Care and feeding of new mill-drill

wrote:


The DTI looks ok and us very usefull, I use a set of endmill holders instead of collets, collets can slip and I didn't need the quick change aspect of the collets.. A good drill chuck is a must. Also a rotary table, angle plate, vee blocks, gee the list is almost endless.....both sources listed are reputable.
DE
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snip-----

Nothing prevents holding drills in a collet, but drill shanks tend to be undersized by a thou or two (by design---twist drills are not straight, they taper towards the shank so they don't bind in the hole) and you'd be seriously restricted as to the number of drills you could hold because of the limited sizes available in R8 collets, which I assume you have. Collets shouldn't be used much beyond a thou or two past nominal for starters, and many of the tap drill sizes are not fractional----so you'd find not many of the sizes you'd desire can be so held. The other problem, albeit it a minor one, is that drill shanks are often quite badly badgered from slipping---which could complicate getting them in a collet. I highly recommend a good hand tightening drill chuck (something like an Albrecht), half inch capacity. They're fast and precise. If you think you'd want to change drills on the fly, you could even entertain buying a Wahlstrom. Big bucks, and sort of dangerous in the half inch size, though. The 3/8" capacity Wahlstrom is a sweet dream.
Harold
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Harold,

Thanks for the heads up on that one. A crazy idea: turn the shanks so they fit? I do not have a lathe, but will probably eventually get a small one.
> The other problem,

Unless it happens routinely in/from the collets, I could always buy replacements for any pose a problem.
> I

I have a 1/2 in Jacobs that seems excellent to me. I'm confident that I will use it many times, but since it adds roughly 4 inches to the spindle, it would be nice to be able to avoid it when feasible; again, the enemies are the difference in bit/mill position, and the clearance for a change. I do not expect to eliminate head movement and registration problems, but I am willing to throw a little money at things that will help make them rare events.
Bill
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Sure! Why not?
Be aware, though, that drills are (slightly) tapered, with the flutes (induction) hardened. There's a small portion of the typical shank where it transitions from heat treated to annealed. It can be ignorant to machine, so stay back a bit from the flutes, and keep the shanks as large as possible, for strength.
In spite of the protestations of the crowd that insist you must hold end mills in end mill holders, collets, in fact, can be a better system, particularly when you're working under certain circumstances. Both have a place, really, but you can run a (commercial) shop with manual machines without special end mill holders with almost no problems. If not, every place I was employed was having a hell of a lot more trouble than they were aware. The real push for end mill holders is sort of a CNC event. Even the old horizontal machines used to have a collet adapter, which was used for holding anything that was collet diameter when it was required. They work fine, and are more precise and more positive drive than a drill chuck, just not quite as fast and convenient to change.

badgered
Collet use would likely eliminate the problem entirely because of the large surface driving the drill, and the ability of the collet to drive well as a result. They rarely slip, although holding a Silver & Demming drill presents a challenge, depending on how it's applied. . It's all up to you----and the draw bar.

think
a
though.
Yep----that's the reason I find myself using collets for drilling occasionally, even though I have a knee mill. I'm not interested in cranking the knee up and down a few inches for one hole, especially at my age. It's a lot easier to change to a collet. Yet another example of your good thinking.
Harold
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    Good waylube on the ways -- it holds on longer than lighter lubes. Probably Mobil's "Vactra No. 2 Waylube" will be a good choice.
    That will probably work well on the column as well.
    What the spindle wants will vary from machine to machine and from bearing type to bearing type.

    Check on the underside of the vise for slots for table keys. If they exist, make a set of keys a bit oversized. and mount the vise upside down on the table to cut the keys to precise width to match the T-slots. (There should be tapped holes for mounting the keys.) This way, you can drop the vise onto the table, work the keys into the T-slots, and you will be very close. For the top precision, you may need to adjust just a little bit, but for most work the keys will get you to where you need to be.
    If the vise does not have slots for keys, mill slots and drill and tap the holes for screws to keep the keys in place. (You may want two sets of slots -- one for the vise at right angles to the T-slots, and another set for the vise parallel to the T-slots. In that case, I would suggest putting number stamps in the keys and the slots so the same keys go back in the same place each time.
    To get the slots running just right, take a chunk of square steel stock, clamp it to the table adjusting for parallel, and then clamp the jaws of the inverted vise to the stock. (This is presuming that the vise does not have a swivel base, of course.)

    Wipe the table and vise down with waylube before mounting the vise, and you should be fine as long as you don't trap water soluble coolant under the vise.

    There are lots of ways -- depending on the indicator. Since I don't know what your indicator looks like, I can't suggest much -- except that I would use collets instead if I had a choice.

    What you *should* do is stone or file to remove the *raised* part of the dings, without cutting into the rest of the surface. Again, rub with waylube after you have filed, so you don't have bare metal exposed to rust.
    BTW -- if you've got a fuel fed heater in the shop -- beware that aside from possibly introducing carbon monoxide and poisoning you, it is also *very* likely to produce water vapor, which will condense on the cold metal for quite a while until you get the tools warm enough. Better to use electric heat, or put heat sources (e.g. light bulbs) inside the machine to keep it warmer than the surrounding air. (And lots of surface lube again.)

    O.K. I'll leave it to others who deal with this problem to make suggestions on this.

    What is the spindle for your machine? The first hit which I checked on "Rong Fu 31" in Google shows that the one being sold has an R8 spindle, so you will use R8 collets. They are relatively inexpensive, good for light work, and should be tightened by the same drawbar which holds in you drill chuck (which is a *terrible* way to hold end mills, though quite reasonable for drill bits.)
    So -- the search for "R8" collets should narrow things down greatly. You won't need a chuck at all for holding them -- your spindle should do that properly.
    For heavy cutting with an end mill, however, you will want end mill holders -- as collets can let the end mill creep downward, cutting an ever deeper slot. This is especially important as you get up to the 1/2" size of end mill or larger.

    Hmm ... something like that could be nice for re-zeroing a DRO (Digital ReadOut -- a device for numerically displaying the coordinate positions so you aren't having to spend as much time making sure that the leadscrew backlash is not fooling you.

    You have my thoughts for the moment.
    Good Luck,         DoN.
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Not just "very likely"; burning hydrocarbons produces primarily water vapor and carbon dioxide. Propane C2H6, butane C4H10, acetylene C2H2, methane CH4, combine with oxygen O2 (combust) to produce primarily H2O and CO2.

And again once the air cools and can no longer hold its water. All the moisture you made comes back out in your shop. The only way to get rid of it is to vent it and replace it with cool dry air, at a net loss of heat. You have to pretty much keep it at constant, non-condensing temperature. It's better all around for the tools and accuracy; metal expands when it warms up. How warm is warm enough? You shouldn't see your breath, and your hands shouldn't shake. Hypothermia also hurts accuracy.

Halogen worklights are incredibly good heaters. A bright workarea helps eyesight, thereby enhancing accuracy. This one is a win-win, except during the hottest summer nights, when you should be out and about with the kids anyway.
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"Mike Young" wrote:

vapor
CH4,
<pedant> Propane is C3H8; the C2H6 you listed is ethane. </pedant>
Jon
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Don,

It has keys, but they are too small for the slots. Sounds like a good project.

It has a swivel base, but it is currently bolted so the pieces hold their orientation, and I could leave it that way, I suppose, if I blow for a rotary table. As people have observed, the tooling options are endless (part of me does not mind that very much<g>). I understand what you are saying about a tight fit. In fact, it explains some things from my past; Ron must have done that, and a damn good job of it too (no surprise).

I am very much leaning toward the ER32 solution, but want to read a little more before buying them. Basically, I do not care (much) about the height of the chuck, but I do care about the relative height between the business end of a drill bit and an end mill, and about the vertical space required to make the common changes.
One question about ER32, and put this to the seller I listed, is how much room does one need to change a collet? It looks a lot more spindle friendly than changing an R8 collet.

In Florida we tend to struggle with too much heat, so it's not likely to be a concern. However, this will be my first winter in this house, and an electric space heater might find its way into the garage/shop. The house itself has gas heat, and I might also "forget" to close the door leading to the garage when I'm working.

It is fascinating to see the varied opinions on this. Most of my experience was with collet chucks, and I recall enjoying using them. I will try collet mounting some bits to see what works. Do you have a recommendation for end mill holders that would compete with the ER32 collet chuck set? I am not so much worried about quick change as I am in the clearance needed above the work.

As I recall, I was taught to prevent backlash by trusting the dials only in one direction after a "find". Instructional corrections/additions are more than welcome. I did very little precision work, and usually cared about one a couple of dimensions at most, so it wasn't too difficult to cut/count/cut.
Bill
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Bill Schwab wrote:>

Since you don't need to remove the chuck, and the collet closer is not as deep as the collets, the vertical space needed to change a collet is just a little more than the hight of a collet, which is 40mm.
The friend who pointed me towards the ER system has a Myford mill with an R8 spindle. Although he has almost the complete set of R8 collets he decided to switch to ER and never regretted it. Unlike the R8s, each ER collet covers a 1mm range, so with ER32, for example, the complete set of 18 collets allow you to grip any diam. from 2-20mm. Neither of us have yet experienced the problem of endmills working their way out of the chuck. It could happen, of course, but we haven't had it happen.
--

Regards, Gary Wooding
(To reply by email, change feet to foot in my address)
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It is generally accepted that end mills should not be run from chucks, due in part to the hardened shanks, which do not hold well by that method, nor are they supported properly for the serious forces generated in the cut. It's far different from a twist drill, which has a soft shank and typically does all its cutting on the end, so there are no side forces. While you can, and probably do, achieve a level of success, such a setup is prone to eccentricity, chatter and hogging, which is reduced by the use of a proper collet setup. These words I say in the hopes of helping a newbie. I realize you folks know it. :-)
Harold
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Harold, Gary,

That's a lot better than R8.

Harold, to clarify, are you saying the ER32 is a poor choice because it does not adequately grip endmills, or are you simply telling me not to put endmills in my shiny new Jacobs chuck (which I would not do)?
Elsewhere in the news, my edge center/finder arrived today. It's a Starrett, which seemed to be the most heartily recommended of such gizmos. How long is it likely to last?
Bill
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snip----
due
nor
typically
you
to
proper
newbie.
Sorry for the confusion. I'm not familiar with the ER32, which may or may not be a good accessory. My only comment regards any kind of quick change device is that they often extend the spindle, to accommodate the larger devices that permit the quick change. That tends to diminish rigidity, but that can be a good tradeoff, depending on the situation at hand. If the ER32 doesn't function that way, and holds similarly to the typical collet, I'd heartily endorse it.
My comments were strictly for the use of end mills in a drill chuck. That is a real poor choice and should be avoided like the plague. Having said that, on rare occasion I've used an end mill in a drill chuck, but not for milling as such. More like a spot face, but even that is not a good idea.

Not long. I bought my first edge finder back in the late 50's and it's starting to show some wear! <g> (I ran a commercial shop for 16 of those years).
Edge finders tend to be speed sensitive. Play with yours and make a determination where it works best, then run it there. My 1/2" edge finder (some bastard brand, not Starrett) likes about 2,100 RPM. YMMV.
Harold.
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Bill Schwab wrote:

The ER system does not have an endmill locking system such as such as is found in the Clarkson and Autolock systems, so, in theory it is susceptible to allowing the cutters to work themselves out when making heavy cuts. In practise, things seem different - at least for the members of my model engineering club. One member, a retired toolmaker of immense experience, uses MT collets in his Centec 2B. Another member, the one who pointed my towards the ER system, eschewed the Clarkson system in favour of R8, and then switched to ER. Neither have experienced a cutter working out - nor have I. This could be because, being hobbyists, we don't take the heavy cuts that are common in industry. Of course, your mileage may vary.
As far as overhang is concerned, my ER32 chuck is slightly shorter than the Clarkson, so from that point of view at least, it is slightly better. The friend who uses MT collets is better off though; his collets don't protrude from the spindle so there is no overhang at all. He does, though, need to release the drawbar (and tap it out) every time he changes a collet. And being that much longer than ER collets he needs more space below the spindle.
--

Regards, Gary Wooding
(To reply by email, change feet to foot in my address)
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Gary,

I am part hobbyist and part gainful prototyper. Neither personality is worried about taking deep cuts.
I called J&L for some advice and ended up ordering an ER-32 set that has just arrived. My increased motivation was generated a couple of days ago. I was removing my chuck (with which I am still on speaking terms<g>) and was having trouble releasing it - then I suddenly had no trouble releasing it. Ouch!!!!! (I always was a master of understatement).
I briefly considered going with a smaller ER chuck to get slightly smaller collets, but liked the range of the 32 and decided to get it. Looking at (vs. thinking about) the 3/32 inch collet, I am becoming more convinced that I made the right decision.
The box also contains a DTI and the cheapest dovetail mount I could find (for starters).
My edge finder (actually a combined edge/center finder) continues to mystify me a little. Per Harold's comments, I will try running it a little faster to see what happens. So far, I don't see quite what the instructional movies on the net show. Instead of clear side movement, I get more of a whobble. Is that what the combined finder does, or am I just running it too slowly?
Bill
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snip----

You guessed it! I assume you're speaking of a device that has a head of given size----such as 1/2" diameter, and is held to the main body with a spring? If so, they perform poorly at slow speeds, as I said. When it's running at a good speed, it will stay on center when so placed with a finger, and ride the edge of a part without moving away until such time that the edge of the finder no longer has any clearance. At that point, it smartly snaps to the side. If you run it too fast, it will pull away, often causing some damage to the finder. When you're running at a good speed, it will simply stay off center, riding the edge of your part. Set your dial or DRO to zero at that point, reflecting the radius of the finder, so the centerline of the spindle is at 0, not the edge of the finder. Once you've done that, repeat the operation to insure that you are really at 0. It's easy to overshoot the first time, but the second time you have a clue where 0 should be. If there's any doubt, repeat a third time. You should be able to locate an edge within a thou repeatedly.
Harold
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Harold,

For my next session, I will run up the speed (after re-reading the max RPM spec I saw) and give it a try.
> If you run it too fast, it will pull away,

Dial backlash question: if I advance to the edge, back away to repeat and then touch again with the dial locked in place from the first pass, is it reasonable to expect the resulting two backlashes to cancel each other? I think you've implied that, and it makes sense, but I want to make sure that I am not getting the wrong idea. I understand that the dial readings in the backward motion would not be correct.
Bill
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snip--

That's correct. When you back off, to properly deal with backlash, always back off too far, then turn to your mark in the same direction as you did originally. That rule is across the board, whether you're using your edge finder or positioning. I make it a habit to routinely work from the left side and back side of parts, so the dial reading is always right handed, or with the dial. Only under rare circumstances do I not. That means if you're working from the center of a part, you must keep backlash in mind as you work the far side of center, and the left hand portion of center. If you use the same sequence routinely, it becomes second nature and you don't really have to think about it.
A note here: Use your (high quality-buy a good one. I recommend a Starrett C305R) 6" scale for every move. It will tell you if you've turned the handle a turn too far, or even catch a mistake if you transpose some numbers. Carefully applied, you can read a scale to .005" without much difficulty. That will save you tons of trouble. It is especially important when you're stepping off holes, where you have a multitude of chances of making scrap. Use the scale until it becomes routine, just like working with backlash. Touch your spotting drill or center drill to the piece, and measure the dimension from your reference point. It takes a moment to do, but far less time than making a new part. You'll improve your quality immensely if you follow this advice.
Harold
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My favorite is the C604RE. Those are the ones with the 'end reading' graduations, for fitting into tight spots. Actually really handy!
Jim
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Harold and Susan Vordos says...

Starrett
A model I really should include in my toolbox. I can't tell you the number of times I could have used one.
Thanks, Jim.
Harold
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Harold,

I think I follow. It gets to another question, which is whether you work in absolute or relative (rezeroing) the dials? It sounds as though you do not rezero. In that case, a "lap counter" would be handy, but the scale probably does pretty much that.

No argument here; it makes sense. With the ER set, the changes involved would not be all that time consuming, and it beats starting over.
Re the edge finder, I think I get it now, at least for edges. I flipped the belts, and fiddled with a little more speed. I saw definite lateral movement, and then realized that the motion was smaller than I was expecting. Now that I know what to look for, I can see it at the speed I was using before. I have yet to set the dials to check for repeatability, but will try that next.
Bill
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