Care and feeding of new mill-drill

Chuckle! Mortising? If you could see my red face (embarrassment), maybe you'd understand.

I hate wood work, and I know almost nothing about it. I'm not sure I know what a mortise is. The wood work I've done is for pattern making, and I work like a machinist, not a wood worker.

End mills are available in a huge array of configurations, starting with stub models that are intended for slotting, right up to the long ones (dies sinks) intended for milling large faces or deep pockets. I think the best advice I could offer is to buy that which best serves your purpose, and restrict their use to wood alone. Once you've run a metal cutting tool on metal, that fine edge you need for machining wood without splintering is gone. Carbide end mills are now cheaper to buy than HSS, something I am still struggling with. It goes without saying, they'll serve you better than HSS will in the long run. Choose 2 flute cutters for wood, not 3 or more. Run them flat out---even if they're HSS. You won't be over driving them.

If you have a choice, carbide should be a C2 grade, best for wear resistance, and the choice for almost all non-ferrous use. If they're the newer carbide (micrograin), you may not have a choice, but anything you get will perform quite well, especially in wood. Look at machining wood much the same as machining aluminum. Greater chip relief is desired, as well as more generous cutting reliefs and rake angles. HSS end mills are available with grinds for aluminum, and they are generally marked clearly on the shanks if they are. They have greater relief angles, and often polished flutes, so they are better suited for wood than would be steel cutting tools.

Key is the file, which must not cut aggressively. I've posted more comments on this addressed to Karl. I really don't recommend a stone, although it certainly can do the job, albeit with a caveat.

Moving such things isn't a problem if you incorporate some pipe (and it's on concrete). Once you have a machine on a few pieces of pipe, assuming you have concrete as a floor, you can move it anywhere you desire, usually without assistance. You have to keep juggling the pipe as it moves under the rolling machine, so having extra hands can be useful, but not necessary. You can move a machine that weighs tons by that method.

Yep. All depends on the work at hand. I don't care how large one's machine may be, a job always comes along that won't fit. Murphy's law! Still, in general, I understand your comments and agree. Sounds like you've given this some good thought before jumping.

Cool! You do understand!

You don't really need that reference hole, not as long as you have some fixed datum points as I suggested. If you had to make parts to print, you'd understand that you're not always at liberty to stab in a tooling hole, so you learn to work from surfaces that are available to you. In keeping with that thought, when you do multiple pieces, it's really nice to hold them identical in size (deduct from that, *on size*, not from one end of the tolerance to the other), even when it doesn't matter. That way you can use any edge as a reference point, a situation that often arises. That's all a part of the things you learn as you progress in the trade. Might not make much sense to a beginner, but it will the first time you encounter a problem that can't be otherwise solved. I have the T shirt on that one.

Oh yeah! An indicator held by anything but the spindle won't help you make setups as they relate to the spindle. You can find center of anything that you can span using an indicator. Even square or irregular stuff. Hex, octagon, etc. You can locate dead center of a shaft, or your vise, and do it reliably. Using the drill chuck, as you've already suggested, you sweep sides of items, locating the low point, then make them identical @ 180 degree intervals---which often necessitates moving the indicator off the part by raising the quill so you can index to the opposite side. It's like sweeping a bore, but working on the opposite face. Get creative. There's really no rules on how you can use your DTI---and it doesn't matter if you introduce error by offsetting the probe-----not as long as you're making comparative readings, one against the other. You don't care if the reading has any particular value, you're just trying to get surfaces to read the same. Center.

See above. You work *from* the spindle.

In wood, or aluminum, that's likely to be fine, but keep your quill as short as possible at all times. That keeps the machine in the most rigid posture. Being a mill/drill, you'll have to compromise on that, but it's not likely to be a big deal unless you use some large cutters, or take some unreasonable cuts. Non issue in wood.

Welcome! Hope some of my ravings help. Do rely on others, especially if they're skilled. Learning from self taught people can have its own set of problems, depending on where they got their information. Learning how to do something stupid from someone that does it that way doesn't make it right, or good. At first, it might be hard to differentiate those that know from those that don't, but your experiences will help you sort them out.

Harold

Tim,

It is cheaper than I expected, and I will proably get one some day.

That explains the drops. At least it's dripping vs. running dry. How does one know when to stop pumping? I sometimes wonder whether the ports are filled or I'm missing the target. What is the correct tool to use with the ports?

The mill came with a paper weight shaped like a vice. I forget what I bought with it (went with the recommendation), but it definitely feels like a real vice.

Bill

There are those than can do things and then there are those that .... Yahoo!

There is likely a big difference between the machines you used and a mill-drill, the subject of this thread. Mill drills don't have the mass, scraped ways, or ball screws found in the bigger machines. An experienced, skilled operator on a heavy, well-tuned BP can hold the tolerances needed for precision tooling work. Operators with those skills are hard to find these days as most are retired or dead. My experience with mill-drills using the handle dials is a tolerance of +/- .01 on a good day. Add a DRO and you can cut that error in half, maybe a third with some practice.

When I set up our shop a couple of years ago, we skipped manual mills altogether and installed VMCs. The old mill drill is still around, but it's rarely used. On a VMC, anyone who can properly load the vise will turn out parts with accuracy better than +/-.002, all day long.

Get a squirt can oiler with a needle tip. There is probably a special hose fitting for those little ball-end ports, but I never used one. The needle tip pushes in the ball and lets you squirt in a shot of oil. Way oil contains thickeners that make it sticky enough so a film remains on lead screw threads and the ways.

The ways are certainly scraped on the import mill-drills.

The Acme type lead screws use the same principle as a stock Bridgeport Series 1, although lighter and less precise. Ball screws are not common on Bridgeports.

It is a smaller machine and less massive, but the weight is appropriate for the scale of size.

Your experience of 0.01 tolerance is much worse than mine. The errors of my machine are a few 0.001 and repeatable.

Harold,

Not to worry. At the risk of over simplifying, a mortise is a slot. I made a couple of nice ones by plunging and hitting the feed. One can then square the ends with a chisel or simply round the ends of the corresponding tenon, which you have no doubt figured out is the thing goes into the mortise.

Thanks!

I like the file idea, but am in no hurry.

I will file that for the future, but there was a slight upward slope toward my garage. The 1/2 inch lip seemed like Everest. I used a $140 engine hoist that is no-frills but very serviceable. Interestingly, pipe solved the problem. I used it against a wood block on the ground (to protect the concrete) and then pushed against the back of the crane and over the lip it went. This reminds me that owe I the crane some rustoleum.

I hope so. If not, the worst I've done is buy a seriously good drill press; I suspect it will be able to do a lot better than that.

:)

I started out asking for an example, but unless you find problems below, I think I am starting to follow. My main concern now is having enough room to get a DTI in and out with enough spindle left to mill. However, I suspect that a DTI and my rubber mallet will give me a way to recover from moving the head.

Ok, I think I am on the right track. It helps to be the guy who makes the print. If I want a reference hole, there will be one, maybe two ;)

It makes sense from a woodworking perspective. The tolerances are laughably larger, but I suspect the idea is the same.

I think I am following. So far, I have a dial indicator but not a DTI - to be corrected shortly. If I can arrange to get that on and off the spindle with depth left to mill, then I think we've solved the registration problem (as I think you were saying from the beginning).

Thanks again!

Bill

Hello all,

I did some more searching and found a few items on Amazon. Rather than post links that will wrap, I've given numbers that appear to be unique. If you "search amazon" for the numbers below

B0007CXIQE - indicator holder B0002PCU4C - DTI B0007TVKHG - collet chuck set

you should go straight to the items. I would appreciate your opinions one whether this stuff looks worthy of use.

A DTI of some description seems inevitable, and the holder seem reasonable (unless it looks like junk to you). The collet chuck is just enough money that I might wait on it, especially since your opinions were divegent on them.

There is something else that I might be able to use to advantage. Is there anything stopping me from holding drill bits (that fit) in collets vs. a chuck? If not, I might be able to buy a few collets of interest, say to hold bits associated with few hole sizes I care to tap (again, it's good to be the guy making the print) and buy some time for my wallet to heal before thinking about the collet chuck set.

Thanks again. You guys are great!

Bill

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

snippage.....

A vertical mill is a glorified drill press when compared to a horizontal mill for removing metal, IMO. At least that was my view when I used a Bport and a Cinncy side by side. Each has it's own virtues...

Get a Yahoo email address first then join the group using the yahoo email address.

DE

It's better than that. It will teach, or refresh, the fundamentals, which are all important.

You're a damned good thinker, Bill.

Harold

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

With all due respect for the skills and talent these folks have, most of which I envy like you'll never know, they wouldn't last a day in an old method machine shop, assuming they could get in to begin with.

The ongoing struggle those of us have that have worked in the trade, especially the "old way" (sans CNC) is with people that can't differentiate between making chips and making parts. I've witnessed a tremendous amount of that since I began following machining forums a few years ago. You could likely teach a monkey to turn on a machine and start making chips----well proven by the fact that I can do it. The problems start when you have to leave behind the item you're striving to extract from the metal you're carving-----and only the item----to specs.

At first glance, machining doesn't appear to be much of a challenge. Like welding, folks get the idea that because they've burned some rod (made some chips) that they understand the process, and the difference between them and a guy that does it full time is they enjoy it, and the guy that does it full time doesn't (he's likely half right). Such people, in my opinion, are

*new*, or very uninitiated. It takes skill and experience to make parts, repetitively, to print, in a timely fashion. There is no substitute for the skill (CNC excepted)-----it does not come from a book, it does not come from your best buddy-----damned few are born with it. It comes from the school of hard knocks, with long, hard hours of getting your hands dirty, and with proper guidance, so you use good procedures that insure a minimum risk of scrap and injury.

Nothing serves as a come to Jesus session better than handing an unskilled person a print, material, no op. sheet, and point them to a machine, and ask them to produce a given number of parts that will pass inspection. Sorts them out right now! Like welding, you can't fake it. You can do it-----------or you can't. Those that know the difference can see through you with no effort. It's like playing a piano. Almost no one does that without paying dues.

I don't suggest the CNC guys don't have the proper knowledge to do their magic on a CNC-----and probably better than most of us can on a manual machine------but one skill set has little to do with the other----unless-------the operator has been in both places. Our very own michael is one such----as are others. These guys are the best of all worlds, for they can do it by either method. To the man, though, I have a dime that says that once they've done it with CNC, they don't really want to revert to the manual machines again. Not if they're trying to make a living. The work is simply too difficult.

I'll go out on a limb and state that a guy with nothing but CNC experience is unlikely to be any better on a manual machine than I am on a CNC---------and that speaks volumes about their inability, at least in my mind.

Harold

According to Bill Schwab :

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.

[ ... ]

Unfortunately, those "pounds" were units of mass, not monetary units, and while the Clarkson end mill holders are a very nice design, Clarkson end mills (those with the threaded top end) are *very* hard to find in the US -- and his email suggested that he is in the US.

I've got Clarkson collet chucks in NMTB 40 taper for my Nichols horizontal mill (with vertical head), but I don't yet have usable end mills to try with them.

Enjoy, DoN.

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.

Harold , The machinist school I attended years ago was run by a gentleman of considerable skill and experience. If you were able to graduate ( and a lot didn't) a job placement was likely assured. It was all *old school* as you describe, and fully comprensive. One of your peers I would say.

He ran a tight ship and had a reputation among several manufactures for turning out quality job candidates. He also steered us away from bad employers..

I worked my tail off and only managed a 3.25 average, one of the highest in the group but was I disappointed. It was not as easy of a program as I had expected but much more rewarding. The highest marks usually went to those working in the trade and being sent in by their employer.

I later became friends with his son and was told that it was a pretty good score . The program is now all cnc and caters to a couple employers, and no longer enjoys the reputation it once had. I might go back just to compare and to see how I would do.

DE

Propane is C3H8; the C2H6 you listed is ethane.

Jon

"Harold and Susan Vordos" wrote in news:43474a2a snipped-for-privacy@newspeer2.tds.net:

I disagree. A skilled CNC machinist has every skill and then some that are required to machine parts on manual equipment. That being said I'll be the first to admit that there are a lot of semi-skilled CNC "machinists" out there. They know how to change tools, set offsets, use an indicator, etc. They are skilled operators really. They can set up a CNC machine and operate it, but they don't have the experience required to process a part. I've seen these guys try to use manual machines and frankly they scare me.

On the other hand there are the CNC machinists who develop the process, figure out the work holding, select the tools and write the programs. They could work in any "old method" shop and survive just fine. If anything they might bring a little fresh insight with them. They are also used to having to think about every single detail before they start cutting a chip, a discipline that many manual machinists lack. Writing a CNC program forces you to think about every single step on a micro level ahead of time. If it ain't in the program the machine won't do it. CNC machines in general move a whole lot faster, have more power, and run at higher speeds. This forces you to consider work holding a lot more carefully than you would have to otherwise.

I started in the trade on manual machines at a time when only the biggest companies had CNC. Eventually I learned CNC and wound up working as an application engineer teaching CNC programming to people who had never used one before. The statements I made above are very broad and general. Certainly CNC allows you to process a part differently than you would on manual machines. For example if you are machining a part out of a block of steel, on manual machines you might blue up the block, scribe lines, and rough it out on a band saw. On a CNC you would hog it out right on the machine. So a CNC guy might have to learn a few methods, but I'm sure they would be fine. Having taught CNC, often manual machinists have to learn trig and other new skills.

Very true, but I take exception that you can't learn from a book. Studying from books while getting hands on experience will shorten your learning curve more than floundering around and trying to figure out things by trial and error. Taking night classes at a local technical college is another great way to speed up the learning process. Often night classes are taught by folks moonlighting from their day job in a local factory.

If nothing else I know enough to know that I don't know everything. Reading helps me stay current. Everyone should subscribe to trade mags, scour libraries, and go to machine tool shows. You can learn a lot just by reading tooling catalogs. I've attended classes at Kennametal and Sandvik. It's time well spent. A good machinist should always be looking to learn.

Well said.

Again, it depends on the skill level of the CNC machinist. CNC has changed the work environment in the shop. In larger companies, often it's hard for a machinist to develop skills beyond set up and operation. The highly skilled guy takes care of feeding multiple machines programs and processes.

CNC machines output a lot more work with fewer employees. This fact often convinces people that manufacturing is dead in the U.S. Not so. We are still the worlds largest manufacturer, but that work is done with far fewer employees than in the past. The operators spend more time feeding the machines and material handling than in the past. Often they just don't get the opportunity to advance beyond that point.

Most of the really good skilled people come out of small places that do short runs, prototypes, model and tool making. As there is more opportunity in that type of environment to learn. Job classifications are less defined and often as an employee you are thrown in water that is way over your head.

From what I see there are far too few highly skilled people out there and there is a lack of formal training programs to teach those skills.