Tool Coaxial indicator

[slow-poke]

I'm toying with the idea of adding a coaxial indicator to the toolbox.

For those of you that have one, how often do you use it?

I'm trying to determine if this is going to be one of those tools you wonder how you managed without or one of those tools you forget you have because you never use it.

 

[combustable herbage]

An earlier thread on this topic some ideas.

N

Thread 'Aliexpress Coaxial Indicator'

Nov 14, 2023

AliExpress is having their 11.11 sale - basically $5 off per $25 to a max of $20.

I found this little gem on there

https://www.aliexpress.com/item/100...a2g0o.cart.0.0.24a338daoryOpz&mp=1#nav-review

I don't really "need" this but thought it would a cool tool to have just in case I might need it (can never have enough tools)

Not sure I can trust the reviews on the level of accuracy or quality.

You think its worth a shot?

• neer724
• Replies: 57
• Forum: Tools, Work Holding, Cutters, Bits

 

[David]

If you have a CNC mill with full probing capabilities I don't see a significant need except for bores deep in a work piece where a 3D probe can't reach.

 

[PeterT]

The Chinese knockoffs (of Blake) are generally not that well made. They take up a lot of vertical real estate due to their body length & spin probe. You have to fiddle with the arm tension a bit so it tracks along the surface but doesn't actually scratch the part, because the springs are bigger to make the internal mechanism move. There is also a stationary arm that sticks out which you have to hold in the plane of measurement, just more work & fiddle factor. The Blake style dial increment is typically 0.001" so you could do as well with any 0.001" reading DTI mounted on a dovetail stem/post or arm which comes in the kit or is available. Or get a tenths reading 0.0001" of you require more. I quite frequently use my Noga centering mini arm with DTI or gauge whichever best suits the purpose. You can reach almost any orientation & lock in place with one knob twist. But all this is more for manual machining, looks like all the CNC kool kids use those electronic probes?

 

[Susquatch]

For those of you that have one, how often do you use it?

I actually have 2 of them. One I purchased and another that I got in a Kijiji haul with a bunch of other stuff. I don't use them very often, but when I do, they are worth their weight in gold.

The nicest thing about them is that they can be set to make the dial needle visible no matter which way the spindle is turned. They can also be used with the spindle engaged - albeit slowly.

They can do inside and outside measurements so they can be used in bores or on cylinders, and they come with several different probes that allow very deep or shallow measurements. I use mine on my lathe and on my mill. I've even used it on my drill press a few times.

I think my only bitch is that mine are only half thousandths not tenths. But I don't think you can get one that reads in 10ths.

There are always many ways to do things, but I find I use mine more often than might be obvious to many.

I don't think these rank very high on the wish I got it sooner scale though......

 

[Dan Dubeau]

I can see the usefulness of one for sure but got by for many years without it though. If I found a great deal on a good quality used one, I'd probably buy it, but can't see myself every buying one new at this point. Same story for a 3d taster.

I much prefer indicators over probes for precision work. Probes have their place and all, but they only ever tell part of the story. Great for speed and production throughput on certain things though. I think a coax is a great in between where you can "see" the things a probe wont show you, but you gain the speed over just an indicator. A great example would be dialing in a worn out bore to bush it. A probe probing 4 points won't tell you much about tru position, or out of roundness, but it will find the "center" of the 4 points you probed. A DTI sweeping the bore will tell all, but is slow, and fiddly to setup (from scratch), and most likely will involve mirrors. A coax will show the out of round condition, and let you dial in the tru position based one what you see, and where the wear is.

A 3d taster is another one that has it's merits too, and more closely replicates the functionality of a probe. More useful for picking up square/rectangular shapes a lot quicker than using an indicator, or edge finder. Would be great for doing production/finding center of rough stock etc. Especially on machines without probing interface.

But again, neither are cheap, or required. An edge finder, and a DTI are pretty cheap, and are just as versatile for a wide range of setup needs. I was never able to justify the cost of either the coax, or taster beyond the "I just want one" reason. Outright setup speed was never a big factor in any of the work I mostly did, and when It was, I had a machine with a probe. And learned it's limitations.... Accuracy was, and neither the taster or coax were more accurate than a DTI.

Those are my opinions....

 

[djberta]

I have an 80 dollar one off amazon and won't go back to other methods. It is unreal how easy it is to setup and use. I am no expert, still I think it is a great tool. I used mine multiple times to find center with my rotary table.

 

[ChazzC]

I use mine occasionally, primarily for deep holes or large diameters (despite what the instructions say, you can adjust the probes just like on a DTI). You do have to account for the length of the probe being used, but only if you are trying to use for absolute measurements.

Most of the complaints I’ve seen are with regard to Z-height (haven’t had any issues on my LMS 3990, but I do have a 2” riser block on the column) and those who complain about limited dial travel/probe movement (because they didn’t take the plastic ring off before using).

I got mine from LMS at Cabin Fever in 2019 for about $60 on special sale (wooden box).

 

[PeterT]

What I do quite often is take advantage of DRO. Put the DTI in with ball probe pointing down. Traverse to one size of hole to DTI contact, press DRO zero/null. Traverse to opposite side, click "1/2" or "center" whatever your function is. Usually this results in hole center determined within a thou in mere seconds regardless of hole/circular feature size. Repeat in opposite axis & typically TIR is within a half thou by rotating spindle around the perimeter as final check. With DTI there is no reason to power the mill. Put it in neutral & rotate to any position you like.

 

[jorogi]

Sounds like a couple of projects for you, there a interesting plans for both.

 

[Johnwa]

I use mine occasionally (a few time a year). It’s definitely less frustrating than using a regular indicator.

 

[Proxule]

I go out of my way to use it, Love the thing, Especially the Asian ones that are marked in .01mm
Gluck

 

[Tom Kitta]

I use mine at least 10 times a year. It is super easy to get a center.

Sure they take a ton of Z space. But with power feed on Z its not that bad.

 

[jorogi]

 

[Mike R]

Since getting the Tormach, and successfully integrating the 3D touch probe I haven't used my import version, but I used to use it a lot on the old mill. Its good for finding centers of round things as its name indicates, and can get you within about a thou or 3 depending on the quality of the surface being indicated on. If you need better than that then you need to switch to a dial test indicator.
I'm terrible at parting with tools I no longer use, but maybe this is one I should part with to help me with letting go, or I should hold on to it until I find a new use for it.

 

[140mower]

parting with tools I no longer use,

I recognize some of the words, I just don't think I have ever seen them put together in that order before.

 

[Mcgyver]

It's a nice to have not a necessity, but is sure nice to have! Besides, part of fun is building up the collection and it does speed stuff up. I use it often enough. It's graduated in 1/2 thous and you get can get the needle so it doesn't move... here's a shaky video I did with a steady indicator hand (see 1:59 to about 2:12). No movement - that has to be pretty well centred. Mine is a used blake bought in good condition. Tools like this imo are in a category where it makes sense to buy quality, both for accuracy and longevity, so I'd watch for a used blake to come up.


(

1:59 to about 2:12)

 

[Chipper5783]

IMO the co-ax indicator is not a game changer. It is handy for setting up a bore or pin centre location. As others have mentioned, there are other good options. I use it about once a month. It has other uses too. You could use it to tram in the mill vise or dial in a 4J setup (perhaps there is an obstacle you need to work around).

However, for me, the 3D Taster gets used multiple times on every setup (I’m usually using multiple stations for each setup). The 3D-T gets its own holder and gets to occupy premium real estate (safe and easy to get to). Compared an edge finder (that I used for years), love the 3D-T.

The co-ax makes for such an easy validation, so it has a place (and I seem to need to do a lot of check, double check, triple check). Good excuse for a cool tool.

 

[ChazzC]

I'm terrible at parting with tools I no longer use, but maybe this is one I should part with to help me with letting go, or I should hold on to it until I find a new use for it.

I’ve seen videos of a coaxial indicator being used to align a tailstock . . .

 

[PeterT]

I’ve seen videos of a coaxial indicator being used to align a tailstock

I don't have my clone anymore to test, but I would evaluate if it is being affected unequally by gravity acting on the probe/mechanism. Its apparently a no-no with a DTI. Richard King? (scraping guy) speaks to this all the time. If I recall at best you could evaluate the vertical plane but not the horizontal plane (top & bot of center). Now maybe the COAX springs or mechanism is different but I'd want to confirm beforehand.