
3)use what you have. they aren't bad unless you are using doing things -very- intolerant of runout, or you want to use metric and odd sized tooling taig does not have collets for.

the 3/4-16 spindle is still used on the taig lathes, which makes sense as thats what a lot of the lathe tooling is threaded for. as such, i recycled my old-style mill spindle and converted it to a rotary axis/indexer as you can get a chuck from taig (or sherline) to fit right on that thread, and the dovetail plate fits right on the mill table.
so, if you wind up with one extra, auction it off as a current lathe replacement part, or convert it into an awesome rotary table for turning with the addition of a chuck, stepper motor, and a timing belt and pulley.

[cameraguy]

forgot, the adapter is taig part #1045ER, it's $27
(Taig Tools - Desktop Milling Machines and Lathes.) for blurry picture.

also, i don't think there was a specific cut date for the old style spindles. they sold both standard and er mills side-by-side for a number of years, with the er being an additional cost option. it may have started many years ago with proprietary only, and i don't see they offer anything but the er16 now, but there was a huge length of time both were in their catalog together.

[lsces]

The ER16 spindle has been around for a few years, and currently both options are still available. The bearing modules are essentially the same, with the same clearance down the middle of the spindle ( around 1/4"? ) but the ER16 nose has a larger diameter taper and thread so that the larger collet can fit inside. The ER16 collet is around double the length of the original Taig one, and provides a larger range of sizes, while the Taig collet is better suited to a fixes size, only having short narrow slits. That said, the bearing area is only a little shorter on the Taig, as the ER16 is relieved at the inside end.

I've got some pictures which I'll push to the website later ... one shows the collets side by side ...

[Jeff-Birt]

You can also replace just the spindle cartridge, for about 1/2 the price of a whole new spindle. It is easy to do, you only need about 10 minutes, an allen wrench, and a heat gun (and gloves!) Or you can buy a new ER spindle and keep the older style 3/4-16 spindle in case you ever want to use a lathe chuck on the mill.

[pepperwood]

OK! Lets see if I got this right? The mill I'm considering has the "old spindle" configuration. I will need smaller collets (1/16") in order to carve wax designs for jewelry casting.

If I was to purchase the er16 adapter I could use the smaller collets that would be more suitable and available for the application. Then change back to the "old spindle" to use the taig accessories. Such as a drilling chuck, 3 jaw chuck, etc. that thread onto the old spindle if needed? Sort of like having the best of both worlds, if the run-out is within reason.

Just a thought? I believe that small end mill holders are available or could be made to implement the process, although as you pointed out would shorten the z axis and maybe run-out somewhat??

Since I don't have a hands on taig mill in front of me as yet for review. Your posting helps me to get a better idea of what is taking place. Thank you cameraguy as I'm beginning to get the picture.

[Jeff-Birt]

You can use a jacobs chuck with the ER16 spindle as well, you just need the right adapter for your spindle style. With small bits you will be better off with the ER16 collets as run-out will destroy small bits quite quickly. If you have a full set of ER16 collets you can use a great number of drill bits without an adapter. Where shorter drills will work I like to use the carbide micro drills, all of them have a 1/8" shank, so I cna use a 1/8" collet.

[pepperwood]

You can use a jacobs chuck with the ER16 spindle as well, you just need the right adapter for your spindle style. With small bits you will be better off with the ER16 collets as run-out will destroy small bits quite quickly. If you have a full set of ER16 collets you can use a great number of drill bits without an adapter. Where shorter drills will work I like to use the carbide micro drills, all of them have a 1/8" shank, so I cna use a 1/8" collet.

It is becoming apparent that I may have to rethink the "old spindle" methodology. If I understand correctly, and correct me if I'm wrong, you're referring to the "old mill adapter for the ER16 and/or the individual end mill holders for the smaller mill bits? That will have enough run-out carving wax patterns at 10,000 rpms to destroy the bits quickly. Most mill usage will be but not limited to carving wax patterns.

I do not have any of the ER16 collets, As yet, I'm looking forward to purchasing a Taig CNC complete with the package to set up and start the cnc learning curve. I have zip, zero, nada, knowledge of equipment, accessories, etc. required. So it would be easy for a seller to take full advantage of this when suggesting or selling me a machine.

Being on a fixed limited SS income The price on that "old style spindle" type that was offered seem promising. Little by little with the input of those on the forum I'm beginning to come up with some good tips like yours to consider and help clear the way. Thank you very much! PW

[cameraguy]

if you get a chance, buy the ER spindle upfront.

that said, if you have an old-style spindle already, you will be just fine doing jewelry. really. every bit i have ever used for jewelry wax used an 1/8" shank. even my .005 mills. 1/8" shank is standard.
runout is still minimal enough with the old style, and anyway wax won't cause bit destruction problems with chatter like hard metals would. also, the bits that small for wax carving are very short so runout isn't an issue anyway. put on a 3" long bit and end runout that far away might be noticeable between the two collet types, but at 3/4" of length you would have a hard time even measuring the difference.

also, i would avoid replacing the cartridge, just get a new spindle unit if you go that route. the cartridge kit is $97.50, the whole new unit is only $117. you don't save anything.

whatever you do, DON"T use a Jacobs chuck. They are only really ok for drilling - they are horribly inaccurate for micro milling. like at least an order of magnitude worse than the other options.

[Jeff-Birt]

with respect camera guy, the run-out with the original Taig collets can be quite bad. The bits jewelers use are very small and any appreciable run-out will be bad news.

The number one killer of small bits is dropping them on the floor, the number two killer is run-out. You can 'see' the first but not the second.

[cameraguy]

I'll go with that. You have experience with a lot more machines, so if the collets have a lot of variance you would know that best.
I have only played with the old collet type on just two spindles, and on those it was actually quite acceptable. Guess I just got lucky! If you have had experience otherwise, I'll defer to that.

Guess that means you can just use the spindle for a handy indexer. Works great for that job!

[pepperwood]

with respect camera guy, the run-out with the original Taig collets can be quite bad. The bits jewelers use are very small and any appreciable run-out will be bad news.

The number one killer of small bits is dropping them on the floor, the number two killer is run-out. You can 'see' the first but not the second.

Hear Hear - Good observation. I would have to agree with the general consensus that the original old style collets may not be up to snuff? How about making or purchasing an end mill holder say for 1/8" endmills, or smaller, for the old style collets? Could that be done and have tolerable specs & results. There is also the length of the mill holder and mill may contribute somewhat to having too much, whatever that would be, of run-out? PW