Zero Setters (For Tool Length Offsetting in CNC's)

=========== In case you didn't notice, all but one of the companies [rajshreeengineers] or their web sites are located outside the US.

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Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).

Les Paul made one too--called it a Paulverizer IIRC.

Or maybe it was Mikey--who called it a Mikeabrator.

Hmm wonder if he's even still alive....curious if anyone's heard from him lately....

TB:

Ahh yes, the Millabrator. Funny you should mention that. I had one for years, and a regular in amc asked me about it some months back. I'd only used it about twice since I had it, so I sold it to him.

About Santa Cruz Mike, it seems once China (or Taiwan), swallows you up - you're seldom heard from again. How many posts have we seen from Hamei in the last 5 years, eh.

yubyub

Give a man a fish and he eats this evening....teach him how to fish and he will live a lifetime without hunger....

The antithesis goes as follows :

"Build a fire for a man then he will be warm for the evening...

...BUT...

*Set a man on fire* and he will be warm for the remainder of his life....

cade. =A0One of

the bottom of

what's wrong with using a regular jo-block ?

what's wrong with using a regular jo-block ?

a jo-block is too easily scratched

chinese 1-2-3 block usually is more than sufficient

--added benefit, if they get much cheaper due to the bungled US Treasury efforts towards equalizing fair trade over the past decade then we can continue to import for cents on the dollar ( in comparison to the true cost of mining and producing steel ), and if the dollar keeps droppping we can eventually melt them down for scrap and get more than we paid for the freaking abominations im the frist place and subsequently sell them all back to China.

Good plan if it werent for the wal-,art lawn chair and the trade deficit where mcdonald's is having mctoys made in mcChina for the Mcmovie indus try

R:

First: If it's an inspection grade Jo-block, it will CEASE to BE one after a very short period of time due to the scratches it receives sliding ON your parts and UNDER the sharp edges of your tools. Now don't get me wrong, I've used dowel pins to set tool length offsets for years on parts which are too small, or because of geometric constraints are not able to support a Zero Setter.

Second: When you ARE able to use a Zero Setter, it's quicker. To use your Jo-block, dowel pin, 1-2-3 block, whatever, you have to bring the tool down below the block/pin height, then crank the spindle back up to slide the block/pin under the tool. You may want to double check the height if it's a close tolerance part. With a Zero Setter you just come down and when you get close you slow down to .001 increments and watch the indicating dial go to zero and you're done. You don't have to go back up & down, or do a double check. It's the same whether you're setting tools off the top of your part, off the vise, or off the table. A Zero Setter is quicker.

In my opinion, probably the worst way to set TLO's on a CNC is to use the shim stock or cigarette paper method. WAAAY, too much chance of chipping the sharp edges of your carbide tools, or gouging your part. Plus it's often the slowest method, since you are just creeping up on the shim trying to be double careful to NOT chip the tools as I just mentioned.

========= I ain't Bob, but its too expensive and too hard on the jo blocks.

Frugal approach is to use a gauge pin and roll under the tool as you back off. Dowel pins are even cheaper, but not quite as accurate. Dowel pins may also be under/over nominal size. Buy 1/8 or 0.100 ZZ pin gage for 2.00$US

buy 1/8 X 2 dowel pins for 16 cents each. [minimum order quantity applies] Anyone for ZigZag, E-Z wider or if you're old enough Bull Durham cigarette paper?

Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).

Unka' George:

I don't know about that. Case hardened and ground dowel pins are virtually never undersize. They are usually very accurately .0002 oversize (+ or - .0001). Stainless dowel pins can often be on-size.

Perhaps the more correct advice, even for the gage pins, is to verify the diameter with your good mic or .0001 indicator, set with a known good jo or space block. Most likely not the time/place to use your "verynear" calipers...

Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).

Unka' George:

I'd say measuring first is excellent advice no matter WHAT you're using to set your tools. Gage pin, cigarette paper, dowel pin, Zero-Setter, even a Jo-block, and especially a 1-2-3 block.

EASE to BE one

uicker. =A0 To

Your absolutely right. Just can't seem to convince the "others". I've broken & chipped more carbide inserts & small EM's than I'd like to remember. I've have my own "poor mans" setter. It was sold by SPI & others maybe

40bucks? Basically a 2" spring loaded flashlight with 3 red lens around the circumference- uses (3) 357 watch batteries. Sweet, I'm not that careful when power feeding down on it. It has about 1/8 travel. Touch it - back off in .0005" steps till it slides out - type in 50.8 -I'm done! All the tools in the Hurco carousel are set with one tool touch. If I'm sizing blocks, I set off the parallels & go up my finished block thickness for Z0. Comes out +-.0005 w/o much effort. Usually -.0005 because of the insert pkts not quite the same in the face mills & she's gettin worn. Only one problem with the new Hurco- its insulted some how, so the flashlight does not work. Oh well, its a spring loaded 2" feeler gauge now & saves me on batteries.

If the contour does not allow me to get the setter on it, I slap on the indicator & use the machine Z readings to get a reference number from the part to the back area of the vise top / table or somthin stationary & use that to set new tools on calculating the ref. number in.

Gil:

Ya know, I've got one of those 2" Continuity LED Tool Length Setters you're talking about. I used to use it ALL the time before I got my first 1" tall indicating Zero-Setter. It was good, but the Zero-Setter is faster. Although, on large machines & Horizontals the the continuity setter can have it's advantages, since you don't have to be right IN the machine and on top of the Zero-Setter to see the dial as the LED's are on the side. On the Horizontal you have to hold the LED setter by hand on your part. For face mills that have to be set accurately, I check each insert (usually only three for the face mills we used), and set TLO's for the lowest insert.

Now that's strange, the Z axis ways are on the same casting, right? I wonder if it could be related to the use of ceramic bearings in the spindle? Maybe connect a wire from the spindle drawbar mechanism to another part of the base. Or put a refrigerator magnet contacting the spindle nose and the head? Or a wire with a couple of alligator clips, one clipped to the sheet metal, that other in your hand - so that you can touch the tool holder when cranking down to complete the circuit.

I've set from the bottom like you explained above in certain unusual cases. But I tried to not make a habit of it. It only takes one or two times getting a phone call, or distracted and forgetting to allow for, and enter, the finished material thickness to ruin your whole day. :(

I'll add one minor detail. When setting TLO's for tiny tools, like .005 diameter end mills and the like, I tend to use .0625 dowel pins. Since just BREATHING on those minuscule puppies tends to snap them off. LOL

EASE to BE one

uicker. =A0 To

I fully agree with the last paragraph of your post; I have not had any kind of trouble using jo-blocks, I don't need to slide the entire block under the tool, just the edge of the block needs to pass under, when it does that, I have my height. The small problem I see with your setter ( which is a lot better than the electronic one they used at my old shop ) is the need to clear a larger base for it, and even then you might not realize a chip or deformation in the table might cause the setter to sit askew, or if there is a mechanical error, with a jo- block I can at least feel the table surface to ensure this is not happening. A cheap jo-block set off ebay can provide a few disposable jo-blocks, a 1 inch block will still measure 1.000" and if you use the same method to set your tools all the surfaces will be consistent will each other. I have not used a dowel to set a tool height, but I imagine it might be hard to tell when one is just scrapping the tangent of the pin or cleanly passing underneath; with the edge of the jo-block the setting is much more certain.

Raamman:

Sorry, didn't mean to create a group lynch mob as a result of your original question. Which was a valid one. And as a matter of fact, I personally HAVE used a 1" high round Jo-Block for TLO setting. But it was from my personal cheapie set that had two 1" blocks. And it's quite extensively scratched now FROM that usage. I wouldn't even want to TRY to "wring" it against any other blocks for fear of damaging the other ones.

You're correct, the Zero-Setter I used isn't perfect, nor advisable to use in ALL situations. But when you CAN use it, I've found from personal experience that it's the best all around method for quick setups, for me at least. About a decade ago I did a bunch of timed runs of setting tools to see which method I was using at the time was fastest. I posted some of the results in here (amc).

Try it. You hold the dowel against the tool as you're cranking up the Z in .0001 increments. It slips right under the tool with no chipping of the tool edge.

BottleBob wrote:

Here's a post I made in 2003:

==============================================================

I've set tool lengths with an indicator setter from the table surface (I have one of those Millabrators), I've set them from the fixture surface, from the surface of the parallels in a vise, from the vise surface itself, from the top of machined vise jaws, etc. Some methods may be more advantageous than others for certain classes of work, but generally I've settled on using the top of the part for 98% of the work "I/we" do. We even leave -1.0000 in the Haas Z offset position, because it's become the shop standard that we use a 1" set block off the top of the part. As far as tool setting devices go, I've used paper/cellophane, dowel pins, 1-2-3 blocks, an Led Lighting conductive setter, the aforementioned Millabrator, a 3/4" diameter X 1" high gauge block, but my favorite is SPI's 1 inch high indicating setter with a .0005 Mitutoyo indicator attached to the side. A 1-2-3 block is usually much too clunky for setting .010 dia. end mills, or .015 drills and such. The SPI indicating setter is fine for setting small or large tools. If the indicating area is too small to support the indicating setter I sometimes use that 3/4" round gauge block I spoke of, or even a 3/16 or 1/8 dowel pin. One trouble with using a gauge block is that the sharp edge of the carbide cutters can scratch the surface of the gauge block. For speed, I haven't found anything that can beat an indicating setter. I did a timed run in the Haas Thursday just in case I'd have time to post about it. I set tools 10 through 20, with tool 10 in the spindle while being on the TLO offset page. This machine has about a

30 inch Z travel compared to our 20 inch Fadals. Anyway, pushing the timer and setting the 11 tools to within tenths took 4 min. 11 seconds. Now I don't normally set EVERY tool to tenths since it's usually only critical where you want multiple tools to cut the same surface with a minimal step, but I did it for this exercise to show how quick it can be done. About off-line setters: On our Fanuc controlled Makino, it's easier to set the tools off-line and enter the numbers into the control. A definite dinosaurian procedure compared to the tool setting features of the Haas or Fadals. Off-line setting, writing the numbers down, and manually entering the numbers into the control greatly increases the opportunity for mistakes. Anywhere along the line, in reading the number, writing it down, entering it into the control, transcription or transposition errors can creep in.

In summary, there are numerous ways to skin a cat, and it depends on the type of work YOU do, whether one method of setting TLO's may be more beneficial than another for you or your shop. ==============================================================

Here is what I wrote in a thread in March of 1999. (I've combined parts of two posts together)

===============================================================

When I started doing tool length offsets I used a 1-2-3 block, I changed to a 1 inch diameter X 1" high gage block out of my cheapo gage block set. The smaller block was much more maneuverable and easy to use. I recently bought one of those 2" high round set blocks that are spring loaded and light up when they are touched. Yesterday was the first day I started using it. I think this thing is the cat's meow, although the light could be brighter.

Today I timed how long it took to do tool length offsets in the Fadal with 6 tools. They were already in the carousel and the readout was at "enter next command." From hitting the first button on the control to tool number 6 being put away with all the TLO's set, it took 3.06 minutes. ===============================================================

Now these are on different machines (Fadal vs. Haas), but the actual cranking down the head shouldn't be all that different. Actually it should take more time on the Haas since it has a 32" Z travel compared to the extended head 24" travel on the Fadal I used.

But in my other post, setting 10 tools in the Haas with the Indicating Zero-Setter took 4 min. 11 sec. (or 25.1 sec. per tool). Setting 6 tools with the LED Continuity Tool setter took 3 min. 6 sec. (or 31.0 sec. per tool).

Actually IMO, a 5 sec. different per tool is too small a difference (and too small a sample size), to declare a definite winner.

BB, I like this one 2.000 high.

Looks easy to read. Got to keep an eye on that little inner dial though, eh?