• Scam Alert. Members are reminded to NOT send money to buy anything. Don't buy things remote and have it shipped - go get it yourself, pay in person, and take your equipment with you. Scammers have burned people on this forum. Urgency, secrecy, excuses, selling for friend, newish members, FUD, are RED FLAGS. A video conference call is not adequate assurance. Face to face interactions are required. Please report suspicions to the forum admins. Stay Safe - anyone can get scammed.

Aliexpress Coaxial Indicator

Only 5 reviews but all 5 star. Makes me suspect they hired them. If that was 50 reviews I'd be happier.

The price is amazing! Too amazing.......

I'd go for it in a heart beat if it was Amazon knowing I could return it.

But I'm very leery of metrology stuff like that on Ali without LOTS of reviews.
 
Only 5 reviews but all 5 star. Makes me suspect they hired them. If that was 50 reviews I'd be happier.

The price is amazing! Too amazing.......

I'd go for it in a heart beat if it was Amazon knowing I could return it.

But I'm very leery of metrology stuff like that on Ali without LOTS of reviews.
The one I posted has 142 reviews.
 
I will cast the 'save your money' vote, and that is hard to say coming from a Tool guy haha. I had one, actually make that two - a bad Chinese copy & an actual Blake. By the time you get it mounted, make 6" of headroom to accommodate the inconveniently long body, screw in the right indicator arm, hold the side arm while powering the machine on low rpm, fiddling the XY table feeds wheels until the dancing needle stops.... you could have an DTI tell you the same thing & probably well on your way to machining. And if you need to measure to a tenth, you bolt on a tenth DTI.

For typical holes / centering 0-2" I use my DTI with dovetail post included in the kit. For anything bigger, I use mini Noga arm which can set up to any surface within seconds.

BTW, Stefan just posted a very neat indicator with some interesting features (drawings available). His usual weapon of choice is the C-arm type, lowest pic.



1700002411069.webp
1700002700665.webp
1700002771827.webp




1700002892168.webp
 
I have one of these, it’s probably good for +/-0.001” without too much effort. Quite handy for getting my rotary table lined up on the mill, and really good for getting my lathe tailstock aligned.
 
has any one checked them out, i.e. mount something something known to be round, dial it in, then remove the coaxial indicator, then mount an DTI indicator in the spindle as Peter shows and check the same item? A coax is a great convenience, I use mine all the time, but it introduces a source of error not present when using a DTI directly as Peter shows; is more of a pain but the best approach to get the highest accuracy..

Its just a question of how how much is that error, i.e. if it is small enough for the tolerance you're working to, all is good. That imo is the go/no go test on whether a coax is good or not in that if there was error in the coax, its going to be between its rotation (it is a spindle) and the nub you mount in the mill's spindle.
 
Last edited:
has any one checked them out, i.e. mount something something known to be round, dial it in, then remove the coaxial indicator, then mount an DTI indicator in the spindle as Peter shows and check the same item? A coax is a great convenience, I use mine all the time, but it introduces a source of error not present when using a DTI directly as Peter shows; is more of a pain but the best approach to get the highest accuracy..

Its just a question of how how much is that error, i.e. if it is small enough for the tolerance you're working to, all is good. That imo is the go/no go test on whether a coax is good or not in that if there was error in the coax, its going to be between its rotation (it is a spindle) and the nub you mount in the mill's spindle.

One of my unfinished projects is a custom 3 axis tramming tool (all three axis at once). I had planned to make something similar to the co-ax indicator to facilitate that, but since I have a co-ax indicator already, if it works why go to extra trouble.

It won't be soon, but winter project time is here. I'll follow along and see if anyone comments. If not, it will just take a little longer to get you an answer..... LOL!
 
I just put this video up and it shows the use of a Blake coaxial indicator. I think the things are amazing, with zero movement on a .0005" needle is gotta be close to a tenth. (coaxial part starts at 1:05)

Anyway, thought it germane to this topic

cheers

 
I have one of the various ones like the one in the original post. It has served me well.

In deference to @PeterT concerns, both my regular use milling machines have plenty of height to get to use it. I find it a little awkward to use, but it serves a purpose. With the long arms, it can get in to measure in places that I cannot use my DTI for.

I really like Stefan's device, but I don't need project #4193 right now.
 
I think what Peter and now me are after is an example of where a dti with a noga arm wouldn't work and the coax indicator with the long arms would, I am struggling to think of many opportunities like that, I guess if you had to register deeper into a part that the dti couldn't the long arms have an advantage.
 
Back
Top