# Coaxial Centering Indicator-are they to be had?



## jjtgrinder

I am considering the purchase of a coaxial centering ind for the shop.  Enco has the SPI model on sale. What do you more experienced guys think about these?  Also I would like to hear your experience using the Enco dial test indicators(606-4712).  I know a "interapid" would be great but if I drop it or something it's damaged. Enco has this stuff on sale now.
Thanks for your help - the grinder.


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## Tom Griffin

The co-ax indicators are an expensive extravagance that you don't really need. I own one of the original Blake co-ax indicators and I barely use it, certainly not enough to justify what I paid for it. It's quicker to just use the edge finder or a dial test indicator to center on a hole or shaft. Save yourself some cash and buy one of the Indicol universal indicator holders instead. I can clamp one of those to the spindle of my mill and find the center of a hole with a DTE in less time than it takes to get a co-ax indicator out of the box. They also take a lot of room in Z so to use them always involves a lot of cranking the table of the mill up and down. They are very cool, just not very practical.

Tom


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## Tom Griffin

I have been thinking about it, but the Steven's has been taking all of my time. :headscratch:

Tom


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## jjtgrinder

TLGriff said:


> The co-ax indicators are an expensive extravagance that you don't really need. I own one of the original Blake co-ax indicators and I barely use it, certainly not enough to justify what I paid for it. It's quicker to just use the edge finder or a dial test indicator to center on a hole or shaft. Save yourself some cash and buy one of the Indicol universal indicator holders instead. I can clamp one of those to the spindle of my mill and find the center of a hole with a DTE in less time than it takes to get a co-ax indicator out of the box. They also take a lot of room in Z so to use them always involves a lot of cranking the table of the mill up and down. They are very cool, just not very practical.
> 
> Tom


Tom and all,

Thank You for the help. This is very good information.

I would like to know your thoughts on the Enco indicator i am considering.

The Grinder


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## 8ntsane

Hi Grinder

I guess it depends on the end user, as to how much it will get used. I have two Coaxe indicaters. I have the Blake that I bought yrs ago, and paid way too much for. Its a great tool, and I do use mine enough that I bought a import clone for general use around the the shop. The clone was only about 60 bucks. I can say the Blake, and the Import are with in .0005 of each other. So as long as your paying the long dollar, the import would be a way to start, and if you felt you used it enough, and wanted better quality then move up to a better brand. Personally I like the Coaxe, but thats just me.

The DTI, is again a great tool, and I have a Interapid, and 3 imports. The imports at the price, are cheap enough that if you do drop it, just drop it a second time, straight in the trash can   at 30 bucks, they are not worth worrying about. So I would probably pick up the imports, and get a feel for what you like. Then if you dont use them much, sell them, or move up to better quality later.

Maybe I use mine more because the mill has power feeds on all axis, and cranking the knee up and down is not a issue on my machine.


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## Tom Griffin

jjtgrinder said:


> Tom and all,
> 
> Thank You for the help. This is very good information.
> 
> I would like to know your thoughts on the Enco indicator i am considering.
> 
> The Grinder



I've gone through a lot of dial test indicators over the years and am pretty much down to one, an Interapid. Yes, they are expensive and probably hard to justify for a hobby machinist, but they are tough. I've dropped mine many times, banged it against parts with the power feed, done pretty much every abuse possible short of launching it accross the room (although that has been the demise of at least one other ) and it just keeps working. I'm not a full time machinist any more, so it doesn't get as much use/abuse as it used to, but I have used this same indicator for many years when I was. I'm pretty sure I bought in the late 80's.

I can't speak for the current Enco indicators, but I would seriously doubt they are very shock proof like the better quality indicators (Interapid, Starrett, Brown and Sharpe, etc.). Some corners have to be cut to sell them for such low prices.

Tom


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## jgedde

TLGriff said:


> I've gone through a lot of dial test indicators over the years and am pretty much down to one, an Interapid. Yes, they are expensive and probably hard to justify for a hobby machinist, but they are tough. I've dropped mine many times, banged it against parts with the power feed, done pretty much every abuse possible short of launching it accross the room (although that has been the demise of at least one other ) and it just keeps working. I'm not a full time machinist any more, so it doesn't get as much use/abuse as it used to, but I have used this same indicator for many years when I was. I'm pretty sure I bought in the late 80's.
> 
> I can't speak for the current Enco indicators, but I would seriously doubt they are very shock proof like the better quality indicators (Interapid, Starrett, Brown and Sharpe, etc.). Some corners have to be cut to sell them for such low prices.
> 
> Tom



My take on the coaxial indicators is that they are a nice to have item, but not necessary.  But, I defy anyone to get centered within a few thou faster with a DTI than a coax (notice I qualified my fast opinion with "a few thou")...  But, on the other hand the DTI is far more sensitive and accurate and doesn't require much, if any, Z axis change or quill retraction after use.  However, it's nowhere near as quick and convenient.  If I want fast, I use the coax, if I want accurate I use the DTI.

I own a coax, and use it from time to time.  Its main use, for me, is to quickly reset my lathe tailstock after a taper cut.  It's not a replacement for a test bar, but gets me very close.

All in all, if you have the cash, go for it.  But I'm with Tom so far as if you don't yet have a go_od _DTI, get one first.  A Compac, B&S Bestest, Interapid, Tesa/Etalon, Mitutoyo or even a B&S Last Word or a Fowler (not the import X versions) are more accurate and reliable than the el cheapos.  I used to have an Interapid which met with an unfortunate accident and now have a Compac.  It's been bulletproof and has outlasted a half a dozen import cheapos - it's worth every penny.  The Interapid was nice because it had an integral spindle, but had to be set at a weird probe angle to be accurate for measurements.  The Bestest is automatically reversing which is a feature I simply don't see any value in...  The Last Word requires you to flip a switch to reverse direction - annoying.

A good DTI is worth its weight in gold.  A good dial caliper and a good DTI should, in general and in my opinion, be in your toolbox before a coax. 

By the way, a coax indicator isn't hard to make yourself...  I saw an article on it somewhere...

John


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## AR1911

I agree with the buy cheap, upgrade later theory.
Mine cost $48 shipped from ebay. Looks decent quality, nice wooden case, have not used it yet, a year later.


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## george wilson

Well,I guess I am the only one here that uses his BLAKE co-ax,and wouldn't want to be without it. Contrary to the other comments, I have heard that imports are not accurate,and should be avoided. Several machinists on the Practical Machinist's Forum have said to avoid them. If it is like other Asian imports,I'd nearly guarantee that whether or not you get a decently  accurate one is going to be a matter of pot luck because Asian quality control is IFFY at best. I NEVER believe the inspection sheets that come with their machines. I just set up my machines and adjust them myself.  I have been lucky to get Asian machines that were not full of sand,and not accurate.  My friend who works at NASA,running the machine shop,got a 14" Jet whose apron was FULL of chips. He had to send it back. Not an easy job! My first 10" Jet was o.k.. That was in 1975.

I find my Blake indispensable for centering up holes within .0001". One special use I have for mine is I have a 3/4" arbor table saw,and can only buy 5/8" hole saw blades. I keep a small boring head with a carbide bar set for this job. The co-ax makes it so much easier for me to get the saw blade perfectly centered. I've also enlarged saw blades for others. It depends upon what you are doing. I also have the center punch locator. It is easy to very accurately align holes that must be bored accurately in location.

I have had neck surgery(fused 2 bones) and can't twist my neck around too much to see a rotating indicator,so the co-ax is a HUGE convenience. I HAVE seen the Blake used in professional shops,too.

I'll admit I did not pay full retail for mine. I got it new for $100.00 in a used tool place. I like mine so much that I picked up one for my shop at work,and another for my co worker and friend,Jon. If I lost mine,I would pay full price for another one. I just can't twist my neck around trying to read ordinary indicators.

P.S.: Last word indicators are cute,but they aren't NEARLY as good as a decent indicator of more recent design. They are just not nearly as sensitive,and their probes do not move with as light a pressure as a good one. An old design,I guess. Usually I like old,but these aren't the greatest any more.(Maybe they never were). I have 2 which I bought decades ago when I didn't know any better.


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## george wilson

I think that Asian inspection sheets are just tossed into the package!! Really,I do.


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## 8ntsane

george wilson said:


> I think that Asian inspection sheets are just tossed into the package!! Really,I do.



I do believe what George says.
As I mentioned before, I have both. My Blake, is a great tool, and the asian coaxe as I also mentioned in a earyer post is as good as the Blake. I dont know if its a hit and miss thing, but the Blake in my eyes is no better than the import.

The quality of the blake is certainly better, but back to back tests showed me that I can use either one, and the two equal in accuracy. I bought the import as a back up for the Blake. I figured if the blake was to get damaged, the import would get me by. For the price I paid for the import, it was a good value.

I know all about the threads over on PM about these import co axe indicators. 
Most over there have this deal about, if its not made in the USA, it just isnt any good at all. And I do have to question these people, first off, do you, or did you ever own a import co axe? My guess, that they never owned one, or even used one. These same people will bash the import product to the ground, with out using both, and giving it a fair evaluation.

These import co axe indicaters have been around a long time now. Like most things they make, if they do alot of them, its only a matter of time untill they get good at it. When I bought the import, I told them, I have a Blake! And I would compare there import against the Blake. I had asked them, if I was not happy with the import, would they have any problem with me returning it? They told me, please do compare, and if there is a problem, they would like to know about it.

The generalization that everything built offshore is no good, as far as Im concerned is false. And Im sure the main reason most dont use the co axe is the cranking of the knee, and the time and effort it takes to do so. I wouldnt know about that, my mill has power feeds on all axis, and I dont even have a crank on my Z axis. Its got a hand wheel just for fine tuning. But then, I guess if it takes that much energy to crank the knee up and down, a co axe with not be a tool for them either.

Just the way, I see it!


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## Hawkeye

If someone who is using a round-column mill-drill is thinking of getting a coax, keep in mind that they need quite a bit of vertical space between the spindle and the work. This means that you will need to bridge that distance when machining the part you have so carefully centred. Holding your end mills in an ER style collet holder will help, as will using a drill chuck in the spindle for those types of operations, providing you used an R8 collet to hold the coax.

Otherwise, you could lose some rigidity if you extend the quill to it's limit to reach the work. If it won't reach, you'll end up lowering the mill head, which will ruin your centering job.

Other than that pain, I kinda like mine. Only about $64 at LMS. Not a Blake, but I'm no George Wilson. :tiphat:


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## 8ntsane

ike that is a good point . The mill drill machines would be very limeted on travel, and the round coloum machines wouldnt be much good for the co axe indicater. It depends alot on diameter of the work piece as to what lengh probe is used, and how much knee travel required to use such a tool.

For me, I like them, and seem to reach for it alot.


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## Hawkeye

The real problem is that mine has no knee. All of the vertical movement has to come from the quill or the head adjustment on the round column. The last time I used the coax, I realized that I want a knee mill. And so the addiction continues.


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## george wilson

I used my coax when I still had a round column mill drill. It was the larger size model and not a mini mill,to be sure,but there was room to use the coax.

The problem with round column mill drills,I THINK,is that the higher the head is raised,the more the column might bend,causing some degree of misalignment after you've centered the hole,or punch mark  with the co-ax,and crank the head back down to use a milling cutter. If you are just going to drill and bore out the hole though,you'd leave the head cranked up anyway.

I've said I THINK,because if the heavy head was pretty well balanced on the round column,it might not deflect to any problematic degree. Anyway,I did some good work with my round column mill. The next step up was my Bridgeport type.


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## Hawkeye

George, I imagine yours was not much different than mine. Whenever possible, I like to crank the head down so I'm not extending the quill any more than an inch for milling, with preference for R8 collets to keep the cutter as close to the head as possible for rigidity. When I use the coax, I'll change to the ER holder because it is a bit closer to the height of the coax.

Since I've been using the VFD paired with the built-in tach to set milling speed, I haven't had as many cutting issues, so quality isn't bad. Not quite ready to extend the quill the full length yet.

Still feeling the craving for a knee mill, though.


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## Splat

I am a mill newbie but not to metalworking. When it comes to costly purchases I like to research until my head's about to explode, then make a purchase that I won't (hopefully) regret. Buy as good a product as you can, and sometimes you must stretch your budget a little. With my first DTI  I went for quality because the less expensive ones aren't that much more than what is considered reliable. I got a Bestest 599-7031-3 from Penn Tool. I've careful not to bang it around, drop it, or engage the spindle while it's still in the collet. If you're the very forgetful type than get something like a Mitutoyo. It's not garbage but it's better than an SPI and most other Asian imports. FWIW, check Long Island Indicator for more info on brand reliability.


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## GK1918

Not need, although nice to have center finder does and has done the job for years.  Another good thing
is I turned a .500 to a 60* very very sharp point so I can verify.  Just another acc.     sam


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## ScrapMetal

I've actually procured the raw materials and plan to make a co-ax indicator based on the one in "The Machinist's Bedside Reader".  I've got a little too much on my plate at the moment but once I get freed up this one is pretty high on my list.

-Ron


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## toag

if you change out set ups alot, a co ax is nice, i think they are way quicker than a TI.  that said i would use a co ax , then grab the TI to get it spot on.  I had a cheapie import... they just don't have the stuff for frequent use.  I found it nice to use, and not getting the mirror out was almost worth the cost of a blake, almost.

I agree with others that an interapid is almost a must have.  bought a metric one a long time ago and it is a work horse, and i am not easy on tools.  i bought the metirc because i rarely use it to actually measure but i do use it to get relative position, and center stuff all the time, and it was $40 on ebay 4 years ago).  I had a bestest, and i have a puppitast, and have burned through import cheapies.  the interapid is my fav no contest.


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## darkzero

AR1911 said:


> I agree with the buy cheap, upgrade later theory.



I am the total opposite but to some extent. Starting out & with many items to buy I would probably buy some cheap. I've learned that depending on what it is, buying cheap just ends up leaving me having to spend more on something good & tossing out the cheap. So to avoid that I rather buy used/new quality over new cheap depending on what it is.

I got rid of all my cheap measuring tools, good thing I didn't have a whole lot. Most my measuring tools are used Mitu that I got for great deals. All my dial & test indicators are Mitu that I got for new China prices & some were practically brand new. But for those of you who don't/won't do ebay, sorry, I come across great scores very often.

I have a Blake co-ax, can't tell if it's ever been used. Again one of those great deals & avoiding buying cheap. I agree with some of the others, in general to most people it's not a necessity but IMO it's much more useful than using a DTI as an alternative.

Those Indicols, never used one before & I heard they were great so I bought a new one on sale from Enco. For some reason I never could get it to be consistent no matter how tight I tightened the thumb nuts. It had cosmetic damage from shipping & thought it might be defective so I had it exchanged. The replacement didn't lock up tight either. Not sure if I was just unlucky or if the new red & blue ones just aren't the same. It just wasn't for me so I sold it. Got a Noga NF1018 instead, the lock up is much more solid, & it's positioning is much more versatile. Better yet, no more sore fingers & having to use the dovetail stems. Only downside is it mounts in the spindle instead of around the spindle but that doesn't matter to me.


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