Care and feeding of new mill-drill

This is the dark side of advancing technology; more accurately, it's a consequence of a lack of respect for history. One thing that really scares me is the speed with which drafting machines/tables disappeared from our educational system( at least it seems that way). CAD software is great, but I think it should follow some descriptive geometry on paper. Making printable lines was silly when was told I would be forced to do it (we never actually bothered), but the drafting experience was very useful.

Bill

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). 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

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.

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

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

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.

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.

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

Bill Schwab wrote in news:DSX1f.10993$ snipped-for-privacy@newsread1.news.atl.earthlink.net:

The math alone is worth it. Then you add in the ability to lay out things in wood for projects around the house, and you've got skills that serve you well for a lifetime.

A perfect example of experience, and the opportunity to have "hands on". It's hard to beat. For them, especially if they had ability at the outset (not everyone has), they had a leg up. Sans the schooling, that's precisely how I was trained. Once I got my feet on the ground (not a pretty picture until that magical day) I was a fast learner, but I "practiced" the new found skill daily,for 8 hours.

I agree! I'd have been damned proud had it been me, and I congratulate you for your dedication, devotion and obvious success.

Harold

snip-

He lacks experience, which sorts them out instantly. That's what makes skilled people. Knowing how something is done does not mean you can do it. That's the part that separates those that can from those that can't. It was evident in any shop I ever found employment. Ever watched someone work that is *good*---really good? He has hands like everyone else, but how he manages the machine and problems at hand is often far different from others. It's not what he does, but how he does it. That is what makes skilled people------and always has. How I wish I could say it always will-----but CNC has changed that.

If you've had any experience in the manufacturing field from the perspective of the guy on the machine, you know, as well as I do, that there's always one or more "hot shots" in the shop with a reputation for having the ability to do it right, every time. If their co-workers don't have ego problems, they'll gladly tell you how good the other guy is------and openly admit that they can't duplicate his/her performance. I've seen it time and again.

That being said I'll

Not a fair comparison, for I was discussing "machinists", and have already accommodated skilled CNC operators. I stand by my comments. My years in the shop prove I'm right----but keep in mind I've been away for about 20 years now. Can't speak for what's happening today.

Yep----that was my accommodation for the skilled guys. .

Which, in part, is one of the reasons that a CNC operator is unlikely to be successful on manual machines, not having experienced them beforehand. . Not having that experience, his thoughts are often improper for the application at hand.

For example if you are machining a part out of a block

The point at hand is people transitioning from one level of technology to the other. I've always maintained that each of us can be so trained. My comments suggested no opportunity for that to occur. A CNC operator with no manual experience is unlikely to land a job in a manual shop, and is even more unlikely to be able to hold it. Not without some training. Why would he be expected to be able to any more than a person such as myself (with NO CNC training) be able to do the same thing in reverse? Makes no sense, and is rather disrespectful of the skills that experienced people have in each camp, skills that often have come at a high price.

Then you didn't understand my statement, or you choose to distort that which I have so clearly stated------which is *experience* does not come from a book. You can read a book day in and day out and have a firm understanding of a process, but that it can come out of your hands, or not, is proven only by doing it----and is further enhanced by doing it again and again (experience).

I'm a strong supporter of reading technical publications. Fact is, I learned how to refine precious metals from a book, but reading it gave direction only----it meant little until I got my hands dirty.

By the way, that venture went on to become a viable business, from which I retired, selling the business that I founded, quite unintentionally.

Thanks. Just speaking the truth.

Harold

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.

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

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

snip----

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! (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.

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.

I have an ER32 bison collet chuck that I use on my horizontal mill with a #30 spindle. I used it to hold small endmills (less that 1/2) and to hold woodruff key cutters. It works wonderful for both. (I also have end mill holders but carbide endmills dont have flats)

My first big mill was a jet mill drill. Switching from drilling to milling without moving the head was tough. I bought an Erickson DA180 collet chuck for it. Double Angle (DA) collets are primary made for drilling but I have used them to hold small endmill without any problems. They also make special collets that with an NP postfix intended for holding endmills. These NP collets have a button that engauges the flat on the endmill. Read all about them in the J&L catalog.

Beware that both systems are pricy. I paid about 200 for the Bison ER32 collet chuck from Penn Tool. I think the erickson 180 cost me double that because the collets are expensive. I bought mine on sale from Enco. Now that I have the collets, I have various chucks to use them in various ways. R8 collet chuck for the mill, MT collet chuck so I can use them in the lathe tail stock. Another big plus with the 180 collet chuck is that it will run about as true as you can get a drill to run.

chuck

chuck

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) 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

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

1. 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

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.

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

Gary,

My first fiddling session with an ER32 went well. The spindle to nut space is very acceptable, and the collet changing is indeed much more agreeable than changing R8 collets.

As for ER32 vs. 25 or 16, using a 3/32 bit has put my slight doubts aside; 32 was the right choice. That bit is pretty small and I like the range of the 32.

Figuring that drill bits would be the trouble spot, I started drilling holes in some scrap steel slotted angle. A 1/4 bit slipped on me once, but some additional tightening took care of that. I got it right on a later second attempt, probably using a little more care with the start and break-through and being a little more forceful with the spanner. To my pleasant surprise, the bit appeared undamaged by the slipping; it is a little harder to see whether the collet suffered any ill effects, but I doubt it. I get the sense that it will work at least well enough to drill starter holes in the correct places, and will probably handle most of my drilling.

In the (re)indexing discussions I've read, I have not seen mention of using short/stubby drill bits. It occured to me when I noticed the length of my 1/2 bits. Of course I would drill a starter hole, so lining back up would not be a big deal, but it raises the question of whether one could get a short bit, or just use an appropriate endmill to drill shallow but wide holes? I recall reading that endmill is not the correct type of cutter because it does not cut to the center, but my "endmills" do have flutes that cut from the center line outward. Is there any problem with drilling with them?

I paid mid-range based on prices people report. The collets seem to be quite nice, and were the bulk of the cost. I might have been able to save a few bucks elsewhere, but was getting good technical info and decided to take the guy's advice since the price was reasonable. The chuck bothered me a little at first. It felt like it might be trying to cross-thread, but I think some of that was operator error and some that the threads were a little sharp. Having run the nut over them a few times, it's getting easier to use. I am also catching on to how to release the collets from the nut. It was interesting that I did it correctly by accident a couple of times, and then started having some trouble.

How do you recommend storing the collets? They are in a plastic box, relying on lack of movement to avoid collisions. Can I safely make a wood rack, or is that asking for rust?

The DTI is definitely a winner for vice alignment; much simpler than the contraption I rigged up using a plunge indicator. Next will be to figure out how to get it in position to sweep holes.

Bill

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

My favorite is the C604RE. Those are the ones with the 'end reading' graduations, for fitting into tight spots. Actually really handy!

Jim